Pilot House Delamination Fixes

[Beta Don]

And yet another question, once the core is suctioned out, do you take out the original core skins (leaving the inner and outer fiberglass skins hanging in the breeze) then resin up the coosa board and slide it in? I can see the latter, you just replicate the size of the old core.

If you are leaving the original core skins in there however wouldn't that make it too thick?

The 'core skins' are probably a layer of fiberglass mat. They wet out the end grain balsa with polyester resin, lay a layer of matt on top of it and wet out the whole thing

When you try to take out the balsa, you're going to be left with that layer of mat and it's going to be very rough because the resin will have penetrated unevenly into the balsa. I can't think of an easy way to get inside that 1/2 inch void left when you vacuum out the balsa - How would you smooth out those rough sides so you could slide *anything* between them? How would you even get in there with something to wet out the inside with epoxy so you could force the coosa into the void? Honestly, I don't see you ever getting an evenly bonded surface between the inner and outer 'skins' by trying to force a wetted out piece of coosa in there

If you were doing a lay-up from scratch with a piece of coosa in the middle, I could see where you could get a good bond to both sides of the board, but even then, is coosa as structurally strong as end grain balsa? I don't know

Just my opinion, but I think you'd be better off all around by leaving the balsa, drilling the holes and pouring in epoxy. If you find you need to do the overhead of the windows, of course you'll have to remove and replace the balsa with something as you couldn't do a pour above the windows. The overhead space is smaller - Why not try the coosa above the windows if you must replace a rotted core up there and see how it works before you remove all the balsa coring and find it's nearly impossible to replace it?

Don

[Jay Knoll]

When I did my repair I used exterior grade ply that I sealed with west system. I had to plane down some pieces due to the rough interior surface. After that kicked I brushed as much west system as deep as I could into the void. Then I loaded up the bottom 1/3 of the board with a heavy layer of west, slid it into the cavity, then proceeded to coat the remainder of the wood as I drove it down. I then put a bunch of clamps along the opening. After the west kicked, I injected more where I could (there were some gaps between the skin and the filler) let that kick. Then I trimmed to the final opening size, and applied more west to seal the newly cut edge.

[Vic K]

When I did the cabin top and the pilot house top I started by drilling holes and trying to fill. In the end had to remove the outer skin of fiberglass , dig out the old rot and replace it with exterior plywood soaked in west epoxy or foam if there was a curve. Then replace outer skin set in a epoxy/silica mix. Then sand, fill, sand, fill etc until smooth.
A lot of work but it was worth it. I can walk any place on the boat with no sag or soft spots.
Vic

[Beta Don]

FWIW, you're getting some great advice from folks who have 'been there, done that' whereas my advice is largely hypothetical since it comes from experience with previous boat projects and not with my Albin specifically, so . . . . weigh their recommendations much more highly than you do mine

If you have to drive the filler into the cavities using a hammer and a block of wood, you might have better luck with a new ply core than using coosa board - You could probably hit it harder before something bad happens

Don

[rnummi]

Thanks Don.... The whole pilot house is now drilled and ready for "fill" with the exception of port bulkhead. What about a 1/4 thick panel? Fill both sides after insertion.

[Beta Don]

Thanks Don.... The whole pilot house is now drilled and ready for "fill" with the exception of port bulkhead. What about a 1/4 thick panel? Fill both sides after insertion.

I think that would probably work. Cut the panel about an inch too short so you have a large space to pour the epoxy into and then fill that space with a piece of solid wood later. If you use slow hardener, the epoxy will flow down into the voids and it should make a good bond

I wonder how much weight Albin actually saved by coring the walls of the pilothouse with balsa - When you stick a window into the cored panel, you're almost guaranteed you're going to eventually get water intrusion into the core. Wet balsa can't be much lighter than a solid panel, can it?

Don

[rnummi]

I agree. As I have previously observed.... it looks like a BMW but is built like a Yugo. So I'm now down to the following... I have approximately a six inch void all across the front of the pilot house. I have drilled through the remaining core from above every 1-2 inches or so to allow a "pour" from the top down into the void. A couple of questions for those that have been there....
1. Do you (or did you) use git-rot to seal the balsa core (and allow to dry) before pouring the epoxy?
2. When I start the pour, isn't this going to cause significant exotherm? According to West, you layer it one on the other. I was actually thinking of going to get "casting poly resin" to pour down the tubes thus filling the void (and avoid burning down my boat from exotherm).
3. There is nothing to seal the bottom of the pilothouse (i.e. I scraped out the rotten core from the bottom using a bent saw) is taped wax paper sufficient to stop the epoxy from pouring out the bottom?
4. I also have a can of duraglass, I was going to fair the lower pilothouse to deck after pour....or, should I use it before to provide a base for the epoxy to pour on to?

