Recently I bought Grumtine for the first time.

I've never been in an art class before, I'm completely self taught and am sorely lacking in some basic knowledge areas. So when I was browsing and saw that such a thing could clean brushes I instantly grabbed it.

As I go to clean my brushes after painting today I decide to use the Grumtine. I poured a little in a plastic cup and mixed some water in with it so I could have more volume in the solution to wash my brushes.

I leave it for about 10 minutes or so as I was distracted to the phone only to come back to a disintegrated cup laying on the floor with the solution all over the floor!

And Now I'm afraid to use it again. All I can think is that I bought some sort of acid that will ruin my house, supplies, and maybe my exposed skin as well.

I've googled for information but all I can find is that it's a paint thinner and acts as substitute to turpentine for cleaning brushes. Although I didn't use it for thinner this time around I'm not to fond of the idea now...

Anyone know how to use this properly?

Any advice is welcome!

What you've stumbled upon is a paint thinner similar to Turpentine or Mineral Spirits. It's not an acid, but it can be somewhat hazardous to your health. The reason your cup dissolved is that that Grumtine is an organic solvent, meaning it will dissolve many (though not all) organic substances (including many plastics.) Because it's hard to know what plastics will be affected and which won't, your best bet is to use glass or metal to hold the liquid in the future, as they will not dissolve.

Grumbacher's "Grumtine" product is, a far as I have been able to figure out, basically the chemical d-limomene, an essential oil derived from citrus rind. It can be used as a direct substitute for turpentine or mineral spirits, as you mentioned. This basically means that it's a brush cleaner and paint thinner for use with OIL paints. You didn't mention whether you were using oil, acrylic, watercolor, gouache, or tempera paint, but you only need chemical paint thinner with oil paints. Everything else is water-soluble, meaning water is the only thinner and brush cleaner you will need (heck, you can even buy oil paints that are water-soluble!)

In addition to dissolving all sorts of things Grumtine also retains many of the properties of Turpentine and Mineral Spirits that make those substances hazardous. It is an eye and skin irritant (so avoid too much contact with your skin), and its fumes are a lung irritant. There haven't been a whole lot of studies done on the long-term respiratory effects of d-limonene, but when using a paint thinner of any sort, it's best to work in a well-ventilated area (even when the thinner is labeled as "odorless" or it's odor is pleasant, it may still be releasing dangerous fumes, so keep your work area ventilated.) Finally, many paint thinners like this are combustible or flammable, so keep it and its vapors away from open flames and sparks and things.

That's the basic safety stuff. I wouldn't water it down, as water isn't going to help it do its job. When using it to thin oil paint, just wet your brush a little bit at a time and mix it into your paint until you reach the desired consistency. I'd also use a wooden or metal (or glass) palette (not plastic) with solvents like these.

Don't be afraid of this stuff, but do be safe and smart. Also, remember that you only need a solvent like this if you're painting with oils.

I hope this helps! If you have any other questions, feel free to ask.

Can this be used as a thinner of Oil paints so one can spray or drip or wash on the oils to create a runny effect?