On Oct 11, 6:57 pm, (DoN. Nichols) wrote:
O.K. My turn to ask a question instead of answering them.

I just picked up an air hammer with a set of five chisels.

I won't comment on how to use it, people have done a reasonable job of
that already, but I'll describe a job I did recently that I couldn't
have done without an air hammer.

I'm working on rebuilding a 1939 Plymouth roadster, which is a
complete rust bucket now but should be quite a beauty when it's all
done. I wanted to remove the body from the chassis to work on them
separately. They are connected by about 10-12 1/2" bolts, each about
4" long, with a 2" diameter washer under the nut (next to the body)
and a large heavy hex nut. Rust has completely consumed the nut,
bolt, and washer, effectively making them one piece (trust me, I tried
with a 1000 ftlb impact gun, with no success). My procedure was as
follows:
Use plasma cutter to remove as much of the nut as possible. I used an
O/A torch on some of them, but the plasma worked better. In
particular, my plasma torch is smaller, and fit better in some tight
corners. There shouldn't be anything left keeping the bolt from
slipping through (it won't because of all the rust).
Take a 5 lb sledge and hammer sharply 3-5 times on the various
surfaces to loosen the connection.
Use a straight chisel in the air hammer and aim it between the washer
and the chassis. A 1-2 second blast should pop it off.
Now take the pointed chisel and stick it on the top of the bolt.
Hammer the bolt back through the chassis. Repeat for all the bolts,
hook up the chain hoist, and lift the body off the chassis. The
entire process took about 4 hours.
Through experimentation, I found that the air hammer worked much
better than just using a chisel and sledge since the vibration had a
much better effect on the rust.
ww88