Hot Rod Forum banner

Shrink methods

4K views 26 replies 14 participants last post by  123pugsy 
#1 ·
Have a fender with a couple of dents just above a body line. I've hammered it out but maybe a bit too much. So I stopped and am thinking (story of my life :D ) I have a shrinking hammer. Also have torches. I dont yet have a shrink disc. Funds are tight so new tools right now are out.
I am not fooling myself into thinking this will be a filler free repair.
I do want to do my best.

So being a guy with limited bodywork history which would be the safest way.

Torch or shrinking hammer?
I understand that some questions are to hard to answer w/o seeing my work
or work piece. I can post pics tonight if needed.

Thanks!
 
#2 ·
lots of on line info

I've never used a shrinking hammer, I have read that they don't work. there is quite a bit of metal work info posted on this site, do some searches, also check out the metal formers sites, Metalmeet , metal shapers etc, I use a torch for bad deformations, heating the spot about the size of a dime to a dull red then hammer and dolly it down,cool repeat at a new spot will pull down the bad spots but " Kill" the metal in that spot, I have a small shrinking disc made from a SS plumbing cleanout cover. the shrinking disc is usually after you have done quite a bit of work on a bad panel.
 
#3 ·
Unless you are really good at heat shrinking with a torch, I would have to say use the hammer. If you don't truly understand EXACTLY what the metal can and will do with the heat you can really make a mess out of it very fast. Then you will be up the creek for sure.
 
#4 ·
Practice

If you haven't used the torch method get some practice pieces. sometimes a body shop will let you have a practice fender from their recycle dumpster , tell them you will bring it back after you are done . My nephew used to stop by a body shop when walking home from Jr High. and watch thru the open door. The owner (one Man Shop) talked to him and answered a lot of questions, The Kid did some pretty good paint jobs before he got out of high school. Now He has a jewlery store, makes a lot of custom stuff and uses a mini torch to put it together.
 
#5 ·
Boy,

I would use a shrinking hammer as a last resort unless you like your Metal "tenderized"-

In a pinch, go to your local Kitchen Shop and buy the thickest Stainless Steel Cooking Pan (with the shortest sides), bore a hole in the middle and mount it to your 6-8" Grinder-while wearing a Face Sheild, put it on the Metal to be shrank and place it on the Metal-turn on the Grinder, and let it run against the Metal for about 30 seconds or so. When you turn it off, leave it on the Metal until it has stopped-

Then, have a bucket of water with a rag in it nearby, and squeeze the water out of the rag and place it on the Metal-it should steam (or you didn't leave it on there long enough)-do this unitl your get your desired shape. Don't run it until the Metal turns blue, that's too hot!

Using a Torch is an art, a shrinking Disc will always ride on the highest part (the stretched part) and it smooth controllably-it will make you feel like a metal master-

Better yet, just buy one of these (this is the one I have and it is the original):

http://www.ebay.com/itm/Shrinking-D...0892197147&pt=Motors_Automotive_Tools&vxp=mtr
 
#6 ·
First thing you do, and I MEAN this if you want to learn this stuff, toss that "shrinking hammer" in the trash can. Or, take you grinder and grind the head smooth as I did with the one I mistakenly bought years ago.

They are a JOKE and do nothing but destroy metal.

There are many youtube videos on shrinking but honestly, I had some serious disagreements with every single one of them. This one is as close as I could get to just your basic shrinking.

http://www.youtube.com/watch?v=GN4RosIrEPg&feature=related


There are some other guys here with a lot of Tin skills that will likely pop in on this one. But for a basic quick shrink the video shows it ok. DO NOT put the back side of the hammer on the panel, why on earth the guy is doing this is beyond me. Your very basic shrink is heating a tiny spot then cool it with air or a wet rag. This is your basic, you can get a lot done with it. Quickly get the torch right to the metal, heat it to red or near red and pull away and cool, it's that simple.

Where you would do this is another story, on the middle of a hood, you are going to be in deep trouble.

The next step would be where you see the guy hitting right around the edge of the heated area "Pushing" metal into the most heated area.

Brian
 
#8 ·
Thanks for all the reply's. Keep 'em coming. I find that I learn stuff going over the same thing when somebody phrases it different than I've read before.
I do lurk on a few metal sites. I like the All metalshaping the best.
I know I can learn this stuff I've been doing well at banging dents out its the ones with creases that are really hard.
I tried to blow up a pic as a "before" but to really understand I'll snap some pics tonight with a straight edge and maybe a pic or 2 from the good side.

