mirror/ antenna sized holes

[tech69]

if it's welded the guy wants flush results. The price for hole saw bits seems pricey for this. Do tin snips cut good enough for this if I trim it up after? Seems so but not sure. Might just recommend bodyman tape and kitty hair but want to weigh out my options.

[Len]

Why are you cutting, can't you just weld and level with filler?

[Roger J.]

I think I know what your saying....You're trying to make a patch for the antenna hole?
If it were me, I'd stick a piece of tape over the hole and use a razor blade to cut out the template for the hole. Stick the tape template on your patch metal and cut it out. You might still have to trim it a bit, but that will get you real close.. This is assuming that you're butt welding it.

[tech69]

Precisely. Sorry for not being clear. I'm thinking that's probably the best way too. So now I got a a plan for the small holes and bigger ones but the small rectangle oval ones sound like the most work. Thanks guys.

[tbm3fan]

Just had to make a patch to fit a hole from a CB antenna in my truck. Took a compass and drew out a 1 1/2" circle and used snips to make small straight cuts around my tracing. Then took it to a grinding wheel and rotated it around and around till it came out at 1 3/8". Fit perfect and used two small magnets to hold it for the first tacks.

[tech69]

encouraging to hear. Thanks for that.

[terranaut]

There's what I call the scratch to match method. Cut out your rough patch piece, oversized. Hold it up to the back side of the antenna hole and scribe a tight line around the hole. Trim with aviation snips. The elegance of this method is it works for irregular shaped holes as well as something simpler like a round hole. With a tight fit, you can tack it in place then planish the piece out for a perfect fit in hole. Finish with parent metal weld, no bead to grind off, little distortion. Planish the seam to stretch the shrunk up bits.

And there you have a perfect "John Kelly" metalfinished patch.....No bondo. I'm a rank amateur and I've had some success doing this. Its almost easier than trying to level body filler.

For doing small holes, like emblem holes, punch out "plugs" with a whitney roper style punch, (my HF cheapie seems to work fine) drill out the hole to a perfect matching size with a Unibit type drill (again, my HF cheapies seem to be holding up pretty well). Place the plug in the hole, planish it so its wedged in the hole, fusion weld with no filler. Planish and you're done. Credit Ron Covell with this method. Beats the "glob it up with MIG wire" method. Key to good welds is clean paint and rust free metal front and back. The drilling out part both cleans the edge of the hole and trues it to size.

I'm trying to get away from the Iowa school of welding...."The bigger the glob, the better the job."