Time to recore

Chris Campbell · Post by **Chris Campbell** » Mon May 04, 2009 9:09 pm

Well - the one thing I thought I wouldn't have to do on my boat is upon me - opening up the deck and recoring. I bought this particular Yankee 30 in no small part because it's deck had already been recored - but the cabin top had not, and despite the fact that it seemed very firm, it is, in fact, wet. Seems that it has quite a thick outer skin which explains my not noticing it. Well, that and the fact that maybe I didn't want to see it, of course.

I know that there have been umpteen threads on this subject, and this site, in conjunction with Tim's, represent a full credit course on the subject, for which I am extremely grateful. I will be reading lots of it for a second time before I cut the top skin off, I can assure you.

Here's the entry on my site that discusses it: http://www.ramoak.com/yankee30/40/let-t ... airs-begin

What I need to know is what I need to order to start out. Here's my plan: I'll cut off the top skin, reserving it for re-use (despite the fact that I'm going to be sanding off the nonskid, it's a good layup, and thick - I'd rather not learn to laminate glass at the same time if I can avoid it). I'll scoop out the mush that was a core. I'll lay a new core in thickened epoxy, and cover it in epoxy as well, and then lay the skins back in place.

What I don't know is whether or not I need any glass cloth (for the joints between the skin sections), and if so, what kind to get? I have a roll of 6 oz cloth, but I know that there are all kinds of other cloths available, and that the stuff I've got takes forever to build up into any kind of thickness. Do I need to order something else? And why?

Thanks,

Chris

PS - and if what I've said my plans are are ridiculous or ill-advised for some reason, please don't hesitate to tell me!

Quetzalsailor · Post by **Quetzalsailor** » Tue May 05, 2009 9:14 am

Chris,

Your plan is bang on. Tab the old outer skin back into its adjacent area by scarphing. Easy to grind the scarph shape in after the skin is bonded. Check out my rudder repair pictures on Photobucket/Quetzalsailor etc...been there, done that, but for far fewer linear feet of scarph, and I was not rebonding the whole area of the skin. Your problems will include mixing and spreading enough filled epoxy fast enough for the rebonding day and clamping adequately to ensure no voids. Might be time to learn vacuum bagging (the remaining and repaired cabin top is one side of the bag; an old blanket, perforated hose and plastic sheet taped beyond the scarph is the other side).

As for the scarph itself, you can do it a few feet at a time or continuously. Precut strips of 'glass in appropriate widths. Experiment with dry 'glass to determine how many layers and how much wider each strip is. Don't use 'glass tape, except to use up your old stock; the selvage edge has a little rib and subsequent layers don't lie as comfortably flat and dense. Easy enough to cut a (short) stack of 'glass with a Stanley knife and metal rule.

D

Shoalcove · Post by **Shoalcove** » Tue May 05, 2009 12:02 pm

Hi Chris,
I assume you have a source for your materials but if not, OP Plastics on Mosher Drive in the Burnside Park have what you'll need.
Have fun,
David

Chris Campbell · Post by **Chris Campbell** » Tue May 05, 2009 8:54 pm

Great. I'm reassured. Will be moreso once this is behind me, of course! I'll be documenting each step, as required by common decency, and will post both here and on my site.

I do have source for supplies, David, but thanks for the tip. The friend of mine who helped with covering the shed (Jim Newell, Lifeline Marine Services) will be able to source stuff for me, which is great.

Thanks!

Chris

Clint · Post by **Clint** » Wed May 06, 2009 5:23 am

Could you take step by step pictures and maybe we could use that as instruction for anyone else who is thinking of recoring the deck? Like me.......

Chris Campbell · Post by **Chris Campbell** » Wed May 06, 2009 6:16 am

I will happily take step-by-step pictures and post them for all to see - mistakes and all! But I have to say that I'm not the one to use for instruction - that would be our gracious host and his many successful recores!

http://www.lackeysailing.com/seaglass/seaglass.htm
http://www.lackeysailing.com/iota/january08/10708.htm
http://www.triton381.com/projects/resto ... ecore.html

And there are more, but I can't find them just now. There are also many sequences in this forum which document Tim and other's work on their cored surfaces which will no doubt be better than mine. Not that it'll stop me from making an example of myself, naturally! It's always possible to learn from "what to avoid" as well as "the right way".

Chris Campbell · Post by **Chris Campbell** » Wed May 06, 2009 8:12 am

If I choose to not re-use the top skin (which I keep reading that people with experience recoring seem to recommend), I would plan to do the new layup with epoxy, since I like to do everything with epoxy. That said, I've never done something that would require so much epoxy to be mixed so quickly, and don't know how I'd go about it without creating one of those smoldering hazards that others have warned about.

How do people do large layups with epoxy without setting the place on fire?

