DonB Don Bonar Prairie Village, KS (80 posts) Registered: 09/09/2011 10:06AM Main British Car: 1971 MG-B 95 GM 3.4 V-6 |
cutting thru skim coat
I'm in the process of cutting an additional opening to engine bay thru my front (welded on) valance. I know under the paint is a skim coat and I'm asking for the best way to cut with minimal chipping to the finish. Shape is roughly as seen on after market Fiberglass offerings.
Options I see (in no ranked order) are: pre-tape and cut thru the tape with cutting wheel on grinder (seemed to work well on drilling small trim holes. perhaps first score with a shop knife? First drill rounded corners? Clamp a flexible guide as a straight edge? My cheap air saw vibrates WAY tooo much! Tips form my body experts? Thanks Don |
billymgb1000 bill gaulin harrisville R.I. (74 posts) Registered: 11/30/2012 12:31AM Main British Car: 1974 MGB V8 LS1 5.3 |
Re: cutting thru skim coat
I would use the grinder with a cut off wheel and use the tape that will help too.
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Preform Resources Dave Craddock Redford,Michigan (359 posts) Registered: 12/20/2008 05:46PM Main British Car: 72 MGB V6 3.4 |
Re: cutting thru skim coat
X2 on the grinder, you can get a nice thin cutoff wheel 1/16" on a 90 or straight unit.
Dave |
DiDueColpi Fred Key West coast - Canada (1366 posts) Registered: 05/14/2010 03:06AM Main British Car: I really thought that I'd be an action figure by now! |
Re: cutting thru skim coat
Hey Don,
I would tape off the area and mark off your finished opening size. Then go back and mark off a slightly undersized opening, say 1/8th to 3/16ths smaller. Use the smaller opening as your cut line and cut away with your grinder and 1/16th wheel. Make sure that your wheel is rotating into the painted surface so that it won't lift the paint or filler. Watch the tape for heat damage. If it bubbles or lifts slow down and let the area cool. The tape will show damage before the paint will. Once the opening is cut, trim the remaining material with a die grinder or a hand file to your final dimension. Once again file or grind into the paint so that you don't lift or chip it. Remember to paint the exposed edge to seal it and stop lifting of your finish. Live like you mean it. Fred |