Like many here, I am on a lifelong quest to improve my varnishing skills. At the moment I am wrestling with the problem of cleaning my brush after a varnishing session. For the record, I use Schooner 96 - no complaints, and fairly high quality brushes.
The issue is that it is very, very difficult to get the brush clean using standard Home Depot grade mineral spirits. I use a 'four coffee can system' for cleaning brushes comprising one can that is kept clean and three cans labelled Dirtiest, Dirty, Clean. The used solvent is allowed to decant in each of the three cans, with the gunk scraped out of the bottom of each of the cans. I re-fill the 'Clean' can with new solvent, and move used solvent progressively from the clean can to the dirty can to the dirtiest can. You get the idea. Anyway, it's a pretty rigorous process.
Regardless of how anal I am about the cleaning process, at the end there are still little bits of varnish balls stuck to the bristles. The next time I use the brush, sure enough the finish is rough with the embedded specks of varnish left in the brush. Back to the cleaning station we go. After two or three go-rounds over the course of a couple of days the brush is again clean enough to use. Gd help me if I leave the brush hanging in the solvent (even the clean solvent!)...it comes out looking fuzzy like the bitter end of a mooring line that's been allowed to dangle overboard.
Here are my questions:
1. Are there different grades of Mineral Spirits, some more potent than others? Maybe my problem is that the Home Depot solvent simply isn't very good at dissolving the varnish?
2. Is there a better choice of a solvent for cleaning brushes? Would turpentine be more effective? What about one of the hideously expensive proprietary solvents like Interlux 216?
I've read all the discussions about storing brushes in diesel and so forth. All interesting discussions, but right now I am focused on cleaning brushes after use.
Insights and Wisdom from others eagerly sought.