Bellows Pt. 3

I had a little time after work to finish the individual bellows. Next step is the reservoir...

Bellows Pt. 2

Today I touched up the inside bellows surfaces with a final sealing of shellac in preparation for gluing on the bellows cloth. This seems like one of the more intimidating aspects of the project, because I feel like I'm not going to find out if I'm doing it right until after the cloth is in place and the glue has thoroughly dried. Only then can I test it, and if it's got major problems, I'm faced with the prospect of tearing the bellows apart and starting on them again.

One of my main concerns is to make sure I have the right amount of glue on the edges - not enough, and I don't have a good airtight bond. Too much and I risk getting glue on the cardboard stiffeners inside.

In order to guard against having unseen drips of glue coming into contact with the edge of the stiffeners during the assembly process, I went along the edges of the stiffeners with a colored pencil. My son has dozens of colored pencils and after testing a couple by scribbling on paper then running the paper under the faucet, I found one that seemed to have very good water repellant properties. I figured that if I waxed the edges of the stiffeners with the pencil, then any stray glue would be less likely to adhere to it.

I then followed Melvyn Wright's procedure ( http://www.melright.com/busker/jsart89.htm ) and spread a thin layer of glue along one length of both boards as well as the end, made sure everything was aligned, and worked my way around the bellows with the cloth.

Once I had the cloth glued in place, I cleaned up any bits of excess glue that I could see, then sandwiched the bellows between two padded boards and loaded it down with 25# of weights to act as a clamp, since I don't have any regular clamps wide enough.

Tomorrow evening I'll be able to tell whether everything's fine, or if I need to go back and fix anything. Until then, I've got my fingers crossed....

Bellows Pt. 1

I've been working on the bellows, and thinking about how I might dress them up a little - in case anyone ever cares to take a peek up underneath the organ. I was thinking it would be nice to have some brass accents around in various places, and then I came up with the idea of using brass grommets as decorative inserts in the bellows board valve holes. I got a pack of 3/8" brass grommets (originally intended for making tie points in canvas or other fabric). The pack contained 24 two-piece grommets, a cutting tool and a flaring/setting tool set, all for about $6.

I drilled some slightly oversized holes - since I found that the 3/8" grommets wouldn't fit into a 3/8" hole. I also sanded down the valve area of the bellows board (which I had sealed with shellac), in order to ensure an absolutely smooth surface for the valve flap and permit glue adhesion for the ends of the flap.

Not having an anvil to work with, I set the grommet on top of the concrete on my patio since I didn't want it bouncing around when I hammered it. I did not use the washer half of the grommet, since I figured that once it was flared on both ends, it wouldn't come loose.

After flaring the straight end as much as I could, I noticed that the grommet would still swivel around a little. This didn't concern me in regard to air flow, but I didn't want the thing rattling like a tambourine. To solve this, I left the bottom half of the flaring/setting tool in place, and knocked down the top of the grommet with a claw hammer. A ball pien hammer would have been preferable, I think, but I had to use what was on hand.

Once the hammering was complete, the brass lay flush with the surface, pretty much.

Here are the bellows boards and center boards drilled, each with a set of six 3/8" holes

For the valve flaps, I went with regular blackout cloth inline valves as mentioned in John Smith's supplemental instructions. Since I had spaced out the grommeted holes 1 inch apart on centers, I found I needed to make the valve flap 7 1/2" by 1 1/2" to make sure I had adequate coverage. I also cut some hardwood holders for the valve flap ends and drilled them for use with #2  3/8" long brass slot head screws. I sanded these little holders down for thickness to make sure the screws would go about halfway into the 1/4" plywood board.

Here's what they look like with the cloth hinges in place, and ready for having the bellows cloth glued on tomorrow.

Reservoir Pieces

This weekend I've put the crankshaft on hold and I'm working on the reservoir box and the bellows. I cut all of the pieces for the reservoir box and laid them out to figure out where they needed to be sanded or trimmed.

I made the air tube outlet piece from a solid piece of hardwood.

I glued and pinned the sides of the box together then clamped it until it dried making sure it was square.

I also stained the 1/2" battens at this point, figuring it would be tricky later on, once the bellows cloth was in place.

I sanded and gave the air outlet piece a couple of coats of shellac as well. I also shellac sealed all of the wood surfaces of the bellows and reservoir, and since I had the shellac out, I sealed all of the lower parts of the pipes as well.