caprail and hull/deck joint

[BALANCE]

I seem to be taking apart more than putting together. I decided on a color scheme which got me sanding the bulwarks exterior, which got me pulling out to old caulking between the caprail and the bulwarks. Bear in mind I have many leaks and this could very well be a primary source of many. I may have mentioned before that the hull/deck joint on Westsails is an ongoing discussion because of leaks. My intent was to paint the bulwarks the same color as the topsides and I wanted the paint to be beneath the caulking. Some people have removed the caprail and put down a polysulphide, others have glassed it over instead of the poly. Most people just recaulk every few years and manage to stay dry down below. Here is what one person did and his drawing of what he found when the caprail came off (not necessarily my situation).





In the next week I will decide if I need to remove the caprail. Below are pictures of what I've found in just removing the caulking. There is one area specifically that is concerning me as I can see bare fiberglass - no gelcoat - just a rough uneven edge. My concern is that I might not have the 'luxury' of simply recaulking. I would say that this area of concern represents about 4 feet on one side (out of 32 on each side). Underneath/behind the 'pink' ish stuff that I pulled out was a pastey brown substance that I could roll into a ball but within 15 minutes or so, from being exposed to air, I'm guessing, it dried up and was no longer pliant. I have no idea what either of these two substances were. I've never seen old caulk turn pink...



This one shows the worst area behind the caulking. In this area the gap between the cap rail and the hull is bigger than the rest of the boat.



This one is not very well focused but depicts (what I deem) to be ok, just in need of caulk. I realize, just to be clear, that whatever I do has to be done in all areas.

[Rachel]

I'm trying to reconcile what I see in the sketch with what I see on your boat. The sketch shows a little "tang" of fiberglass on the hull that sticks up and covers over the "raw" edge of the outside of the deck (i.e. inside bulwark) lip... I wonder is that missing in places on your boat? Was yours built in North Carolina and the other person's in California and that's the difference? Or am I just not seeing things correctly...? (Sorry for all the questions instead of answers.)

Rachel

[Tim]

What holds your caprail down? Is it screwed into the hull/deck flanges and therefore reliant on sealant to prevent leakage through those holes? Hopefully it's just these holes that are leaking, and not the actual hull-deck joint.

I think exterior beads of sealant like you are suggesting do not work. In fact, we were just making fun of an "instructional" video in another thread that depicts this very "technique. It doesn't work, and it's not the right way to do anything.

Perhaps an external bead would slow leaks for a short time, but if you have leakage through the caprail fasteners or other portions of the hull-deck joint, the only way to do this right is to remove the rail and rebed properly.

Sorry...

I don't think your construction is the same as that sketch. From your photos, the deck flange extends all the way to the edge, without the little "tab". That is the raw edge of the deck you are seeing. The external bead of caulk was probably as much intended as a cosmetic thing to cover this edge as anything.

[Capn_Tom]

What holds your caprail down? Is it screwed into the hull/deck flanges and therefore reliant on sealant to prevent leakage through those holes? Hopefully it's just these holes that are leaking, and not the actual hull-deck joint.

The caprail is held in place by screws through the hull deck joint so bedding beneath the caprail and along the edge is helpful in keeping water out of the screw holes.

I don't think your construction is the same as that sketch. From your photos, the deck flange extends all the way to the edge, without the little "tab". That is the raw edge of the deck you are seeing. The external bead of caulk was probably as much intended as a cosmetic thing to cover this edge as anything.

I believe the drawing on the left is "gee I wish they had built it like this" and the one on the right is closer to reality. The joint is the same as the one in the drawing the gap is just larger. The "tab" extends in off the hull and the deck turns outwards forming a flange that bolts on top of the tab. The width of the space between the outermost part of the deck flange and the side of the hull is 1/2 to as much as 3/4 of an inch. The filler used in this joint was a flexible putty. The probable cause for the poor fit is that the upper edge of the hull was not ground down smooth with the deck flange so the wood is riding high on one side or the other.

I started building the new caprail on my w32 last weekend so I am up close and personal with these issues!

[BALANCE]

Tim - I've spent over 8 hours with my nose 4 inches from what you looked at (for how many minutes?) and you can tell that my hull deck joint is good? What am I missing? Which picture made that clear to you?
The caprail is screwed down. The genoa track is also on the caprails. I have removed about half of the fasteners on the starboard side, I could not get the other half out. 10 out, 10 still in. Of the ones I removed, some were bolts, some were screws with no real order (like bolts where there was easy access down below...). I know for a fact that this area is one of my leak sources. Either from the caprail or the track, or both. If the caprail has to come up, the good news is that the stanchions are not on there.

