laying down epoxy coats (after coat after coat)

Builder's Forum
1

Well, as will about everything else involved with making my Dory, i am finally getting a process down when about 80% done with it. so I am going to pass on the tips i have learned regarding putting down coats of epoxy. I wish I had done it right from the beginning.

One, dont use so much. i am finding now at the end that i can mix up a cup of epoxy in a big red cup only about 2 inches up and that will last the whole coat. by laying down more but thinner coats you have FAR less drip lines to deal with afterwards with sanding. just be patient and build up the coats slowly. it will take far less time than sanding off all the prior coats to get rid of bumps and drips and then doing it all over again. 

 

Two, dont use a roller pan, wastes too much. just pour out a little on the boat from the big red cup as you go, very little really needed.  mixing sticks are found in your kitchn, use plastic forks. work great.

 

After each time you roll a side, go over it with a chip brush or spong brush to smooth it out before it hardens. Dont wait too long and plan on doing it more than once. that will also spread out any inciptient drip lines. go back in about 15-30 mintues and do it again with light pressure. check again another 15-30 minutes. 

 

Sanding, it really is  pain and it really is necessary. i put some paper on a stick and go over it lightly first to reveal the drip lines and uneveness to work on. if really significant I go at it with a scraper first. but skipping any places will not save you in the end, you will have to go over it all and probably many times.

Early in the process on the outside hull, fill in your lapstrakes with thickened epoxy. do that slowly enough so that you probably go over it all about 3 times, building depth as you go. they will run in the middle of the night and cause hellashious drip lines if you do too much at once. it isnt a level surface. Pour the thickened epoxy driectly into the strake gaps and smooth out with rubber scraper or chip brush or both. come back 15 minutes and 30 minutes and 60 mintues latter to scrape drips or you will regret it.

 

I am on the finishing laps for my epoxy work. looking forward to turning that corner and getting to painting and varnishing, more to learn...

 

David

 

 

 

2

Hey David...you probably are past this point, but one tip I picked up on is to do like you did on the strake laps but also to dribble in the epoxy on last coats so the lap fill is not concave, but just barely convex, thus covering the edge of the plywood, then when sanding the lap fill, do not sand down the epoxy on the corner/edge of the plywood, and when sanding the flat surface of the strake, do not sand across the edge of the strake, keep sandpaper an eighth of an inch or so back from the edge of the strake, again so the epoxy totally encapsulates the corner/edge of the plywood...I had to go back and add epoxy to ensure the edge of the strake plywood was fully encapsulated to reduce abrasion damage.  Be interested in other builder's comments on this topic.

3

   When applying multiple coats of epoxy, I always used a roller pan with one roller and use a dry foam roller to go back over to take up any excess. It does take a lot of sanding out of it. Also when you go to apply the next coat wait until you can put your finger on the epoxy and find its still sticky but none comes off on your finger then your ready for the next coat otherwise that too will create sags and lines.

Bruce