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Hi guys and gals..

I started laying down coats of the EM6000 over SB112 pore filler. The epoxy had been leveled to 400 and final scuffed with a fine scotch-brite. I let the body rest for 2 days at 70 degrees. The prepped surface looked perfect. I did a wipe down with DNA and let that sit for an hour. The shop was at 45% RH and the temp was about 63 degrees. I sprayed the first coat of finish and portions of the guitar back turned flat and cloudy as if contaminated. Hoping it wasn't fatal, I continued to apply 3 more coats. The gloss came up on the surface but there was a random haze under it.

I did the neck and head plate using Zpoxy under exactly the same conditions, on the same day, and it looks clear and perfect. The Zpoxy only arrived a couple days ago..Otherwise..

I used my digital gram scale good to .01. I mixed to the count of 60 in a fresh plastic cup each time. The SB112 appeared to cure properly. I took great care not to sand through to the wood. I used 3M Gold non-stearated paper. The B&S are Wenge, so there shouldn't be a resin/pitch contamination problem.

I had the same problem on my last guitar (no problems before these 2), though only in a spot or two. Embarrassingly, this is the guitar I had to take to the one week intensive with Somogyi on guitar top voicing.
The guitar did make it onto the podium during a blind listening test, so I'm doing something right..

Any thoughts, aside from the obvious.. carefully taking it all back to bare wood and starting over?

Cheers, Michael

The hardener will darken a tiny bit over time, but should still be usable. Sounds like an Amine blush which would mean too much hardener. Did you use the correct ratio for mixing by weight, 100:44?

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Hi Brian

I'm pretty sure my math was right.. I was doing 5 grams to 2.2 grams, using a digital scale good to to decimal places.

I've never heared that term before.. Amine blush.. Just did a search.. cool.. love the internet.. The surface of the guitar really did look perfect before and after final leveling. It's more like a reaction between the epoxy and the EM6000. I was using KTM9 on the last instruments and I will say the EM6000 is much easier to work with. I just can't go back to nitro.. I've shot way too many gallons over too many years.

Thanks, M

Poly amines are some of the chemical building blocks of epoxy. To much hardener will leave an excess of amines that will generally show as a cloudy haze. But your math its correct. I have enquired about shelf life of their products and their chemists told me that age of components would have no effect on function, only clarity.

_________________
Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Thanks for looking into it..

It is probably something off with the epoxy. Other than that I would consider that perhaps the DNA softened the epoxy and it didn't have time to reharden?

_________________
Joe Beaver
Maker of Sawdust

That is a solid possibility.. I did let it sit for an hour..

Thanks, Joe

Todd

They say it likes 60-80 for best cure temp. I'm spraying in my basement spray booth (60-65) then moving the part into a 70 degree house to cure. As I sanded the finish and epoxy off of the body the imperfections didn't go away until I got to the epoxy layer. I'm suspecting the DA.. Are you spraying nitro or WB?

Thanks

I have to say that I'm really liking the Zpoxy. It flows out better and seems to have a longer working/open time. I know some folks don't like the amber tint.. As I'm only pore filling the back and sides, I don't have problem with the color.

Thanks again for the comments.