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How to Keep Metal from Warping While Bead Rolling

Almost anytime you try to add a wide or deep bead to a thin piece of metal; or multiple beads to the same piece, you will find the metal starts to deform or warp. You may get perfect beads in the piece you’re working on, but it suddenly looks like a metal potato chip. That is because the bead roller stretches the metal as it presses beads into it. If you have an English wheel you can fix this problem before you begin. This problem is especially bad when rolling beads that don’t go all the way to the edge, or rolling different length beads in the same panel. Follow along as we show you a simple way to keep your panel straight when bead rolling.

Mark on the panel where you want to roll beads.
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  • Make sure to tighten the bead roller to the same position for each bead. I like to pick a position of the adjustment screw and always start and stop at the same spot each time. By doing this you can count the number of spins of the adjustment screw to get the same depth bead each time. Once I had the dies in the Eastwood Power Bead Roller adjusted to the desired depth I ran three beads in the 20 gauge steel panel.
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  • These three beads deformed the panel in 2 directions in a way that is very hard to undo without ruining the perfectly formed beads you just rolled into it.

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Try this simple trick – Now let’s try it again, but first we’ll stretch the area where the beads are going to be just a little with an English wheel beforehand.

    • Start by installing the lower die with the highest crown in your English wheel, and mark out your desired lines for your beads. Then install the panel in the wheel with the the crown on the lower wheel centered on the bead line. Tighten the wheel down so that there is moderate pressure on the panel.

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    • Wheel the area of the bead, keeping your passes very close together, while staying within a 1/4″ of either side of your line. Since the bead takes metal from the edges when it forms, the English wheel can solve the problem by stretching the metal in that area so that there is more to steal without deforming the whole panel.

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    • As you can see, there is now a little bit of a bulge in the panel where we wheeled it, but it doesn’t have to be as large or deep as the bead you want to put into it.

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    • Now, do the same thing anywhere you are going to roll a bead into the panel. You are left with a panel that is bent and deformed much the same way it would be after the 3 beads were rolled into it.

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    • You may have to straighten the panel with your hands in order to get it into the bead roller.
    • Now roll the beads in the panel like the first time, pressing the newly stretched areas back down the opposite way from how they are stretched.

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    • If you have done it right, after rolling 3 beads into the panel it should be very close to flat once again. The final result is a panel flat enough to be easily welded into your project without having to fight the warpage from bead rolling. The panel might not be quite perfectly flat, but it should be close enough to be easily corrected by hand or by the shrink created when welding it.

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    • Like everything with metal fabrication, practice makes perfect and you will want to practice pre-stretching with the English wheel in order to learn exactly how much you need for a given bead shape or metal thickness. This can also be done by hand without an english wheel by hammering on-dolly on the same area you’d roll in the wheel. But do realize that it takes significantly longer to get the same stretch you’d get in a wheel in a few passes.

-Matt/EW

19 Comments

  1. Hi All,
    1. To anneal work hardened aluminum, coat the panel with the soot from a smoking acetylene torch flame. Then use a neutral flame to heat the panel and burn off the soot. Accordingly, the aluminum will have reached the annealed temperature.

    Hope this offers an alternative.

    Best to all. Stay well.

  2. Good question! You’re only rolling the panel a few times through the wheel so it wouldn’t be enough to work-harden the metal enough to be noticeable; if at all. I’m sure on a molecular level any type of stretching or shrinking work-hardens the metal, but the amount we’re working it before bead rolling isn’t enough you’d notice. This process would be the same on aluminum, you’d just need less pressure on the wheel or less passes through the wheel. You can also anneal aluminum before or after to get the softness back from working it, but that’s mainly only needed when putting substantial shape into a panel.

  3. You could hammer “on-dolly” on the area you’re bead rolling to pre-stretch the panel. Bead rolling needs a bead roller to make the beads or you need to make a buck/hammer form the metal into.

