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Spot weld removal?

W

wayjon0

Member
I bought a spot weld cutter at the local auto body supply, but the bits are wearing out quickly and it doesn't seem to work very well (this could be the user behind the drill). The drill bit is the kind with the plunger. Is there a better way to do this?
 
I used pilot point DeWalt drill bits and a flat bottomed chisel. Spotweld cutters never worked worth a crap for me.
 
you have to take your time with the drill bits. I found on average I would get around 20 holes drilled per bit. Some more some less.
 
Yeah, spot weld bits don't last that long, but if you use cutting oil on each spot weld, it'll help the bit last longer.
 
This is the type I have and there is no way I'm going to get close to 20 out of this thing. I tried adding a little 3 in 1 oil, but didnt see much improvement. I'm thinking I'll try the pilot point Dewalt bit.

Thanks

spotweld.jpg
 
I used the better bits sold by NPD. A little oil and judicious application of pressure helped them last a long time. I removed my cowl (170+ welds) with just one bit no problem. If you get crooked, you'll snap off a tooth in a heartbeat.

I think the bits are awesome. You just have to be patient and develop a feel.
 
I use a regular "jobbers" length (short) ~5/16 dia. cobalt drill. it has a bit of a flatter point. Go easy and you can tell when you get through the first layer... (usually some rust shows up). If you get most of the top layer what's left usually pops right off. I've taken hundreds and hundreds of spot welds out this way. Gone all the way through less than 20 times maybe.
 
Thank you all for the help, the new Blair bit works much better.

I'm guessing even the low end plasma cutters will work on this gauge of steel? Made a few cuts with an angle grinder and cutoff wheel and that stinks.
 
+1 on the Blair cutter and Snap-on's Rotabroach. :)


The key is to turn them slow and use a drop or two of oil on the tip. Also keep the pilot nice and sharp and center punch the heck out of the welds before you get after it to keep it from walking. Eastwood carrys the replacement cutters 3 pack (six cutting surfaces) for $18. Get em at CJPP's with free shipping!
 
Dang, you guys are hard on bits. I used cheapo Harbor Freight bits and pulled my cowl apart with losing only one bit after like 80 welds. I couldn't figure out how to flip the bit over to use the other side so bought a second one to finish the other half of the cowl. So if I had been able to flip the first bit I would have made it through with only one.

I found the key to be holding the bit square to the metal (don't tilt it) and let the bit do the work (don't get impatient and push too hard).
 
with the spot weld bits mark the weld with a center punch first, this keeps the bit from walking. Lateral loading is what snaps the teeth off quick on the Blair or similar styles. I use these when I want to drill through only the first panel... then after that panel is removed I grind off the "circles" saving the panel underneath. On large structural spots the welds are sometimes 3/8" of an inch and these are too small if you dont hit dead on center then you have to still chisel. If the welds are large and/or I dont care about drilling through the panel underneath I use the Dewalt bits as well.

Either way, get some of this stuff! http://www.toolrage.com/prodview.asp?sku=BLR-11750

It's the best! If your car is on a rotisserie set it up so you are always drilling down... run a sander along the seam so the spot weld locations show up nicer, go through and center punch them all (really not needed with the Dewalt bit but wont hurt), then put some of the rotobroach lubricant on your finger and smear it on every weld, as you move from weld to weld the heat from drilling the previous hole melts the lubricant and puddles in the spot weld depression lubing your bit!

This is my preferred method and with ONE Dewalt bit, I did a complete torque box, two floor supports, a front floor and toe board, two trunk drop offs, two inner fender extensions & both outer cowls. I also use an air drill which is fairly low speed... this keeps the heat down as well.
 
As always, everyone on this board offers good advice.

I think the best thing to do is find what's most comfortable and what works best for you (in terms of correct drilling depth, proper separation, etc) and stick with that.

Personally, I have a dewalt pilot point, a hole-saw type cutter and a regular kobalt drill bit. I like to take an area, start with the pilot point in each weld, then come back with the Kobalt. The hole-saws leave a lot to be ground out later, and sometimes i puncture the second layer with the pilot point (becuase it sticks out about 1/8 in.) The kobalt is flatter, but walks A LOT. I've developed this method and it works well for me.

A lot of times, you'll know when you're through the first layer because you'll get a little *puff* of rust.
 
When removing a panel that you are going to scrap, if its the top panel and you have good access, you can take your side grinder and grind until the metal is paper thin. Then you can pretty much peel it right off. The sheet metal is pretty thin, so it doesn't take too long. I didn't really like the idea when I heard it, but it really does work great and its fast. We recently installed a new bedside on a pickup, and removing the long rows of welds was sooo much faster using that method. Of course, there were some that had to be drilled. I wouldn't do it in every instance, but, in some cases, its the fastest way.
 
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