Shrinking Wheels, do they work? Yes Sir

shrinking wheel , I didnt use one until a few years ago, I feel confident I can do anything and get out of trouble.

any high spot I have I use the wheel on , shrinking with a torch is touchy, can hurt the metal easily, and shrink in the wrong place alot of times .


The wheel always shrinks the right place . Ive been thru 5 of them.

its the loudest tool but it sings sweet in my ears.

I even made a 2 inch one for my die grinder to use on stainless trim.

anybody doing body work should use one, will remove any "oil can"

and let you save panels with low crown . cant say enough , but the guy selling them at sunchaser tries to sell you to much, I use his rubber backing plate, then the fiber ,and disc. -CF

 

Yeah, like we talked about before, really amazing tools! Wanna post a pic of your mini one?

 

I could have used one today. would have saved me lots of time and frustration it sounds like...

 

i'd like to see pics of these discs and the related parts. especialy that mini one you made Cole. i've heard of people making their own but have never seen one in person or even a good picture.

thanks.

 

Explain how they are used...I was thinking of buying one.

 

The "serrations" on the surface of the disk create the heat needed to shrink the metal. You work a much larger area than the old torch method.

 

Do a search here for Posts by John Kelly. He sells a version of the disk and has done a few tech responses on the subject.

 

Theres a guy on this forum selling them for about $60. Thats too much, when you can make your own out of a lid for pots and pans. However he does say his NEVER wear out. They do work unbelieveably well.

 

Don't have too many good pictures on this computer, but this will give you an idea of what you can do with one.
This dent was filled with lead. About 1/4" deep.
Took out the lead.
Was left with a stretched out area.
Straightened the edges.
Brought the area up...still too much surface area.
Several cycles of heating with the disc, then cooling ( disc shrinking is the only time I use water to cool)
Panel is now tight and reasonably straight.

 

more

 

Does anyone make a 4 1/2 inch version ??

I already have a good 4 1/2 inch angle grinder, so would like to try one out without having to step up to a new grinder.

Otherwise, it's into the pot cupboard for a saucepan lid !

 

Info from John_Kelly here....

I need to get one of those....

Brian

 

OK, so you just use the disc for the heat source instead of the torch?

With that in mind , I have 2 low spots that have canned "in" instead of out. Should I work the lows or the highs to get them to pop back up?

 

John Kelly's the man to talk to.

Here's his site with links to his shrinking disc and some of his tech articles on Metalshapers.org.

http://ghiaspecialties.com/

Oh... and just ignore all that VW stuff...

Ooops.

 

Roothawg, I was taught that you pick up all the low spots, then work down the high spots. Repeat as needed

 

I have worked low areas from the backside in odd circumstances.

 

Metal has memory, the disk plays with it on a molecular level. That help?

 

And I have a 4" long scar on my leg to prove it....

I have used up (literaly) 3 of the discs, then I borrowed my neighbors Dent Dr.. It is a dent pulling system, that includes a shrinking tip. After trying it a few times, I will never used my shrinking disc again. I can shrink a bit or several times over a panel, and control where and how much it shrinks.......

I deffinately will get one of these for myself. I believe they are called the Dent Magician now, and I even saw the guys at Boyds using one to pull dents.

Not cheap at About $600, but well worth it to remove oilcans or reshape panels so that you get smooth transitions from the quarter to the door, to the front fender, etc.

Hotroddder

Here are a couple of pics, kinda hard to see, but the quarter on this nomad was bulged out just before the door opening. I was able to apply probably 400-500 shrink spots on the panel in a grid pattern and got the panel flat to the edge of the door. I did the same to the door skin to remove the bulge there as sell. Now you dont want to remove the crown that is in the door panel, just any bulges that don't give it a nice smooth crown over the panel.......

 

Not any one tool is the silver bullet, we also have a Spitznagle that we use witht he shrinking tip when the disk wont cut it. Never come to a fight without a full quiver!

 

The shrinking disks are an easy way to "check a panel" without removal of material.
I bought one from Bill Stewart when he was an apprentice for Scott Knight. $35 and a Saturday morning seminar on it's use. Just watching Scott operate the yoder up close was worth the trip.
I recently bought a Niagara bead roller that came with crimping dies so I can make my own disks now!
Great idea using a mini disk on trim. You never stop thinking, Cole!

 

Yeah what he said, but the only reason I knew that is cause the guy from sunchaser said it over and over and over that last time I watched his sell at a G.G. event

 

I'm not a chemistry wizzard, but here's my understanding of the process: I think it works by changing the grain structure in the metal- heat the metal up enough, electrons get excited; as it cools the grain structure becomes more dense/finer- which works to locally shrink the metal. this is exaggerated by how much heat you put into it and how fast you cool it.

