Drilling Spot Welds, What do you use? Options

[obscurity]

I have been drilling spot welds as I work on my car and it occured to me that there may be a better way (or maybe I am being to picky). I am curious what everyone else uses.

I have been using a spot weld cutter. It looks like a short drill bit with a pilot point and little cutters along the edge. It will cut through the top layer or steel but not the back layer (usually). They will cut about 10 welds before being hoplessly dull. When I was buying them at $5/bit it was fine but that company went out of business and the ones I find now are $25/bit. Are these the right tools to use or should I be just using a drill bit allthe way through the weld.

Any help or tool suggestions would be appreciated. (IMG:style_emoticons/default/smile.gif)

Thanks,
John W.

[ConeDodger]

That is what I use... They run about $15/bit at an autobody supply near me.

[tat2dphreak]

a decent one will drill more than 10 spots... or should. remember the welding metal is usually softer than the metal around it... the metal around it will dull the blade faster.

I have one that I've used for quite a few spots(I've lost count) and it still works... I can't remember what I paid, tho I remember thinking it wasn't cheap for a single bit.... then I ended up needing it more than I thought I would.

[sean_v8_914]

harbor freight spot weld drill I use has done 3 suspension consoles, 3-4 battery trays and 2 trunks. they try to walk if your technique is off, this breaks the pilot tip. I drill a small 1/8 pilot dimple. start teh "circle" cut slow then lay into it once the "cut track" is about 1/16-1/8 deep

[993inNC]

I just did my floor pans recently and used a standard bit (sorry don't recall the size). I drilled until the bit got dull and then ran it through the bit sharpener, worked like a champ. The only issue is you can't drill quite as deep and I used a chisels to get under the pan and pop the last fringes of metal holding on. One bit, worked it down to a nub (IMG:style_emoticons/default/biggrin.gif)

[dion9146]

harbor freight spot weld drill I use has done 3 suspension consoles, 3-4 battery trays and 2 trunks. they try to walk if your technique is off, this breaks the pilot tip. I drill a small 1/8 pilot dimple. start teh "circle" cut slow then lay into it once the "cut track" is about 1/16-1/8 deep

Yep, exactly what I used too, but I only used it on one suspension console and it worked like a charm. I started using a regular drill bit, but this was much easier to use and less damaging to the metal underneath.

[rjames]

Would cutting fluid help with keeping the bits from getting dull?

[jasons]

You know, I found using an air chisel CAREFULLY worked better than a spot weld bit. Or, using a small cut off wheel to grind down the spot weld, then pop it with the air chisel. Once you get the seam lifted up a little, the air chisel just pops it away, leaving a minimal amount of weld to clean up.

I must stress the word CAREFULLY. You can do a lot of damage with the chisel if you aren't careful.

BTW, if you are dulling them, maybe you are turning them too fast. Also, a touch of oil on the bit before you drill might help too.

[jim_hoyland]

What size is recommended for say removing the spot welds for a bumper backdate project ( '75 914 )

[Bleyseng]

What size is recommended for say removing the spot welds for a bumper backdate project ( '75 914 )

Are you finally going to jump to the "darkside" of early chrome bumpers? (IMG:style_emoticons/default/chair.gif)

[McMark]

I buy a huge box of cheap drill bits and use those. When one gets dull I toss it and grab another. $50 for 115

[Porcharu]

I use the solid type spot weld cutters. These are much better and last much longer than the 'tiny hole saw type'. I got 5 for about $12 on ebay.

[obscurity]

I use the solid type spot weld cutters. These are much better and last much longer than the 'tiny hole saw type'. I got 5 for about $12 on ebay.

The kind I have been using us the solid type. I have actually never seen the two piece version. I can't actually find them on Harbour freight but I will check e-bay.

john

[Larouex]

Everyone of those cheap, HF buys will leave you pissed off and unhappy with the cleanliness of the job. I tried them all and have done 100's of them with my Wurth bits. I recommend them highly.

Wurth Spot Weld Bit

Cheers,
Larouex

[rick 918-S]

I don't drill spot welds unless I absolutely have to. I grind them an slip a sharpened flat blade screw driver between the pieces and pop them. This wrecks the piece I am discarding and leaves the piece I want to clean up and save from being swiss cheesed full of holes from drilling too deep or making a bunch of thin spots that blow through when trying to reattach the new piece.

[strawman]

If you're going to be tossing the piece you're removing, just grind down the spot in the outer/upper metal piece and then use a cold chisel to knock it loose -- much faster than a spot weld cutter. I use a round-head bit in an air die grinder.

If you plan to re-use the piece you're removing, then using a good quality spot welder cutter is essential. I used to use the el cheapo Harbor Freight ones, but they seem to be made out of powdered iron and break at the most inopportune times. Regardless of the cutter you end up using, I'll echo the advice above about drilling a small pilot indentation and spinning the cutter at a relatively slow speed.

Best of luck!

[SirAndy]

The guys at the body shop have some special drill bits they use with a air-drill. Those last forever without going dull and the air-drill makes for very quick drilling.

I watched them remove whole panels in just minutes ...
(IMG:style_emoticons/default/smash.gif) Andy

PS: I have to ask what brand the drill bits are. I bet they are not cheap ...

[1968Cayman]

In the past I used a spot weld removal tool; if you're doing several cars or several panels that can become expensive.

Now I used DeWalt Pilot-Tip bits. They don't run like other bits and you can usually buy a complete set for $17- and use at least four of the bits to drill welds (all of the pilot-tipped ones if you don't mind the larger holes).

[roadster fan]

Just my .02 but I have drilled hundreds of spot welds with the smallest size of these (5/16" i think) from the set I have and it is as good as new. Cut steel like butter! Blair Rotabroach.





Jim

[Richard Casto]

When drilling, I use a 3/8" Blair Rotabroach. If you do not use cutting oil they will dull within a handful of uses. But if you use cutting oil they last quite a long time.

As much as I love the Rotabroach, I also grind down the spot weld and pop apart and sometimes just drill straight through using a regular drill. It just depends upon the situation.