Thanks,

Chris

Quetzalsailor · Post by **Quetzalsailor** » Wed May 06, 2009 8:54 am

Work in the coolth (not tooo cool).

Use slow hardener.

Don't over mix (Watch how the mixing is going; the resin and the hardener have different indices of refraction; when the mix is uniform, it's enough. Beating the livin' daylights out of thickened epoxy seems to set it off more quickly.)

Mix what you can get applied in time (have a loyal, trained staffer mixing the next batch).

Spread early and fast.

Get the stuff out of the bucket and into a thinner, wider, mass (like a roller pan, so that it does not get warm as fast).

While you can mix a second batch in a container that's just been emptied, it will go off faster and the third in that container is really fast: use multiple containers.

The foam brush is constantly 'stirring' the epoxy in the foam as you use it; it will go off sooner than the bucket.

Pre-decide where you will place/throw the smoking brush or container (it's soooo upsetting to heave the brush only to have it hit a lifeline and come back at you!); you may be wanting to continue the work and you won't want to take the time to think. Place the potentially hot stuff, containers, rags, brushes, on something well-aired and non-flammable until it cures.

Post by **Tim** » Wed May 06, 2009 9:47 am

Once you spread the stuff out it becomes a non-issue. So mix small-ish batches (not too small, but only your own experience will teach you the proper amount for YOU to mix at any given time) and spread the material out into the job area as soon as it's mixed. This goes for both thickened and unthickened resins. I never mix more than will fit in a 1 quart pot, whether thickened or unthickened. If I know I will immediately need more (such as for laminating a large section of cloth), I might mix 2 or 3 of these quart pots at once, knowing that I will immediately pour it onto the surface in question.

Never mix a "spare" pot that you don't plan on dumping immediately; this is how you get the smoke bombs. It's better to keep running back and forth to mix a new batch when you need it. Yes, it can be a pain, but it works. Working alone isn't always ideal and cheery, but one finds ways to do anything.

Learn how to quickly mix batches, whether thickened or unthickened. If you have a trusted helper to mix, great. It's completely do-able even alone, though. But you have to find your own rhythm and means of working. One way does not work for everyone. Make sure your helper, if applicable, KNOWS how to mix resin. This is not the time to learn.

Your working time once you've eliminated that condensed mass (i.e. in the pot) is significantly longer, and very workable. Avoid leaving resin in the pot any longer than necessary. Work quickly, but not too quick lest you make mistakes. You have plenty of time to wet/roll/squeegee the cloth once the resin is spread around. But don't be lackadaisical, either. You have to keep moving.

I dislike the slow hardener and always use fast, but do what works for you.

Working in cooler temperatures is better than hotter, if you have the choice. Avoid working under the summer noonday sun, even in your building, at least till you have your own sense of how the epoxy will react and are comfortable with your own sense of its working time and your ability to match it. You will quickly determine this.

You can work with conveniently-sized sections of cloth. Just overlap the seams. This avoids any sense of urgency in trying to wet out a coachroof-sized piece of material in time. That is simply unnecessary and will lead to problems.

Never use a pot that has started kicking. It's not worth the $5 to risk using pre-kicking resin, ever.

Experience is all. You will make mistakes and you will learn from them. So start with a comfortable level of whatever chore, and work your way into larger ones as your experience and comfort level grow. You have to find your own way within the bounds of some basic advice.

If you use any resin system that has silly pumps, throw them away for this job. You will waste way too much time and drive yourself batty. Learn how to multiply and divide by factors of 5 if you use West System (or else by whatever ratio you happen to be working with), and measure the resin and hardener directly from the bulk containers into separate pots first, then mix them together. Scrape the pots carefully, but don't fret about the minimal residue left behind; it won't affect your ratio appreciably. If you're doing a large job, you can pre-pour a series of resin and hardener containers to make the process quicker while you work. If you're worried about using too many containers, then figure out something else that works. Containers are cheap and you just need them. Period. Buy a case.

It's really not rocket science, but you will have to figure out your own way based on others' advice. Mix and match the suggestions as you see fit. If you're really inexperienced, then learn the basics on something before diving into a major job.

And don't over/pre-think it too much. Figure out your plan, and do it. Overthinking wastes time and makes everything harder than it really is. Really, it does.

Shoalcove · Post by **Shoalcove** » Wed May 06, 2009 11:53 am

That's great Chris. I know Jim a bit as well from the Binnacle. Has he gone out on his own?
Good luck with the project.
David

Peter · Post by **Peter** » Wed May 06, 2009 12:19 pm

If you re-use the old skin, and don't vacuum bag, I read somewhere in this forum about using bundles of asphalt roofing shingles for weights. Sounds like a good idea, as the bundles are quite flexible, and heavy!

Oscar · Post by **Oscar** » Wed May 06, 2009 12:40 pm

On my way to Home Despot for more sand bags......

