Mason Jar Stabilizer

By Chris Crawford (October, 2009)

This tutorial is based on two paragraphs and a sketch found in Jim Hrisoulas' book “The Complete Bladesmith”, where he talks about making a stabilizer from a brake bleeder hand pump and a Mason jar. My method of construction is a little different than the one found in the book.

This is a very easy project to construct, and I've had great results from it. With this stabilizer I can pull and hold about 23 in.Hg for an hour or so at a time.

The stabilizer is built from the following parts: a Mason jar, a Mason jar lid and ring, a couple zip ties, some type of rubber, a break bleeder hand vacuum pump and hose, and a screw on metal bleeder nipple.

Disassemble the bleeder nipple. Drill a hole in the lid that is only large enough for the narrower piece of the bleeder nipple to go through. Make two rubber gaskets with holes smaller than the narrower piece of the bleeder nipple. The holes in the rubber will stretch to allow the bleeder nipple to pass through. The pieces of rubber that I'm using came from an old bicycle tube. Push the narrower piece of the bleeder nipple through one of the rubber gaskets. Then push it through the hole in the lid. Place the second rubber gasket on it, and screw it into the wider part of the bleeder nipple. Tighten it down. If you did it correctly, the small end of the bleeder nipple should be sticking out of the top of the lid.

Attach one end of the hose to the hand pump and secure it with a zip tie. Run the other end of the hose through the jar ring, and secure it to the bleeder nipple with the other zip tie. Be sure that the jar ring is orientated correctly or you will not be able to screw the top onto the jar.

Minwax Wood Hardener is my stabilizer solution of choice. I modified a coarse strainer to make it easy to retrieve the scales, or whatever I'm stabilizing, from the solution. The entire strainer has to fit into the jar, so I had to do a little cutting and bending.

To use the stabilizer, fill the jar about 2/3 full of wood hardener, put in the strainer and scales, tighten the lid, and get to pumping. You will start to see bubbles rising from your scales as you create a vacuum in the jar. I usually pump to about 23 in.Hg and let it sit for an hour, and I'll pump more if I see the bubbles stop rising. The pump will have a small pressure release valve directly under the pressure gauge. Release the pressure in the jar, and use the strainer to remove the scales. Let the scales dry and you're good to go.

I hope the tutorial was informative and enjoyable. Please email me if you have any questions or comments.