The Rot Doctor


Subject: How much product do I need?
Date: Tue, 10 Feb 2004

My '86 Endeavour 33 has 3 areas of rot & delamination in her plywood cored deck.
One is on the foredeck and appears to be dry but de-laminated. It covers an area of 4 square ft. or so.

The other two areas are the side decks from the shrouds back to the genoa tracks encompassing a total area of about 30 square ft. The side deck areas both have water in the deck core.

My plan of attack is to remove the deck hardware & fix the leaks, drill & dry the core, inject CPES through the holes into the core, and follow it up with L & L Resin.

Does that sound right to you?
How much CPES and L & L do you think I'll need?

Thanks, Dave C.


When dealing with these types of areas it can get really tricky to estimate the amount of product needed. For instance, if an area is soft, but not rotted to dust, it will need a fair amount of CPES™, but not much L & L™ Resin. If the area is largely voids, you will use less CPES but much more L & L Resin. Since you haven't drilled into the area yet, it is very hard for me to judge your needs.

Thirty square feet of core, assuming a 1/4" thick core, would fill up about 47 gallons. So if the wood is so soft that it is almost turning to dust, it will be able to absorb about 47 gallons of CPES if the deck is 1/4" thick. If the core is already turned to dust, it would take about 47 gallons of L & L Resin to fill up 30 square feet of core, again assuming a 1/4" thick core. If the core is 1/8" thick, divide the numbers in half. If thicker, you will need to multiply these numbers.

These are worst case scenarios. The core is almost never this bad, at least not over the whole 30 square feet. My best guesstimate would be about 10% to 25% of the worst case calculations. So between 4 and 10 gallons of either product, depending on the condition. This could easily be less. Since most rotted areas are a combination of each type of damage, you would probably use at least a couple gallons of each. Without drilling into the core, it is very hard to tell. Since it will likely take you awhile to dry the core, you could drill the holes and then order based on what you see from there. Many times people will buy a two gallon unit of each product and see how far that goes so that they can estimate the total amount needed and make a second order.

I hope this helps, and let me know if I can help further.