Repair mast step mounting core and cabin deck?
- Thread starter jmczzz
- Start date
Hawk, Thanks a lot for this info. Question should I try to fill the void UNDER the existing good ply? I could stuff some ply blocks coated in epoxy under there, drill some holes and squirt some liquid epoxy down on top of that, cut out all the ply visible and fill then put the cut out ply back in the fill above that and replace the top skin, OR what?
You are right the reason I cut all that up is the flex and I thought I had more rot than turned out. I think it the under AND above voids should be filled? I appreciate your input, James
So you have additional voids UNDER to good plywood seen in the pics? So that means there is also a gap between the ply core and the cabin liner? If that is the case I'd say the best option is to drill holes and fill with epoxy... hopefully these gaps aren't very large.
unfortunately I think that by design there are voids under almost the whole thing (luke I would guess that you have voids too if you cut yours up). from what I could tell when I had mine open there was no attempt made at bonding the ENTIRE liner to the cap skin, I am thinking it was just glued in strategic, structural places. the liner (where exposed and as far as I could see with a flashlight) was as clean as new with no remnant of fiberglass or resin anywhere on it. I think that trying to fill the whole thing with thin epoxy would be a waste of resin and time... that being said, I did push thickened epoxy in as far as I could just for the piece of mind. it appears to me that the cap was built (picture in the mold) as the skin, then the 1/4 ply then thickened epoxy to "seal" it and glue it anywhere that it made contact with the liner. obviously, anywhere that it did not would leave voids (if your is like mine that gap is on the magnitude of 3/8" of an inch).
if it were me I would do whatever gives you the greatest piece of mind while KEEPING in mind that it lasted the way it is for 40 years (will you still be using it 40 yrs from now when it would fail again???) also keep in mind that you would almost have to try to do it as poorly as the original design (meaning it would last longer than 40 years)
IF you do cut up the existing would (personally, I wouldn't if its good) try to leave several inches around the perimeter so that your wood and skin seams do not align as that would make for a much weaker end product.
if you still want to talk more feel free to shoot me a pm and I can give you my number or give you a call...
if it were me I would do whatever gives you the greatest piece of mind while KEEPING in mind that it lasted the way it is for 40 years (will you still be using it 40 yrs from now when it would fail again???) also keep in mind that you would almost have to try to do it as poorly as the original design (meaning it would last longer than 40 years)
IF you do cut up the existing would (personally, I wouldn't if its good) try to leave several inches around the perimeter so that your wood and skin seams do not align as that would make for a much weaker end product.
if you still want to talk more feel free to shoot me a pm and I can give you my number or give you a call...
Interesting subject, and it just so happens that I'm in the middle of writing an article for the MainBrace concerning the re bedding of the mast step on the MK-II's, but the construction method used on all the versions of the C-22 are very similar. Yes there are voids between the deck and the liner. As already been discussed, the factory placed plywood between the cabin liner and the cabin/deck. When ever I drill a new hole in the cabin top or deck, or when ever I remove a piece of hardware, I use my Dremel tool and undercut the plywood core. The factory bonded these parts together with what appeared to be globs of thickened resin, and on occasion, this is what I find between the liner and the cabin or deck. This resin mixture was evidently applied in a haphazard way, which lead to voids. When I removed the mast step several years ago to rebed it, the wood was bone dry. So after I undercut the coring in the mounting holes, and also the mast wiring penetration, (which was relatively close by), I taped over the holes in the cabin liner, and using warmed WEST epoxy slightly thickened with high strength powder, I started pouring the epoxy resin into the holes. The warmed resin flows much better, and will be absorbed into the wood better. I ended up pouring over a quart of resin to fill three little holes, and the mast wiring penetration, so never knowing what I'll encounter, I always have a good supply of WEST epoxy on hand. I could feel the cabin top and portions of the cabin front get warm as the epoxy kicked off inside. So the voids are now indiscriminately filled with solid epoxy which strengthens the boat even further. After the epoxy cured, I redrilled the holes, and now "if" water ever leaked past the hardware, it won't penetrate into the wood coring. The WEST epoxy website has great information on fiberglass repair, and re bedding hardware on fiberglass boats.
Don
Don
food for thought: resin is kinda heavy... in small quantities no big deal but if you start pouring like crazy trying to fill voids (that have taken 40 years to show any signs of trouble) you can add some weight. more weight up there will change the righting moment and contribute to heel. 1 qt wouldn't be a problem, but the voids that I saw in mine (see pic, I had quite a large area to view what was going on) I could seriously see gallons disappearing if its like that over the whole cabin top...
and here is a close up where you can get a feel for the depth of the void as well as see that it was CLEARLY never bonded to the liner
and here is a close up where you can get a feel for the depth of the void as well as see that it was CLEARLY never bonded to the liner
Thanks to all you fellows, what a wealth of experience based knowledge this forum gives. (I'll re-read the info Don references also) I See I am not the only C22 owner that has discovered and grappled with this issue. I think I will try to use some combination of making some holes and filling and pushing epoxy coated ply pieces in the voids so as to stop the flex of the areas in the cabin top that I have cut the skin off. I will use some f-glass cloth or how about some roving material to build a mast step area.
I also (as discussed previously) cut out an inspection hole in the forward settee area where the mast compression post is supported. I can see there is a 5 - 6 inch gap between the top of the post's support box and the wood block in there. I think that area needs to be better supported. The flex in the top deck was enough that the compression post had pushed down enough without breaking anything to let my privacy curtain rod support separate from the cabin skin inside the cabin.
Complicated to explain but I just think the flex has to been eliminated for best results all around.
James
I also (as discussed previously) cut out an inspection hole in the forward settee area where the mast compression post is supported. I can see there is a 5 - 6 inch gap between the top of the post's support box and the wood block in there. I think that area needs to be better supported. The flex in the top deck was enough that the compression post had pushed down enough without breaking anything to let my privacy curtain rod support separate from the cabin skin inside the cabin.
Complicated to explain but I just think the flex has to been eliminated for best results all around.
James
Just throwing this out there in regards to no bonding on the liner... Not all boats have an inner liner. Some or all S2's are a good example. Catalina may have been fully aware of the lack of bonding but did not see this as a problem
If you've found solid, dry material then I would start putting it back together
