Pipe Soldering Turntable

by Randy A. Bergum

Background

In the world of organ repair it is sometimes necessary to build a tool or jig to complete a job. After having taken receipt of a rank of reed pipes with a few broken resonators, I contacted Steuart Goodwin to ask how the experts would repair them. Steuart described a turntable that held the reed block in place, and also located the matching resonator above it, permitting a quick and trouble free soldering job. It was decided (!) that I would prepare a reed block soldering turntable like one he had seen in a factory, so we distilled the essence of the tool into a list of simple requirements.

The turntable had to allow for:

Adjustments to hold a wide variety of block sizes,
Centering of the block's resonator hole to the center of rotation,
Short or tall resonator heights, and
Keeping the resonator centered over the matching block hole during soldering.

After a few sessions of napkin sketching at the local coffee house, the design was born and construction began.

Description

This tool consists of a base with a turntable, and a metal frame with an adjustable arm holding a guide rod to position the resonator over the block.

Mounted to the base is a turntable made from a potter's banding wheel, chosen because it has a low profile and quality bearings on its axle mount. The wheel has a block slide that allows horizontal alignment of the block shallot hole with the centerline of rotation - there are many different sizes of blocks, and the location of this hole varies. The slide has two tapered pins that receive a wood jig, used to hold the heated reed block during soldering. There is a set of 6 wood jigs, each with a different size hole to fit the most common diameters of reed blocks.

The metal frame consists of a fixed post with a traveling arm that holds the resonator guide rod. The travelling arm can extend up to 5-1/2 feet, or can be turned upside down to fit the smallest sized pipes.

Clamped into the travelling arm is a guide rod made of 3/8" stainless steel 36" long, with a tapered point that fits into the reed block, aligning the resonator and reducing solder leakage where the shallot must fit. The other end of the guide rod is drilled and tapped to accept another extension rod of 36" for those really big jobs. A quick release clamp is used to pinch the guide rod after adjustment, and a wooden cone slides onto the rod and into the top of the resonator being soldered. The cone has a brass bushing that allows easy rotation of the resonator as the block turns.

Fig. 1 - Pipe Soldering Turntable Fig. 2 - Upper Mount Extended Fig. 3 - Upper Mount Lowered

Fig. 4 - The Reed Block Jigs and Cone Fig. 5 - A Dry Run Assemply of Parts

To Use the Turntable

Select the wood jig to hold the reed block. Adjust all parts in a "dry run" before you are ready to solder.
Apply a whiting solution to the top face of the reed block and the resonator where you DON'T want solder to go, and allow to dry. This will stop solder migration and makes for a tidy connection. If the whiting is not totally dry, it will peel off when heated.
If installing a resonator with a new bottom piece, ream the reed block with a 45 degree countersink to clean the area to be soldered. Remove no more material than necessary to scrape away the lead oxide and crud. If reblocking a broken resonator, take a very sharp chisel and cut the bottom of it just square. Chisel the solder bead on the block close to within 1/8" of the top surface - this allows a square fit and not too much change in the speaking length of the total assembly.
Heat the reed block on a hot plate - experience is the best gauge, but you can use a laser thermometer to check progress. Don't gauge the whiting surface, as it will be cooler than the block. The melting point of lead is 621 degrees F, and 63/37 solder is 361 deg.
Place the block onto the table, place the resonator onto the block and lower the guide rod and cone.
Apply flux to the joint. Your soldering iron should be at least 250 watts with a temperature controller inline. The strategy is to have the iron a little bit hotter than the melting point of the solder - this will prevent meltouts in the resonator.
Melt a glob of solder with the tip of the iron and tack the resonator in place in 2 spots, then apply it to the joint. After the solder is in place, run the iron around to make the bead slightly convex. You may have to go around a few times to get the bead evened and smooth.
Let the joint cool, then clean off the whiting with a water bath, drying thoroughly afterwards.

Allow for 1,000 solder jobs before you even get close to apprentice position in a real pipe making company (!)

Fig. 5 - Repaired Kinura Pipe - Note Ceramic Washers Added To Insulate The Block

About the Author

Randy Bergum pulls the strings of World Leaders from Fullerton, CA. His hobbies include arguing with the voices in his head, running with scissors, and Belt Sander Drag Racing.

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Fig. 1 - Pipe Soldering Turntable	Fig. 2 - Upper Mount Extended	Fig. 3 - Upper Mount Lowered


Fig. 4 - The Reed Block Jigs and Cone	Fig. 5 - A Dry Run Assemply of Parts