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Epoxy For A Finish.


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I've been considering different types of finish to use on my current build, and I have found a solution that sounds good to me... Epoxy! (I am talking about an actual clear-coat, not a grain filler) After a little reading, I found out that epoxy is actually a type of polyurethane. I know the big factories spray two-part polyurethanes, so could that actually be a type of spray epoxy? I don't have spray equipment though, so I was thinking of using something like this --> mirror coat

I can't find any reason why this wouldn't work for a guitar, but I searched and haven't seen anyone else use epoxy as a finish. Why wouldn't they? Am I missing something obvious?

Thanks in advance! :D

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from the site:

"MirrorCoat is a pourable, self-leveling bar and tabletop coating. It works well on many surfaces such as wood, ceramics, plaster, masonry and some plastics. MirrorCoat cures to a glossy, smooth finish that is scratch and stain resistant. Cured MirrorCoat is waterproof and unaffected by alcohol."

I read that as you create a "pool" and fill it with the epoxy and gravity makes it set level, any leaks in your "pool" and you lose your epoxy.

I don't think you could use it on anything other than flat surfaces.

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I read that as you create a "pool" and fill it with the epoxy and gravity makes it set level, any leaks in your "pool" and you lose your epoxy.

If you watch the video they have (link-> mirrorcoat video ), they don't really create a pool. They just pour it on, brush it even, and the surface tension apparently keeps a thin layer on. This is still a reasonable concern though, as the guitar that I will be finishing is a carved top. I do not find this concern to be more so than with any other finish which would be applied to a guitar (by hand), as most finishes are very low viscosity, and would therefore also run if applied too thickly.

Any other reasons why this wouldn't be suitable?

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Wes did an epoxy finish some time ago - be prepared for LOTS of level sanding. Also, if you apply several coats and end up sanding though the top coat, you will see witness lines when you buff out.

But it will buff out to a very very nice gloss if done right. Mirror Coat is the epoxy of choice for fretless bass fingerboards.

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Thanks for all the help! :D

Wes, what epoxy did you use? Do you think all epoxies would end up feeling sticky? Did you use more than one coat? How thick did you get the finish to become?

After further reading, it seems that the "two-part poly" used by factories may actually be this "LPU" . Am I correct?

I would still like to use epoxy to build up a nice thick finish with minimal coats, even if I have to topcoat it. However, if you think a similarly thick and hard finish could be achieved with a standard brush-on solvent based poly, or something like the previously mentioned "LPU", with less effort, then that's what I will use.

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+1 for sticky Epoxy.... I wouldn't do it. There is a reason everyone uses it as a grain filler and follows up with Poly or Lacquer. For the most part unless Epoxy is fresh it might not harden clear and hard. I have had the worst luck with local Epoxy that was on the shelf too long.

I have had good success with ZPoxy from the local Hobby store, it dries fast, hard, buffs well and was able to use it to repair the finish on my Road Flare Red RG550. However I would not finish a guitar in it.

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Would it be reasonable to try to build up a factory-thick finish with a poly applied with a brush? The only finish I've ever done is tru-oil, and even after 20 coats it was still paper thin.

Also, is everyone sure that all epoxies (mirrorcoat) would end up sticky? I can't imagine wanting a sticky fretless bass fingerboard...

But it will buff out to a very very nice gloss if done right. Mirror Coat is the epoxy of choice for fretless bass fingerboards.

I see what you all are saying about stickyness, but I just want to make absolutely sure about mirrorcoat, so please don't take any offense. :D

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some finishes are epoxy resin based...I don't know how they deal with the stickyness...you want some finishes to "grab"(think table)..

I am sure if fumed silica was added to the epoxy base in a small amount it would soften it right up,but it would also make it a satin finish rather than gloss...

If Erik says Mirrorcoat,then I would trust him...I am sure they have a formula that is not sticky to the touch....I base my comments on the 2 part epoxy I attempted to do a satin finish with a few years back...I also encapsulated a rock in it...very "grabby"...your skin tends to stick to it and rash after heavy contact.

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Would it be reasonable to try to build up a factory-thick finish with a poly applied with a brush? The only finish I've ever done is tru-oil, and even after 20 coats it was still paper thin.

Also, is everyone sure that all epoxies (mirrorcoat) would end up sticky? I can't imagine wanting a sticky fretless bass fingerboard...

But it will buff out to a very very nice gloss if done right. Mirror Coat is the epoxy of choice for fretless bass fingerboards.

I see what you all are saying about stickyness, but I just want to make absolutely sure about mirrorcoat, so please don't take any offense. :D

I was just warning about using epoxy from Lowe's or Home Creepo... I would hate for you to make some of hte mistakes I have made and ruin perfectly good bodies. Good stuff like System 3 are supposed to be used for those things. System 3 should be measured with a scale so you get the proper amount of hardener hopefully mitigating any mistakes in the mixing that would lead to stickiness. Also the stickiness of cheap epoxies eventually cure hard unless they are just complete junk.

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NEVER use epoxy from Home Depot, unless it is to fill small dings that will be covered over with something else. Use the real deal.

System 3 Mirror Coat is nice and hard and buffs out like the devil - it is the commonly-used epoxy you see on wood bar tops. Next time you're at the pub raising a glass, give it the fingernail test. Good stuff. Here's an example on a 6-string fretless bass fingerboard, the reflection is a tree in my neighbor's yard:

JasonRefin30.jpg

BUT - you need to measure out the proportions EXACTLY correct. 2 to 1 by volume, or 2.27 to 1 by weight (easier with a gram scale), if you veer off that ratio only a little, you'll end up with stickiness. And obviously mix it well. It is fairly fluid, so it will flow out nicely on a horizontal surface.

Other epoxies are apparently more forgiving on the ratio, but I've not tried them myself.

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