Deck to Hull Joint

[HeaveToo]

Nice work.  The lines look nice and clean.

Question:  Epoxy will be a rigid material when it dries.  Is there any torquing of the hull that would mean you would want something less rigid, like 5200?

[MacGyver]

Looks Great!

Mac

[thomeng55]

Hi all... well I completed the repair on the Deck to Hull joint.  I have the process I used and pictures at http://sailtomcat.com/hull-deck-joint-repair/

I am anxious to see how it all works out.

Thanks for all the advise.

Tom

[archimedes]

Great pics and description.   I've never seen that part of the boat taken apart - always wondered what it looks  like under there.  From what I hear,  that is a fairly common leak spot on these boats.  Nice to know how to fix it.

Thanks for post this.

[NateD]

Nice work.  The lines look nice and clean.

Question:  Epoxy will be a rigid material when it dries.  Is there any torquing of the hull that would mean you would want something less rigid, like 5200?

Interesting question. I don't know what Hutchins used to seal the hull to deck joint at the factory, but I'm guessing it was something like 5200. On the one hand, the joint has a tendency to leak after a number of years, so that is a mark against using 5200, but then why is the factory using it? Although some boat makers do glass over the flange. Are theirs designed with less flex? I don' t know. My guess is the epoxy will create a strong enough bond with the ground-out fiberglass that it will maintain it's bond even as the boat flexes a bit. If I have to repair just a section of rub rail like this, I think I would try epoxy.

[Bob23]

One train of thought in this area is that you want the joint to flex a bit. Maybe if there's no give there, a crack could appear elsewhere? I dunno...I'm not a marine mechanic. And I've never repaired that area in my 29 year old 23. When I do it, I'll check back here and further pick Mac's brain.
Bob23

[MacGyver]

To me, due to the structure there, making it rigid isnt a issue. If you have a bottom up or top down strike on that edge, the damage should replicate the same, and the repair would be similar.
Likewise a hit from the outside towards in, would cause it to be on that edge, pushing in, and the damage would be the same if done with 5200 or Epoxy. This surely could be extended as far as a debate goes, and is just based on what I have seen occur over the years. When I repaired mine, I didnt take it lightly, and this exact repair was the decision I made as well, then my coats of paint overlapped to further seal the area.

Keep in mind that the area is bolted together, and not really meant for flexation, it is a rigid point in the boat. a flexing of this spot would allow the boat to flex improperly when slung, etc. so the top helps maintain the form of the bottom, and etc.

Like I said though, that is not to say it cannot be damaged, cause it can, it is a vulnerable part, but If I was to repair a spot due to heavy damage, It would be repaired as one piece, not 2, and that I have done a few times over the years without issue.

Mac

[thomeng55]

I thought I would share my thoughts on the Epoxy Resin vs 5200.

I decided to use the Epoxy resin, although I seriously considered the 5200 solution.   The reason I decided on the epoxy is twofold:

1) I trust MacGyver's input.  He has been doing this for a while, he did a similar repair and I have used his insight on other projects to complete success.

2) I figured if the epoxy solution didn't work for some reason, or cracked in the future, I can always grind out the area again and use the 5200 then.  But removing 5200 to do the reverse???  arghhh.. no way.

[Shawn]

"Question:  Epoxy will be a rigid material when it dries.  Is there any torquing of the hull that would mean you would want something less rigid, like 5200?"

I think there is a change to the hull shape. Measure shroud tension on a trailer right before launch and then put it in the water and the tension changes.

When I did the hull/deck joint on Serenity I used 5200. 

My Sabre's hull/deck joint was done with butyl tape from the factory and as far as I know was never redone. It is still completely dry after 34 years. I believe the geometry of the joint is a little more complex though as well. Could be worth considering butyl tape on a Compac hull/deck joint too. It certainly works well for any deck hardware sealing.

Shawn

[Bob23]

Good point on the butyl, Shawn. But that would mean opening up the flanges completely so you could get the tape in. Definitely the best way to go...and maybe the hardest. Funny how the 2 almost always go together, ayuh?
Bob23

[Shawn]

I had the flange completely opened up when I did mine. A little shocking how much the hull flexes with the deck disconnected so getting butyl in would have been ok. The hardest part for me was the rub rail.

Only thing to watch for with the butyl is that the interior teak trim is actually screwed into the sealant of the joint. The butyl is probably strong enough to hold the screws in place but 5200 is likely stronger for that.

Shawn