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Discussion Starter · #1 ·
I'm trying to tap an area down that's about 2"x3" using a hammer and dolley.
Would heating it up first help and if so would a smaller propane torch work?

TIA
-Joe
 

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It's best to try to remove it without heat, especially because it sounds you as though are inexperienced. When working the dent you also have to work the sorrounding area because the metal you shrink has to go somewhere. While it may not be overly apparent, the metal surrounding the dent is usually higher. Years of metalworking provide you with the skills to work a dent/dents. Reading alone will just get you started with principles. Overwork a dent and you end up with a beer can. Apply heat the wrong way and you will make a mess. Just about all dents can be removed without heat.
 

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First off how did the dent get here?
Did another object strike the surface and leave behind a dent or has any type of welding taken place around the dent?

Those are a few questions that need to be answered as they each have different repairs.

Without more information avoid heating it with a torch, you more then likely will make it worse.
 

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A high spot is usually caused by a low spot somewhere else. Take a look at the whole panel and see if you can see the dent that is causing it. That's where you need to be working. If it truly is a high spot caused by something striking the panel from the inside, a shrinking disk would be the easiest and safest way to take it down, especially for a novice.

Do not under any circumstances use a propane torch. It will only make matters worse. Panels can be shrunk with heat, but that involves alternating heating and cooling of concentrated areas using an oxy-aceytlene torch and a wet rag.
 

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Discussion Starter · #6 ·
Hey Tom, thanks, I've seen that video before and it still amazes me.

It's on the firewall, and it does have a low spot next to it. I am trying to smooth out the panel better. It's just a weird dent. I am able to get behind it with a hammer to get the low spots as well sinces it's close enough to the heater core opening and I have both the front and back removed from the car (as well as everything from the firewall forward).

I guess this just might be too much for me, I'm trying to do what I can and learn from it.

Thanks,

-Joe
 

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Ive worked in many body shops with lots of varying techs and NEVER seen something like that work.

The ONLY time that method works is removing small shallow dents like hail dents and its takes more heat then a hair dryer just waved over it. That video leaves much to be desired and doesn't show the whole picture.

A little dent theory may help you out. For every action there is a equal and opposite reaction. That being said, when that metal was struck driving the metal down and in turn also stretching the metal at the impact point causing the low spot. The stretched or expanded metal had to go somewhere so it went out and thus causing a high spot to surround the low. The initial action was the impact or low spot, the equal opposite reaction is the stretched metal and the high spot.

Anyways, you need to use the hammer OFF dolly method and raise that low spot while you lower that high spot. You place the dolly directly behind the low spot and push up with light pressure. Now from the topside you hit the high spot down with the hammer.

You need to hold the dolly and hammer like this, the dolly is under the low spot and the hammer hits the high spot, the hammer and dolly DO NOT come into contact.



The way am reading this is that you are hitting low spot out with the hammer so my question is, where is the dolly placed, the outside?

It sounds crazy but placing the dolly UNDER the low spot and then hitting the low spot thus hitting the dolly actually raises the low spot up. But you need to first address that high spot and lower it by placing the dolly under the low and tap the high down with the hammer.

Heres a few crappy you tube videos that might help you out
http://www.youtube.com/results?search_query=sevtchevelle&search_type=&aq=f

Since the firewall is a relative flat panel you want to avoid as much hammer ON dolly contact as you can. Since the hammer ON method is direct contact with hammer and dolly you are stretching the metal changing is surface area and changing its shape. By using the hammer ON method you can add curve to that flat panel which you dont want, so you need to focus the majority of your hammer and dolly work as hammer OFF. If you do use hammer ON just by lightly and do not try to bring that low spot up with a few taps.

If you do add curve to that panel you then need to heat shrink and for a novice with limited tools that's a nightmare in the making. The hands down BEST tool for shrinking metal is a shrinking disc, its nothing but a piece of 304 stainless steel spun at a high rpm generating heat.
So try and limit the hammer ON usage...Eric

Shrinking disc on a high speed grinder.
 

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Hey Eric, I had previously watched the videos, great work there, btw, but where is a good source for the shinking disk, and what are the specifics on the grinder?

Thanks
 

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Hey Eric, I had previously watched the videos, great work there, btw, but where is a good source for the shinking disk, and what are the specifics on the grinder?

Thanks

The disc shown in the pic and video is made by John Kelly. He now only makes a low crowned disc and no longer produces the flat disc which is shown.
I have both the flat and low crown disc, I like the flat better because its what I have more experience and hands on time with but each style has its place. The low crown disc works great on curved or concave panels.

Notice the slight curve in the disc, this one is the low crowned disc and not perfectly flat like the other disc shown and like what Wray sells.


The flat disc, notice the turned edge for safety. Also helps keep the disc stable.
Regardless of which kind or who you buy from ALWAYS check the disc for minute cracks!!!!!!!!


For the flat disc the ONLY one I recommended is made by Wray Schelein
http://cgi.ebay.com/ebaymotors/Shrinking-Disc-english-wheel-shrinker-40-Willys-MG-327_W0QQcmdZViewItemQQ_trksidZp3286Q2ec0Q2em14QQhashZitem5882e87eb0QQitemZ380153396912QQptZMotorsQ5fAutomotiveQ5fTools

For the low crowned disc John Kelly
http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=9980121727059

As for the grinder mine is made by milwaukee, its 6000rpm 15 amp, 7-9 in high speed grinder.

http://cgi.ebay.com/ebaymotors/Milwaukee-Electric-Tools-6088-20-GRINDER-7IN-6000RPM_W0QQitemZ110422486317QQcmdZViewItemQQptZMotors_Automotive_Tools?hash=item19b5b16d2d&_trksid=p4506.m20.l1116

You can use a 3400 rpm grinder but it takes longer to shrink a panel but make sure its a 7-9 in grinder.
 

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I wonder if that would work on the small dents I put in my quarter panel ???
I did it this weekend, and never would have believed that it worked!!!! I had a soft dent in my '69 hood that bugged me to death (think the lady I rent the garage from stepped on it while I had the hood off doing a engine swap).

Dent is in the original SS hood. When you would push on the dent before, it would just spring back to its dented state. I used a heat gun for about a minute (got the surface as hot as I dared to), and then sprayed the keyboard cleaner on it upside down. The dent did not pop back out on its own, but when I pushed on the back side of it with two fingers, it popped back out. You cannot tell that it was ever there, and the paint was not harmed.

True story, and I had a witness there who was as dumbfounded as I was. Try it. If it works, it is a cheap fix!!!
 
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