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You can re-use pure copper washers ...
I agree with DiverRay.
When you torque your banjos, the copper washers are work-hardened. You can re-use pure copper washers, but only if you anneal (soften) them first. My usual method is to:
1. Clean and inspect them. Reject them if they have any cracks or very deep grooves;
2. use a common propane torch to heat them, one-at-a-time*, to cherry red color;
3. quench it immediately in some room temperature, clean engine oil;
4. remove the oil with solvent;
5. rub it with some medium Scotch Bright to minimize the tarnish, then re-use it.
The Method in my Bent-McKinley "Aircraft Powerplants" textbook:
"Gasket Servicing.
Used (copper) gaskets should be annealed by being heated to a cherry-red and immediately quenched in light motor oil. After the quenching, the oil should be removed with a solvent and the gaskets immersed in a solution of 50 percent nitric acid and 50 percent water to remove oxides. After the Acid bath, the gaskets should be carefully rinsed in running water and dried."
They go on to say that new gaskets ARE better than used ones, so YOU make the choice!
* I form a small hook on the end of an 8"-length of stainless steel wire to hold the copper gasket. If you use pliers, the heating is uneven. If you use your fingers, they hurt a lot afterwards! :O
RLMcD
I agree with DiverRay.
When you torque your banjos, the copper washers are work-hardened. You can re-use pure copper washers, but only if you anneal (soften) them first. My usual method is to:
1. Clean and inspect them. Reject them if they have any cracks or very deep grooves;
2. use a common propane torch to heat them, one-at-a-time*, to cherry red color;
3. quench it immediately in some room temperature, clean engine oil;
4. remove the oil with solvent;
5. rub it with some medium Scotch Bright to minimize the tarnish, then re-use it.
The Method in my Bent-McKinley "Aircraft Powerplants" textbook:
"Gasket Servicing.
Used (copper) gaskets should be annealed by being heated to a cherry-red and immediately quenched in light motor oil. After the quenching, the oil should be removed with a solvent and the gaskets immersed in a solution of 50 percent nitric acid and 50 percent water to remove oxides. After the Acid bath, the gaskets should be carefully rinsed in running water and dried."
They go on to say that new gaskets ARE better than used ones, so YOU make the choice!
* I form a small hook on the end of an 8"-length of stainless steel wire to hold the copper gasket. If you use pliers, the heating is uneven. If you use your fingers, they hurt a lot afterwards! :O
RLMcD
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