The Rot Doctor


Date: Wed, 11 Nov 1998

I picked up a 1978 starcraft tent trailer this fall which I determined to have significant plywood rot in the area of the four extension posts and and in the roof along the perimeter.

I plan on removing trim to get at the wood but am unsure how much CPES to use. I have the trailer covered and expect to do this in the spring after the wood has a chance to dry.

I would like to know about your injector system and how many ounces can be injected from each syringe fill. Is the injector supplied with the 2 qt or 2 gal kit?

I would expect that since the plywood has delaminated in several spots, I will need to use significantly more CPES in these areas. I know that it is difficult for you to tell how much I would need but, for the sake of helping me to make a rough estimate could you guess how much CPES would be needed for a well rotted 4'x8'x3/4 inch sheet of plywood that was delaminating?

I am thinking that it would be possible for a single sheet in this condition to require as much as 2 qts by itself. Would that be unusual? Thanks for your expected reply,


The 2-quart unit is probably a safe starting point. You do want to give the wood all the CPES it will readily accept. For plywood, it's best to start at the top and let gravity pull the CPES down. You can later inject at lower points if you believe it might be beneficial.

You may also want to consider following the CPES with a little Layup & Laminating Resin if there are voids. The L&L Resin is also slow-setting and will flow down with gravity. CPES mixed has the consistency of diesel fuel, so it is not a filler, but a wood restorer and rot preventer. The Epoxy Putty is also a good filler, if you can get it into the vacant spot.

The Injection Kit is a separate item, at $22.61 for the syringe, needles, tubing, spare gasket and lube jelly. The syringe holds 50 ml, which is about 1.69 fluid ounces. Not a large amount, but more than your average syringe. You just stick the end in the mixed CPES and pull it into the syringe. An easy process. The syringe must be cleaned with Epoxy Solvent, sometimes during the process if it seems to bind, and certainly afterwards.

Come back if you have additional questions.


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