Results expected from a Planishing Hammer

[theKbStockpiler]

I'm trying to make some patch panels and I have read where a Planishing Hammer is used to smooth out the lumps.

My question is ,how is the amount of stretch dealt with after the panel is smoothed out? How do you judge making the panel smaller so it is the correct size after smoothing it out makes it bigger?
Thanks for your experience and expertise!

[Ol'fogasaurus]

"Planishing (from the Latin planus, "flat") is a metalworking technique that involves finishing the surface by finely shaping and smoothing sheet metal."

It is a learned skill and there are many ways of accomplishing it from several types of hammers, dolly's, an English wheel, and a planishing machine plus bad words. Finesse is the key/operating word here. There are videos on the several ways to do it.

Lee

[SCOTTRODS]

With the planishing process, you don't necessarily change the metal by stretching it... your goal is to smooth it. There is often some stretch, but should be avoided if you can. Hand planishing and machine planishing are mostly the same, but a machine can be set up to do less damage by stretching, where doing it by hand is often a cause of stretch. In any case, you can easily shrink the panel either before or after your smoothing is done... typically with heat and sudden cooling using a torch or a shrinking disc. Heating the metal up with either source by friction or fire, then cooling with compressed air or even wet rags will generally shrink metal in small enough amounts to help slowly cure an over stretched panel.

I'd recommend doing some research to get the results you wish, if you are the DIY guy. If not, find a local shaper that can either help you or will do the job for a good price. Time is money so be prepared to pay for their time.

[theKbStockpiler]

Thank you for the response!

I'm making some progress with my present skills but I'm missing stages in between. I'm damaging the panel along with shaping it so afterwards I have to remove the damage which takes a lot of time. I lumped up my panel so I used a English wheel to try to flatten it out. Even while using light pressure and a rubber cover on the wheel, it still stretched it out.

[Ol'fogasaurus]

https://www.aviationpros.com/article/10 ... ying-power

https://www.hotrod.com/articles/hrdp-10 ... from-home/

Just think of all the ways you can bend metal and there are so many more ways of doing it.

Check out video how tos.

[SCOTTRODS]

Thank you for the response!

I'm making some progress with my present skills but I'm missing stages in between. I'm damaging the panel along with shaping it so afterwards I have to remove the damage which takes a lot of time. I lumped up my panel so I used a English wheel to try to flatten it out. Even while using light pressure and a rubber cover on the wheel, it still stretched it out.

Are you familiar Pro Shaper . com? Wray Schelin?

I just saw this week he is starting to offer video streaming of some of his videos he has put together, since not everyone can afford to take the time or pay the big bucks to attend his shaping classes. Says you can download them as well. but they do have a low low cost of 99 cents each to watch or download. I'd say one of the best prices other than free, which you can get watching Lazze videos and some others as well. I'm not a great shaper myself, but have been studying and practicing a little here and there and have gotten ahead of myself too. I can do some very rudimentary work so far, I'm pretty good with using my Shrinker and Stretcher set, and can easily damage metal as well... (like you are having issues with). I went over board to the point of buying some larger equipment I likely will never get confident enough to use to make money, such as a huge louver press outfit, which I finally decided to sell recently... Still available to anyone reading... It won't be cheap to buy, but it will be cheaper than buying a new one or even building one with the Mittler Brothers kit.

Anyway... keep at it and give us an update here and there on your progress. I find sometimes, that I learn as much from a flailing and trying to learn person, as I learn from the seasoned pros...

[Jadewombat]

Yep, Metal Meet Forums is great. Lotta expertise over there.

[theKbStockpiler]

Anyway... keep at it and give us an update here and there on your progress. I find sometimes, that I learn as much from a flailing and trying to learn person, as I learn from the seasoned pros...

Once I get my piece finished ;if I get it finished actually, I'll start another thread on it specifically.

I used a regular pneumatic hammer on top of a small anvil to flatten out the lumps and it worked pretty good. With light blows it seemed to leave the stretched areas and flatten everything else. I will have to go back and use heat to shrink the stretched part down.

