Thoughts on fixing warpage after the fact?

[Complete_Loser]

Plasmacam 4x4, hypertherm t45v, book settings, 16ga p&o


I staggered my cuts on this, and paused a bit. Just wanted to see how bad/good my first one turns out.

Is there a way to possibly take the warpage out with a torch and quench rag? Or other methods?

[tactical328]

So i've never done torch and quench, but I have cut a relief slot in the warp and fill welded it back together flat.

[adbuch]

Depending on how this will be mounted, I think the warping gives the illusion of the flag blowing in the wind. You could try using a shrinking disc on a small angle grinder - like used by the car guys. Or an English Wheel to help smooth it out. Torch shrinks would work for the large stretched areas. This would be multiple small shrinks the size of a dime. Requires oxy/acetylene torch, hammer and dolly, and damp rag along with the proper technique. You may be able to find a youtube video showing the proper technique.
David

[tinspark]

The way I get "most" of it out is to carefully stretch the burnt edge back out.
When the plasma cutter heats the edges of the metal.
that edge shrinks more than the rest of the sheet as it cools. Since the metal that doesn't get as hot doesn't shrink as much in those larger areas and has nowhere to go, so distortion occurs.
I personally would avoid adding more heat to it

with this assumption/ hypothesis (LOL!!)
I use my 120 lb anvil and a small peening hammer to stretch plasma cut edges back out

If there a few spots that are needing it worse than others, try those areas.
Leave the finished side at the anvil and mark and peen the back of the work piece.
Use a felt tip pen and sample a small area by placing a series of dots every 1/2" or so and only peen 1/8" deep and see if it flattens out.
It goes pretty fast once u get the hang of it...
I have used this method several times and it does work

[SeanP]

Sometimes it's stress in the sheet, I have had some sheets flat but parts come out like a banana, should have sent some back but usually find some job for it.
Guess that's another advantage with cold rolled.

[tnbndr]

Personally I would just go to 14 or 12 gauge. Another way, if you have a roller is to roll waves in the flag. That will straighten or hide any warpage.

[adbuch]

Dennis - I agree. For something that large, thicker material would be better. I use a lot of 14 ga. myself for artsy stuff. What sort of roller do you use to flatten warped panels?
Thanks,
David

[tnbndr]

What sort of roller do you use to flatten warped panels?

I don't use a roller to flatten warped panels. I would roll that flag to look like it is waving in the wind. The warpage would flatten out or be less noticeable.
I have an old Whitney 390E that I modified with a chain drive and gear reduction motor so that I could work alone. Hand roller is a pain.
It is a 36" and rated for 16 gauge but I can roll a 12 gauge 12" wide fire ring with it. And of course narrow pieces of 1/4" for certain things.

[Complete_Loser]

Personally I would just go to 14 or 12 gauge. Another way, if you have a roller is to roll waves in the flag. That will straighten or hide any warpage.

16ga costs me $100/sheet.
And 12ga costs me $254/sheet.

[adbuch]

What sort of roller do you use to flatten warped panels?

I don't use a roller to flatten warped panels. I would roll that flag to look like it is waving in the wind. The warpage would flatten out or be less noticeable.
I have an old Whitney 390E that I modified with a chain drive and gear reduction motor so that I could work alone. Hand roller is a pain.
It is a 36" and rated for 16 gauge but I can roll a 12 gauge 12" wide fire ring with it. And of course narrow pieces of 1/4" for certain things.

Roller.jpg

Thanks for that clarification Dennis. I missed the part where you said you were rolling waves into the panel. I've got a Pexto slip roller similar to yours. I purchased mine new about 22 years ago. Mine is only rated for 22 ga. at full width, but will do thicker panels in narrower widths. I originally purchased it roll copper sheet for cooling jackets. I think the copper was around the equivalent of 16 ga. I like yours better, especially with the motor drive.
David

[tnbndr]

16ga costs me $100/sheet.
And 12ga costs me $254/sheet.

Added cost may be worth it if it eliminates problems that you are having with lighter gauge.

[adbuch]

16ga costs me $100/sheet.
And 12ga costs me $254/sheet.

Added cost may be worth it if it eliminates problems that you are having with lighter gauge.

Or split the difference and go with 14 ga.
David