Chris Campbell · Post by **Chris Campbell** » Wed May 06, 2009 4:09 pm

I've ordered enough 18 oz. biax cloth to reskin the cabin top, and am leaning that way now.

Thanks for the advice, Doug and Tim! This will be the most extensive fiberglassing job I've done, which is a bit daunting, but I think you're right, Tim - jumping in is the clue. I can always fix my mistakes later. In the meanwhile, however, I think I'll knock off a few smaller jobs first, as you suggest.

David - yes, Jim has gone out on his own with Lifeline Marine Services, and is now the only mobile swaging service in the Maritimes. He plans to work around the whole area, showing up for the major regattas and travelling to any job large enough to be worth his while. He'll no doubt do the bulk of his work here in the Halifax area, but I think he should do well elsewhere as well. Knowing Jim, the service he offers will be so good that it'll be hard to book him before long!

Cheers,

Chris

Shoalcove · Post by **Shoalcove** » Thu May 07, 2009 6:54 am

That's great Chris. Do you have a contact number? I was about to call around to get a new headstay. I'd rather give him the business.
Good luck with the re-core. I start prepping the hull for a paint job next week. I decided to stick with Perfection paint since I have some experience with it and am satisfied with the results.
Cheers,
David

Chris Campbell · Post by **Chris Campbell** » Thu May 07, 2009 8:00 am

Lifeline Marine Services: http://www.lifelinemarine.ca/

Jim's using info@lifelinemarine.ca as his email address, and his number is (902) 476-1759 (as you can easily see on his website)

He's pretty excited about being on his own, and is already getting busy, which is no surprise!

Cheers,

Chris

Shoalcove · Post by **Shoalcove** » Thu May 07, 2009 5:08 pm

Thanks Chris. I'll give Jim a shout.
David

Chris Campbell · Post by **Chris Campbell** » Fri May 08, 2009 3:28 pm

Looks like I haven't ordered anything yet, since the local supplier doesn't carry biax. Which actually brings me to a question I've been wondering about for some time: what's the difference between the various types of cloth, and when/why do you use one over another?

I've seen biax mentioned here (and triax) and thus thought it was what I wanted - but I don't really understand why, and was just going along with what I perceived to be the right thing. I do understand that if I use the 6 oz. cloth I've got on hand I'll be putting layers down until I'm blue in the face to get the 1/4-3/16" skin thickness I want, but what's the difference with using biax (presumably with sewn on mat) over a heavier weight of cloth? My understanding of mat is that it's used to avoid print through when using roving - but if you're using cloth, is it needed?

Thanks!

Chris

Rachel · Post by **Rachel** » Fri May 08, 2009 5:41 pm

I can partially answer, although there are many people here with vastly more knowledge than I have.

The thing about regular cloth is that the fibers run at 90ª to each other, so when you have the cloth going over an edge, or with strain in a certain direction, then often only 50% of the fibers are actually coming into play. With biax that has fibers running at 45-degree angles, all of them are being "used" to a strength advantage.

There is also a reinforcement that looks like biax (I forget what it's called... uni-directional, maybe?) that is also stronger than regular woven cloth for certain applications. I think that in that cloth all the fibers are running parallel in once direction (that would be the "uni"....) and you make sure to orient them in the proper direction, and that's why that type is still stronger then woven cloth? It's recommended for certain specific tasks but which ones they are escapes me at the moment.

Biax doesn't always have mat on it, I don't believe. I have some wide (5" or so) biaxial tape (Episize brand) that doesn't have any mat stitched to it. However I believe that mat is desirable as an inter-layer when deck re-coring.

After thinking about all of the above I'm not sure why biax would be stronger for re-laying up an entire top skin, but I still have the feeling that it is. I hope someone else explains it :) I could see why biaxial tape would be stronger for tabbing the old skin to the old deck edge since there is a stress "line" at the crack between the two sections, so there doesn't seem to be any sense in having any fibers running parallel to that line (which 50% of the fibers would be when using regular cloth in the typical orientation).

Rachel

PS: Dave Gerr's "The Elements of Boat Strength" has some good information on this. If I had it to hand I would sound much less fuzzy :)

Chris Campbell · Post by **Chris Campbell** » Fri May 08, 2009 9:10 pm

I've now spent a bunch of time googling and reading, and think I'm coming to understand a bit.

First - thanks for responding, Rachel - your explanation did make sense - although I found myself thinking that if the fibers weren't going in the right direction you could just turn it 45 degrees and then they would be (like the Shreddies square vs. diamond campaign I see on billboards) - but of course that means you have awkward shaped cloth to fit to your job, so it's not really an answer.

