Introduction and coming rail sealant question

s/v Groovy · Post by **s/v Groovy** » Fri Feb 23, 2007 2:52 pm

Hello all, I've been lurking for a while, mostly admiring all the very fine work, it makes me want to go build a shop and refurbish my Pearson Renegade full time. But for now , It's one project at a time. My wife and I bought 'Groovy' (renamed after much ceremony according to John Vigor's article) a year ago, and sailed every chance we get (34 days in 2006). Last year I took the mast down, and secured the clanging wiring with the 'zip-tie' method. added an anchor light replaced the steaming light and replaced the VHF wire. We live in Seattle so the mast doesn't come down annually, in fact we had a great sail last weekend. I inspected the standing and running rigging, replaced only what was bent or bad. Refinished the spruce spreaders etc...Trying not to go broke. Other than that it has been removing everything, washing all the lines, having the saild recut and adding leech lines to stop their fluter, and generally cleaning up. We love our yar little vessel.

My question is I have removed the wood coming rails for refinishing and am curious the proper sealant to use, from what I see 3M 101 is a good way to go. I was thinking silicone, applied, screwed in 90%, then once cured tighten to form a sealing gasket. There are enough screws that i think adhesive is not necessary , but I'm a newbie so let me know...

good to meet everyone, and thanks for the advice...

Post by **dasein668** » Fri Feb 23, 2007 3:43 pm

Your coamings shouldn't require any sealant at all. The screws should be more than sufficient. I take mine off every year and don't use any sealant at all. In really snotty conditions, yes, some water comes down into the cockpit behind the coamings, but when the conditions are that bad, I'm probably wearing foulies anyway...

If you feel the need to prevent this, I would install with just screws, then run a bead of 101 or LifeCaulk down the joint.

You won't hurt anythign by bedding the whole back side of the coaming, but it will be much harder to remove later. Polysulfide caulks are surprisingly tenacious, despite not being a true adhesive.

I won't use silicone on my boat?it is virtually impossible to remove the nasty thin film that remains after you peel away the "gasket" and it prevents anything else from sticking properly later down the road. Silicone brings up some real upleasant responses around here!

Post by **Tim** » Fri Feb 23, 2007 4:17 pm

Hi Groovy, and welcome!

s/v Groovy wrote:I was thinking silicone...

Nooooooo! No silicone!

This is something most of us have learned the hard way, so please listen to those who have been there! When I installed my new coamings in 2001, I applied small dabs of silicone at the screw hole locations. After two seasons, I decided to remove the coamings for refinishing, and had a bear of a time getting the things off the boat. It was a very unpleasant experience, and is one of many reasons why I advise against any use of silicone on the boat. I made my mistakes using it, and learned that lesson some time ago.

In fact, the back sides of my coamings still bear small patches of silicone that I couldn't get off. Miserable, afwul stuff, that. I fought it for days before succeding using small guitar strings to saw through the silicone. It was painful, and despite great care I still damaged my coamings somewhat.

As Nathan said, if you want to prevent water from running behind the coaming and thusly onto the cockpit seats, then run an external bead of sealant (NOT silicone or 5200--polysulfide) along the top edge of the outboard seam. I'd carefuly tape both sides of the seam first, run a bead, and smooth it out nicely before removing the tape.

Note that white polysulfide, particularly 3M 101, turns an ugly brown when exposed. I'd suggest the Lifecalk mahogany or teak brown instead.

s/v Groovy · Post by **s/v Groovy** » Fri Feb 23, 2007 4:31 pm

Ok, Silicone is out, I spit on the silicone, it is dead to me, but...

The comings attach from the inside of the cabin at their forward point. Three screws from the inside into the back of the coming rail on each side, I was getting a drip into the cabin from one. When I removed the rails there was the remnants of failed sealant around every screw hole along the whole length. I thought that every time a screw or bolt goes into or through the boat keeping the water out was a concern.

Maybe a pic would help, but I cant figure out the whole posting a picture thing yet, but http://www.renegade27.org/ has plenty of pics, Including Hiriolonde, which is beautiful.

Oh, and thank you for the welcome, this is a great site, it is very nice to meet you.

jpmathieu · Post by **jpmathieu** » Fri Feb 23, 2007 4:45 pm

WELCOME ABOARD

Maybe a pic would help, but I cant figure out the whole posting a picture thing yet, but http://www.renegade27.org/ has plenty of pics, Including Hiriolonde, which is beautiful.

You have a great question for Dave, I believe he just replaced his coamings recently. Im sure you'll here from him later. I still have yet to tackle the coamings on my renegade, they are in tough shape.

Good Luck.

Post by **Tim** » Fri Feb 23, 2007 5:02 pm

Yes, you should seal where the coamings screw into the cabin. I put a good dab of polysulfide at each screw location when I install them. (Triton coamings are essentially the same setup.)

This is easy enough to remove later on. I take the coamings off annually for refinishing.

s/v Groovy · Post by **s/v Groovy** » Fri Feb 23, 2007 5:54 pm

sorry to be so niave, but should I use a dab of polysulfide on every screw hole or only the 'through the cabin side' ones?

Rachel · Post by **Rachel** » Fri Feb 23, 2007 7:48 pm

s/v Groovy wrote:Ok, Silicone is out, I spit on the silicone, it is dead to me...

OK, you're in! ;-)

Welcome!

--- Rachel

Hirilondë · Post by **Hirilondë** » Fri Feb 23, 2007 8:22 pm

I can't resist, and you don't seem to need any more comments, but......Silicone should be illegal!!!!

