Saturday, July 14, 2012

How to Disassemble Rusty Mining Artifacts

Removal of nuts & fasteners from equipment: This is a very frustrating task and many times you want to save the specialized bolting materials. I have found that the use of chemicals (Kroil) and heat (torch) have the best results. Just using torque to remove the nuts from the component will generally destroy the nut/component. I have found the use of Kroil, a chemical that actually reduces the rust down to allow the nuts to be removed works well. Many of the old mining artifacts use National Fine threads and the chemical may not work. If you heat the nuts up to “red hot” you will almost always successfully remove the nut without damage.
NOTE: Kroil can only be ordered from the manufacturer; it cannot be purchased in stores.
Kano Laboratories Inc.

1000 E. Thompson Lane
Nashville. TENN 37211-2627

Removal of cast iron pulleys from shafts: Cast pulleys are very susceptible to breakage if you try to use a steel hammer to remove them. You need to resist the temptation to use that method. In most cases there will be a key in a keyway. You should try to drive the key out using a hammer with a piece of stock as a push device. To remove the pulley you should use heat on the hub to swell the steel hub and then slide the shaft out using a soft metal mallet, applying it to the hub and not the outer rim. If this does not work, do not force it. If the shaft/ pulley are portable you could go to a machine shop that has a hydraulic press and have an expert remove the pulley from the shaft.

Removal of tappets from stamp shafts: You may want to move or remove the tappets from the stamp shaft. This is a common move to make the shoes all the same height from the dies.
NOTE: Only move the tappets on the stamp shaft if it is absolutely necessary. I have known groups that have moved the tappets and could not get them to stay in place. It seems the old miners had a better ability to fix the tappets in place.
If you have to move or remove a tappet from a stamp shaft you need to be careful that you do not break the tappet since they are made from a cast metal and could break with too much shock from a hammer.  You should use a good size torch with a rosebud to heat the entire tappet. The heat will expand the tappet for removal. Once you heat it to red, you can use a soft metal hammer and hit the tappet near the fat part of the tappet. This will shake the rust loose and you will actually see the rust come out between the tappet and the shaft. You should try to move the shaft after you have removed enough rust to move the tappet. The original fit of the tappet to the shaft is loose and once the years of rust have been removed the tappet should move freely on the shaft. At that time you can move or remove the tappet.  

If you have any comments on better or different ways to disassemble equipment, please respond in the comments section below.


  1. The photo is awesome. How unfortunate that Arizona leaders cannot see the value in preserving this unique part of state history.