On Tue, 2 Dec 2003 jpero_at_sympatico.ca wrote:
> While everybody else is talking about cleaning up the leakers,
> Is this chemical is good use to dissolve rust on steel screw is
> rust seized in the potmetal or aluminum distributor?
I don't recall ever working on a computer that had an aluminum
distributor.
The more common problem with steel screws into aluminum parts, such as
drives, particularly if subjected to weather, etc., is for the head of the
screw to rust, but the aluminum hole that it screws into to corrode.
Usually the best approach is to get it out where you can work on it.
A penetrating oil, OR COKE, if permitted to soak into the hole overnight
will sometimes help loosen the grip.
Then use tools that fit TIGHTLY to the head of the fastener (use 6 point
not 12 point for hex), and DON'T use a #1 Phillips for #2 fasteners!
If it is too late, and somebody has already buggered the head, then use
Vis-Grips #5WR.
If the head breaks off, anyway, then you'll need to drill out the broken
fastener. If possible, use LEFT-HANDED drill bits - they will tend to
loosen instead of further tighten the stub.
Easy-Outs will sometimes work once it is drilled, but when the Easy-Out
breaks off, then it REALLY gets fun.
If you can't get the stub to unscrew out, then drill it out almost to the
threads.
Once you get it out, then gently run a tap down the hole to clean up the
thread. Use a "Re-Threading" tap if possible.
If you bugger up the hole, then put in a helicoil. If it is too far gone
for a heli-coil, or needs more strength, use a nutsert.
When you reassemble, get rid of all damaged fasteners, even if they "might
still be good for one or two more times".
Use an "anti-seize" compound on the new fastener when you reassemble, to
reduce the binding for next time.
--
Grumpy Ol' Fred cisin_at_xenosoft.com
Received on Tue Dec 02 2003 - 19:18:54 GMT