On Mar 8, 11:30*pm, Dave wrote:
ac1951 wrote:
many thanks for the comprehensive response ....
I have to admit that I was thinking you were going to end by saying
"tie the steel band around your wrist as a reminder never to try
removing silicone from aluminium" *
thanks again

Just remember to keep the angle as low as possible and practice on
another piece of ally first. The angle should be as close to zero as is
possible. If the cutting edge is sharp, you should not have any problem.
Remember, if there is a burr under the cutting edge, it will cut into
the surface you are trying to clean up and make a scratch. I have done
this many times in the aerospace industry and never left a scratch when
I learned the way to do it. Practice first and then dive in. Try to hold
the blade in your hand, so that it is curved, so that the cutting edge
is horizontal, this will/should get you under the sealant.

I doubt that you will have to get right down to all the metal, as you
can normally use sealant over the top of traces of the last one.

Anyone care to comment?

Dave

OK job done,
I didn't use the metal band suggested by Dave but he set the idea. A
combination of using disposable safety razors and a kraft knife held
at a very shallow angle did the job...

thanks
Andy