Wednesday, July 4, 2012

Panel Making

I've been back to panel making, inspired by recent conversations with Golden technical support. The following took place over the past five days.

Birch plywood now replaces hardboard (masonite). I had a sheet of 3/16th's laying around. In the future I will probably increase thickness as there was a bit of warping with a couple of the panels. Ya, some were just fine and I don't know why.

Birch plywood (3/16")
After cutting to size came a bit of sanding with 100, 150 and 200 grit to round off the edges and corners and a light scuffing with 200 grit over the entire panels.

Rounding edge and corner
I opted to use GAC 100 before applying gesso. I like the idea of isolating the raw support from the gesso. Maybe different woods have varying absorptions? I don't know, but perhaps this helps to take some variables out of the picture.

Golden's GAC 100 dries to a tacky touch. Stack panels and they will stick slightly together, coming apart with a clicky grip. There is no sanding to be done with this stuff. Brings the grain out nicely, doesn't it?

Two coats of Golden GAC 100
In the previous post we found that the new sandable gesso does not need base coats of regular gesso. I still have the old stuff here so needed to firstly apply a couple of coats of "regular" gesso. There was no sanding with these coats.

Two coats of Golden Gesso
My workflow is to lay out the panels and walk them to my painting station one by one. Paint a side and put it back. Once done, restart with the other side. It helps to assure me that I equally coat all sides. The gesso products dry to touch so quickly that I can paint nonstop.

Keeping order
Here are the first two coats of sandable gesso. I experimented with various toning media. Acrylics behaved just as nicely as aqueous dispersions. Wish I would have had a tube of deep dark acrylic. It takes a lot of pigment to pull down that gesso. I now think of it as white paint!

I let these first two layers of sandable gesso dry for a day and then sanded with 150 grit to remove most brush marks. The surface was already quite smooth but I just wanted to knock it down a bit. Must one wait a whole day before sanding? Perhaps an hour or so would be adequate. Not sure...

Toned with Golden Acrylic (left) and toned over with aqueous dispersion (right)
Here I tested dry pigments premixed with water using a palette knife. Although the pigment appeared to be well mixed...

Mixing wetted pigment with Golden Sandable Gesso
When I began applying sandable gesso toned with my mixed pigment I was in for a big surprise. The gesso went on very light with dark streaks. Essentially I was mixing my paint on the support! I considered halting work to properly mull the gesso but kept on, eventually applying two coats front and back to all panels.

It will be well worth my time to try mulling pigment (that is, rather than just mixing with palette knife) and mixing with sandable gesso. I use my dry pigments for many purposes already so why not use them here as well? I thought I'd prefer acrylic in a tube but I'm leaning back to my old friends. (I recently inventoried my pigment collection--over 60 of them!)

Streaking pigments
And here's my results! Tomorrow I will give them a light sanding with 150 grit to level them off. I may go to 200 or higher grit with a few as I begin experimenting with first applications of oil paint.

Final coats drying

No comments:

Post a Comment