For those that may need to form up some patch panels but don't have those shrinker/stretchers at your disposal, here's a how-to on tuck shrinking. Here are some "tucking" pliers I made out of neccessity when forming up a replacement piece for rust repair, and I'll have to admit, their biggest flaw is not providing accurate, consistent tucks. Of course, the operator could also be flawed..... The more consistent the tucks, the more consistent the distance between them, in the end, the more consistent our radius will be. To improve on the tucks I'll start out by making a tool that will more accurately duplicate consistent tucks. We'll start off by finding a pair of vise grips suitable for the job, which in this case means the jaw serrations are starting to wear and round off. Finish what has started by removing the serrations to produce a nice flat jaw on the bottom, and cut the top one off at about 30 degrees from its original position. I had some extra long shouldered 3/8 bolts, perfect round stock for the job. Three of them were cut off to 1-1/2" length. Now because we don't have a fancy shrinker-stretcher machine likely means we don't have a lathe either. No sweat, use this economy model made by Dewalt... To set the spacing for the "fingers" the first is clamped in the vise grip jaw, centered. The outer is placed next to it and then welded down the outside, center finger removed, and then welded down inside. Repeat for opposite side, then weld center finger.
Our new patch panel is bent up with about a 1" flange. Reference marks are placed one inch apart... The first tuck shows how the radius starts to form. Slide the parallel fingers all the way against the bent panel and then squeeze the jaw closed. This will help to get the same depth of tuck each time. Where I used an O/A torch, you should also be able to accomplish similar results with a hand held propane torch. (use what you have that works) Heat up the raised portion of the first tuck until it glows nicely, then use a low crown body hammer (or suitable substitute) to flatten the tuck back into the flange. Repeat for the remaining tucks... You can see we have a nice consistent radius, but likely it is not enough. Mark the next set of reference marks in between the first ones, just to stagger the shrink area to a new portion of the flange that has not been shrunk yet.. Where our flange is starting to form a radius, the outer edge has a tendency to remain flat. Rolling across a nice round piece of pipe while holding down gently on the edges will help (or whatever is handy....I will not be held liable for repurcussions from using stuff from your wife's kitchen..) Repeat the process of heating and hammering the tucks.... Depending on how wavy the flange gets, you may have to go past the radius you are looking for to allow for flattening the flange ....and a comparison of the first and second, repeat as neccessary until you reach the radius you need.
Nice post. Just wondering what advantages you find to heating each tuck up before hammering as opposed to just locking the tuck with a hammer blow on the end and hammering flat cold? Seems it would take quite a bit more time to have to heat up each individual tuck before hammering. Not a critique just curious about you technique.
It seems to not have as much "bounce back" as when it's done cold, but that may be just me. I just laid the torch across my lap while hammering, so I don't think it added too much time over hammering cold.
This is good stuff for so many builders here. We need more low buck tips instead of silly-topic threads IMO He, He, that would be a disaster for me I am accident prone. I did make a simple copper wire hook made from house wire and wrapped it around the back of the torch at the seperation joint, and I just hang it on the back of my hand truck.
i was fiddleing around with tuck shrinking a while back, made a tucking fork, i had trouble with the tuck just flattening out, so i cut an old file apart and made two block with the teeth pointed towards each other, kind like this ______/\______ /////////\\\\\\\\\ then when i hammerd the tuck it pressed down onto the file pieces and didn't open up as much.
The key to stopping them from opening up is to crush the open end of the tuck down. That locks it place so the front doesn't just flatten back out again. If you try and flatten it with the end open you will have a very hard time getting much shrink. That was why I asked about the heat as I wondered if it made it easier to shink the tuck without crushing the front like in the picture. The picture is from oj's thread on tuck shrinking.
Hey, Great post & tech, MP&C! I;ve found that if you flatten the two end tucks first, the piece doesn't return to its' semi-flattened shape as much. I'm guessin' this traps the metal in the flange and holds it from escaping to its' old shape. This also works to trap a shrink when repairing a stretch in , say a door skin that has been gouged by a bumper etc. A shrink at each end of the stretched area helps to trap the stretched metal, and helps it return to normal thickness throughout the gouged area. If you fail to trap the stretch, it may travel into an undamaged area of the panel, and ''the chase" is on! Again, a great post! '' The one thing all nations share is the fear that a member of the family will want to be an artist "
great post. I love that you dont' have a shrinker, but you make welds that pretty on an old vice grip to make a tool that will work.
Pretty neat. Fatabone and Clark! made a similar pair and did a tech on it awile back. Great idea and practical..way to go!
nice I'll admit it was my frustration with tuck shrinking that led me to buy a shrinker stretcher.. your method is great, albit, certainly more laborous than owning the shrinker / stretcher. there are situations where this process might surpass the shrinking stretching machines abilities.. for instance.. have you attempted to shrink a larger flange? (say like 3")
The great part is you can see his lancaster style shrinker in almost every picture but he still shows how to do it the low buck way!!
Very helpful. I make most of my own metal shaping tools, and none of the tucking tools I have made were consistent. I'll be making one the visegrip tuck tools real soon.
Good tech and good discussion!! I often use heat to shrink flanges and it works great. One thing I'd like to add is it may work better if you clamped the panel in the vice the other way. Then you could pull the panel into the bend as you put the tucks in. You tend to get stretch on the flange making the tuck if the panel is resisting. Thanks for posting, I like the vice grip!! Jeff
Thanks for the feedback guys.. Theoretically the tucks can be whatever length you'll need, where shrinkers like the Lancasters are limited by the throat. Just like tucking forks made of longer length, you would likely need a larger diameter of the rod with that extra length to prevent deflection. I'll probably make a set of longer ones just to try it out...... Thanks Jeff, i was looking for something that would produce more consistent tucks, the vise grips seemed the right choice.
Thread of the year dude! Im saving this one to read carefully......just what i needed! Thanx a bunch.
Hey, I like that - think I'm going to make me a pair. And it might just be me, but the first thing I thought of when I saw the pliers in action was Flipper! "What's Flipper trying to say?" "He's going to form a curved flange in some sheet metal..."
Great thread, I don't do any body metal work but it looks like I may have to start, this is a great way to get the basics to get going, is there a possibility of Ryan putting a separate section up for metal tips.
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