Rot Doctor


Date: Mon, 04 Oct 2004

Sir, I am building a 7′ x 24′ replica of a civil war Ironclad ship. The boat will be wood stringer-frame construction covered by plywood. The hull will be flat-bottomed 1/4″ plywood, as will the casemate. Is this Elastuff 120 used with fiberglass cloth? If so, I figured 2 coats, then fiberglass cloth with 3rd coat applied with roller? Then my question would be if something like “Thompson’s Water Seal” coated over by a good thick polyurethane would suffice for the parts topside? Could you give me an estimate of the Elastuff 120 volume/price per gallon purchased through you.

Thanks, Jay R.


Elastuff 120 is used as a waterproof membrane on its own. It is not used with fiberglass. Elastuff 120 is more flexible than the wood, and so will flex with the wood without cracking. If you want to use Elastuff 120, prime with CPES, then coat with Elastuff 120. Finish with coats of bottom paint or other paint. If you want to use fiberglass cloth, I would suggest our Layup & Laminating Epoxy Resin. It is excellent for this purpose.

I would not suggest using Thompson’s Water Seal on any wood for any purpose, but I would absolutely not use it on wood that I was planning on coating with a polyurethane. The Thompson’s Water Seal will prevent the polyurethane from sticking to the wood. Prime the wood with our CPES, then top coat with the polyurethane of your choice. Our Elasta-Tuff™ 6000-AL-HS would be quite suitable for this purpose.

Elastuff 120 is available for $157.18* per 2-gallon unit.

Let me know if you have further questions.


* Current pricing on all our products can be found on our Product Information page.