What I have found a couple of times now that makes perfect sense is summed up in this quote from here:

If you are asking "is regular woven fiberglass as strong?" the answer is NO. Regular woven cloth has the fibers go up and down over each other. These crimps have to straighten out before the fiber takes a useful load. The extra stretch means the fiber is not as strong, and is stretchier. Biaxial IS lots stronger than woven cloth, so you need more cloth of equal weight to replace it.

So it's better in two ways - one is that you don't have to skew the cloth 45 degrees and make lots more cuts to get fibers running in more useful directions, and the lay of the fibers doesn't inherently weaken them. Makes sense!

I also just spoke with a friend in the business about it and he tells me that if he were putting a skin on a cabin top he'd do it with mat/roving/mat, and use polyester resin since I'm not building a raceboat. Hmm. He has a point.

Still have a long way to go to understand this stuff,and there are lots more types of cloth, but at least I'm moving in the right direction.

Rachel · Post by **Rachel** » Fri May 08, 2009 9:56 pm

Chris Campbell wrote:I also just spoke with a friend in the business about it and he tells me that if he were putting a skin on a cabin top he'd do it with mat/roving/mat, and use polyester resin since I'm not building a raceboat. Hmm. He has a point.

I wouldn't do either of those things, personally. Not because it is or isn't a raceboat though.

I would use epoxy because it makes a better secondary bond than polyester does. And since you aren't building the boat from scratch, your bond to the original layup will be secondary (mechanical), not primary (chemical). A lot of times yards use polyester because it will set up much more quickly, and in business time is money. And it may be perfectly adequate. But for my time and money, and my boat, I'd use epoxy.

I also can't see why one would use roving for a cabin-top. It's got a big, knobbly weave that you'll have to fill in, and... just... why? Many of our boats used woven roving to begin with, but you can see on the inside of the cabin that it's a chore to fill in (the big, "burlappy" texture, if your boat has it, is from woven roving). Again, not that it wouldn't work, but.... I'd use something else.

Rachel

bcooke · Post by **bcooke** » Sat May 09, 2009 6:12 am

I also just spoke with a friend in the business about it and he tells me that if he were putting a skin on a cabin top he'd do it with mat/roving/mat, and use polyester resin since I'm not building a raceboat. Hmm. He has a point.

That is absolutely terrible advice.

And that is why I have no faith in 'people in the business'. Too many of them are ignorant of basic maintenance practices. There are some excellent, highly skilled people in the marine industry but your friend is not one of them.

Post by **Tim** » Sat May 09, 2009 6:50 am

Chris Campbell wrote:I also just spoke with a friend in the business about it and he tells me that if he were putting a skin on a cabin top he'd do it with mat/roving/mat, and use polyester resin since I'm not building a raceboat. Hmm. He has a point.

It's a point, but not a good one. But if you're looking for the absolutely cheapest possible way to barely squeak by, this is the way to go. It's not good, but it'll be cheap.

We have spent quite a bit of time and energy on this forum in the past making efforts to carefully explain why epoxy is the resin of choice for all repair work on fiberglass boats. It seems that there is a school of thought out there that refuses to differentiate between repair and new construction techniques. An all-epoxy laminate on a new boat might be expensive and exotic enough to limit it to the racers, and polyester resins still make good and viable new constructions, but that's not what we're talking about here. We're talking about how one goes about making the best possible repair to an existing vessel, with the benefit of hindsight into all the problems that cropped up over the first couple decades of fiberglass boat production. Using polyester and roving for repair work is simply stepping way, way backwards, and the use of epoxy resin in repair work has nothing to do with being "racy".

Similarly, advancements in fiberglass materials have made the old mat/roving process obsolete for all intents and purposes: yeah, it works, but it is inefficient, creates resin-rich laminates that are weak for their weight, and just doesn't make any sense any more. Ever. Yeah, I used some 10 years ago, but that was foolish and we have all moved on substantially from there.

You don't have to use biax; it's commonly used because it's so readily available, it has excellent strength/weight attributes, is economical, user-friendly, and is a good all-around fabric. However, there are choices, such as similarly stitched material that has its fibers oriented at 90°, in a variety of weights and weaves. This is the material from which late-model production boats are generally built. But lacking a truly compelling reason to go a different route, why would you?

Post by **Tim** » Sat May 09, 2009 6:53 am

Rachel wrote:A lot of times yards use polyester because it will set up much more quickly, and in business time is money.

But at what cost? Quality? Ability to stand behind one's workmanship? Pshaw. Pesky details.

Stay away from these yards. Knowingly choosing the inferior route is just the worst sort of practice.

bcooke · Post by **bcooke** » Sat May 09, 2009 7:46 am

Speaking of the old polyester versus epoxy debate, -not that there really is any debate- I worked for an organization five years ago that insisted on doing some composite repair work with polyester resin. I jumped up and down and complained to no avail.

A few months ago, amid hard economic times, I found myself employed by the same organization again. Lo and behold all those repairs have failed and I have been asked to fix them again - properly this time.

