oil finish Mixing my own True Guitar Finishing Oil

[Bizman62]

There's all kinds of wipe on oil finishing products that can give a mirror finish when applied a sufficient amount of layers. I've been using Crimson's Guitar Finishing Oil which I've heard is a counter engineered and modified version TruOil or something similar.

So after having read articles and seen videos about how that type of finishing product used to be common knowledge back in the fifties or so, and how people forgot the recipe because of moving to cities and losing the paths to agrarian wisdom I've been toying with the idea of mixing my own so I could change the buildup properties at will. Plus that the price would be a fraction of the commercial products!

The basic recipe is very simple but what held me back was the terminology: The word "poly" was used in all of the recipes and for what I know it translates to "lakka" (<lacquer), both of which cover all sorts of more or less clear finishes. Obviously water based ones were out of the question but with the rest there was still too many question marks for me. Finally yesterday I met a painter who shed some light to the matter.

So, to the recipe: In all simplicity there's Boiled Linseed Oil (BLO), turpentine and poly. The basic mix is one third each but by using more turps it penetrates better and with more poly it builds up faster. Simple as that! Obviously the main issue with poly is not to use water based ones. I'd also rather use something that can be diluted with mineral spirits/White Spirit as pine turpentine can be substituted for that . Basically you could use mineral spirits instead but somewhere I read that there's a higher risk of combustion with that.

I searched through my storages and found a can of solvent based clear Urethane Alkyd - but where's the "poly"??? Well, it's actually Polyurethane but they often seem to drop the Poly off. Oh well... The product can be diluted with mineral spirits and as it also seems to contain pine oil I felt safe to mix some pine turpentine into it. Plus some BLO -  which in Finnish is called "vernissa" (<varnish)! Anyhow, they all seemed to mix easily, no lumps whatsoever! I'll wait until tomorrow to test it.

 

[Bizman62]

Today I tested it on some scrap wood and boy did I like the result! It dries in a quarter of an hour, is almost colourless and leaves a nice sheen with just one wipe. Here's a sample on an offcut of an earlier build. The dark stain on the left is from the steelwool+vinegar, in the middle it's just bare wood. Nogal, cherry and merbau with birch stripes to be exact.