It should be no secret that I have a very profound love of working on wood panels. Very rarely do I use canvas, linen, or any other fabric substrate. The reason is very simple. I love the resistance of wood panels. I like to be able to push, grind, and prod the paint as well as put down gentle, single strokes. There is something magical to me about the glassine quality of paint moving fluidly across a hard and smooth surface. I usually only resort to canvas when I want to paint large and worries such as weight and warpage of wooden panels become significant. So my interest in aluminum panels mainly concerns using them as a means to paint larger with a similar handling as a wooden panel but with lessened weight and warping concerns. I have no interest at all in copper because of it's malleability and higher density than aluminum.
My initial line of research was to price out artist ready aluminum panels, still with the mind that they would be rather exorbitant. I was very much mistaken! In fact, large panels of 4mm thick aluminum were about the SAME price as an equivalently sized canvas of medium to low quality level!! If I was to use linen, it would be almost twice the price of a same-sized aluminum panel. This jaw-dropping find fueled me to undertake a little study.
I found 3 small scrap pieces of aluminum panel. These were all raw material with no surface treatment. I believe that many of the commercially available panels are anodized which provides for a level of bondability for primer and paint. These do not have that.
3 Little Panels, Ready for Cleaning
Step 1 was to make sure the panels were nice and clean. Nothing will destroy the ability of materials to bond together quite like oils like the ones typically exuded from us humans. To do this, I used Isopropyl Alcohol and cotton balls. Alcohol is very nice and volatile and will cut well into most all organic oils such as those left from fingerprints. I scrubbed with amply dampened cotton balls until the cotton came away relatively clean looking.
Panel 1, clean
And Panel 3..
Look at some of the grime (and Sharpie ink!) on those cotton balls.
Some of the literature I read discussed being able to paint directly onto the anodized surface. Since these panels have no surface treatment of any form, I wondered how they would take paint with no primer. One of my common techniques is a nice wash using mineral spirits so I decided to check that out on the long aspect ratio Panel 1.
Wash on raw panel
After a day of curing, I checked the integrity of the paint film. It is not uncommon for a wash to be a weak paint film. However, this wash totally failed to bond to the panel at all. I was able to totally wipe it away with a finger. The gesso I typically use is rather absorbent so the weak paint film is able to bond with it without significant pigment loss or dredge-up when applying the real paint. So, at least for these non-anodized panels, washes directly onto the unprimed surface will not work.
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Coming soon, part 2 - Priming!