The Stovebolt Site Forums The Shop Area Paint and Body Shop drilling through fresh powder coat

Just a general question. Can one successfully drill a 1 3/8" through a flat piece of 1/8" metal without ruining the pc? Considering adding a marker light to a light bar I built for the 860 I am working on. Not a big deal if it isn't advisable.

Bill, perhaps a hole saw or roto-bore would do a decent job of it. Was the light bar media blasted prior to powder coating? I've found that a local machine shop uses a conversion dip process (less labor intensive) that was rather ineffective in that the powder seemed to scratch off as if it were paint. Similar jobs done with a media blast prep of the surface, and you couldn't beat the finish off with a stick.. So I would consider what prep process was used as to whether the PC will adhere well through a drilling operation..

Good point Robert. It was pretty clean (new metal) so not real sure what type of prep was done. Would 2 stage paint have been less likely to be affected by drilling?

I think my biggest worry would be the heat generated in the drilling process.

Alternatively:
Can you contact the powdercoaters for advice?
They might be able to offer some suggestions/tips.

In any case, put a piece of painters masking tape around the area. Also, use a center punch first (after taping) so your bit doesnt wander. Use a sharp bit and spray some canola oil on the end of the bit to keep the heat down. Drill slow rpm for metal. The tape helps hold the PC down around the hole. DO check with your powdercoater to see if they have any other tips. I feel your pain, doing any drilling on fresh paint is always high pressure.

Bill, if the powder coat is fairly thick it will "chunk out" on you around the outside of your hole as you drill. The key is SHARP bit and as always start with a size or two smaller. I've done it successfully, but not cured and being a little heavy requires some patience. You can do it.....let us know your experience afterwards.

Yes, I like that advice alot... use very small drill bit to start.

I favor step drills for clean cuts. Regular sharp drills and working your way up works too. Not uncommon for me to use 3,4,5 drills to get where I finally want to be.

Dennis

Just a thought, but would slowly and carefully scoring it using a razor knife around the perimeter of the chosen drill size work? The knife would be of the hobby type with the wedge shape mounted in a pen type holder. I have used this method when cutting thin veneer. It's slow and gut wrenching, but usually works for that.

May also help to drill from the inside/back side. By the time the cutter gets through the panel it will have warmed up the temp a bit where there it less likely for chipping to occur.

Thank you all for all the great advise. I will let you know if I end up doing this and report back how it went.

1 3/8" is a pretty big hole. I'd suggest scribing a line the diameter of the hole you want right down to bare metal (maybe make a template to trace around). Then center punch and drill a series of 1/8" holes all around the perimeter and "connect the dots" with a small saw blade, or a 1 1/4" hole saw, etc. Finish off the hole with a half-round file. A hole saw will wander unless the drilling is done in a drill press with the workpiece clamped firmly to the press table.
Jerry

I used Blair brand "Holecutters" to cut the 13/16 hole on the fender for an antenna and a 3" to cut th hole above the rear view mirror for the speaker (both placed per accessory manual specifications). After using a center punch to dimple the surface, I was amazed at how precise holes were, with no "walking" and no damage to either painted surface. I wouldn't hesitate to use them to cut holes in another painted or powder coated surface.

Bob

For a hole that size you might want to see if you can rent or borrow a Greenlee hole punch. There is no danger you will damage the surrounding finish.