Portrait Artist Forum - View Single Post

Richard Budig · 08-11-2005, 07:34 PM

Jen:

Those pesky brown stains may have come from the tempered masonite. As I understand it, there is UNtempered masonite, and tempered masonite. I read that the difference was that tempered masonite was made with oil and a lot of heat, the reason being that it was for use out of doors. The untempered masonite, the article said, was made without the oil, and was for use indoors where the elements (rain, snow, I suppose) would not affect it.

Later, I learned from my son, a carpenter, that the difference is not oil, but this: tempered masonite is made with extra water and a lot of heat and pressure. Untempered is made with water, also, but no heat or so much pressure.

Now that I've really confused the issue, I can't tell you which is correct, either.

But, if you used tempered, which, supposedly, is made with more water and heat, those stains could be from leaching out some of that stuff that was"made" from the heat and water. Whew! Who knows.

I have never had this brown stain problem with my untempered masonite. However, where I do get leaching is if I use a felt tipped pen to mark the masonite, and if I forget and use it on the side I'm going to paint. When I start the gesso, it continues to leach up through the layers of masonite.

Unless someone can tell me more, I'm going to go back to using the smooth side because it seems to be sealed tighter. The rough side acts like a sponge. Even after three or so coats of gesso, and fairly thick ones, too, it still sucks up the new layers of gesso.

By the way, you can make some interesting textures on your masonite panely bu applying the gesso with various things like a small whisk broom, or a wallpaper paste brush.

08-11-2005, 07:34 PM	#3
Richard Budig Juried Member Joined: Oct 2002 Location: Lincoln, NE Posts: 260	Jen: Those pesky brown stains may have come from the tempered masonite. As I understand it, there is UNtempered masonite, and tempered masonite. I read that the difference was that tempered masonite was made with oil and a lot of heat, the reason being that it was for use out of doors. The untempered masonite, the article said, was made without the oil, and was for use indoors where the elements (rain, snow, I suppose) would not affect it. Later, I learned from my son, a carpenter, that the difference is not oil, but this: tempered masonite is made with extra water and a lot of heat and pressure. Untempered is made with water, also, but no heat or so much pressure. Now that I've really confused the issue, I can't tell you which is correct, either. But, if you used tempered, which, supposedly, is made with more water and heat, those stains could be from leaching out some of that stuff that was"made" from the heat and water. Whew! Who knows. I have never had this brown stain problem with my untempered masonite. However, where I do get leaching is if I use a felt tipped pen to mark the masonite, and if I forget and use it on the side I'm going to paint. When I start the gesso, it continues to leach up through the layers of masonite. Unless someone can tell me more, I'm going to go back to using the smooth side because it seems to be sealed tighter. The rough side acts like a sponge. Even after three or so coats of gesso, and fairly thick ones, too, it still sucks up the new layers of gesso. By the way, you can make some interesting textures on your masonite panely bu applying the gesso with various things like a small whisk broom, or a wallpaper paste brush.