This follows up a previous thread, "Recipe to restore VOCs?", in which I asked about improving the performance (water repellency, longevity) of the new low-VOC oil-based deck stains. I didn't get much back that was useful. I've looked online at a lot of MSDS (material safety data sheet) documents, and found that pure linseed oil (the traditional base of most oil paints and stains) is essentially ZERO VOC. Raw linseed oil takes a long time to dry (tung oil takes even longer), hence the addition of drying accelerants. "Boiled" linseed oil adds a broad range of solvents and drying agents to speed this up, and THESE are the things which determine the VOC level, toxicity, carcinogenicity, etc. It can STILL be VOC-compliant. THEREFORE, it should be perfectly legal ANYWHERE to add raw or (compliant) boiled linseed oil to any oil-based paint or stain, assuming no compatibility problems. (Does anyone have a serious objection?) The question I have is: HOW MUCH? Like, some fraction of a cup to a gallon? In comparison, the solvents turpentine and mineral spirits are essentially 100% VOC. Is there a good reason to add a solvent to this recipe as well? Does it further reduce drying time, or control the viscosity, or keep the additives/colorants/etc in solution, or maybe help soak the oil into the wood? If so, how much? Or can it be ignored? Has anyone experimented with this, successfully or not?
- posted
15 years ago