Question on re-coring cap rails

[zendora]

My cap rails near the aft part - around the rod holders - are soft. I am attempting to re-core them from underneath so I don't have to take the entire cap off. This would be a massive project beyond my skill level, and I think I'd have to cut somewhere across the forward bulkhead to get it off (Savage). Removing the cap is not an option at this point. The sections I'm repairing are roughly 3 feet long by the width of the cap rail.

So far I have removed the old fiberglass skin on both sides from below and removed most of the rotten wood. I think it was balsa core. There is one section of plywood that held up a lot better - wet but not rotten. I have not removed that section yet, as it's in there pretty good.

My plan for the re-core is to use 3/4" marine ply with some thickened epoxy and cover it with 6 or 9 oz cloth. The good news is it doesn't have to be pretty, at all this is being done on the underside of the cap rails. I'm planning on holding the new wood in place with either some big clamps, or with a bottle jack and the tire jack from my car while the epoxy cures. At this point I'm looking for some suggestions and constructive criticism. Any tips on getting the wet plywood out, prepping the surface, holding the new plywood in place, materials to use or anything that will make this project easier?

I'll post some pics this weekend.

Thanks,
Mike

[Max_Florida]

I would probably still consider myself a "beginner", especially compared to some of the guys on this board... but here are my thoughts:

Removing the Old Wood - Wood chisels and a hammer to lightly tap it. You have to be careful not to angle it too much or you will punch through the top layer of fiberglass. A flathead screwdriver works pretty well too. Once most of it is out then you want to let it dry and then hit it with some kind of a sander. I don't know what kind of space you are working with a but a small "mouse" type sander with 60 or 80 grit paper would probably be your best bet.

New Core - How thick was the old core? 3/4" seems thick for cap rails?

(Test fit wood before bonding it)

Bond the new wood to the top layer using resin thickened with an adhesive filler like Cabosil or one of the West Systems blends. Remember to wet both surfaces with resin before applying the thickened epoxy.

A jack might work. When I did something similar(backing plates for cleats) I used sections of 1x2 that I had cut specifically for this purpose. I just wedged them in there to hold the wood in place. If you make the epoxy adhesive thick enough(peanut butter consistency) it won't take much pressure to hold it up.

Laminating - Working upside down is going to suck(I would think). You are probably going to want to use fast curing epoxy and to let it start to thicken slightly before you start laminating. Probably working in small sections with small batches would be best. Maybe something like using 6-12" sections and staggering them so the seams from different layers don't line up? (Not sure how good of an idea this is, but I would think that larger pieces = more weight = going to sag easier? Again - not sure how good of an idea this)

Tip: Apparently vinegar stops the chemical reaction of epoxy and can be used for clean up(hands, tools, etc.). I wish I would have known this as I usually used acetone and apparently that stuff is really really bad to get on your skin. You can also save your mixing cups and re-use them - just "crack" out the hardened epoxy.

[Blue197320]

I just did something similar on my contender. luckily the rear gunnels on mine are removable. I had to recore them as the wood around the rod holders was bad and further in the wood was still good. I found the easiest way to remove was use a dremel multi-max with Rockwell brand plunge cut blades. takes it right off without a lot of dust. I tried the chisels and hammers and screw drivers. dremel was by far the easiest and fastest option for me.

[DonV]

Ditto on the Dremel multi-max. You can set the depth perfect and it will cut in slight curves versus a straight line only!

[zendora]

Thanks guys. I used a Dremmel type tool and I seriously don't think I would have been able to do it without it. Some of the wood was a bastard to get out, but I was able to get it out piece by piece with the multi tool.

So far, both sides are cut out and sanded and I've cut and dry fit the new plywood. I used the old fiberglass skin as a template.







I taped off and covered the aft gunnels and deck with a painter's tarp as the next part of this project will get a little messy. A friend suggested screwing the new boards in from above to hold them in place, so just I'll use the holes from the rod holders.

[Old'sCool]

Screwing from top is a good suggestion. Use SS just in case they break off. You don't want them possibly rusting and bleeding through later on.

[Normagain]

If you have a Harbor Freight nearby, extra long C clamps work pretty good and it looks like they may be long enough to fit there. I used these a bunch of times doing my rebuild. I used 6 mil plastic sheeting so they don't stick to whatever you are using as bedding.

[wattaway2]

good thought normagain-- might also think about putting tape over the threads of the clamps god know fiberglass overhead gets every where

[zendora]

Great advice, thanks guys. I am going to screw the boards in place without the thickened epoxy to make sure that will work. Otherwise I might try the clamps. Good call on the tape and plastic wrap.

[sidelock]

Why can't you simply cut a few pieces of wood slightly longer than the height between the deck and the bottom of the plywood and wedge them in place ?