I must say, the I-told-you-so's have been delicious :-)

Zach · Post by **Zach** » Sat May 09, 2009 10:12 am

Tim,

Thanks for the explanation on wetting out larger areas. The mixing alone bit has been whats kept me dragging my feet on cutting off the upper skin and laminating new on the side decks of Pylasteki.

Zach

Shoalcove · Post by **Shoalcove** » Sat May 09, 2009 10:26 am

Chris,
I'm pretty sure that I got 1708 biax at OP Plastics. I just got up after working all night so my info is suspect but I'd call them. They may be open on Saturday's.
I've no business/family etc connection but they did give me a hat once.
David

Chris Campbell · Post by **Chris Campbell** » Sat May 09, 2009 10:41 am

Well. Good thing I didn't say anything to ignite anyone's passion! In my defense, I wasn't actually proposing to follow my friend's advice, was just posting it. In my friend's defence, he told me several times that he's not an expert of any sort on layups, and what he said he'd do if it was his boat is nothing like what he does professionally. And his boat is steel, with an aluminum and cold-molded cabin top, so make of it what you will.

I will confess to thinking that using regular old cloth for the job might be good enough, but now think maybe I'll go for the biax! Why not - it'll give me better experience than otherwise, and for the size of repair I'm doing, the cost difference is really immaterial.

Now that I'm back on track (phew!) - I will ask for advice on how thick to make my layup and how many of layers of what it will take to do that. What have others done for cabin tops?

Thanks,

Chris

Rachel · Post by **Rachel** » Sat May 09, 2009 11:59 am

Tim wrote:
Rachel wrote:A lot of times yards use polyester because it will set up much more quickly, and in business time is money.
But at what cost? Quality? Ability to stand behind one's workmanship? Pshaw. Pesky details.

Stay away from these yards. Knowingly choosing the inferior route is just the worst sort of practice.

I didn't mean to imply that Chris should choose polyester for any reason at all; personally, I never use it on my own projects. I guess I was just trying to explain one reason his friend might have recommended it, but I probably should have left well enough alone.

Sorry if I was unclear,

Rachel

Post by **Tim** » Sat May 09, 2009 1:03 pm

2 layers of 1708 = 3/16" thickness. You said your top skin was fairly thick, so you may need three layers to approximate the original thickness. 2 well-found layers is likely sufficient from a strength perspective, but make your new the same thickness as the old (inasmuch as you can).

Post by **Tim** » Sat May 09, 2009 1:05 pm

Rachel wrote:
Tim wrote:
Rachel wrote:A lot of times yards use polyester because it will set up much more quickly, and in business time is money.
But at what cost? Quality? Ability to stand behind one's workmanship? Pshaw. Pesky details.

Stay away from these yards. Knowingly choosing the inferior route is just the worst sort of practice.
I didn't mean to imply that Chris should choose polyester for any reason at all; personally, I never use it on my own projects. I guess I was just trying to explain one reason his friend might have recommended it, but I probably should have left well enough alone.

Sorry if I was unclear,

You were not unclear, having made your own position clear in the sentence above, but that statement still required comment lest anyone think that "time is money" is an excuse for poor workmanship and inferior materials choice.

That is all.

Chris Campbell · Post by **Chris Campbell** » Sun May 10, 2009 6:53 am

I started to remove the top skin yesterday, after spending a bit of time sounding the deck (correct term? whacking it with a mallet and listening) to see if I really needed to do the whole thing. It's hard to say - the top skin is thick enough that the only places that sound really bad are near the exposed edges, so I decided to start there, and after sticking a screwdriver 6" into the rot from the saloon hatch, marked it off and made a cut that distance from it.

As I expect anyone who has done this will know, the top skin doesn't just automatically come off then, unless there is nothing at all left to connect to the bottom skin, which is unlikely. Bits of core that haven't given up the ghost and pillars of resin from gaps in the core when it was laid up will still hold it on, and I struggled (am still struggling, since I left it unfinished) to remove the top skin from all areas.

I made another unpleasant discovery, that the bottom skin is so thin that it's going to be very challenging to avoid damaging it. I was worried about that last night, but somehow today am feeling alright and that I'll simply lay in another piece of glass on top of it to make up for the damage I do and all should be well (thoughts and opinions encouraged).

The construction is made more convoluted by the fact that the interior liner was glued in with lots of glue, making it seem like a third skin after a second core - but there are a lot of voids in the glue so it's not really structural. But it will be a nuisance to get out if I decide I want it out later.

I've done more of a writeup on my site, here, and have started a gallery for all images of the renovations, here.

