Subject: Cruiser Deck Repair
Date: Sun, 21 Dec 1997
From: ROCCO B.

I wrote earlier about a deck repair job on a fiberglass cruiser. You recommended drilling out holes in the deck to dry it out before injecting resin. Well, I've started the work, and have found that all areas that need shoring up are accessible from below. I would rather complete the repair job from the inner skin so as not to disrupt the non-skid finish on the deck.

Based upon recommendation in the book "Fiberglass Repair Manual," I have drilled one inch holes (with a hole saw) about four inches apart in the lower skin. I have found that the end-grain balsa core is rotted in isolated contiguous areas, and I have been able to actually break up the rotted areas of the core for the most part entirely by probing with various objects (wire hangers, screw drivers, etc.) After breaking it up, I sucked out the debris with a shop-vac. What is left is the upper skin (about 1/4") and lower fiberglass skin (same thickness) with the holes in it as above. The core (or space left by it) is about one half inch at most. I feel that with this excavation, by the time spring comes, I will have both the space left by the removed core and dry balsa adjacent to it to do something with. I would like to inject your epoxy resins into the deck, but with the open space, I am concerned about the cost of the "open" areas of the deck needing a lot of epoxy resin to fill the voids. I would rather stuff a filler into the voids as much as possible, and then fill the remaining space with resin.

My main question is, what do you recommend for a filler to stuff into the void through the one inch holes, while still allowing the resin that I pour in from through deck penetrations above (I have fitting holes in the area that caused the problem, and I will inject the resin into these holes) to completely fill and bond the skins and filler together resulting in a "one piece" solid deck? I would really appreciate if you could recommend one of your products for the resin, and the solid filling material.

Very Truly Yours,

Rocco B.
Cherry Hill, NJ


Hmmmm...this is why we generally recommend keeping the old rotten wood in the deck, drying it and then using the Clear Penetrating Epoxy Sealer/resin to harden everything up again. No fill problems.

While you have the open 1 inch holes below, I would now with a brush and/or syringe and hose soak the remaining interior balsa with CPES. I would do this twice, flooding in as much as it will take before running out somewhere. The balsa will suck up the CPES, the CPES will cure and the balsa will have high resistance to future rot. This ain't gonna be fun! Buy yourself one of the $25.00 3-M organic fumes masks, get a pile of old rags to catch drips, and then squirt it in. Because you're injecting it into a confined space, it will take some time for the solvents to evaporate away and leave the cured CPES. I'd give it a couple of weeks between applications. We have just completed testing on CPES and balsa (you'll see it on our web site in about a month) so we know that balsa soaks the CPES up big time.

Following this, the best solution would then be to re-install end grain balsa pre-soaked in the CPES, but this may be impossible to do through 1 inch holes. You can think about it, though. You can get pre-cut balsa, but it may take some phone calls around to find the company that can get it for you. Assuming this is not a reasonable suggestion (and if I were receiving it I might very well consider it unreasonable!), I think the next best solution would be to use our Layup & Laminating Epoxy Resin (for its toughness, flexibility and strength) mixed with generous amounts of micro-balloons into a stiff putty. You can then force as much of this mixture into the 1 inch holes as they will take and then close up the holes, possibly with a smooth epoxy putty such as our Fill-It Epoxy. This would give you a pretty solid structure. Micro-balloons are terrible to handle, but the best choice in this instance.

Finally go back in through the top deck holes and fill with as much pure L & L Resin as the holes will accept. Because your deck holes are small and limited in number, this is why we suggest you go through the interior application of the CPES; it would just take the CPES too long to cure out in an almost totally sealed environment if you waited and injected it from above. The L & L Resin, on the other hand, is pure epoxy and will cure without problems in about 24 hours.

The CPES part of the job can be done in cold weather, since our Cold Weather Formula will cure down to 32 degrees. Likewise the micro-balloon putty and the Fill-It putty, if you were to use that. I would, though, save the final step, injecting the L & L Resin through the top holes until a warmer, sunny day. That way the L&L Resin will remain reasonably thin for maximum penetration. It does have a long set-time, which is very much to your advantage.

I hope I've said all this in a way that is clear. I can perfectly understand your reluctance to pour pure resin into the deck, but at the same time I feel strongly that you must stick with premium epoxy products throughout. You might cut a few bucks off by going for something like Bondo epoxy as a filler, but Bondo is hard, brittle stuff and I don't think you want it in your decks. Micro-balloons are not expensive, if you can keep them from blowing away in the wind (wear a mask when you handle them!)

If you have questions or I haven't been clear, get back to me. I'll help any way I can