The Rot Doctor


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Date: Sun, 20 Jun 2004
Subject: Deck Delam (delamination, and repair from inside)

I have been reading your web site and think that your L&L Resin may be right for me. I have a 1986 Catalina 22 with a delam in the starboard foredeck. The area is about 15" by 18" in size. I drilled several inspection holes from inside the boat and found the marine plywood core to be dry and solid. The top fiberglass layer has simply delamed from the core.

This is not uncommon.

I do not want to drill the top of the deck as it is non-skid and in terrific shape. So here is my plan: Use a 2" boring bit (the kind used to cutout door knob holes) from inside right in the middle of the delam area. Remove the core in the 2" circle and then use a caulk tube filled with L&L to inject the resin into the void all around. I'm hoping the strength of a caulk gun will get the resin throughout the void area. Then put some weight on the top of the deck. After it dries use the L&L to bond the 2" "plug" back in the inside. Your product sounds viscous enough and strong enough to handle this and bond the delam back together.

Will this work? Any other ideas? Thank you for your help. Randy K.

Randy,

Your plan should work just fine. The L&L Resin is definitely strong enough, and it thins as it begins to cure, so it should run throughout the area. When you do this pay attention to deck camber...the L&L Resin will tend to run downhill.

You might want to consider thickening the L&L Resin a little with something like fine sawdust or talc. This will give it a little more bulk and slow the tendency of the resin to run. Just a consideration...I'd have to be there looking at the decking to make the decision.

Have some lacquer thinner on hand for clean-up.

And feel free to come back if you have additional questions.

Doc

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Date: Mon, 21 Jun 2004
Subject: Re: Deck Delam

Thank you for the prompt reply! The deck has a camber of about 10-15 degrees, fairly flat but some curvature. Would you suggest the talc or sawdust in this case? Thanks for your help. Randy

That's enough camber to allow the resin to run downhill. I think I would drill the hole through the high side of the camber, mix the resin, and then using something like an automotive grease gun (clean out afterwards with lacquer thinner) pump the pure resin (no talc) in as many different directions as possible. And then, as you suggested, weigh the deck down for about 48 hours.

If your summer temperatures are running high (above 80 F), I would try to do this in the morning when the temperatures are lower. This increase the time the resin has to run...it sets more quickly, as all resins do, in the higher temperatures.

Doc

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Subject: Re: Deck Delam
Date: Sun, 25 Jul 2004

I ended up drilling four 1/2" holes at the borders of the delam void from underneath in the V berth. I then loaded a quart of Rot Doctor's L&L Resin into an automotive grease gun equipped with a needle-nose. It took two loads. I drilled a hole through a 1/2" cork for the needle-nose and then pumped the resin into each of the four holes. I then put four 50lb sandbags on the deck. Some resin flowed back out through the holes but not very much. After a few days I removed the sandbags and filled the holes with Marine-Tex. The deck is now rock solid and there are no holes on the outside!

I credit the success to the viscosity of the L&L resin and the use of the grease gun to put a lot of the resin into the void. You folks at Rot Doctor were great to work with and offered lots of good advice.

I had written to Don Casey about this problem and he didn't think a repair from below-decks would work. I just e-mailed him the solution and some good words about you and your products.

By the way when I drilled the four 1/2" holes I stopped short of hitting the exterior laminate of course. I then used a nail punch to manually scrape through the final bit of core. I hooked up a vacuum to clean out the four holes. I then reversed the vacuum and put the nozzle to each hole - you could see the deck rise and could feel the air come out the other holes. This helped confirm the extent of the delamination.

Thank you! Randy K.

Randy,

Many thanks from all of at Rot Doctor for taking the time to give us your results with the L&L Resin injection program, and from underneath! The cork was a very bright idea ... no one here ever thought of that.

Doc

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