Finishing

For a long time, I wrestled with what kind of finish to put on the wood. The pipes rely on the wood finish to keep moisture out of the wood to minimize splitting, warping, dimension changes and opening up the glued edges and allowing leaks. From my reading I learned that organ builders used to "paint" the inside of the pipes with glue to insure a good seal. (do they still do it that way??) I had no difficulty deciding what I wanted to use on my pipes: Polyurethane.

For the cabinetry part of the organ, and especially for the keyboard, I first thought of using a warmer finish -- perhaps an oil -- something that would maintain the "intimacy" of touch with the wood. I test-finished several cherry scraps using various stains, oils, tung oil, varathane, etc. Somewhat to my surprise, I settled on using polyurethane -- clear (colorless) for the keyboard, pipes and windchests; and a pigmented polyurethane for the cherry parts. In the end, it was perceived durability of the finish that carried the day: I wanted finish that would last, especially where it would be handled a lot (the keyboard).

The finish was applied of a coat of sanding sealer; both coats were sprayed with a conventional air-sprayer. Not having access to a spray booth, I did the work in my back yard -- on a still day. I did the work over several weekends, and, owing the the fast-drying properties of the sanding sealer, I could apply the sealer in the morning, sand it after noon, spray the Varathane and have it be dry enough to move inside by evening. Some pictures below detail the process.

The one exception to this process is the interior of the pipes -- which were finished using a coat hanger and a bit of sponge -- like a giant Q-tip.

 

Filling the sprayer with a paper origami ladle cup ... single-use, and no cleanup problem.

 

I didn't take any pictures of the actual spraying -- I was too busy spraying to fuss with the camera. Here you see the bits and pieces set out to dry.

 

To apply the finish, the organ had to be completely disassembled ... even down to the keyboard. Here, a cardboard rack keeps the Delrin pin-guides in order.

Here I'm putting the Delrin guides back on the keys. (I'm really not as grumpy as I look in that picture!! :-)

Putting the keyboard back together after Varathaneing. All the internal parts received a coat of sealer and Varathane, regardless of whether they were visible from outside.

The organ partly assembled. After seeing the organ "bare" for so many months, I really like the darker color!

 

 

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