Quetzalsailor · Post by **Quetzalsailor** » Mon May 11, 2009 8:55 am

Chris,

Two thoughts: 1) Don't take it all apart at once, now that you see how much trouble you're in. Take, say, the whole width of the house top by 24" fore and aft and repair most of it. Arrange your new lamina so that you've created scarpfs both onto the remaining boat and in preparation for the next section. Then take the next 24". Continue 'till done then clean up the mess and laps put one more lamina over all. (This is how the folks rebuild badly blistered hulls.) 2) Support the housetop from within and have at it.

D

Chris Campbell · Post by **Chris Campbell** » Wed May 27, 2009 4:54 pm

I should have updated this thread some time ago - I made good progress the weekend before last, essentially getting to the point where I'm ready to put things back together. Since then I've been slowed down/stalled by work and now - get this - a raccoon who moved into my boat and had babies! She's now out of the boat but still in the shed - her babies are too small to move any further than that. I expect in the next few days it'll be possible to move them all into a more natural setting near our neighbour's house (he's a raccoon lover), so I'll be able to resume.

In the meanwhile, I've documented my efforts on my site as usual: http://www.ramoak.com/yankee30/47/long- ... the-recore

Next step will be to brace the cabin top from underneath so I can install core and put weight on it for curing.

In the meanwhile, does anyone have suggestions for fixing a hole in the bottom skin where a previous owner put in engine controls? I don't really have space around it to overlap a bottom skin with the existing skin (on two sides, two other sides I do). Can I do a layup there that doesn't overlap? Should I lay up a solid piece of glass to just epoxy in place over it? Here's a picture:

I just looked at that myself and see that there is still sealant around the opening! That'll have to go. I could have sworn I had gotten all the silicone off my deck...

Thanks,

Chris

Idon84 · Post by **Idon84** » Thu May 28, 2009 12:35 am

Wow Chris. That is looking good! I love the part when things just start to go back together... Makes you forget about all the nasty, dirty work done before.

Post by **Tim** » Thu May 28, 2009 6:14 am

Can you post a picture or two of the bottom side of that hole you're looking to fill?

Chris Campbell · Post by **Chris Campbell** » Sat Jun 06, 2009 1:02 pm

Sure can - although obviously not quickly!

Thanks in advance for any advice.

I'm currently chamfering all the existing holes through the lower skin and liner and will fill them today in preparation for (hopefully) laying the core tomorrow.

Post by **Tim** » Sat Jun 06, 2009 1:12 pm

You may not have the "ideal" amount of space for overlapping fiberglass there, but there's certainly enough to make it more than adequately strong, particularly since you'll be performing the bulk of the repair from above. For an inner skin in this particular situation, you have enough room. I wouldn't hesitate.

Grind off the paint/gelcoat/lumpy stuff around the opening and apply glass as dictated by the confines of the space. You can overlap the glass down the vertical sides as well, if you want, but for this purpose you'll do just fine with the amount of space that's there. Do what makes you comfortable, but there's plenty of bonding area for this particular application.

This is all assuming you have room to get in there and work.

Chris Campbell · Post by **Chris Campbell** » Sun Jul 05, 2009 12:20 pm

Lots of time has flowed by since my last update on the recore - but I haven't given up, nor have I stopped working on it, it's just that I've slowed down for a variety of reasons. Hopefully that slow period is over now, however, and I will be able to put this part of the project behind me in the next couple of weeks (funny how something I thought I could do in a five day weekend is going to take about two months, isn't it? I'd better learn from that...).

First off, thanks, Tim for your advice on the hole from the engine controls - I did manage to fill it in:

Next, I ended up removing the mast partners since the core underneath them was mostly gone, and the partners were nothing special to begin with. My plan to build them up again is that I've left a ~2" ring around the hole in the bottom skin without balsa core, and have blocked the hole itself with a piece of wood wrapped in plastic - and I'll lay up solid 'glass in place to make things strong and rot-proof for the future. I have a question about how strong the partners need to be, though - my plan is to have 3 layers of the 1708 biax around them rather than the 2 layers I'll have elsewhere, and that'll be the only thing I do to make them special. There is the bulkhead for the head on the port side which adds strength also, but it doesn't seem like a lot. Of course it's not a deck stepped mast, so all the partners do is keep the mast in column as they pass through the deck - but do I need to beef them up even more?

As that picture also shows, I've got solid core where the ventilation will be mounted for the head (a solar powered vent for now, maybe a dorade in the future), and solid core around the saloon hatch to prevent water ingress to the core there. I have not, however, put solid core where the babystay track will go between the partners and the forehatch, and I don't have solid core for the traveler. I don't even know where the traveler will go, actually, since I'm replacing it, and I don't have it yet (haven't even decided on a brand!).

This leads to a question: if I don't put solid core to back the traveller, will I pay a price later? I can obviously put backing plates under it for the bolts, but I'll have balsa in the middle - not as strong as plywood or solid. But waiting to figure out the traveler will take at least a few days, and I'd like to get this wrapped up, now that I'm close. Any suggestions?

