Shrinking disk - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Body - Exterior
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-10-2004, 07:55 PM
adtkart@aol.com
 
Last photo:
Join Date: Oct 2002
Location: Newport News, VA
Posts: 3,220
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Shrinking disk

I have seen several references to using a "shrinking disk" for sheetmetal repair. I have tried searching several ways, but cannot find them. Does anyone know where I can get one?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-10-2004, 09:27 PM
crazy larry's Avatar
Member
 

Last journal entry: better comparison before and after shots
Last photo:
Join Date: Oct 2002
Location: East Texas
Age: 43
Posts: 2,298
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
check it out.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-12-2004, 06:19 PM
adtkart@aol.com
 
Last photo:
Join Date: Oct 2002
Location: Newport News, VA
Posts: 3,220
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Larry.... that link only takes me to another board. It does not tell me anyone that sells the disk.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-12-2004, 07:15 PM
crazy larry's Avatar
Member
 

Last journal entry: better comparison before and after shots
Last photo:
Join Date: Oct 2002
Location: East Texas
Age: 43
Posts: 2,298
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i'm sorry. maybe you have to register for it to take you to the page i linked, i'm cookied, it might make difference.

anywho, it's instructions on how to make your own shrinking disk. and there's a link to a site that has some more info....
www.ghiaspecialties.com


on the forum page at metalmeet, scroll down to 'metal shaping tutorials' and click on "make your own shrinking disk".....
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-13-2004, 12:39 AM
Randy Ferguson's Avatar
Ferguson Coachbuilding
 

Last journal entry: '41 Chevy sedan
Last photo:
Join Date: Mar 2004
Location: Robinson, IL
Age: 43
Posts: 388
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
shrinking disc 101

Hi Guys,
I had to repair a good sized area of a '34 Chrysler fender last night before proceding with the replacement of some badly damaged metal. I prefer to repair all I can before a final decision is made of what to replace. There has been some discussion lately concerning shrinking discs. I wish I would have tried one years ago. It would have saved many headaches!!

This fender has had a hard life, but it can be saved. Some replacement is necessary, but most of the badly repaired metal is still decent enough to work with.

If you look closely, you will notice that the previous repairer use one of those metal mutilating shrinking hammers. WHAT A HOAX!!
He also used a course grit grinding disc to remove the paint and probably to remove some of the scaring from the hokey shrinking hammer. Still, it's not beyond repair.




To reveal the high and low areas, a large magic marker is used to ink the entire damaged area.



Rubbing over the surface with fine sandpaper on a block will reveal the highs immediately. As you can see, it's really bad in some spots with general wavyness throughout. This particular area is all stretched and in need of excessive shrinking. I started by running the shrinking disc over it lightly a few times, followed by water quenching. In extreme cases, the metal will turn blue, but that should be avoided if possible. After the metalhas started to shrink some, The slapper and dolly is used to further refine the surface. I place the dolly on the inside of the panel and lightly tap with the slapper on the outside. If you hit the dolly, it will ring. This will show you the placement of the dolly. You can then steer it to wherever you want it. I try to stay off the dolly, so I know I'm not strtching the metal further. Keep the dolly directly against the low spots and work around them wiht the slapper. The mass of the dolly will force the low spot to rise and the light blows from the slapper will knock down the highs. Once the panel feels smooth, The shrinking disc can be put to use again to smooth the area out even further. You only stay on the surface wiht the disc for a few seconds, then allow it to cool, either by water or air quenching. You can speed up the process if you decide to air quench by using compressed air to blow cool air across the surface. I use a squirt bottle to water quench. Less mess that way. A little bar soap on the disc will minimize galling of the metal. The disc should glide across the panel and not remove any material.



After several passes over it with the disc and lightly working the highs and lows with the slapper and dolly, here are the results. I have gone over it with fine grit sandpaper to polish it up a bit for the picture. This gives you a better look at the reflection from the lights. It's not 100% perfect yet, but it's good enough to begin the metal replacement.



I have right at 1 hour invested in this repair. I don't believe this could be fixed any faster with body filler.

Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com
__________________
Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com

Last edited by Randy Ferguson; 07-25-2004 at 01:16 AM.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-13-2004, 02:42 PM
gt2betubbed's Avatar
Kid With A Wrench...
 

