The Rot Doctor


Subject: (Plywood Rot)
Date: Sun, 02 Jul 2000


I have an 18' flat bottom, plywood workboat with a small area of 5"X8" of rot on the 3/4" plywood bottom. It is fairly deep, almost completely through, how can I repair this area and maintain the strength of the bottom? Thanks for any help.


There are a couple ways that you could go.

1. Knock out the really loose pieces, dry the remaining wood and treat with our CPES penetrating epoxy, then fill in the holes with our Fill-It epoxy putty. You may need to make a temporary backing plate when you fill with the Fill-It. Wrap the backing material with polyethylene plastic and you will be able to remove the backing plate when the epoxy cures. Grind everything fair and paint as you normally would.

2. Grind a 7:1 bevel around the edge of the hole. For your 3/4" plywood, this would be 5 1/4" This should remove most of the bad wood around the edge of the hole. Cut a plug from a piece of 3/4" plywood as big as the large part of the beveled hole. Grind a 5 1/4" bevel onto one side of the plug so that it fits into the beveled hole. It doesn't have to be a perfect fit as we will be filling gaps with epoxy putty. Dry and treat the old wood with CPES. Treat the new plug with CPES also. After the CPES cures, smear a thick coat of Fill-It epoxy putty on the bevels of both the hole and the plug. Push the plug down into the hole, and brace it in place until the Fill-It cures. Grind the excess Fill-It smooth, and paint.

Please let me know if I've been unclear, or if you need further explanation.