<aside>I've decided that nothing will be led back to the cockpit now - I'm putting the winches back on the mast and will hoist and reef from there, as I did on Weatherbird. I think the hassle of going forward is less nuisance than having all of those lines in the cockpit - and the safety margin that it provides is only valid until you have to go forward to fix something that's jammed (which Murphy says is when you least want to) - so I'll make things safe for working on deck and leave everything at the mast. This eliminates a huge number of deck penetrations, of course.</aside>

Oh - one more question. The balsa core was drier when it arrived than it is now, as witnessed by it's having curved (the cloth backing didn't swell, but the wood did):

Is this a problem? Do I need to wait for drier weather? It hasn't gotten actually wet - it's just that we've had nearly 100% humidity for a long stretch, so everythings damp. Maybe this and the traveler issue mean that I should wait?

Here's my latest write up on my site: http://www.ramoak.com/yankee30/50/catch ... the-recore
And here's my account of having sailed on another person's Yankee 30 (they sail great! Phew!): http://www.ramoak.com/yankee30/49/damn- ... ail-nicely

Cheers,

Chris

One Way David · Post by **One Way David** » Tue Jul 07, 2009 3:09 am

This is a great thread. I've learned a lot about fiberglass repair. Chris, what are the demensions of your shed? How has it handled the winds you were/are concerned about?

And an answer to earlier posts, why do you have to do large layups? Why not just do a section as large as you feel comfortable with and start where you left off when you return? Even if you used the deck material you removed instead of new, couldn't you just cut it up into managable sized sections? I mean, someone on this site said something to the effect that fiberglass boats are infinately repairable, right?

Post by **Tim** » Tue Jul 07, 2009 6:51 am

Chris Campbell wrote:I have a question about how strong the partners need to be, though - my plan is to have 3 layers of the 1708 biax around them rather than the 2 layers I'll have elsewhere, and that'll be the only thing I do to make them special... but do I need to beef them up even more?

The mast partners need to resist only a slight side-to-side loading. As such, it's the top and bottom skins of the deck laminate that handle this load--and their entire expanse will work together to spread the loading. Filling in the circle (or oval) around the partners with solid glass, as you are doing, and then tying it all together with the new top skin will be more than adequate. Extra material beyond what you suggest is just extra material, and wasteful.

Chris Campbell wrote:This leads to a question: if I don't put solid core to back the traveller, will I pay a price later?... Any suggestions?

Why not just eliminate the core and install a band of solid glass in the area of the cabin trunk where a traveler might go, just forward of the companionway (i.e. the old location)? Then, if you decide to install the traveler there later, you're all set; if not, no harm done. Cover your bases in order to move forward, if you're not ready to make the final determination on the traveler just yet.

Long, long ago, Figment wrote:Damn that it's all connected!

Chris Campbell · Post by **Chris Campbell** » Tue Jul 07, 2009 3:12 pm

Thanks for the reply, Tim - that's what I had felt about it, and it seems in keeping with the original construction, which is of course a good sign. Not that the original construction in all ways should be taken as "the way to do things" - balsa core at the deck edge with nothing protecting it but the teak toerail and bedding compound wasn't a good idea! 20/20 hindsight, of course - much of what was done when the Yankee was built was very good.

Good idea also on the band of solid material where the traveler might go. It wouldn't even have to be all that long - just long enough to cover all the possible spots it might go through. Good thinking, that's what I'll do. I've thought of a few more places needing solid core also, as it happens - the mainsheet (being mid-boom) will be led forward to the gooseneck and then down and back to the cockpit, so I'll need to lead it through (too many!) blocks and back to cleats.

Just to confuse matters, while considering the traveler issue I started thinking of ways to change from mid-boom to end-boom (or at least 3/4-boom) sheeting, which I prefer. Trouble is that with a tiller-steered boat with a dodger (don't actually have one, but will eventually) - at least one who's boom ends near the front of the cockpit - there is no good place to put a traveler. Can't go at the back ot the cockpit, that would make the lead ridiculous, crossing the entire cockpit on an angle. Can't put it across the front of the cockpit , that would make it impossible to mount a dodger. Can't put it across the middle of the cockpit as you would with a wheel (just ahead of the binnacle) - that would interfere with the tiller. So where does it go? On top of a hard dodger? But hard dodgers on small boats are almost invariably hideous - especially those built by people like me without some solid experience in building them. But how about putting it on an arch? Not a Hunter arch, or a Malo arch, but an arch built to replace the aft hoop of the dodger? that way the dodger would be a single hoop ahead of the arch, and would be split into two sections, one ahead, mostly windows, and two wings aft, mostly left off (like what you've just done with Glissando, Tim) but available to keep the weather out when really wanted. So far, aside from the possibility of it also being ugly, I can't come up with a reason this is bad. Oh - I guess there is always the question of why more boats don't have this, which is usually a sign not to be ignored...

