I'm trying to find the best way to prepare my supports so that I can have the longest lasting paintings possible. This is my current process, I use commercially made birch plywood panels that are cradled with basswood. These are the ones I use https://www.currys.com/catalogpc.htm?Category=WOOD_PAINTING_PANELS
This is my current process
1. Sand the panel to make it smoother using fine or extra fine grit paper (usually 220). Wipe off dust or vacuum the panel to get rid of any debris. (I use a dry cloth because I don't know if it's okay to get it damp)
2. Apply 1 coat GAC 100 to the front and sides, and let it dry enough that I can turn it over without it sticking to anything (usually 20-30 minutes roughly)
3. Coat the back and inside edges of the panel, then let it dry with the back facing up for 2-3+ hours (I use a smooth but semi-firm nylon brush to apply the GAC 100, it helps minimize brush strokes)
4. Repeat the process above to coat the front and the back again, but this time let it dry for 3+ days
5. After 3+ days I apply acrylic gesso with a very soft camel hair brush or a soft nylon brush. If the gesso is thick I use a stiffer brush or water it down. I apply 2 coats but if I water it down I add more to compensate, usually only 3, sometimes 4. I wait the around 4+ hours between new coats depending on how cool to the touch it feels.
6. I let the gesso dry for 72+ hours before painting because I've seen that recommended by a few companies/artists including Golden. Then I start painting
I do want to add a few steps to help my paintings be more archival. First I want to start mounting cotton canvas to the panels using BEVA film, before the gesso step. I would then use GAC 100 x 2 coats to help block oil penetration to the canvas. After that I would continue with the gesso step, but this time add a third layer. The third layer would be clear so I can draw my design on the second layer with pencil first and then seal it, to avoid having any graphite transfer through to the paint. Finally I would finish by using a 50/50 mixture of Galkyd Lite and Gamsol to thin out a colour I want to use for the ground layer, and then paint it over the gesso and wipe away the excess to leave an even tint. I was told this is a good way to increase adhesion for future oil paint layers, especially if you do heavy impasto which I want to explore more.
I'm using those specific wood panels because they are the only ones I can access easily where I live in Canada, and I'm using 10oz cotton duck canvas because I can't afford linen (yet). I'm an art/design student, I don't have a big budget.
One thing I saw mentioned in another thread here was that GAC 100 is really bad as a moisture barrier, so I was wondering how much this matters with the panels I use since they are 3 ply and cradled? Do I need to do the priming method listed here instead? http://www.justpaint.org/preparing-panels-for-a-life-outdoors/ - if so, how would that change my current method? Also how much ventilation would I need because I don't have anywhere to work with a ventilation system. I do all my work in my room and avoid anything with fumes, or do it right by the open windows.
I havent painted much all year cause I've been fixated on solving the issue of "what support is best?" and I know that's a subjective topic so I'm hoping someone with proper expertise here can help me out. Thank you for taking the time to read this