Shrinking Hammer
 

What is the technique of the shrinking hammer, and does it really work. I am speaking of the square hammer face that has the sharp points. I can see on my bed panels that one has been used in the past.

Re: Shrinking Hammer
 

Yes, they work. Most likely different techniques but I tend to get the metal hot, hammer, dolly and quench.
It is tedious (read: time consuming) work but often necessary.

Re: Shrinking Hammer
 

A shrinking hammer draws material into little pockets on the surface. I prefer shrinking with a torch for heavily stretched metal surfaces and with a disk for lightly rippled metal. Both methods apply heat but the disk only heats the high spots. It takes a lot of practice to figure how much is good and how much is too much but a person can master shrinking metal surfaces with a lot of practice.

Re: Shrinking Hammer
 

Wise words indeed!

Re: Shrinking Hammer
 

In the "old days" we heated a spot red about the size of a quarter and with the dolly loose on the back work around the circle with the flat smooth body hammer working the metal towards the center of the red circle. As many red sots as required to get the stretch out. I never saw the toothed hammers back then. G.M.

Re: Shrinking Hammer
 

Time consuming and tedious indeed.
Flushed the skirts on my Merc. Heat and hammer shrunk the factory belly out of the skirts. ( count the shrink spots )
I do not use the cross hatched 'shrinking' hammer as it has a tendency to leave un-wanted defects.
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http://i11.photobucket.com/albums/a1...X.jpg~original

Re: Shrinking Hammer
 

Re: Shrinking Hammer
 

I really appreciate the answers, but, would someone please answer the question I asked. I am quite familiar with the smooth faced hammer and dolly heat shrinking technique, but I am asking about the tooth faced hammer. Is heat used with that type hammer face? Is it employed on cold metal?

Re: Shrinking Hammer
 

I am pretty certain both myself and Rotorwrench had answered your question. The "tooth faced" hammer IS for shrinking.

Re: Shrinking Hammer
 

The shrinking hammer is used cold. The principle of the teeth in the hammer head is to push the metal in and thus shrink the surface. I have a shrinking hammer and have tried to use it , but always used the heat shrink and quench method for reliable results.

Re: Shrinking Hammer
 

As I had stated in my first post, there are no doubt numerous methods to use this hammer and shrink metal. I have always preferred to heat the metal and use this hammer.

Re: Shrinking Hammer
 

Many years I aquired the oppsite type ! The air operated hammer. Never really used and will probably take it to Hershey. kc

Re: Shrinking Hammer
 

A shrinking hammer works by driving a bunch of little peaks into the metal, I've never seen anybody get very good with one as anybody that would take the time to get good would realize there are much better ways to shrink than creating lots of metalfinishing work.
I know what you mean Kirk, them old air operated hammers are so out-dated, how much do you want for it and maybe I'll sav eyou from having to take the thing to Hershey?
I prefer a stud welder with shrinking attachment if I am in the middle of a panel, if on the edge I'll tuck shrink unless I can get it in a Johnson type shrinker.

Re: Shrinking Hammer
 

Any time you apply the blow of a hammer to a metal surface (especially if it is backed up with any form of dolly or dense backing material), it has a tendency to stretch the metal. When you use a shrinker head it has to sort of knurl or distort the surface in order to shrink it in any way. This effect is harder to cover up and more filler is needed to do it. I hate fillers of any kind if I can avoid them. Making a large dent into a lot of smaller ones doesn't work as well as it might sound. In my book, the idea it to make the dent disappear entirely and a shrinker head won't do that.

Re: Shrinking Hammer
 

If your question isn't being answered to your satisfaction, perhaps the question is the problem, not the answers. :confused:

Re: Shrinking Hammer
 

Use the hammer hot or cold. Either way it will leave marks which are not desirable.

Re: Shrinking Hammer
 

I have a couple and have found them to be pretty useless. they do more damage than good as stated above.

Re: Shrinking Hammer
 

I'd assume these types of hammers would need to also be used with a file in order to get high spots leveled if you want to minimize the amount of filler needed.

Re: Shrinking Hammer
 

I have never used one myself, but in my body shop classes we were told to not use them for a lot of the reasons stated above. We were taught to use heat and smooth dollies and hammers.

Re: Shrinking Hammer
 

Again, I appreciate the answers. I did get an answer to my question via an email, and I thought I would share it with you all, as it explains the use of the shrinking hammer.


I have both shrinking hammers and dollies and much prefer the dollies.
These are NOT meant to shrink metal by beating little dents into it nor are they
normally used on hot metal . The best function is the ability to hold the low point area
of the metal as you strike it on the high point and thus " shrinking " it . You
do not use these with hard blows . That only ruins the surface . Picture a pointed dent
sticking up with the undisturbed area around it . A normal hammer - dollie will cause the
surrounding metal to spread and this increases the size of the dent . A shrinking hammer
or dollie will hold the surrounding flat metal with the " teeth " so the dented
area only is tapped down . When these are properly used you should only see a slight
knurled look to the metal . I am not the best at describing stuff but if you have further
questions feel free to email me . REMEMBER light blows and NO heat . Also remember the
" shrinking " HAMMER OR DOLLIE GOES ON THE LOW SIDE to control spreading . MANY
as you see are clueless as to the real purpose of these . Also they are not much good for
big shaping projects - just really a finishing tool .