Dressing a pedal-driven grind stone

[Ronald Jones]

Over the summer, I purchased a pedal-driven grind stone. The frame is a little ricketey and feels unstable, but in use, the pedals work properly. The problem lies with the stone which is severely in need of dressing/truing. I estimate that about 1 1/2" will need to be removed till the stone is approximately round, and I will end up with a 12" diameter wheel. I have no idea what the previous owner(s) could have done to put such large dips in the wheel, but I would like to put it to use in my shop. I have used a Norton diamond dressing tool for about 30 minutes, and I believe it will take a considerably long time at the current pace to get the stone into usably condition.

Does anyone have reccomendations for a better way to dress the stone? I vaguely remember reading about steel pipe being used to dress grind stones. The diamond tool is doing its job but the business end is about about a 1/4" thick and maybe 3/8" wide. I am not very knowledgeable when it comes to grind stones, but if I had to guess then I would say it is sandstone.

I appreciate any advice you guys could share.

Thanks,

Ron

[Harlan Barnhart]

Some of those old stones became slightly soft when soaked in water for extended periods. I have heard of soaking the wheel and cutting the excess of with a putty knife. No first hand experience... just what I heard.

[harry strasil]

Yup, more than likely sandstone, and the stone had soft spots in it to start with and those areas wore very quickly as you can imagine.

1. turn the stone slowly and using a black magic marker, scribe a line on one side while it is moving slowly.

2. Using a 1/4 inch masonary bit drill a hole about every inch on the outside of the line.

3. using one of those round wire blades for a hacksaw, cut down thru one of the holes about every 6 to 8 inches all the way around the stone.

4. using several tapered punches, gently drive them in the holes between cuts, till the outer edge pops off, GENTLY AND EVENLY JUST A TAP AT A TIME ON EACH ONE, WITH A SMALL HAMMER, while steadying the wheel from the back side.

5. Now you can use a small right angle hand grinder with a coarse wheel while turning the wheel slowly to finish truing it up.

6. wear safety glasses, and protective clothing and a face shield while operating on the stone.

7. and the most important, never hit the stone or any of the tapered punches hard or you may shatter the stone, the center is held in with lead or babbit metal.

8. As Harlan pointed out, sandstone gets soft when it sets in water, so never let the stone set with water in the trough. this may be what caused the out of round in the first place..

Jr.

[Ronald Jones]

Thank you kindly for the replies and thorough step by step plan. I have not seen the the type of hacksaw blade you describe, but I will look for one of those at the hardware store and borrow a right angle grinder. I only have a small dremel and would likely burn up the motor or all the disks on the final dressing. I will also need to pick up some more tapered punches.

I will work on the wheel this weekend and reply back with my progress. The wheel does not spin through a trough so I will need to make a water cone dripping container in time. Thank you again for the advice.


Regards,

Ron J

[harry strasil]

HF Item # 96274

[george wilson]

Harry means a round wire hacksaw blade with little chunks of carbide all over it. Those blades cut in any direction,but leave a large kerf.

Excellent info,Harry.

[harry strasil]

Thanks George, I have done several that way for customers in the past. It's just knowledge I gleaned from watching some old boys harvest some limestone from a local quarry a long time ago, while I was there doing some repair work on the crusher.

But I had the stone laying on some sawhorses when I did it.

You have a tendency to learn a lot about other trades when you are a working blacksmith. LOL

[george wilson]

I know what you mean. As tool maker,I was involved in all the Historic Trades shops in the museum,and picked up many bits of information.

[Johnny Kleso]

Have you measured thhe stone to make sure its out of round?
Can it be that it is just not concentric and needs a better center bushing?

PS: LV and WC sells diamond dressing blocks that are about 3/8' x 1"

[Russell Sansom]

Curious: Are new wheels available anywhere? Were they originally lathe-turned at a mill somewhere? Or sculpted then turned?

Where I grew up in kentucky, no farm was without one of these. My father would always make a derisive clucking sound when he saw an eccentric stone caused by leaving water in the trough. Some farmers understood it and some did not.