Drilling hole in painted fender

[Bill E.]

My 74 roadster was professionally restored by the previous owner to be his daily driver. It has an aftermarket left fender, two-stage paint, and a lot of other non-NCRS acceptable modifications. For some reason he did not install the alarm lock in the fender although it looks like the wiring is in place. I have purchased the lock but am reluctent to simply take a hole saw to the fender since the paint on the car is nearly perfect and I am afarid that it will chip the clear coat and/or base.

One suggestion I have received is to outline the hole size and take a very sharp small drill and drill a series of holes inside the scribe line, then use a fine file to enlarge the hole to the desired size.

Has anyone tried something like this? Any other suggestions? I really don't want to screw up the paint but I would like to do what I can to make the car whole.

Thanks, Bill #39624

[John M.]

Re: Drilling hole in painted fender

Bill Get yourself a Unibit. It will cut a perfect hole in the fiberglass. I used one to cut a hole in a brand new beautiful black paint job and I was scared skinny but it worked perfectly.

[Bill E.]

Re: Drilling hole in painted fender

Thanks John,

Was the paint clear coat over base or single stage lacquer? I wonder if it makes a difference.

Bill

[Mike E.]

Re: Drilling hole in painted fender

Many times people will put masking tape over the area. That helps prevent chipping paint around the cut. FWIW.

[Ed Jennings]

Agree with Mike *NM*

[John M.]

Re: Drilling hole in painted fender

Bill, The paint on my car is single stage urethane. Maybe the tape would help but I didn't use any and the hole was perfect. The unibit will cut specific sizes so be sure it has the size you want.

[Doug Flaten]

Re: Drilling hole in painted fender

You could outline the hole and cut away the paint with an X-acto knife. Then put the tape on and drill the hole. another FWIW

[Craig S.]

Re: Drilling hole in painted fender

Bill - besides the other good suggestions here, there are slots you have to file in the hole to make the lock fit correctly, and prevent it from rotating as well. I used small ignition files and a correctly sized hole saw on my 74 years ago, and it came out perfectly. At the time, the body was stripped, but I would just use some high grade automotive masking tape prior to the cut operation, and with the ignition files for the slots, it would not be necessary and would probably be more hinderance than help at making the hole perfect. A template from a car with the correct hole cutout would be good to have first, also to locate the hole in the correct spot above the gill vent area. Craig