  4. How is this process done will none other than basic hand tools?

  5. Does using the English wheel before bead rolling work harden the metal? can this also be used on Aluminum ?

  6. For steel to be bead rolled, it may be best to start with aluminum-killed (AK) or silicon-killed (SK) cold-rolled steel. AK is available from most steel suppliers.

    Always use cold-rolled, not hot-rolled steel for beading!

    AK and SK steels are known as deep-drawing steels and they are relatively soft.
    These steels are used in industry to form a part having shapes formed in a large tonnage press without cracking. This steel is also good for panels that must be shaped/formed using hand tools or on an english wheel..

    An alternative, if available, would be to use a planishing hammer with a medium crown bottom die to run along the line of the bead to slightly stretch the steel. After stretching, the panel will better accept a bead without warping.
    Practice on a test panel of the same metal thickness to check your results. Trial and error. Practice makes perfect.

    Hope this helps.

  7. You’ve got to remember that at the factory that the complete panel is forced into a die to produce the ridges—-when you roll ridges into the metal you are chasing/pushing the metal in front of the roller as well as distorting the sides of the die roller contact point—you are actually stretching/pushing the metal the length of the bead which causing the warpage adding to the total distortion of the panel—if it’s possible to secure the edges intensely before rolling beads—(like a picture frame of say angle iron)—this should reduce the warpage significantly—-if you are to roll a bead from one edge to other the edge—-you should bend the panel at the roller bead site then flaten the panel before rolling the bead this will give the metal a direction (prestressed) in the bead eliminating a lot of distortion when you roll the bead on/in the bent edge

  8. Excellent post. Thanks for sharing this.

  9. Metal will stretch regardless of its temper. The temper will just “pliable” or how easy the metal can be manipulated.

  10. Very good information. I wish I had seen it before I rolled a replacement passenger-side floor panel for my 34 Ford (which warped half way through). Couldn’t you prevent some of this problem by using less tempered steel? thanks.

  11. why not try 2 top dies for a bead roller, usind the larger at the top and smaller on the bottom, minimal pressure then do the same as what was done with the english wheel, remove bottom die or both replace with required dies and put it the bead, that should work ok .. or just bead roll and then lightly hit the back (raised curve) with a rubber mallet .. but be careful that can damage the bead if hit to hard ..

  12. Possibly, but the bead roller usually puts lines on either side of the bead, even when done lightly and if you don’t follow that same path exactly you will have multiple tracks. In theory it could work, but I think the repeatability would be very difficult. You’d almost need to run it like you said and then hammer and dolly the area flat first, then bead roll.

  13. You can only shrink or stretch the edges of the panel. The stretch is happening more right around the beads and unless you can get in around the beads you couldn’t stretch the metal. Additionally it will leave tooling marks that would be tough to finish out where as this method requires no additional finish work.

  14. This could be a great opportunity for you! Whats your thought on making two crowned wheels for power roller ( similar crown as english wheel ) and use as described to pre-stretch panel before rolling beads? Not as quick as a english wheel but for the infrequent user a investment of a set of crowned rollers as opposed to a couple thousand for a english wheel would seem like a wise investment. Keylor

  15. You can also use a urethane wheel on the bottom to help prevent distortion.

  16. Couldn’t you also use a Shrinker stretcher to straighten out a already rolled panel.

  17. I have been a customer of Eastwood since the mid 80’s. I have always appreciated the service and products that I have received. I am glad to see that the Company has been proactive in encouraging the use and correct methods of sheet metal repair.
    Thank you, Steve

  18. Nice little forum and most informative, too! Will try the on-dolly hammer technique next time as I don’t have an English wheel. I’ve been hand bending (in the opposite direction) to counteract the bead roller stresses and it’s sort of mixed results depending on the depth, radius and length of the bead(s). Thank you for the insight-
    ful and very helpful “tip”!!

  19. Thanks for the tip.
    What would happen if you did the same thing with the bead roller first using light pressure then turning the panel upside down and pressing the bead the opposite direction, could it work?
    Thanks. Rod