Any thoughts would be appreciated....

[Jay Knoll]

seal it as best you can, the epoxy will find any openings. The duraglass is a great idea, fair that in and it should seal off the bottom (at least from the outside.

I didn't bother with wax paper, I just used blue masking tape and peeled/scraped it off after the epoxy kicked. I think that you really need to get some coring material back in there otherwise you're going to be pouring a fortune of epoxy in that void. Lay in a bottom layer of epoxy, let it kick. Then make up some coring material/shims, put in another pour of epoxy and then start inserting the core/shims as required to fill the void. Be careful not to overstuff, you'll put a curve in the pilothouse that will make it difficult to reinstall the windows (DAMHIKT). "Butter" the core/shims with epoxy, slide in place, let it kick./ Clamp where you can, you can put a caul on both sides of the opening to help keep things flat. Then go back in inject epoxy in the voids that occur. When you're satisfied put a top coat of epoxy/filler (or half time) to smooth off the entire opening.

[Beta Don]

I agree - I've used blue masking tape to 'seal' the epoxy from where I didn't want it to go - Works much better than your wax paper is going to I think

I *think* poly resin (which kicks much faster' is going to generate more heat than the slow curing epoxy. I don't think heat is going to be a problem since the epoxy is spread over such a large area and you have two skins to absorb the heat as it kicks - I doubt the surface of the pilothouse will feel any more than just warm to the touch

Don

[rnummi]

Shows what I know about exotherm. I stopped by Advance Auto to get engine degreaser and I saw poly resin for 50 bucks. Heck of a lot cheaper than west system. Anyway, I already bought the West w super slow hardener. Inre the core: I can do that on the port side (see pic), front is good core down 6 inches or so, the bottom 6 inches is toast. I don't have any way of getting core in there from the bottom. So, I'll pour down the holes to fill the void in front. How about the delam on posts (see pic)? Just inject epoxy w syringe and clamp? Core there is solid.

[rnummi]

P.S. Not that I'm avoiding pouring the resin or anything, but has anyone seen or used "injectadeck"? Seems like close cell foam might do the trick for core replacement? (I'm pouring, w/ mdf inserts, just curious)...

[rnummi]

Never mind it's a scam....

[rnummi]

Ok gonna pour epoxy today.... Wish me luck. Anyone have any idea what the wicking capability of west system w/o fillers? I.e. If I pour down a 3/4 inch drilled hole into good core am I only going to have a 3/4 inch column of west hardened epoxy or does it wick beyond drilled column? Question 2.... Do you epoxy the delam skins first then go for the core? My starboard pilot house wall is fairly solid, I have holes every 4-5 inches bored to find rot. Whole port side was rotten, forward was rotten up 6 inches across whole front and starboard was solid to deck. I'm going to duraglass the base, then pour.

[Beta Don]

I stopped by Advance Auto to get engine degreaser and I saw poly resin for 50 bucks. Heck of a lot cheaper than west system.

You're in Florida and Raka isn't that far from you - Get your epoxy from them . . . . also a heck of a lot cheaper than West System

www.raka.com

larry@raka.com can answer any questions you may have about epoxies, filler, cloth and mat. I've been buying epoxy there for at least 20 years and always been very happy with both the product and the prices

Don

[Beta Don]

Anyone have any idea what the wicking capability of west system w/o fillers? I.e. If I pour down a 3/4 inch drilled hole into good core am I only going to have a 3/4 inch column of west hardened epoxy or does it wick beyond drilled column?

Slow setting epoxy wicks into the grain of wood, even if the wood is in good shape. It will wick into balsa quite a bit. The wood fibers act like the glass fibers in roving or mat to a degree - The fibers strengthen the epoxy so that the net result is something stronger than either the wood or the epoxy resin. After epoxying your core and your delaminated skins together, it's a safe bet the final result will be a stronger wall than the original wall when the boat was first built. Strength is not going to be a problem

Question 2.... Do you epoxy the delam skins first then go for the core?

Looking at your photo of the delamination, I would pour first, so the epoxy can run into the core and outside of the core between it and the delaminated skins. Your first pour will probably run out of sight pretty quickly because you have so many voids. After you pour, clamp the wall together using a piece of 1 X 2 lumber on either side and a couple C clamps to squeeze it together. I would put some blue masking tape on the outside in case you get any spillage which might cause the 1 X 2 to try to glue itself to the outside skin

After the first pour is all set up (overnight) you can remove the clamps and pour the core again. The second pour won't take nearly as much epoxy because A.) The outside delaminations are now glued solid, so no more voids there and B.) the core has been soaked once with epoxy which sealed the wood, so the second pour isn't going to be soaking into any raw wood

Good luck and hope it all goes well!

Don