Last journal entry: The Blower and test fit.
Last photo:
Join Date: May 2003
Location: Cali Baby!
Age: 35
Posts: 1,106
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Please forgive my ignorance, but what is a "shrinking disc"?
I saw your post Randy and the picture of it, but I don't understand what it is nor how it works. Is it a disc that you put on a grinder and actually "grind" on the metal to help shrink it? I've been doing so much reading on metal fabrication because my project has come to a complete halt because I'm intimidated on starting my firewall. Great looking work though! Every post of your's I've seen has been very inspiring!
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-13-2004, 05:03 PM
milo's Avatar
point on positive
 
Last photo:
Join Date: Sep 2003
Location: milogarage Calif.
Age: 57
Posts: 1,665
Wiki Edits: 0

Thanks: 3
Thanked 3 Times in 2 Posts
I remember a guy selling theses things 25years ago. He called them the "Incredible Shrinking Disk"...



I've been watching this thread for WHERE TO BUY ONE ?
too...

Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-13-2004, 05:27 PM
crazy larry's Avatar
Member
 

Last journal entry: better comparison before and after shots
Last photo:
Join Date: Oct 2002
Location: East Texas
Age: 43
Posts: 2,298
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i'll sell you one for twenty bucks plus shipping.

Randy, i need to order like oh, ten shrinking disks. i'll give you 12 bucks each?
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-13-2004, 08:30 PM
Randy Ferguson's Avatar
Ferguson Coachbuilding
 

Last journal entry: '41 Chevy sedan
Last photo:
Join Date: Mar 2004
Location: Robinson, IL
Age: 43
Posts: 388
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
where to purchase a shrinking disc

Hi Guys, please read each post in this forum. Larry has posted two sources for them. One is for $50.00+shipping and the other is a tutorial on how to make one yourself. They are also available from Sunchaser Tools, but they are made differently than the other two you will see and are much more expensive.
It's just a piece of 18ga. stainless steel with a 1/4" flange tipped around the edge. You run it at 6,000rpm over the surface of the stretched panel. No material is removed. In fact, one could asume that it actually thickens the metal, since it is generating heat and forcing the metal to gather into itself. In my mind, this would cause a thickening of the metal by a slight degree. Not worth debating though.

gt2betubbed, Thanks for the encouragement!

Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com
__________________
Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-13-2004, 11:16 PM
milo's Avatar
point on positive
 
Last photo:
Join Date: Sep 2003
Location: milogarage Calif.
Age: 57
Posts: 1,665
Wiki Edits: 0

Thanks: 3
Thanked 3 Times in 2 Posts
The original "Incredible Shrinking Disk" had cooling fins on the back side of it. It kinda looked like a fan clutch...That one might work for a while though
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 05-13-2004, 11:34 PM
Randy Ferguson's Avatar
Ferguson Coachbuilding
 

Last journal entry: '41 Chevy sedan
Last photo:
Join Date: Mar 2004
Location: Robinson, IL
Age: 43
Posts: 388
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Milo,
The original Incredible shrinking disc, as I've seen it has a flutted edge. I suspect it's mostly to keep it from getting a wavy edge, more than cooling qualities. Unless we're talking about two totally seperate deals. The smooth shrinking disc works great and it's actually better on aluminum than the one with the flutted edge.

Randy
__________________
Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 05-14-2004, 12:01 AM
unstable's Avatar
Murderator
 

Last journal entry: 7-26-2014 through 7-27-2014
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
Randy,

correct me if I am wrong here...but technically can't you just skip the portion of the instructions where you put a "lip" on the edge of the disk?

I mean, I thought the only functionality of the lip was to stop it from becomming a giant cutting device.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 05-14-2004, 12:08 AM
Randy Ferguson's Avatar
Ferguson Coachbuilding
 

Last journal entry: '41 Chevy sedan
Last photo:
Join Date: Mar 2004
Location: Robinson, IL
Age: 43
Posts: 388
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
The safety issue is definitely one reason, but it also adds strength.

Randy
__________________
Randy Ferguson
Metalshaping & Kustom Paint
www.metalmeet.com
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 05-14-2004, 07:31 AM
unstable's Avatar
Murderator
 

Last journal entry: 7-26-2014 through 7-27-2014
Last photo:
Join Date: Feb 2003
Age: 35
Posts: 743
Wiki Edits: 0

Thanks: 2
Thanked 4 Times in 4 Posts
so just for the sake of arguing. If someone wasn't interested in building a shrinking disk that would last forever...couldn't they just cut a circular piece, drill a hole and slap it on their grinder?
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 05-14-2004, 09:00 AM
walt's Avatar
Member
 
Last photo:
Join Date: Dec 2003
Location: Santa Rosa Ca.
Age: 65
Posts: 101
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
For a small job all you have to do is flip over a regular sanding disc and use the back side. It will provide enough heat to do the shrinking.
Reply With Quote Quick reply to this message

Recent Body - Exterior posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 06:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.