The Rot Doctor


Subject: dry rot - bathtub
Date: Wed, 16 Dec 1998

I am currently having problems with rot below a window and around a tub in my bathroom. I was about to tear out the tub and floor when a retired plumber told me he had seen a product ( borate solution) put on an old boat, the Wapama, to stop the rot. No one in my area has any idea of such a product. The boards in my bathroom aren't really bad but I need to stop the process from advancing. What product of yours would you reccomend and how to I apply it. Can it be applied without taking out the tub?

Another co. told me that a product called copper napthanate will stop dry rot. There again, we have no access in small quantities. Have you ever heard of this? If so where can I get it"? Please help me with this situation.

Jay B.


Borates (disodium octaborate tetrahydrate) and copper napthanate (as is in Cuprinol Green) will kill rot fungi. The borates work, but are water-soluble, and so don't remain in the wood if there is moisture around. The Cuprinol will work because it is in a petroleum base. It's a mess to use on indoor structures and bleeds through paint and other finishes.

More importantly, neither the borates or the copper napthanate formulas do anything to restore structure to the bad wood. And this is why we strongly urge people to consider our Clear Penetrating Epoxy Sealer (CPES). Mixed, this is about the consistency of diesel fuel and penetrates wood a long way, as the test results on our web site show. It not only encapsulates any rot fungi it encounters, it returns full structural strength to the wood when properly applied.

CPES must be applied to dry wood, which is also the case with the borates and copper. You can allow the deteriorated wood to air dry, or use heater-blowers such as a hair dryer to speed the process. Then the CPES is applied generously, allowing the wood to accept all the CPES it will absorb. Let it cure and then you can fill (if necessary) with our Epoxy Filler and paint.

Whether you need to remove the tub is a good question. It all depends on how far you think the rot has progressed under the tub. The CPES will penetrate a long way along horizontal surfaces, but it's a question of whether the wood is dry enough to receive it.

Tearing out the floor would be necessary only if the wood is so bad that it's falling apart. Otherwise, assuming dryness, one or two coatings of the CPES will restore structural strength. CPES is a premium epoxy, and epoxy is STRONG.

I hope this has been of some help. Come back to us if you have further questions. CPES is available only directly through us. We ship the same day as ordered via UPS GroundTrac.