[Ol'fogasaurus]

https://www.youtube.com/watch?v=GDZxecZzc8o

I was think about this and all of a sudden I remembered that one of my neighbors (across the cemetery) was some kind of a metal worker. He lent me a couple of good measuring tools when I was doing my first engine build. One of the things I remembered seeing was him working metal. Also one of the neighbors had a body shop that also did custom work like chopping cars and it one case building a bubble top for one of the guys in town.

One of the tools he had and used was a metal file that he had bent into a shallow Z. The handle end was fairly short and the other end was fairly long considering. I don't remember if it was a course of fine file (we're talking about more than 50 years ago) but I was told that the files surface was used to shorten the metal from a stretched condition.

http://tachrev.com/JeffLilly/dent_repair.pdf

If you look at the tool pix the slapping hammer/spoon is kind of the shape that the file was bent to.

I tried to find something on the web which is where the top URL came from.

Lee

[Bad Bob]

If you’re stretching the metal, back off the air pressure. Start with maybe 25 psi and work up from there. Get some scraps, run a weld bead and planish it flat. Free handing an air hammer and dolly works well if you can control them. Like Old Fog suggests, make a slapper from an worn out file. Leaf springs work well also.

[theKbStockpiler]

Thanks for the responses!

I was looking at spoons/files on the internet and remembered that I had a thick piece of bent steel that was already about the correct dimensions for a spoon. It has approximately a 35 degree bend in it. I cut part of it down so your finders can wrap around it and it works pretty good. I saved this piece of steel for about 20 years before I got a use for it. I found it is basically a hammer with a big head. As with the air hammer it helped smooth the panel out and if using moderate blows, only the stretched part is left. I did not see any evidence that it could possibly shrink metal without using heat. I'm pretty good at shrinking metal down if it is not in a curve.



Edit: That piece of sheet metal next to it is what I have been working on.

[Ol'fogasaurus]

Since working metal (a wreck is still working metal ) annealing is often part of the project too; not always but often. One of the shows on TV showed a bad bend in a spherical corner of the body, it was either a VW bus or an early Falcon Van but the area was so bent up and had very large amounts of body puddy in it that it had to be chizzled off then annealing was applied before it was hand worked.

As far as the shrinking with the sslap hammer (again, not sure of the amount and size of the styrations on the files surface had), that is what I was told over 50 years ago... passing on info that I can't prove I guess. I think the amount of shrinkage, if does work would be pretty small though.

Lee

[SCOTTRODS]

Shrinking with a Slapping type file is a different process than using a smooth sapper. The surface of the file is just that, file-like and causes the shrinking by design and of course the skills of the user. I've never used a slapping file or a shrinking file myself, but have read a couple of chapters in online books explaining it really well and decided it wasn't for me, as I believe it was for expedient measures (Speed things up) and not really for a quality thing, although it can be both unless you are short the skills... It's definitely a learned process from what I've seen, and time to learn is extensive. I think if it's not "second nature" to do it, then probably saves no time and the possible damage is not worth the trade off on a customer's piece (or you own if its a one of a kind item).

You can't shrink by hammering with a flat smooth piece of metal... just can't.

[theKbStockpiler]

Filler material has to accompany use of the Shrinking Hammer because it basically tucks the metal but down past the outside surface. This makes the stretch go though a farther distance than from point A to point B drawing it in. I don't think it is tried to smooth out the surface after using a Shrinking Hammer. So I guess it is better if you are partially self conscious of using filler.

[Ol'fogasaurus]

Thanks for the good explanations guys. Its good to talk about and explain things that are not in common use now days. I've seen a bit of it done but at the time I was so young that it really didn't make sense nor was it long enough of a watch to see what really was happening (partially the loss of concentration [time] due to being of such a young age). I was told, I partially understood but there also was so much other cool stuff to see....

This was also in the age of "lead" and the gasses it generated, a bit before body fillers came out so, since I didn't have a mask I was lead (pun intended) to on other things; like getting out of the way of work.

Lee