Technical spot weld removal tool

OK, I am moving onto the next phase of getting my 57 ford wagon back on the road-floor pans! I have a plan and road map of what to do and how to get there. But I have spot welds to remove, so I am looking at some tools: I have watched a few videos and some use just a few drill bits to punch through the welds, other use a spot weld cutting bit to just through just the one panel and then use a chisel to separate the panels. What are the opinions of the those who have done it?

Thanks,

Mike

 

Rotobroach. done

 

I've used the spot weld cutting tools from harbor freight on my Studebaker, lots of spot welds, they worked OK, not a job I want to do again

 

Drilling welds isn’t fun,
Separating panels without damaging is easier when the weld is all gone.
About the most I can get out of the best cutters with a good cutting lube is 50 welds.
you’re going to poke thru and have holes to patch somewhere.
Now I’ve been hearing the hot ticket is a mini beltsander. Maybe so but I’ve definitely got the wrong belts and the wrong sander because something is wearing out, breaking or flying off.

 

I found some tools made by BLAIR that are made in the USA, so will look into those. Since I am welding up floor boards I am thinking that I do not want to punch through the rocker just the pan correct?

 

Mostly used a small ball bur in air driven tool, have also drilled them as well. Seems to me, no matter what you use it’s a miserable job and nothing works “good” for every application. Chisel or panel buster takes care of the stubborn ones but also creates distortion that needs to be taken into account and repaired

 

Plasma cutter, blow thru the Weld on both pieces and viola I have an instant hole in the old panel in the exact same place as the original welds and just weld thru to the new panels.

Other than that I prefer sharp drill bits, hate those spot weld cutters. Used several different makes and have several still laying in the drawers at work, all they do is collect dust....


...

 

The Blair cutters work well. Usually when using them if you get them centered on the weld the top panel will pop up slightly once you have cut through.

 

I like the Blair cutters. If you plan to use one of the panels you're separating, cut through that piece. Then you can plug weld through the hole to the new metal and duplicate the original spot weld pretty well.

 

The Blair cutters work well, but its pretty easy to break a tooth off. If I'm not trying to save the top panel, I just use a 3" grinding wheel on a die grinder like these https://www.amazon.com/3M-1991-Reinforced-Grinding-Wheels/dp/B0002SRLF2. Grind until you see the outline of the spot weld appear. Usually when you're about to go through the first panel, it will flash blue from heat and being so thin

 

We use small air belt sanders at work to remove panels just sand the spot weld the use a spot weld chizel to break loose. You can pick up a cheaper model and belts at harbor freight.

 

I've used the regular drill bits, the Blair cutter, and even the solid carbide spot weld drill. But I tried the RotaBroach tool a couple years ago, and it is now the go to tool!

 

Just watched the Japhands/Bennet Kustoms video removing a 29 model 'A' roadster door skin, while I must admit I haven't seen the 2nd. video where the skin is fabbed & installed, I felt it a different approach as most generally the edge is simply ground away then address each spot weld as the remaining surrounding metal is peeled away. In the end the same results but seemed a difficult approach requiring a couple of handmade tools. I can only surmise he wanted the original skin completely intact for dimension reasons.

 

I don’t know the name-brand, but the one I used years ago looked like a mini hole-saw. Pretty easy to use, sounds like what has already been mentioned.

 

I hear this from a lot of guys,,,
I just can’t get it to work.
I’m blaming my equipment so far because I hear so many different people say the same thing that this is the way to go.
The HF belts don’t last very long doing anything that I’m doing.

 

Maybe slow your drill speed down ,nothing kills cutting tools like heat .

 

The HF spot weld cutter worked for me. Really slow drill speed and oil to keep it cool did the trick. A really sharp center punch in the spot weld helps locate the little guide pin too.

 

There is no golden solution IMHO. Try the option suggested above, and use whichever, in whichever combination works best for you.

In the real world, spotwelds are almost never a perfect circle, and more often oblong, incomplete, and offset, making a circular cutter less than ideal at times. IMHO, the Harbor Freight el cheapo spot weld cutter works fine if you go slowly and use lubrication. A Rotobroach would be ideal if you feel the extra cost is worthwhile. HF has the advantage of easily found replacement blades if you leave near a store, so factor that in too, if you MUST get that floorpan section out TODAY.

 

like most have said there will be a different tool for different situations
sometimes even a sharp wood chisel works best

 

I use one of these belt sanders almost every day at work. IMO, easier/faster/better than spot weld drills or grinding wheels. I will say that the best belts I've found are the orange Norton belts. Retain abrasive longer, and don't throw chunks of it off like the 3M Cubitron belts do.

 

I tried the HF spot weld cutter again on my current OT project. It’s still a no go, despite slow drill speeds, lube, etc. I can only get a couple of welds out of each cutter, then teeth break off or round off, rendering the cutter useless.

Best success is with the Rotabroach, although I have been using a regular drill bit on some. The Rotabroach gives cleaner cuts, though.

I bought a belt sander and had good luck on the last project, although the cut isn’t round like the Rotabroach. This last batch of belts is garbage, though. I don’t hnow if it’s cheap belts from a bad supplier, or I am using too co**** of a grit. I am throwing more grit than steel, and can only get a couple of welds per belt.

 

I used the cheepo HF cutter when removing the firewall from my A roadster. It lasted through all the welds on the firewall; but was done for after that. I always center punched the weld, then started a small pilot hole just part way through the weld before using the cutter which helped keep it centered on the weld. As others have said; slow speed and a lot of Rapid Tap did the trick... I got the old firewall out without putting any extra holes in it. However, the replacement had been removed by use of a drill bit cutting completely through. PITA welding up all those holes.

 

I’ve cut a bazillion spot welds. Super easy on sheet metal.
Regular drill bits work. Mini belt sander, cut off wheels…. I like these better than the Blair bits

Ive got one of these
But for me, this thin chisel is the best companion tool with whatever you use.

I don’t like drilling all the way through cause the easiest welding position is generally from the direction you can remove them.
The process is simple. Just look at it like you’re “unbolting” the welds.
The process will use more than just one method. If I’m saving a panel then I use the least destructive method. If the part I’m removing is trash, then the grinders usually are used.

 

I forgot to mention that chisel. It’s great, and seems indestructible.

Easier to control than an air chisel, and I never seem to miss with the hammer and hit my hand. I think mine came from Autobodytoolmart in Illinois.

 

These are what I use. The one on the right was my first one and worked well.

 

Most spot weld cutters make too big of a hole. I prefer bullet point drill bits

 

Most old car spot welds are smaller than new cars.
8mm and 10mm are the common bit sizes.
(5/16-3/8ish) for the “end mill”style.
We were not allowed to use the style that needs a 1/8th hole in the center at work.
Created more work. We used resistance spot welders and the small center hole would have to be welded. Kinda defeats the purpose of the fancy welder.
So I just never got used to needing them.

 

Correct, I should have specified old vs. new

 

Norton orange belts work the best just dont bear down on it let the sander do the work. The higher grit will give you the best results the 36 grit seams to fly apart then you have nothing I can grind off a panel with about 5 belts,

 

Some panels have 15, some 50, some have 250 spot welds.