My original plan was to take some vacation between Christmas and New Years and get the console completely stripped, refinished, and checked off the list. I did that, but it ended up taking much longer than I anticipated.
I began by disassembling the console as much as possible. The pedalboard needed to be taken apart anyway for cleaning and refurbishment. Then I removed several more panels, brackets, etc. from the console just because it is a pain removing varnish from inside corners and little crevices.
Removing the varnish was like a dream. I used a methyl-chloride based stripper and it only took about 5 seconds for the old varnish to wrinkle and peel up. It was a very thin coat. I removed the residue with a putty knife, then scrubbed the surface with mineral spirits then acetone to remove all the wax contained in the stripper.
This is where it took much longer than anticipated. When the console was originally finished, the pores had been filled with some sort of light-colored wood putty. Had I just applied stain and new varnish, the white pores would have looked really odd so I had to figure out how to remove the putty. Bob Flexner recommends using a strong solvent to remove dried putty, spills, etc. The mineral spirits and acetone seemed to remove a little putty, but not very efficiently. I tried a little water alone, thinking it might soften the putty, but it didn't. I tried a little more water thinking that it might swell the pores and push the putty out, but not really. I was planing on using oxalic acid to bleach the wood anyway. Maybe that would soften the putty a little. Yes, it seemed to! Using a soft brass bristle brush, I proceded to scrub each part of the console with the oxalic acid. I either wiped or rinsed it as I went to remove all the putty. All the detached parts cleaned up reasonably well. Then, I got to the console shell itself. This was a nightmare! The pores were considerably larger on these pieces of wood. At first, oxalic acid removed about half of the putty. Continued scrubbing was fruitless. I then resorted to picking it out or each pore with an awl (This is when I began questioning my sanity). Then I remembered how the acetone lifted some of the putty after stripping. I used my brass bristle brush to scrub with acetone (I diluted the acetone with a little water so it wouldn't evaporate quite as quickly). That kinda worked. Oh well. I decided to go back to the oxalic acid. I don't know what the interaction was, but this time, the putty practically fell out of the pores. Maybe I just scrubbed away enough wood fibers that there wasn't anything left to hold the putty. Who knows? Just reading this, the process doesn't seem that bad, right? Remember that an organ console is rather big and has a lot of surface area. I was going at a rate of about 100 square inches per hour. In the end, it took over 70 hours to remove the putty! Had I known that going into this, I would have painted the damn thing and been done with it. If anyone out there knows a more efficient way to remove the putty, please share it!
With the putty removed, I was ready for bleaching. Oxalic acid (same ingredient in Oxy-clean) removes oxidation stains. In the top photo you can see the inverse shadow of a bookcase or something that blocked the sun from hitting the console. That would be removed with oxalic acid as would the black rings on the console top left by an overwatered poinsettia (the stains were exactly the size of a 6" greenhouse pot). I made a saturated solution of oxalic acid, applied that as a drench to the wood and allowed it to dry over night. I then rinsed it off in the morning and allowed it to dry. All that scrubbing left the wood rather rough. I used a series of sandpaper grits working my way from 80 to 180. I was surprised at how nicely it leveled though. Now I was finally ready to apply the stain and varnish.
