Drilling, already painted panels
 

What is the safest way to drill holes in already painted metal panels?

I would like to install hood pins on my Chevelle and I am afraid of damaging the surrounding paint.

Any help on the best way to do this would be appreciated, i.e. drill bit, step drill, hole saw. or anything else

Thanks

Re: Drilling, already painted panels
 

Use a brand new bit so it will be less likely to walk. Also, being new and very sharp, it will cut quickly so as not to build up excessive heat.

Finally, slip a small piece of rubber hose (like a fuel line) over the bit, leaving part of the bit exposed. That way, when you "break through", if you still have pressure on it, the chuck doesn't hit the paint.

I like the bullet point bits. Black and Decker works just fine on sheet metal.

Good luck.

Re: Drilling, already painted panels
 

Maybe want to use a piece of masking tape over the area you want to drill, and then mark your hole. Also a smaller pilot bit first will be easier to line up the bigger, final hole. Lay some rags or towels under the hood to catch the filings and maybe a piece of wood to support the hood while you are drilling while you have it slightly open. You will be able to press on a firmer surface to drill straighter and your bit will end up in the wood instead of any other part of your car.

Re: Drilling, already painted panels
 

Any competent machinist, and probably lots of others as well can grind you a regular drill bit to drill sheet metal. Once you've seen it done, you can do it yourself. It's not really that hard. You can also buy a stepped drill bit that will do a variety of sizes in sheet metal. Handy tool to have.

Re: Drilling, already painted panels
 

The stepped bits are nice cause the hole looks more like it was punched .

Re: Drilling, already painted panels
 

My choice #1...Blair hole saw, drill a pilot hole the size of the arbor....DO NOT rely on a spring loaded arbor pin https://www.yenko.net/ubbthreads/images/graemlins/no.gif

#2 Use a step drill as already mentioned, again drill a pilot hole, about 1/8" first.

Another good choice would be a greenlee hole punch if you could borrow one, and if you have back side clearance.

worst choice in sheetmetal is a twist drill https://www.yenko.net/ubbthreads/images/graemlins/no.gif

And tape the area, as mentioned...and don't be scared https://www.yenko.net/ubbthreads/imag...ns/naughty.gif just Git er done https://www.yenko.net/ubbthreads/imag...lins/beers.gif

Mike

Re: Drilling, already painted panels
 

I got one of those Greenlee hole punches! Wish I had a nickel for every whole I punched in those electrical panels! I could probably buy a BB! https://www.yenko.net/ubbthreads/imag...emlins/eek.gif

Re: Drilling, already painted panels
 

Thanks guys, just looked at Greenlee Hole Punches online those things look pretty sweet. I think I may order a few.

Not that it’s a big deal the Chevelle is just my summer driver. But would someone know the correct size hole diameter that is cut in a cowl induction hood for the hood pin to go though.

Thanks again
Todd

Re: Drilling, already painted panels
 

Fit the bit to size of the hood pin plate. When I drilled the holes in the Gibb camaro I put the old plates on and then drilled the holes.

Re: Drilling, already painted panels
 

The hole cut into the hood is 1"