Thanks again!
 

Attachments

#9 ·
It doesn't sound like you want to shrink much, so I would just use the torch and heat a little spot (not to red or even blue) and cool it with a water soaked rag. If it is just a little bit of shrinking, they you won't need a hammer and dolly on it.
I'm with Brian on the shrinking hammer, throw it away.
 
#11 ·
milo said:
Those taps right after heat get the metal to wake up and get ready to move, Not everyone knows that trick.. :thumbup:
That was a good vid being out in the middle of a hood like that,,

http://youtu.be/P9x7BRTOTMc
Right on Milo, I hadn't seen that video, that is exactly what I wanted to show him.

Brian
 
#14 ·
"The next step would be where you see the guy hitting right around the edge of the heated area "Pushing" metal into the most heated area. "

THAT is exactly what a serrated face shrinking hammer is for, better traction for glancing hits to push the metal into the heat. They are definitely NOT for on-dolly hits trying to waffle the metal. No need to throw them out, just use them correctly.

I would suggest you search the web for Martin Hammer's how-to booklet, lots of good stuff in it from the 1930's.

Be careful shrinking, most people go too far with it.
 
#15 ·
When I went to body school back in 1971. Just the other day. The instructor told us the only thing a shrinking hammer was good for was to tenderize a steak before you put it on the grille. The old car sheet metal was a piece of cake to heat and shrink but this newer tin foil cars takes some getting use to. Just be sure to heat a small spot and don't work it to long. You can always go back in and reheat if its not enough. Alot easier than fixing a warped panel because you got it to hot.
 
#16 ·
Old bodyman, you are right if all one want to do is shrink some metal so it isn't oil canning then cover it with plastic filler. But if one wants move forward in the tin forming skills you toss the shrinking hammer in the trash or grind it smooth like I did. It isn't perfectly smooth honestly because I have a lot of hammers and when I need a real nice smooth hammer I have others to use. This one is still for "roughing" out work.



You can do the exact same thing gathering metal with a glancing blow with a flat hammer. I am by no means a tin master, but I would like to be and because of that I will use the smoothest tools I can on the metal I am working with to the metal remains smooth.

Brian
 
#17 ·
Love the responce! Watched some videos and more that I found.
Quick question: Instead of my Oxy/Act torch (not done setting up)
Mapp gas o.k.?

Some pics from tonight.
Last one is from good side.
 

Attachments

#18 ·
Nonhog said:
Thanks for all the reply's. Keep 'em coming. I find that I learn stuff going over the same thing when somebody phrases it different than I've read before.
I do lurk on a few metal sites. I like the All metalshaping the best.
I know I can learn this stuff I've been doing well at banging dents out its the ones with creases that are really hard.
I tried to blow up a pic as a "before" but to really understand I'll snap some pics tonight with a straight edge and maybe a pic or 2 from the good side.

Thanks again!
That looks like a volvo 164. I used to own one. Had it for a long time, that straight six was a screamer. I have a 264 now, still a nice car but not as much fun.
Brad...
 
#22 ·
Our 262C is perfect for my wife. She's 5 feet tall. Its a bit tight for me I'm 6'
Cool thing is the body and interior are very nice. If I could just finish the 5.0 install. LOL

Never seen a blue one. NICE!

http://brickspeed.net/forum/showthread.php?tid=1784


So body experts if I manage to mangle my body work on this fender.
Would it be within reason to take a patch from another Volvo and weld it in?
I've done well on patches before. Just a thought?
 
#24 ·
Nonhog said:
Our 262C is perfect for my wife. She's 5 feet tall. Its a bit tight for me I'm 6'
Cool thing is the body and interior are very nice. If I could just finish the 5.0 install. LOL

Never seen a blue one. NICE!

http://brickspeed.net/forum/showthread.php?tid=1784


So body experts if I manage to mangle my body work on this fender.
Would it be within reason to take a patch from another Volvo and weld it in?
I've done well on patches before. Just a thought?
Wow, very cool!

Brian
 
#25 ·
I recommend a shrinking disc. Once I used one I never looked back. I actually use it whenever I finish my hammer and dolly work. It really does the trick. The disc will target the high spots bringing them down lower and then you can beat the underside to bring the low spots up and repeat the shrinking application. It really helps to smooth out the hammer marks.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top