Wipe down with Naptha or Methyl Hydrate after epoxy sand?

BigandSmall

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Mar 2, 2012
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Northern BC (FSJ)
I did a leveling sand today and was wondering if Naptha or Methyl Hydrate was acceptable to wipe down with between coats? With social distancing I'd like to use what I have on hand rather than run to CDN tire. Going to add another fill coat tomorrow.
 

JohnAbercrombie

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Dec 7, 2011
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I use warm water on epoxy (dissolves amine blush) - I've been told it's better to wash before sanding to avoid sanding any contaminants into the surface, and I usually remember to do that.
I definitely wouldn't use naptha between epoxy coats. Methyl hydrate is probably OK if it isn't a redistilled product with contaminants. For example, online 'wisdom' says that acetone can be contaminated but I haven't had problems on the few occasions I've used it.
 

RobertNPruden

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Aug 21, 2007
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I keep both methanol and acetone on hand for dust removal. I use no-blush epoxies so I generally never need to do the soap and water rinse. I wanted to support John's comments.

Robert N Pruden
 

BigandSmall

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Mar 2, 2012
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Northern BC (FSJ)
Thank you Robert. I just used the water as suggested by John but later used the methyl hydrate for some detail clean up work. We put a black accent strip on the hull and it needed a light sand for the second coat (epoxy and WS 423 graphite powder). Some of the black dust got into the sanded clear epoxy. Water wasn't taking it all out and it looked slightly dirty. A little bit of methyl hydrate on a shop towel would wipe away the dirty bits easily. System Three epoxy for anyone reading this in the future.
 

Roy222

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Jun 2, 2009
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Even using no-blush wash the hull with soap and water before final finish.
Unless you are a chemist with a gas Chromatograph follow Johns advice about contamination of off the shelf products. But if you a Chemist you already know this.
It is more about what product you are going to finish the boat with. Some finishes hate Silicon.
In most cases it would not matter, however after 300 or more hours of fabrication, it time to get picky.

If you can stick with soap and water!
Some builders will use the boat unfinished for a short time to insure that all blush is gone. That might be over kill.

Roy
 
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