KTM-SV Waterborne Finish

[Darryl Young]

FYI, sometimes KTM-SV will not cure properly on an oily wood so the wood needs to be sealed before spraying KTM-SV. Since I was pore filling with zpoxy, I decided to leave a thin coat of zpoxy on the EIR back and sides. Also, another member on the OLF mentioned he used this method successfully. Most folks like to do this anyhow since it "pops" the grain so well (shellac or something is often used to enhance grain under water based finishes).

The challenge here is to leave a thin coat of zpoxy that completely seals the wood and gives consistent color (no splotchiness) with a smooth finish. I tried different methods.......spreading with a squegee, wiping on with a cotton cloth, etc. Also tried thinning the zpoxy different amounts with denatured alcohol.

What seems to have worked best for me is using a coffee filter and zpoxy thinned about 60:40 with denatured alcohol (by weight, I use a cheap scale from Harbor Freight that measures to the 1/10 of a gram so I added 0.8g of DA to 2g of mixed zpoxy). If I place a small amount of thinned zpoxy on the paper and spread it as far as it will go before refreshing the pad in the thinned zpoxy, it leaves an amazingly thin coat that is smooth. The zpoxy dries much quicker when thinned like this so it has less time to collect dust nibs. Also, the thinned zpoxy probably levels a little better than the un-thinned version.

BTW, I cut the coffee filter in half and folded several times so the "pad" outside the portion of the filter I was holding was roughly 1/2" - 3/4" square. The first time you touch the thinned zpoxy with the folded filter paper, it "loads up" and there is very little left to wipe on the surface of the wood. Subsequently, a tiny amount goes a long ways. The 2g of zpoxy was enough to coat the sides and front and back of my headstock and I still had some left when finished so it's a very thin coat. I used strong lights on a stand so I could see if I missed any spots. The coat is so thin, not a bad idea to use two thin coats as extra insurance no spots are missed. No matter if using 1 or 2 thinned coats, probably a good idea not to sand the final coat so you don't sand through anywhere. The last coats I made were smooth enough there is no need to sand. And if it isn't perfectly smooth, not sure how big a deal it is since I'll likely spray 6 coats, level sand, and then 3 or 4 more coats.........so it will eventually be leveled with coats of KTM-SV on top.