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May 10th

A fairly frustrating day…

Posted by // May 10, 2012 // COMMENT (0 Comments)

Maintenance, , ,

Whew, New Orleans is getting hot! It was 90 degrees and sunny when I went to try and finish up the last couple fiberglass jobs I’ve got left. As anyone who has tried to work with epoxy in this kind of heat could probably have told me, it didn’t go well…

This is my first batch of epoxy 5 minutes after mixing:

I was using West System’s Slow Hardener and mixing in fairing compound to the recommended ‘peanut butter’ consistency (which slows the epoxy reaction considerably by diluting it) but this only bought me a few minutes’ working time. I actually felt the container getting almost too hot to hold and when I picked it up 30 seconds later it had become crunchy peanut butter and soon was one solid mass, too hot to touch. ‘

The chemical reaction in epoxies is both exothermic and heat-sensitive, meaning it produces heat as it cures but it also cures faster when it gets warmer. This means that if you mix too much epoxy at once in a hot environment it can create a domino effect where the warm epoxy starts to cure, causing it to heat up, causing it to cure faster, until all of a sudden instead of a thick goop you have a very expensive little burning hot brick of plastic!

Needless to say, it was a frustrating day. I did find in the end that the slow hardener allowed me enough working time to do some fairing but I had to do it in tiny batches, one or two squirts of epoxy at a time, so it was slow going. By the end of the day I had only managed to even out the cockpit sole a bit and to finish up the last little bit of fairing on my earlier deck core repair.

The cockpit sole still has a little ways to go but it’s getting close!
And the deck should be ready to paint. Hopefully the blue tape protected the fresh paint around the repair.

Well, at least I got something done.

This article was syndicated from Safe At Harbour But Meant For The Sea: DIY Sailing with Paul Calder

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