Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic -- Hot Rod Forum

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

Thread: Shrinking Disc Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


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.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
09-10-2011 09:27 PM
B-1 I remember in the 70's & early 80's there were after-market support kits for Chevy truck hoods. They sometimes folded on the edges about midway back. I didn't realize it was a safety feature though. I'm a believer in this Regal's protection in a collision. Also good to know those thick doors are there. That is one of the reason this car was/is being made usable again. After replacing that hood, at some point later, I think I'll remove the Bondo from the front part of the left fender and do a better job with better tools and products. It was a quick repair anyway. The upcoming shrinking disc (whichever version) is going to be put to work.
09-10-2011 09:11 PM
crash test kinks

in order to meet crash tests there are crinkle points built into the cars. I have seen a lot of gm cars and trucks with the mid section fold. In areas where they salt the roads the hood hinges get rusty and stiff and when you close the hood on one you get the crash safety fold that is suposed ot keep the hood from coming thru the windshield. I have seen some trucks and cars in the bone yard with angkle iron pop rivited to the inner structur on a folded hood
09-10-2011 07:25 PM
B-1 LOL LOL, That's almost good news Brian! I wasn't looking forward to spending even a day on that hood. Yes, the supporting structure underneath has been compromised and would need to be removed and worked separately I think. Then what you said of the folding again in that weak area makes it a lost cause - for a greenhorn especially. I was going to use it as a learning experience, but I didn't want to really learn that much all at once. I'm glad I post those pics. What a relief actually.
09-10-2011 07:15 PM
MARTINSR The shrinking disc isn't going to do any magic on that hood,it's done for. I have a disc, it does amazing stuff, but that hood is done for. A new hood is WAY cheaper than the zillion hours you would have to spend to do anything with it. The worse part is you can't get under it to push up the low spots, and the structure is also collapsed so no matter what you do there is VERY little strength and it will fold again with almost no force being applied to it.

09-10-2011 06:59 PM
B-1 Hi OF, If I were using a shrinking disc all the time, I would definitely get Wray's disc. That's pretty nice of him to send the DVD for free. I'm just working on personal vehicles. Plus, I only have a 4-1/2" angle grinder and would need to buy a 7" or 9" version to safely use it. I'm hoping I can put a handle on my drill to stabilize it and give it a go with a 6-1/2" drain clean-out plate. If that's no good, I'll try altering the plate to fit my angle grinder. If that's still not good enough then Wray's disc is next. Take a look at these pics of the Regal hood. The way the creases are on the edges, I don't know if it'll work. The hood is closed in all pics.

On second thought, it looks like the hood is open on that first pic. It's gotta be. Don't recall it being THAT bad.
09-10-2011 06:30 PM
Old Fool I bought Wray's disc and backing plate. He shipped his video with it nc.

If I was to do it again, Wray would be selling me another setup!
09-06-2011 07:08 AM
B-1 I'm sure guys with experience using this tool do repairs quite easily
@ 6000 RPM. I imagine many know how long to apply the disc without turning the metal blue, but I've read some use the blued metal as a gauge. I tend to look at what Timothale wrote as a better starting point.
No need to do more when less is sufficient. I may be wrong, but I think
the 2,000 - 3,000 Rpm range would be adequate. At any rate, the drain cover/plates I've found on-line are roughly about half the thickness of what Wray's discs are. About 20 gauge is the thickest I've found mention of so far. That should be a little easier to increase the indentation for the grinder nut - still pretty hefty for a hammer blow I think. But if using a drill, it should only take a thick washer, maybe double nutted on the backside (toward the chuck) before it's ready to go. Beware, some of those drain plates are chromed plastic.
09-06-2011 06:07 AM
Irelands child Interesting thread - I've kind of wondered how metal shrinkers work. The 6200 rpm grinder speed as read on Metal Meet is kind of unexpected. One of my LEAST favorite suppliers has a set of on-line instructions that suggests much less - like 2-3000 rpm. Of course, I have no experience with a shrinking disc, so really don't know but would like to try to repair a couple hood sides that I have for my '31 that I screwed up.

Dave W
09-06-2011 05:38 AM
B-1 That's amazing. It's not getting hot enough to turn blue but still shrinking the metal to remove the lump. I can't wait to give this a try.
All the bondo I put on as a kid drove me nuts. Sure woulda like to known about this then. I've got several areas to try it on, The hood I mentioned may need replaced, so I'll get some practice on it. Be great if I can save it though.
09-06-2011 05:13 AM
disc technique

I saw one demo'ed at a car show several years a go, ,someone watching asked to try it and in a couple ofminutes didn't get it to work. the technique is similar to using a torch , hammer and dolly. heat up a spot, it expands, work the lump down, then let it cool and shrink. You kind of float over the surface apply enough pressure to heat up the high spot, enough pressure to force it down then move to another place to let it cool while you heat up the next spot. You usually don't want to put on enough pressure to get a large area blue.
09-06-2011 12:41 AM
B-1 OK, Thanks. I have seen a video demo of this magic in action. A hammer and dolly was NOT used first just to show the discs capability. Pretty slick. Should work beautifully on my F-250 fender and grill, but I'm kinda doubting it will work
on a good sized crease & dimples in my Buick hood. Lighter gauge steel I believe, but the support brace on the bottom of the hood will probably need removed and worked separately. Experimenting will be better than buying a hood off the bat I guess.
09-06-2011 12:23 AM
JeffB There are some pretty decent videos on youtube showing how they are used you might want to check out.
09-05-2011 09:39 PM
B-1 Thanks Sam, I lightly skimmed over those pics before and just now found one @ the bottom of the page where he forms the recess around the hole:

More than a few hits for sure. I'll get the disc in my hands and then can better
think this thru.
09-05-2011 09:20 PM
OneMoreTime Try John at this site..He helped me with my disk..

09-05-2011 07:49 PM
B-1 Well, I'm back to the drill idea. Still gonna get heat on the sheet metal at slower RPM's, just take longer (x3). Sure would like to hear if anyone has used a drill with a shrinking disc.. there has to be.

Here is an 8" SS plate/cover:

Didn't know there were that many sizes for this item.

If anyone has pics of their fabricated disc, feel free to post; don't care if it's
a skillet!
This thread has more than 15 replies. Click here to review the whole thread.

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

All times are GMT -6. The time now is 12:30 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.