I did read that other thread before I posted. I get the hint that you hate silicone. Thankfully I have found no sign of that on my boat. I can't help but wonder though that if silicone is so tenacious, it is obviously a good sealant, or not? As for rebedding the caprail, why would I use say a polysulphide if in fact it will eventually break down again?

R - she's east coast.

Tom, please take a picture of what you have found?

Tim, I 've just reread your post and understanding a little more how you've drawn your conclusion...that raw fiberglass, I'm pretty sure is on the bulwark side. If the deck flange is resting on top of the hull flange, wouldn't I see some sort of line of demarcation? I have found nothing like that. If it is the hull on top of the deck, I could still have a void on the inboard side. I'm no engineer but thinking about the boat out there in weather, doesn't it make sense for the hull flange to be on top? I digress.

[Hirilondë]

Most cap rails from years ago and a few made today are U-shaped. They did not just sit on top of the bulwark, but extended down on either side and actually capped the bulwark. Funny thing that they got their name from their function. Many boats built today have a simple sit on the top type piece like the W 32. Much easier to make and install, and much less functional in performing the task of sealing the joint. Even with a U-shaped cap rail removing and fully bedding is the thorough way to repair leaks, even more so with the flat ones used today.

[Tim]

Tim - I've spent over 8 hours with my nose 4 inches from what you looked at (for how many minutes?) and you can tell that my hull deck joint is good? What am I missing? Which picture made that clear to you?

I didn't say it was good or not good. I only related my thoughts based on the photos that you showed versus the diagrams you posted, which two things don't seem to be exactly the same.

I have no idea whether your hull-deck joint is well-sealed or not. I did say that I hope for your sake that it is well bedded, and that hopefully your leaks come only from the way the caprail is installed and bedded (or not). I am trying to answer based on the information provided , with all the caveats that come along with that.

If the deck flange is resting on top of the hull flange, wouldn't I see some sort of line of demarcation?

That is exactly what I was trying to suggest: that your deck extended all the way till it was flush with the hull. In the left side of this drawing that you posted, just imagine the deck (as drawn) extending all the way flush with the hull, without that little vertical piece that's shown on this drawing. That line you see on your boat, with the raw fiberglass, is that demarcation of the deck (the raw edge) and the hull) the part beneath that raw edge. That is what your pictures suggest to me, but of course I am not there

If it is the hull on top of the deck, I could still have a void on the inboard side. I'm no engineer but thinking about the boat out there in weather, doesn't it make sense for the hull flange to be on top?

One can't build boats this way. The deck flange always ends up on top of the hull flange.

[BALANCE]

Tim, I hope you understood my tone, it had an incredulous how did I miss that smile behind it.

Ok, I think I'm closer to understanding your point although not so sure that is what I saw. If the tab from the deck was flush with the hull..I think it would have to be tapered paper thin at the outer edge for me not to see it?

The biggest gap between the caprail and the boat is under the genoa track...

"Bedding", once the caprail is off..- what would you do? I would rather not deal with this again or take a short cut and handing the problem over to the next person, if I ever decided to sell her. This girl deserves to be dry.

From various discussions on the Westsail board about the joint, it seems that there are lots of inconsistencies from boat to boat despite what coast they were made on.

[Rachel]

I can't help but wonder though that if silicone is so tenacious, it is obviously a good sealant, or not? As for rebedding the caprail, why would I use say a polysulphide if in fact it will eventually break down again?

The problem is that the silicone is tenacious, but its seal is not. So it pulls away in places, you have leaks, and then you can't get rid of the monster.

All caulks will break down eventually (granted some sooner than others). Although polysulfide might not be the longest lasting caulk, you might still choose it for other reasons (such as that it is a good caulk to use with wood). All the caulks have plusses and minuses, so you just have to choose the one that's best for a given situation, considering the materials you're caulking, where they are located, how often you need to get them back apart, etc. Of course silicone is never best ;)

Rachel

[Tim]

This is what I think your photos are showing. Again, I could be wrong, but this is how it looks to me. PArdon the poor drawing modification.




Is this a seam where indicated? If so, it corresponds with that shown in the diagram above.

If not, then maybe you do have the setup as originally shown at the top of this thread.

[BALANCE]

Tim, I understand now (thank you). Can you suggest a way that I might confirm this? That area, where I saw the raw glass is only like that in that 4' area, the rest , when I sand the paint away looks like the other picture I posted depicting gelcoat to the top, a teeny gap where I pulled the caulk and then the caprail.
Once the caprail is off what do you suggest I do, just bed with a poly, 5200 ,or a West System application? Why not make that hull deck joint water tight permanently? Once it's cured, slab on the poly, when the caprail goes back on, I would follow up with a bead on both sides.

