Grumbacher Cobalt Drier Medium for Oil Paintings Jar, #5942, 2.5 Fl Oz (Pack of 1)

dont use much, its qood quality should last a few years

Gets oil paint dry fast and doesn't dry up like others. Cobalt is the best!

m

Muy bueno para adelantar el proceso de secado

Yes, this stuff really does speed the drying time. so much so that I just dip the tip of my palette knife in the jar and add it to my white only (usually about an inch or two from a large tube). If I must have everything dry to varnish the next day, I will add to my cadmium colors and maybe greens. It seems all the other colors dry overnight anyway (if they aren't too thick). You get about 3-4 hours of working time with this tiny 1/4 drop way of doing it. HOWEVER - it is highly toxic - I mean poisonous, and I make sure my carbon air filter is running ... and I hold my breath when the jar is open for the 2 seconds I dip my palette knife in. I went to alternative doctor for psoriasis, and he discovered "cobalt, titanium, and cadmium poisoning" and didn't know I was an artist. He asked, "how the heck did you get these heavy metals?" After treatments for those, my skin problems went away. yes ... psoriasis was healed ... and I have been super careful ever since. That was 18 years ago.

Works well and is potent. I can tell the difference, doubling my drops made Minwax Antique Oil get sticky too fast, hehe. But it helps in the right amount with Tung Oil and everything. It is a top-down drier, meaning it just makes the oxygen bond faster where product is exposed to air (not an inside-out drier). This is extremely helpful in a humid climate. Humidity interferes with oxygen bonding readily with drying oils to cure them, and makes hours turn into days, days into weeks. A few drops of this product makes things dry like a drier climate. Do some research on quantity. I looked up the MSDS and/or the SDS and determined the amount of cobalt in the product and found calculations based on metal not proprietary mix. I believe I settled on 1 ml to one liter, this stuff to tung oil.

For anyone serious in oil painting this stuff is an absolute miracle. I only use a couple drops for a batch that I need dry. Each type of pigment is different, but generally it can take less than an hour too dry. My main word of advice would be to clean your brushes within 30 minutes of using.. I found this out the hard way.

I use this product in my work (painting) the product itself is fine to use, though this was an old bottle as it had leakage at the cap line and the product was jelled a bit. Id order again, though would send back if that happens again.