separating spot welds on sheet metal

[orangeblood]

i have a few metal 35mm slide cases (7 3/4 x 14 3/4 x 2) that i'd like to use for storage of small parts and specialized tools. the cases appear to be sturdy and well made and will be very useful if the organizing slide holders can be removed.

the cases have rows of raised slots that hold each slide upright. the rows are attached to the bottom of the case with spot welds. i'd like to remove them without puncturing the bottom of the case.

any ideas or coaching about how to do this? (4 pics attached)

 

[finn]

Narrow air powered belt sander would work. HF has the pneumatic version. Mine is an Onyx, 3/8” x 13”
I think Milwaukee has an M12 version.

Get quality belts. The Amazon specials aren’t lasting as well as the belts shipped with the sander.

 

[nadogail]

You might get lucky with an Angle Grinder and abrasive disks.

 

[rust in the eye]

End mill

 

[orangeblood]

Finn - thanks
Nadogail - i tried a grinder and it was too hard to control; i ground thru the bottom a few times. any tips on how to avoid this?

rust in the eye - i not familiar with an end mill...i had to google end mill to find out. can you elaborate on how to do this?

 

[cmandp]

About the cleanest and cheapest way is to use a spot weld drill like this:


A band file or end mill in a milling machine would be similar but requires more investment.

You can use the drill bit above in a hand held drill.

 

[GeoBruin]

Finn - thanks
Nadogail - i tried a grinder and it was too hard to control; i ground thru the bottom a few times. any tips on how to avoid this?

rust in the eye - i not familiar with an end mill...i had to google end mill to find out. can you elaborate on how to do this?

If you have a drill press, you could set the depth on the quill just enough to drill out the top of the weld without punching through.

Alternatively, if you have a hand drill, you could use a depth gauge set for just the thickness of one sheet of metal (or perhaps a little more) or make/buy a depth stop like this.

 

[engineer2]

End mill or a flat faced abrasive stone in a drill press.
Cut/grind most of the way through. Pop the piece off with a wood chisel.
Same setup to smooth the scar.
Rustoleum Hammertone Gray paint to make look pretty again.

 

[orangeblood]

many thanks

good ideas to pursue

 

[619DioFan]

HF sells a spot weld cutter for 5 bucks. Never tried it myself but might be worth a try for 5 bucks.

 

[Jack_K]

I use a 10mm belt sander like previously suggested.

For this situation however I might use a spot weld drill bit in a drill press. The only issue is it will still leave a small dip on the remaining panel.

 

[toolenthusiast]

+1 File belt sander

 

[finn]

If you’re going to use a spot weld cutter, skip the HF and get a set of Blair rotabroach cutters.

I gave HF a try again on my current 66 Mustang project, but I simply can’t get them to last for more than a couple of spot welds. And yes, I am using lube and drilling as slowly as I can.

 

[orangeblood]

619DioFan - thanks, i'll check it out

 

[orangeblood]

Finn - thanks, i am going to try the HF $5 first to see if the technique works before getting a better cutter as you mention

 

[Wamsutta]

This thread reminds me of THIS channel. That guy must remove like a hundred spots welds everyday.

 

[rust in the eye]

Finn - thanks
Nadogail - i tried a grinder and it was too hard to control; i ground thru the bottom a few times. any tips on how to avoid this?

rust in the eye - i not familiar with an end mill...i had to google end mill to find out. can you elaborate on how to do this?

cmandp has a better idea. I forgot about those

 

[toplessHO]

wondering if theres a blade hard enough to use on a multitool to get under and glide along cutting welds.

 

[finn]

wondering if theres a blade hard enough to use on a multitool to get under and glide along cutting welds.

If it’s a good spot weld, you aren’t getting under it.

 

[seber]

Dremel with cutting disk. Die grinder would be a little faster if you have one.

 

[speed bump]

Die grinder gets it done but is harder to control. Belt file is usually my favorite answer, grind until the color changes and then use a scraper to separate. I have a 13 inch one but I would get an 18 inch if I was to buy another as the 13 inch belts go quick. 3m 60 grit cubitron belts seem to last the best for this.

The spot weld bits work good but they leave the weld and I typically end up cutting into the base metal. The cheapest way to get into them is get the HF one for the arbor and buy the replacement Blair cutters as they are 10000x what the HF one is. This is not an application I would use them for.

 

[ChevyEFI]

Spring loaded center punch to mark the center of each. Spring-loaded pointed center guide arbor spot weld cutter with replaceable cutter blades.

 

[yhprum]

These are supposed to be pretty good

Mueller Kueps (MKP244805) Spot Welding Drill Bits, 5-Pack

DetailsFeatures and BenefitsDouble Coated (HSSE- Titanium Carbon Nitride)Highest cutting speedUsable for interrupted cutsLongest lifetime for best profitabilityMade in GermanyIncludes (2) 6mm and (3) 8mm drill bits

www.tooltopia.com

 

[californiamilleghia]

" i'd like to remove them without puncturing the bottom of the case."

Is there a way to set the spot weld cutters to only go so deep ?

My use would be for taking apart old cars and maybe re-using the sheet metal panel I removed

 

[545_days]

I have had good luck with grinding on the side to be removed, cutting around the spot weld, folding up the steel to be removed perpendicular to the weld, squeeze with a big pair of pliers and twist on the axis of the weld. Obviously sometimes the wrong side of the weld breaks.

 

[ChevyEFI]

" i'd like to remove them without puncturing the bottom of the case."

Is there a way to set the spot weld cutters to only go so deep ?

My use would be for taking apart old cars and maybe re-using the sheet metal panel I removed

Yeah, the spring loaded pointed pilot tools have a depth setting. It's a screw at the backside. The ones Inised to buy were always set pretty well for regular car steel.

Spring-loaded pointed center guide arbor spot weld cutter with replaceable cutter blades.

 

[rsanter]

Don’t use a drill bit or a spot weld cutter. Both are junk for the application

Die grinder or small belt sander

 

[orangeblood]

a lot of good feedback,,, THANKS

at this point not sure which approach to start with (cutter/bit or narrow grinder) but i am leaning towards using a narrow belt grinder.

i'll provide an update in a few days (when i can actually work on it)

again, thanks