Edited to add: I've just checked the pictures I posted. There are no 'pretty ones' I guess I only took pictures of the ugly area, which might even be longer than 4'. I will take more tonight for comparison. Sorry for all the confusion. I am venturing into unchartered territory and clearly over my head (for now). I will try to spare you all the more inane questions (like about fasteners and fastening). Quite a learning curve here. I will get it, eventually!

[Rachel]

How Tim drew it is what I was picturing, too.

Now if you're saying it only looks like that in isolated areas, and in others the "finished" (gelcoated) fiberglass goes right up to the top, then maybe the "tang" was just malformed or too thin and broke off in some areas. It would be interesting to see photos of some other sections.

Rachel

[Capn_Tom]

The side of the hull above the "tab" is at most a 1/4 inch. It looks to me like some previous interaction with a dock removed this bit from the hull.

[BALANCE]

I did go to the boat but I did not take any more pictures. The only way to really find out is to take the caprail off.
Tom, you might be right. The PO recently mentioned an owie on the starboard side. He gave me no details other than that the boat was left at a dock and should have been put in a shed for the winter but the owner got sick and it never happened. He did not find out until Spring and the caprail from the bow to midships had to be replaced. I guess she took a pounding. In another thread I showed pictures of my repair of the fiberglass on the inboard side of the hawse hole. The outside was much less damaged. I have not yet removed the caulking from the chainplate to the bow as my ladders are not long enough to create scaffolding that high.

Thanks for the input so far.

Update: Tom very kindly emailed me some pictures of his caprail. If mine is like his (or the other fellow's - previously posted), than the tab coming from the deck does not meet the hull, so the raw fiberglss I am looking at is gelcoat chipped off the hull which has no tab turning inboard... Does this make sense to anyone? If I were to epoxy the surface, what is the best way to get it to grab the tabless hull. (I don't think I want to hear this answer).

[Oscar]

If it was my boat and I was going places where mother nature wanted to play submarine for days in a row I would do it right and take the entire cap rail off, grind everything rough and clean, as much as four inches down inside and out, and laminate a big "C" shaped cap on it, nicely shaped, rounded and faired in and I would forget about wood, or if I HAD to have the decorative element I would 5200 it on. Less holes is better.

[Capn_Tom]

If mine is like his (or the other fellow's - previously posted), than the tab coming from the deck does not meet the hull, so the raw fiberglss I am looking at is gelcoat chipped off the hull which has no tab turning inboard

I don't know what year your hull was laid. The early boats had a wooden sheer clamp in place of the fiberglass "flange". If your boat has the fiberglass flange than I imagine it is still intact. The rough glass you are seeing is either the edge of the deck above the hull flange or the remnants of the small bit of the hull that extends above the flange. In either case the problem isn't structural (from a safety perspective) but simply a cosmetic and water entry issue. Filling the voide with chooped glass or other thickened epoxy will be easy enough. If your intent is to paint the sheer stripe this will cover the repair nicely.

[BALANCE]

Hull was built in 1975, East Coast, Kit boat, # 442

[BALANCE]

I have decided not to take off the caprail. I am 99.% sure my leaks are coming from the tired old caulking and most of the leaks from the genoa track. The tracks are off, the holes have been doweled and new tracks going on soon. This weekend I will be recaulking. Once that's done, I will be able to test with a hose.

[Rachel]

I know I'm going to sound like a downer here, and I'm sorry about that.

Your leaks may be coming past the old caulking, but any caulking on the surface is, in my opinion, just a stop-gap to begin with (in this situations). The "real" sealant would be underneath the caprail. Of course there's no problem in renewing the surace caulk, as long as you know that's what you're doing. Re-bedding the caprail would certainly be a larger job.

As long as I'm being Negative Nellie here, I'll just mention that testing with a hose can be helpful, but no leaks showing up that way does not mean you have gotten them all for sure. That's because when, for example, you're pounding to weather, the boat actually flexes and changes shape, a little bit, and this can cause leaks to show up that a hose will never find (and is why people such as the Roths eventually just fiberglassed over their hull-deck joint, after battling leaks for years).

Sorry, I'll go back to my mean little cave now,

Rachel

[Capn_Tom]

If I was about to set off on an extended cruise I would pull the caprail and recaulk the joint. If on the other hand I was just doing some coastal cruising I would try caulking the underside of the rail and see what happens. If it doesn't work out your only out maybe 50 bucks in caulk and a few hours work.

[BALANCE]

Tick tock.

[BALANCE]

Caulking complete. Used Sikaflex 290 DC. The more commonly used ones for this application have a lower resistance to UV. Had a good rain after removing the genoa tracks and doweling the old holes, still had water. Had another good rain after caulking - no water. Will let you know what happens after getting the rail down. Can't wait.