Paint on the topside good; epoxy issue on the bottom...

Anthony A

Anthony A

Well-known member
Hi guys,

I finally had a nice sunny/hot day yesterday, with no other plans, so I pulled the Kara out of the garage to paint it with FME from Lou's shop. I put it right side up on the sawhorses and tried to make the first coat as thin as possible, as recommended, and let it dry for about an hour and half in the sun before putting on the second coat. I let that sit in the sun for about 1.5-2 hours, then turned the boat over to paint the bottom. I had to sand the bottom a bit more before painting it when my wife called me to help with something. I came out about 45 minutes later to finish up the sanding and noticed that there were three or four more areas, about the size of a quarter, where the epoxy was coming off.

This happened before, over two larger areas (these 3-4 areas are in close proximity to one of these areas) - I wrote a post, and after reading the repsonses, ended up sanding the areas as best as I could, then applied leftover epoxy + wood flour mix, which although "bumpy" seems to have worked.

I have two questions.

1) Is it possible I just missed these few spots? In the previous case, I thought it was because of an insufficently mixed batch of epoxy. Could it have been due to that? Or was it due to the fact that I left the boat out in the sun for that amount of time? I heard that epoxy is UV sensitive. Could this have been the result of me leaving it out in the sunlight for that period of time?

2) I will sand and re-apply epoxy + wood flour the first chance I get. I do not want to order more epoxy from Raka, since the areas are so small, and I have two brand-new tubes of epoxy (resin and hardener) from Home Depot (http://www.homedepot.com/h_d1/N-5yc1vZ1xgf/R-100371835/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053). I believe this one is meant for use more as a glue than for building boats... can I use this mixed with wood flour you think?

Your comments and suggestions are greatly appreciated.

Anthony
 
Hi guys,

I finally had a nice sunny/hot day yesterday, with no other plans, so I pulled the Kara out of the garage to paint it with FME from Lou's shop. I put it right side up on the sawhorses and tried to make the first coat as thin as possible, as recommended, and let it dry for about an hour and half in the sun before putting on the second coat. I let that sit in the sun for about 1.5-2 hours, then turned the boat over to paint the bottom. I had to sand the bottom a bit more before painting it when my wife called me to help with something. I came out about 45 minutes later to finish up the sanding and noticed that there were three or four more areas, about the size of a quarter, where the epoxy was coming off.

This happened before, over two larger areas (these 3-4 areas are in close proximity to one of these areas) - I wrote a post, and after reading the repsonses, ended up sanding the areas as best as I could, then applied leftover epoxy + wood flour mix, which although "bumpy" seems to have worked.

I have two questions.

1) Is it possible I just missed these few spots? In the previous case, I thought it was because of an insufficently mixed batch of epoxy. Could it have been due to that? Or was it due to the fact that I left the boat out in the sun for that amount of time? I heard that epoxy is UV sensitive. Could this have been the result of me leaving it out in the sunlight for that period of time?

2) I will sand and re-apply epoxy + wood flour the first chance I get. I do not want to order more epoxy from Raka, since the areas are so small, and I have two brand-new tubes of epoxy (resin and hardener) from Home Depot (http://www.homedepot.com/...&catalogId=10053). I believe this one is meant for use more as a glue than for building boats... can I use this mixed with wood flour you think?

Your comments and suggestions are greatly appreciated.

Anthony
Click to expand...


When they say mix the epoxy for a couple minutes, that is the reason why. I don't mix as long as they say, but it is a risk and a major mess as you can see. It is not the UV, epoxy yellows adn gets brittle in response to UV over a matter of weeks/months.
 
I hear you Tod. There is an art to mixing epoxy, that's for sure. I learned tons with this build. Sometimes it just "goes off" in your hands and gets so hot you can barely hold the container. I put one down once for only a minute or two and it was rock solid when I picked it back up.

Thanks for letting me know about the UV part of my question.

Anthony
 
Anthony,

If your epoxy is getting too hot to hold in your hands - it's too late to use it. Start over with a new batch. Use smaller batches so it doesn't cook off before you have everything ready. Don't use Fast Hardner until you become more adept at using it or better yet, never use it. Slow or extra slow is just fine expecially in the summer. Fast hardener is way too fast for me in the summer unless I am only mixing a couple of ounces. Also, after you have mixed resin and hardener together and are ready to use it dump it into a large flat area so it spreads out - slows the cook off time. I use disposable plastic plates from the grocery store.

There is definately an art and skill set to using epoxy. Being good with it takes time. I finally feel I'm not bad with it but I am completeing my third boat and have used in the neighborhood of 18 gallons of the stuff all together. It still surprises me at times.
 
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