Showing posts with label preparing panels. Show all posts
Showing posts with label preparing panels. Show all posts

Sunday, September 23, 2012

HOW TO PREPARE PAINTING PANELS, part 2

Some 100 boards (3 sheets plywood) drying outdoors
along with my rolling folding table

1.  Cut (or get someone to cut) your boards into sizes.  It's a good idea to choose a few sizes and make a lot of those, to limit the number and sizes of frames you need to buy.  Since these paintings will have to be framed, the frames will be your biggest expense.

You'll want to choose your sizes with consideration to warping.  I tested a 12 x 16, and it was plenty stable.  In this batch I am going up to 18 x 24, the largest size that I stock multiple frames for.  Anything larger and I think you'd need thicker board.  And the whole package would end up pretty heavy.  Some artists paint on larger boards.  They are mostly young guys.

2.  Knock off any rough edges with a knife or sandpaper.  I personally keep this step to a bare minimum.  In fact, I am philosophically opposed to sanding.  At every stage of this process I am doing everything I can to avoid sanding.  This particular board has a side that is a little soft.  Some of the cuts came out rough if that side was upward on the saw.  I will use the other side whenever I can, knowing that some paintings will be losers and I will end up painting on the other side when I retire the image.  Still, choose the best side to go forward with.

3.  With your sealant (I used 50/50 Gamsol/Galkyd) coat all the edges of the board, plus one side.  Let the boards dry 24 hours.

4.  With your sealant, again coat all the edges of the board, plus the other side.  Let the boards dry 24 hours.

The point of sealing the board on all sides is to prevent warping.  Also, it keeps that back side from getting scratched up in case I choose to use it later.

First coat in pink, 2 coats in taupe
Next step is your ground.  I am using Gamblin Oil Painting Ground.  You could use Acrylic Gesso instead.  It dries faster.  I find that the oil painting ground is a much better surface for painting on.  My colors hold their intensity and do almost none of that drying in where the colors look dull and extremely matte.

If you like to tone your canvas on location, you can use the ground in white.  I like to have a color already on my board.  I've gone through various stages with this, most of the time choosing a gray of value 4.  Now I'm starting to play with some other colors, as you can see above.  These are great fun to have peeping through your image.  If you are using Acrylic Gesso, color your gesso with acrylic color.  If you are using Oil Painting Ground, color it with oil paint.  A little experimentation will reveal your personal preferences.

5. Choose the best side of your board.  Take a palette knife or scraper and knock off any major bumps, leaves, or bugs that decided to become part of your art project while it was drying outdoors.  Coat the board with a thin coating of ground.  There's a good video on how to do that HERE.  You don't need to put color in this layer, because you'll be covering it up.  Let this coat dry completely.  In 90 degree heat in Portland it took my boards 24 hours.

As you can see in the photo, this first coat leaves quite a bit of the wood grain showing.  If that's the texture you like, you could stop here.  But I want all those lines pretty much filled.

6.  Take a palette knife or scraper and knock off any new bumps.  Get the brush hairs, before they become permanent ridges.  Then coat the board with a second coat of ground.  This layer should be the color that you want to finally paint on.

If you're a lover of smooth texture, you would be sanding between all these steps.  As a former watercolor painter, I kind of enjoy random textures.  I have taken a cat's paw firm roller and gone over the board, giving it a gently bumpy texture that kind of reminds me of watercolor paper.  I love it.  You might not.  Be my guest and sand it smooth.  Or just smooth everything out with a brush.  You could even press a canvas into it to get a woven texture.  But if you're going to do that, it would probably be easier to paint on canvas glued to a board.

If you still have a lot of wood grain, you might want an extra coat.  Otherwise, you're good.

7.  Let your boards dry a good long time before stacking them one on top of the other.  You don't want to press out all those nice bumps that you just made.  If you have any warping, a nice stack of boards will pretty much flatten one another.  It's a good way to store them.

Then, have fun painting!


Saturday, September 22, 2012

HOW TO PREPARE PAINTING PANELS, part 1

Testing Sealants

I have decided to try painting on panels.  Why?
-All my friends do it.  HA!  Since when has that mattered?
-They're less work to finish and frame.
-They're smaller to store.
-They are more stable support for thick paint.

Why not?  
-They have to be framed (as opposed to gallery-wrapped canvas, which can have its sides painted.)
-If you put them in panel carriers the edges get smeared.
-They are heavy.
-If you buy them instead of making them, they are really expensive.

So I probably won't use them for air travel, but let's try this out and see if I like it.

So I ask everyone I know and do an internet search on how to prepare them.  As usual, I get a bazillion answers, and have to resort to my own testing.

I have settled on 1/4 inch sandee plywood from Home Depot.  It has a fully filled core, birch veneer, and smooth surface both sides, though one is very soft and will definitely be second choice.  I buy a sheet and have my husband saw it up into appropriate sized bits.  (This involves cleaning the garage, but hey.)

I take some of the scraps (there shouldn't have been any, but who knew the saw blade would eat up so much wood?) and use them to test sealing finishes.  Above are my squares, testing Gesso, PVA size, GAC 100 from Golden, and a 50/50 mix of Galkyd/Gamsol.  I finish both sides plus the ends.  Then I soak them 24 hours in a tub of warm water to simulate humidity and dry them in 90 degree sun to test for warping.

The GAC 100 softened slightly on the surface.  This might not happen if it's cured longer than a day, but I decide to eliminate it except for in travel situations.  The Gesso and the PVA size panels warped slightly.  The winner?  50/50 Galkyd/Gamsol.  Which means they have to be done outdoors.  Better get busy making enough panels to last til spring.