I used CPES on a commercial project a couple years ago with good results. Not a boat, but a 100-year-old log house. The stuff is effective but overpriced. Turns out I live in the same area code as the Rot Doctor, so I paid the man a visit.

It would be a mistake to think that the source of the building block for a chemical retains any characteristics of the source after it has been refined. I have seen no evidence that "wood-based" epoxy is any more flexible than petrochemical epoxy. Phenol is phenol, whether it comes from a tree or an oil well. There is also the issue of whether flexibility compromises strength - I believe it does, so how can it be an advantage? There are lots of cheap fillers that can be added to epoxy that make it more flexible, but the main reason for their use is to reduce the cost of the product. Nonyl phenol and butyl acetate come to mind - if you see them in the MSDS, you have a cheaply made, low-strength product.

We invited the Rot Doctor and his supplier to substantiate their claims on this BBS about 2 years ago, and a very interesting thread is in the archives. I believe that the concensus was that the claims were hype, the product is too expensive, and similar results can be obtained at far less cost by other means.

: Hi Folks,

: I was wondering if anyone had any thoughts on wood derived epoxies? I first
: learned about this yesterday while looking at the
: http://www.rotdoctor.com .

: Their site says "Featuring wood based epoxy resins that are designed to
: penetrate wood, resist and repair rot in all boat and home applications.

: Our epoxy products are formulated from resins derived from wood. They bond
: better, are tougher and more flexible than standard petroleum-based epoxy
: resins. You might as well buy the best."

: I like the idea of more flexible...