[Jon Aronstein Mill River Music]

Hi Matthew-

I have been using Osmo on Guitars and other woodworking for about 15 years. I love the stuff, and it is still a bit confusing at times to understand their products. They have oils with less wax, waxes with less oils, etc. I have always tended to use it on Electric guitars, as I was never thrilled with the idea of the waxes penetrating onto the pores and potentially inhibiting the movement of the soundboard. I am not sure if this is a real concern or not. That being said, they make some products with less waxes that behave more like a standard oil varnish, which some people have used over the years on acoustics. Once you get to that point though, I am not sure that it makes much sense to use this vs more tried and true varnishes like waterlox, tru-oil, etc. It is imperative that the heavier wax based formulations are not built up on the surface- this will cause scratching and other unsightly issues. The waxy finish lives inside the pores, and depending on the wood, you generally would not want to sand much more than 220 or maybe 320 on soft woods in order to allow penetration of the material into the wood without buildup. You can use the waxier finishes with a top coat of the more oil based varnishes. They also make a thinner formulation for more penetration of wax and color. I am happy to talk to you in person about navigating this, but do not know if I could really explain more in writing. I have also used Saicco’s clear and Rubio Monocoat, which are similar products. I prefer the Osmo for a soft satin with color, whereas the Rubio is nice as a clear. Here is a video someone shot of me a long time ago that shows our results from Osmo based finishes that we would color with Mineral pigments and some other little tweaks. https://www.youtube.com/watch?v=4T4nsz6LD8U

One great thing about these is how repairable they are and how great they feel. I will say I have never been inclined to use it on acoustic Soundboards, though on Necks it is awesome. I think it could work but would depend on what you are aiming for and would require some trial and error. Again, happy to connect on the phone or zoom to discuss the technicals further.

[Jon Aronstein Mill River Music]

We use surgical tubing at our shop too. Often just slide the right size over, spray it in, and let gravity work for a few.

[Jon Aronstein Mill River Music]

I have found that if I don’t hit the frets with 320 paper, I am likely to see some scratches when all is said and done. 320, 400, 600, steel wool, and then whatever further polishing you want to do (higher grits of paper or micro mesh, buffing wheel, etc). 0000 Steel wool is often described as equal to 400 but that is definitely not the case on frets. Even after 600 it adds something to the process. We have found that micro mesh alone, for some reason, never gets as nice of a finish as using traditional sandpaper. We have a 6″ (stationary) and 4″ (mounted to the foredom) buffing wheels that are good for final polish, using menzerna medium to fine compound depending how shiny you want it. I try to remove all nut to bridge scratches from leveling before crowning with 320 or 400, and then only have side to side scratches to manage after the crowning. And, use the 300 grit z file instead of the 150 maybe??