 

A thermos is like that.
Keeps hot things hot, cold things cold.
What I want to know,
Is how does it know the difference?

 

Actually, John Kelly's version doesn't have serrations. They're not necessary, although the Sunchasers one has 'em. I think that John's is somewhat safer and easier to control.

I think the references to metal memory or excited electrons is the sort of stuff that adds unecessary confusion to shrinking disks. It's no mystery.

The disks are stainless steel. When used on a grinder, they generated a lot of friction (without much actual grinding), and the friction creates a lot of heat. Because the disk only hits the high spots on the panel, only the high spots get heated by friction.

You can quench the hot high spots and heat shrink the areas just as you would with a torch. The only "magic" is in the fact that the disk only hits the high spots.

 

Here's my scenario...
I seamed the hood on my 50. Cooled it, made sure the metal was cool to the touch...blah blah blah.
On each side of the hood seam, right at the back...there are 2 gradual oil cans going away from the seams. They can be felt by hand but not really seen. I know if this car ends up black it will stick out like a sore thumb.
I just wonder if I use the disc on the top side if it will cause it to go deeper?
I don't know if the bracing is in the way, on the inside.

 

It sounds as if you need to stretch the low areas first. Anywhere that you weld will shrink the metal...think of welding as tiny little hands grabbing and twisting the metal in on itself. This will help you visulize what needs to be done...stretching. You need enough crown in the metal so that it stays up, then use a shrinking disc to locate highs and lows while tuning up the panel.

My shrinking disc has a safety edge and will not cut your leg like the sunchaser one can. If you have a sunchaser disc, I recommend leaving it spinning on the metal until it stops as a safety measure.

The shrinking disc is very simple. Heat shrinks. The most controlable way to apply heat to sheet metal is with friction using a disc because it glides over the high spots shrinking them down.... no guesswork.

You can go back and forth between stretching and shrinking many times without fear of hurting the metal. When I made my first shrinking disc, it opened up a whole new way of thinking about sheet metal work for me. Everything becomes more simple when you know you can correct almost any 'mistake".

I cannot think of a more useful tool for sheet metal work.

My DVD on how to make steel flares from scratch has some shrinking disc use in it, and here are two albums and an article with shrinking disc information:

http://metalshapers.org/101/jkelly/index.html

http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980121727059

http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980124046566

My DVD album:

http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980138836765

Thanks for the kind words about my work guys! I'm working on my second DVD right now. It will have a lot more information about custom metalwork for do-it-yourselfers. I might be making a custom torpedo shaped trailer if I have time to fit it in. My concept is to make metal work as simple and un-magical as possible.

If it is low, bump it up.

If it is lumpy, smooth it.

If it is high, shrink it.

No magic metal memory or molecules mentioned.

John www.ghiaspecialties.com

 

Hotrodder wrote: "And I have a 4" long scar on my leg to prove it....

I have used up (literaly) 3 of the discs, then I borrowed my neighbors Dent Dr.. It is a dent pulling system, that includes a shrinking tip. After trying it a few times, I will never used my shrinking disc again. I can shrink a bit or several times over a panel, and control where and how much it shrinks.......

I deffinately will get one of these for myself. I believe they are called the Dent Magician now, and I even saw the guys at Boyds using one to pull dents.

Not cheap at About $600, but well worth it to remove oilcans or reshape panels so that you get smooth transitions from the quarter to the door, to the front fender, etc.

Hotroddder

Here are a couple of pics, kinda hard to see, but the quarter on this nomad was bulged out just before the door opening. I was able to apply probably 400-500 shrink spots on the panel in a grid pattern and got the panel flat to the edge of the door. I did the same to the door skin to remove the bulge there as sell. Now you dont want to remove the crown that is in the door panel, just any bulges that don't give it a nice smooth crown over the panel......."

That tool will work, but it makes a series of small hard shrinks, not an even shrink like a shrinking disc does. I have done similar corrections on cars with a shrinking disc...very quick and easy to do. I once used a disc to shrink a quarterpanel down a full 3/16" over an area about 20"X20".

Hotrodder, Just in case you missed some of what I wrote above, and you ever want to use your disc again, leave it spinning on the metal until it stops for safety. I'm not sure why the video that comes with the sunchaser unit shows Ken stopping it on a carpet scrap. It does not make any sense to pull it away from the metal before it stops spinning. I liked the video by the way. It has some good information in it. It looks like we are pretty close...if you ever want to come over and play with a safer shrinking disc, talk custom work, whatever, give me a shout: ghiafab@msn.com

John www.ghiaspecialties.com

 

So, John how would you suggest stretching the metal in my situation? Hammer the original area which was welded?

 

Yes, I would hammer the metal at the weld and any area that turned blue from the weld. Do you have a picture of the area?

John www.ghiaspecialties.com