Grumpy Mechanic
Member
Has anyone ever used a metal shrinking wheel. It attaches to a angle grinder or sander .I purchased it from a outfit in California . Was wondering if anybody has had good experience using one and there opinion of it.
Metal shrinking wheel
- Thread starter Grumpy Mechanic
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whateg01
Well-known member
Useful if you do any metalshaping. Used to be some ok videos out there. More controllable than a flame. Is there something you want to know about them? They aren't really rocket science.
KwikFab
Well-known member
Shoot I can shrink anything with a flap disc, might get messy though 
Can you take a picture of this tool? I'm curious to see it
Can you take a picture of this tool? I'm curious to see it
whateg01
Well-known member
Just a metal disc that goes in place of a grinding disc. Run it on metal that you want to shrink. Metal gets hot.Shoot I can shrink anything with a flap disc, might get messy though
Can you take a picture of this tool? I'm curious to see it
OP
Grumpy Mechanic
Member
I'm getting ready to weld replacement wheel wells inner and outer . Just wanted to know if I get any warpage if this will work. I know it's not rocket science but after I use it should I douse it with water? Just looking for your guy experience using one and what kind of results . Fixing my wife's Dodge Ram 1500 4x4. Thanks in advance for any input.
I have used them to tighten up a "popping" spot on things like doors and hoods. But I don't know anything about them really, it rubs metal, metal gets hot, no more flexy spot. I wipe the spot with a wet rag after because I saw that on the interwebs.
OP
Grumpy Mechanic
Member
I didn't take a picture it's a 8" stainless disc . I probably could of swiped one of my wife's stainless pot lids and used that.
OP
Grumpy Mechanic
Member
I didn't take a picture it's a 8" stainless disc . I probably could of swiped one of my wife's stainless pot lids and used that
OP
Grumpy Mechanic
Member
Thanks Wild Bill I appreciate it.
DocsMachine
Well-known member
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The corrugated ones are incredibly loud, so double up the hearing protection.
Doc.
Doc.
Motown
Well-known member
Here's a picture & link to a shrinking disc.
Hot Shot Shrinking Disc
A must have for professionals and home sheet metal shaper, to be able to bring a panel back into the correct shape during repairs or panel finishing. Made from stainless steel, the disc is designed to fit any standard 9” sander/grinder/polisher The disc enables you to shrink back...
cornfieldcustomsltd.store
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Pontiac787
Well-known member
I’ve got one of the pro shaper discs. Works well just make sure you have a grinder with enough rpms. Tried it with my Dewalt polisher when I first got it and it just didn’t spin fast enough to create the heat. It’s a great tool for when you get a bit carried away with planishing you welds and over stretch.
I personally don’t quench after use. Just let it cool on its own since water and raw steel aren’t a good mix. Oh, you can use scraps of bar soap to lube the disc so it doesn’t gall.
I personally don’t quench after use. Just let it cool on its own since water and raw steel aren’t a good mix. Oh, you can use scraps of bar soap to lube the disc so it doesn’t gall.
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whateg01
Well-known member
Generally speaking, if fit up is good, you won't be needing to shrink anything. The welds will shrink so you'll have to stretch them back out.
yhprum
Well-known member
If you haven’t seen this, it’s a good outline of what a shrinking disc can do, but it won’t work miracles without some hammer and dolly work to go with it.
OP
Grumpy Mechanic
Member
Wow thanks whateg01,Motwn,Pontiac787 Sh*tbox and yhprum for all the information you guys are a wealth of knowledge. I have the same wheel as you have Sh*tbox. I to tried it with my old craftsman buffer with bad results .
I since aquaired a old craftsman grinder I like the soap trick I'll have to try that. I'm good welding in pacthe panels that won't be a problem .It's just I hit the metal sometimes a little hard with my hammer and doily and cause high spots. Figure I would use this to knock them down. That corrugated one is cool looking. Thanks again all of your help .
I since aquaired a old craftsman grinder I like the soap trick I'll have to try that. I'm good welding in pacthe panels that won't be a problem .It's just I hit the metal sometimes a little hard with my hammer and doily and cause high spots. Figure I would use this to knock them down. That corrugated one is cool looking. Thanks again all of your help .
yhprum
Well-known member
I think you need 6000 Rpm, on the waffled style disc. Some guys use a wet rag, or a spray bottle or a blast of air to cool down the base metal.
Sweetcorn
Well-known member
I love them.
I have two that get used regularly.
I would recommend practicing a little on some scrap metal to get a feel for it.
I use an air blast to quench.
Check out Wray Schelin on youtube. He makes it look too easy, but he's a master of these things.
I have two that get used regularly.
I would recommend practicing a little on some scrap metal to get a feel for it.
I use an air blast to quench.
Check out Wray Schelin on youtube. He makes it look too easy, but he's a master of these things.
Max Power
Well-known member
I have the smooth type shrinking wheel. High speed is a must. I spray the panel with very soapy water. Works great for me on production body repairs.
MP&C
Well-known member
Any “warpage” typically caused by welding is because the weld will shrink up as it cools, causing it to lose some of the length along the weld seam. This in turn causes an up and down wave to form in the adjacent area as the unaffected metal tries to deal with the shrinking along one edge.
You don’t fix this shrinking with more shrinking, that will only result in any outward crown of the panel pulling in, and any inward crown (valley) of the panel pulling outward, resulting in a loose panel (you’ve removed the shape) that will give you a loose oil can. You want to planish the weld as you go to stretch back out what has shrunk, using a hammer and dolly.
MP&C
Well-known member
I’d suggest reading through this thread for some insight…
www.garagejournal.com
MIG welding settings for body work?
Maybe some of our more seasoned welders can help me get set up to do some automotive body work. All I have to work with is a big old 200A Lincoln MIG. I use CO2/Argon mix. Right now, I'm running .035 wire, which I assume is too big for sheet metal. I'll get a roll of .023 and some tips. Voltage...
www.garagejournal.com