Is it ever connected!

David: I may be mistaken in my sense that I have to do large layups - but I do believe that things'll be stronger with chemical bonds (which can only happen if the epoxy is still tacky when new stuff goes on). You're right, though, we do assume that these things are infinitely repairable, and I'm tying my new top skin into the old, which is definitely not a chemical bond, so it probably could be done in chunks. I know that for putting the core in I want to do it in one shot - otherwise I'll have to clean up the epoxy that squishes out of the sections I do first...

Shed dimensions: 36' long x 18' wide x ~20' high at the peak. So far it has held up to the winds - but the worst we've had since I got the covering on was 45 knots from the north for 3 days (I kid you not - never let up, we were getting nutty by the end of it), so I'll still be nervous for next winter's storms. The 3 days of 45 knots did push in the north-facing knee wall, which is why I've now got braces in place to hold it secure. Can't complain about the shed, though - great design, easy and cheap to build, just takes awhile, especially if you work as slowly as I do!

Cheers,

Chris

Oscar · Post by **Oscar** » Wed Jul 08, 2009 4:55 pm

If it was me I would put solid glass anywhere there will be hardware.....traveller, baby stay, hand rails, whatever..... The moment you drill a hole that goes through balsa you have to either oversize it and pour epoxy then re-drill it, or you start the potential for rot again. Not what you want to do after all this work.....

Chris Campbell · Post by **Chris Campbell** » Wed Jul 08, 2009 5:00 pm

Absolutely! No way I will let any water anywhere near my fresh balsa!

I'm going to spend more time tonight creating areas of solid core - I'd also forgotten about the handrails. There sure are a lot of holes in a cabin top, even when you eliminate the halyards going aft.

Cheers,

Chris

Oscar · Post by **Oscar** » Wed Jul 08, 2009 5:49 pm

There sure are a lot of holes in a cabin top, even when you eliminate the halyards going aft.

Speaking of which, why don't you mix up one more tubby of "Smart Balance" and put a pad where the blocks and stoppers WOULD go IF you were to lead the halyards aft.....you know, just in case.

And oh, take pictures and sharpie the measurements to the solid pads before you cover it up......that way you know exactly where they are on that future date....

Chris Campbell · Post by **Chris Campbell** » Thu Jul 09, 2009 6:23 am

Quite right. I'll do that, just in case - and put them in reasonable proximity to something else that I can find later, hopefully...

Chris Campbell · Post by **Chris Campbell** » Sat Jul 11, 2009 11:07 am

Cutting out core and preparing cloth for the solid spots - and have a question: do I need to actually lay up with cloth, or would it be just as good to mix up batches of epoxy thickened with chopped cloth? Seems to me that the strength I need where it's solid is just compressive, not in shear or any other direction. Is that right? Might save me some time cutting if I can just hack it to bits and mix it in.

Thanks,

Chris

Oscar · Post by **Oscar** » Sat Jul 11, 2009 11:37 am

I would use a filler instead of chopping glass up myself. Wood flour comes to mind. It's cheap and strong. I buy supplies here, and they are most affordable:

http://www.raka.com/

Chris Campbell · Post by **Chris Campbell** » Sat Jul 11, 2009 12:54 pm

Just read on Tim's Lackey Sailing site that on both Glissando and Iota he cut out layers of glass and laminated in place. I've ordered more of the 1708 since I was going to run out anyway, so now there's no reason not to laminate glass in place (other than the blister I've gotten on my thumb from the scissors).

Here goes a lot of cutting!

Oscar · Post by **Oscar** » Sat Jul 11, 2009 2:47 pm

May be overkill.....all you're doing is avoiding water intrusion and compression.....but it will definitely be strong enough!

bcooke · Post by **bcooke** » Sat Jul 11, 2009 7:24 pm

Just read on Tim's Lackey Sailing site that on both Glissando and Iota he cut out layers of glass and laminated in place

I did basically the same thing. Its about a day and a half project plus fairing and painting. Using the biax with the matt stitched on the back (1708) builds up the thickness very quickly. Thickened epoxy would probably work but I would guess it takes about the same amount of time because you have to be careful about heat buildup. Since you are spanning a larger area its nice to have the fibers to tie it all together. What amounts to a huge slug wouldn't be as forgiving of flex as cloth. Filler makes nice plugs but cloth is what the boat is made of after all. Stronger has to be better right?

As for biax being more expensive than filler, I am not sure about that. The filler might be more resin rich than the cloth laminate. I could easily be wrong about that though. I never considered the cost of the biax since I bought it in a ten yard roll and still have plenty left over.

it's solid is just compressive, not in shear or any other direction. Is that right

Well, its also part of the cabin top skin structure too. You should probably have some cloth in there to tie it to the rest of the cabin top skin.