I was making a metal repair on a door jamb and thought it would make a decent little tech piece that shows how to shrink metal with bsaic hand tools. I had already cut and cleaned the rusted area before it occured to me to create a tech piece. The repair was for the leading edge of the door jamb where it transitioned from the sill turning upward while leaving a perpendicular edge to hold the gasket. The pics are not high quality, shop camera you know, use them along with the description of what i'm doing. The first 3 pics show the rusted area; the sheet metal marked to bend; the bent piece with the vice and the two hammers i used. Vice and hammers all all the tools you need to form the sheet metal. I don't know the proper name for that body hammer, some kind of a verticle blunt chisel but that is what is used to make the tuck.
To make the tuck i open the vise jaws to 3/4" or so and use the chisel end to make the bend, you don't want to hit so hard to tear the metal - just get it humped up. I close the jaws to about a 1/16 or so and slide the piece in as far as the bend. I pull the metal to accentuate the bend while tapping with the ball peen on either side and guide the bend to keep it straight. I open the jaws and slide the sheet metal in far enough to support both side of the bend. With the ball peen strike the peak at an angle to drive a flat lip into the front of it. The pic showing this has reflection on the formed lip. When you've formed this lip you can just pound it on thru and down (if you don't create this lip you won't be able to shrink, you'll just be pounding a bent back flat, got to have the lip). The last pic shows how much you shrank it with just i tuck.
Just keep working around the flange, keep the tuck hieght and distance apart consistant and you won't have radius issues. When you start trial fitting you can then deal with the radius. The tuck size i demonstrate is just an easy one to work with, experiment with tighter, wider and deeper tucks - once you get the concept you can really take off with some of this stuff. The final pics show the piece ready for trial fit and the piece tack welded. I am adding the pics after i write this and going from memory. The time from bending the flange to tack weld was about an hour. I could have spent more time planishing and finishing the metal but this isn't a duesenberg, the flange is covered by gasket anyway. I'm not trying to show how to make any particular piece, i am trying to show how to shrink metal along an edge. This technique is basic to metal shaping and forming, get this down and next thing you'll be making a soccer ball. Good luck, oj
Great tip. I tuck shrink a lot because I do not have a shrinker stretcher. I have never tried it on the vice like that. I will be trying that.
Very nice adaption of the tuck shrinking process OJ! Using the vice to hold the metal and put holding tension on the tuck to allow it to be crushed makes this a very effective way to make a curved flange.
Nice job! There are a million ways to tuck shrink. Everything from folding the metal by hand making something shrinkable with a hammer, to big fancy machines. My youtube videos below have 2 short video sessions on a few methods of tuck shrinking. John
A good technique, This is very similar to one of the techniques I show on my DVD but the method I use gives a little more control of how much shrink is created. you can see the results in my youtube footage.
The Jalopy Journal