That said, Welcome Groovy.

There are some things that almost all of us agree on, like silicone. There are some things for which there are at least several very good ways to do it. Cockpit combings are the later. If they look good, are comfortable to lean against and keep a goodly amount of deck wash from entering the cockpit then they are most likely well done.

Mine were fabricated, dry fitted and then varnished with 12 coats. Then they were completely bedded to the boat, screwed in countersunk and bunged. Then many more coats of varnish were applied (including extra build up coats on the bungs) . Every square inch of teak that touches fiberglass is covered in Sikaflex 291-LOT. I have no intention of removing mine until it is ready to be replaced or something else major happens such that they are in the way of the remedy. Nowhere is it written that my way is any better than the others mentioned above. I just like the look better and I am willing to deal with varnishing in place.

One comment I will make regarding both easily removable vs semi-permanent concerns the degree of bedding. If you intend to keep them installed then I highly recommend a thorough bedding to keep any moisture from being trapped and therefore causing strange biological growths which may cause unsightly appearances and sometimes unpleasant fragrances. If you choose the removable method then bed sparingly if at all to minimize the chance of causing damage during removal. With frequent removal growths shouldn't really be an issue. Even if you choose the semi-permanent you should keep in mind the semi part. In other words even though you may have no intention to remove the combing, it really should be removable. I therefore think that products like 3M 5200 and Sikaflex 292 should be avoided at all cost.

My question is I have removed the wood coming rails for refinishing and am curious the proper sealant to use, from what I see 3M 101 is a good way to go.

From what I have heard it is. The 2 products I am most experienced with are Boatlife Lifecaulk and Sikaflex 291. Lifecaulk is a polysulfide mildly adhesive bedding. Sikaflex is a light duty adhesive polyurethane. I choose Sikaflex simply because I like how it is to spread and clean up. Both products yield good results for bedding items that you know you will remove someday.

Good luck with your project. Oh, and glad to see another Renegade owner here. http://www.renegade27.org/ and our e-mail list are a great resource as you already know. But there just aren't enough of us to get nearly the attention and access to resources that we can get here.

Jason K · Post by **Jason K** » Fri Feb 23, 2007 10:53 pm

sorry to be so niave, but should I use a dab of polysulfide on every screw hole or only the 'through the cabin side' ones?

Welcome to the forum!

Sealant at just the cabin side screw locations will be sufficient.

Post by **Tim** » Sat Feb 24, 2007 7:16 am

I only seal where the screws penetrate the cabin. Commonly available polysulfide caulks include 3M 101, LifeCalk (NOT Lifeseal), and probably a generic West Marine-type brand. Polysuflides are good all-around sealants because they are very strong, but generally easily removable and flexible. Polysulfide is pretty good for every sealing job on board. Don't use 5200 or the comparable Sikaflex heavy-duty polyurethane for any sealing that might ever be removed, as these are permanent adhesives. The lighter-duty Sikaflex polyurethane, as well as 3M 4200, are OK since they don't have the permanence of the heavier-duty versions. But you don't really need the adhesive performance of polyurethane for bedding and sealing wood or hardware on deck.

If you decide you'd rather call your coamings a permanent fixture, and continue finishing them in place (like Dave chose), then I would follow his installation plan and seal behind the coaming for the reasons he stated; countersunk and bunged screw holes are nice if you plan to keep the coamings on the boat in perpetuity.

Since I remove mine each year, I don't seal behind (except at the cabin), and have to live with exposed screw heads and finish washers. It's a compromise either way. Annual removal also allows me to keep the area behind the coamings clean and dry, eliminating the potential for nasty organic growth or what have you.

Another bedding option is the traditional Dolfinite compound. I've never used this product, though I've removed pieces that were originally installed with it. It seems to be interesting and effective stuff.

s/v Groovy · Post by **s/v Groovy** » Mon Mar 05, 2007 1:54 pm

As luck would have it, very soon after I removed the coaming rails the temp dropped back below varnishing weather, we actually had 6" of snow in Seattle. We are again back in range and a few more coats have been applied, as the varnish builds the project continues....

My next question is how to remove the old sealant. I have no idea what it is, except it is white and pretty tough. If it ever had adhesive qualities, those had failed before I removed the rails. There are 2" dia circles around each hole the entire length. It seems that a blob was applied for every screw before tightening.

Is there a best type of scraper? a certain solvent to try first?

Post by **Tim** » Mon Mar 05, 2007 2:10 pm

Use a scraper first (a putty knife or 5-in-1 tool will work best without damaging the substrate), then solvent to remove any remaining residue. On the wood, you can use sandpaper for the final residue as well, as long as the sealant wasn't the dreaded silicone.

For solvent, paint thinner (mineral spirits) and acetone are the two most useful--and least potentially harmful to the boat--that you should have on hand. Paint thinner is safe on just about anything; acetone may harm certain paints and other finishes, and often damages plastic, but is safe on fiberglass, gelcoat, Awlgrip, unfinished wood, and other surfaces.

keelbolts · Post by **keelbolts** » Mon Mar 05, 2007 5:50 pm

Groovy,
One word: Dolfinite. Dasein668 makes good sense when he states why he doesn't bed his coamings in anything, but, should you feel the need to bed your coamings, Dolfinite is a widely available, traditional bedding compound. ALL of that other geewiz stuff has adhesive qualities. Dolfinite does not. It is a bedding compound. It is designed to rest between two components and keep the water out. As it is oil based, you will have to renew it every couple of years or so.

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Introduction and coming rail sealant question

Introduction and coming rail sealant question

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