Official Luthiers Forum!

Hello All,
I have applied 2 coats of z-poxy pore filler, sanding lightly with 320 grit between coats. The first two coats, I squeeged across the grain, the last coat I wiped on with Zpoxy dissolved in Denatured alcohol. I will be spraying KTM9. Before I lacquer, how much sanding should I do? Do I need to attain a smooth as glass surface? It is kind of hard for me to tell where I am at as the pore filler is hazy after sanding. I paid special attention to any runs, bubbles and that kind of stuff. I don't beleive that I have sanded through to wood either. Is there any easy way to check that. I was going to try naptha but I am unsure if it is compatible with the z-poxy. Thanks again for all of the help!

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John Nowicki

I am guessing the coats were very light if you got away with 320 sanding .. I usually use 150, and it takes a bit of effort, but I wouldnt call it heavy sanding. After the second coat is sanded (I watch for milky areas that indicate a thicker film of the Zpoxy, and sand that off), i do the thinned coat. after that, its a quick scuff at 280, and then continue on with the finish.

If you wnet totally thru ont he thinned coat, that area may look lighter than its surrounding area .. the Zpoxy imparts a slight amber hue ....

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Thanks Tony,
The 320 was not rough enough to do the job, I got out some 120 and really got the B & S looking good. I followed up with 240, and 320. I use the foam 3m sanding blocks, they work well, just rinse them in H2O to clean them out when done. Boy my wrists are sore! I had already sealed the spruce top with 1 wipe on coat of z-poxy and denat. alcohol. I will sand that smooth and reseal prior to spraying. I really like the way the zpoxy made the grain in the top come alive. Now I know what the wood is supposed to look like after pore filling and sanding. Thanks so much for the help! There is no substitute for doing it yourself. My flamenco already has been played/string tested without a finish...soon it will be the real deal!

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John Nowicki

Lacquer over KTM9?????????? Why?????? vynel sealer yes but I would have some concern about KTM9 under nitro

pardon my typo

"Vinyl sealer"

I think he was referring to KTM 9 as the lacquer?

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Jim Kirby
kirby@udel.edu

I was referring to KTM9 as the Lacquer......

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John Nowicki

In my best Buckwheat voice.....Ota

KTM9 works well over sanded zpoxy. (needs to be sanded or otherwise cleaned to remove the amine blush) I'd stick with the alcohol and avoid naptha.

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Joe Beaver
Maker of Sawdust

I've never heard of putting epoxy on a top. Is the weight not a concern?

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Formerly known as Adaboy.......

Most people that will use epoxy on a top do so solely for color and will dilute the epoxy by 50% with alcohol so it is about the same viscosity as 2# shellac cut. Weight is not the big issue using full strength epoxy on a top but rather the damping it will cause. I would not use a full strenght cut of epoxy on a top but I have in the past used a 50% epoxy 50% alcohol cut of Zpoxy. The guitar turned out fine but I have been sizing all my tops for several years now with egg whites, plus I don't use Zpoxy anymore for back and side pore filling. Not that I find anything wrong with it. I just find CA pore filling more efficent both cost and time wise.