wood rot under mast in grp dinghy

While inspecting the plywood partition of the under mast "cuddy", I found some rot. Two sides of the ply were completely rotted and I found that 3 of the 4 glassfibred timbers had also rotted, much of it to powder. The forward mast position fibreglass had cracked (the wood below had crumbled) and I could see daylight!

It appears that there is a water channel running from the forwardmost compartment through the cuddy to a space under the cockpit sole. The bottom timber seems not to have been protected from this water.

I have cut away the remaining glassfibre and timber remnants and bought hardwood replacements.

The problem is - what to treat the new timber with to protect it? I had thought to use Bondaseal on the timber and plywood with marine epoxy Plastic Padding to fill voids around the timber other than the water channel.

curlew's picture

I think the standard thing to use is epoxy resin such as West System with a filler powder or fibreglass matt/tape as necessary. Maybe others will correct me. I also treat any suspect wood against further rot by soaking in blue antifreeze (ethylene glycol), leaving 24 hours and then drying thoroughly with a heat gun.

I hadn’t heard of treating with antifreeze, it sounds simple and logical. Don’t have a heat gun so might try a hairdryer first!
Will look atWest System as well. Don’t think that I will fibreglass again as I may replicate the original problem.