Rot Doctor


Subject: spraying cpes
Date: Thu, 03 Jun 1999

Your aerosol spray kit, then, is the venturi type?

I can’t tell from the picture or the text. But since it is your recommendation to use that sort now I am guessing it is that sort. Please confirm.

FYI - My application is sealing the underneath side of a plywood deck. It is a year old installation, never been finished inside. It is not rotten, but it seems to me your sealer applied now will make it that much longer before it is rotten. And paint will adhere well, yes? It will be painted white, probably Interlux Alkyd paint.

- Rick


Yep, the little kit is a venturi sprayer. Bear in mind, though. that it only sprays about 14–16 oz of product per cartridge, so you might go through a few cartridges before you got your ceiling sprayed.

You are right about CPES-spraying the underside of the deck. It would give the wood good future protection, as well as providing a superior base for the paint. If you did spray with CPES, you should pay particular attention to cracks and crevices where the ply end-grain might be reached. If the CPES gets into the cracks, it will seep into the end-grain. This is good. That’s where the rot and general deterioration most often gets started. You should apply all to these areas that the wood will accept.

If it were me, I’d consider going to a rental place and renting a venturi sprayer and compressor for a day ($25.00??), buy a can of xylene for running through the unit when the epoxy starts to clog it and for final clean-out of the unit, and then go for the project.

Be careful of the CPES solvent fumes. If you are outdoors you’re probably okay, but do remember that the fumes are strong and not good for your lungs on a prolonged basis. If this is of any concern to you, then a mask capable of filtering organic solvents might be appropriate, When I use the CPES in tightly enclosed indoor places I use a mask made by 3’M and can’t smell a thing. I think I paid around $22.00 for the mask.

Come on back if you have additional questions.