straightening out steel

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Hey all,I cut a piece of 1/8 steel sheet with my torch. It's dimensions are now 20" x 48". The problem is that it's now warped / bowed. What do you guys normally do to fix something like that? reheat it? I can post pictures if anyone wants to see but I figured most of you have seen a piece if warped steel before axehind
Reply:A lot of what you do to straighten it depends on what you plan to do with the piece next.If it's being welded to a frame, you pull it down & tack it.Appreciation Gains You Recognition-
Reply:This is going to be a door to a a gunsafe I'm building. So it needs to be pretty flat. axehind
Reply:How in the hell much did you warp it?It should pull down flat when it's attached to the frame, and between beating and shrinking you should be able to get it flat.Appreciation Gains You Recognition-
Reply:I warped it by cutting it out with my torch. I should of used something else to cut it but I wanted some practice with my torch.axehind
Reply:Did you forget the part about clampin it to a heavy hunk of angle iron and usin that as a straightedge?How many inches of wow do you have in the sheet?Appreciation Gains You Recognition-
Reply:I've found that if you crank your torch up and pitch it to 30 degrees twards the direction you want to cut, you can rip though thin material pretty fast and minimizing warpage. But as for a standalone piece with it being wowed out, I'm not sure how you would get the wow out other than heat the peaks up and cooling them down quickly.Common sense in an uncommon degree is what the world calls wisdom.
Reply:I suppose It's not too bad. It bows about 1/2 - 3/4 of a inch.axehind
Reply:Aw I thought you said it was wowed.  You can easily pull that much back in with clamps and weld it to the frame.Appreciation Gains You Recognition-
Reply:1/8" is pretty thin so I would do what Franz said, but you can if you so desire screw around with shrinking the metal with the torch.Just break out your rosebud and start in the center of your sheet. Heat an area nice & red then take a wet rag and cool rapidly. this will (if done on the opposite side) shrink it the opposite direction.The process could take some time, but I have found it handy to staighten out welds on tubing where my welding warped it like a pool stick"after a long day of doing nothing...its gooood to kick back" Pumbaa
Reply:Now here is a question. With what tool would you have cut the 1/8 inch steel with? I have used a jigsaw in the past but I have yet to find a blade worth a damn when it comes to cutting steel.axehind
Reply:Originally posted by Franz Did you forget the part about clampin it to a heavy hunk of angle iron and usin that as a straightedge?
Reply:I've you've got many days and lots of money, you can do what they do on American Chopper and use cut-off wheels.  Or what they use on the screen savers to 'mod' out they computer cases is a nibbler(around 700 bucks). You can buy a personal laser that is run from your PC for around 10k. Personally I like plasma, but a torch with a tripple ot(sp?)(000) works for me.Common sense in an uncommon degree is what the world calls wisdom.
Reply:Since I have plasma, that's how I would have cut it.  Back before plasma, I porbably would have torched it.The trick to torching thin sheet is clamping it between 2 pieces of heavy angle, witch act as a heat sink.  That reduces the heat travel, and eliminates the warp factor considerably, usually to the point only minimal anvil touchup is necessary.BTW, it helps considerably to remember the angle gets hotter than hell in this process, and cuts down on consumption of burn cream, as well as hand immersion in the pearl bucket time.Appreciation Gains You Recognition-
Reply:Thin materail can be straightened after cutting if one is careful.  You will need a good hammer and an anvil.  If you don't have that you will need something like a sheet of one inch plate.
Reply:I hit the wrong key sorry...  take the light guage material and peen it along the edge to stretch the flame shrunk area.  I usually start with a blow every two inches around the perimeter struck directly at the edge, no more than a quarter inch in.  The buckle should start to disappear.  Go around again in between your original blows.  A word of caution here!  If you peen the edge too much the sheet will start to oil can the other way because now you have stretched the material too much.Once you get the hang of it it is a five minute job.  This procedure can be done on material up to quarter inch .  At this thickness you are using a small sledge and working up a sweat.
Reply:"This procedure can be done on material up to quarter inch . At this thickness you are using a small sledge and working up a sweat."NOT if you're doing the procedure properly!  The helper swings the sledge, while the weldor moves the material and designates where the material is to be struck.Sledgomatic will quickly improve a man's torch technique.Appreciation Gains You Recognition-
Reply:I've done that.  Went and bought the material, measured it all up nice and square, get the torch and cut, whoops, wow, big time.  So, slapped myself in the head, put that piece aside for scrap, as I will re use it, went and bought another sheet, had it sheared.Depending on the quality of the door that you want, thats what I would do. Another way is too bond a thicker sheet on the inside, clamp it all down, this could work as well.What I have found, once sheet is wowed, trying to get it back with heating etc, is hard at best, especially if you want it true flat.  You could also make a frame and tack it on the inside.  Depending on how you designed the door.Plasma would have been my choice, then cleanup with a light grinding, can almost get it to the sheared look. Clamp a heatsink as mentioned here too.There's a method to the madness, disregard the method and the madness begins!!
Reply:I'm going to be putting a frame on the door. I'm thinking that will help straighting it out for the most part. The bad part is that I got some welding to do on the door, like putting the frame on it, so I'm wondering how bad it will get once I do that.axehind
Reply:might of used a zip cut(and a mask)jim
Reply:BigRig, you want to explain about using trunk paint and or undercoating to hide wows and screwups here?Appreciation Gains You Recognition-
Reply:Whats a zip cut?axehind
Reply:very thin disc's made by walter for cutting.. i don't have a plasma and tend to use these quite often ps i am not affiliated with walter just think that these are the best of this style
Reply:i have been using some norton zip disks, work pretty good for me, i think the gator grit from home depot work a little faster thoughStangnetShop Full Of Stuff. Joey
Reply:Heh Franz-yup, he could use bodyfiller as well for the wow, I was going to earlier post that, but not sure of the skill level.Done that type of repair oh maybe three million times.  I would complete the door and mount it, aligning the panel as best as possible with or without a frame built on the inside.Then grind the outer section so that the bodyfill aheres, then apply bodyfill and use a board sander to make completely flat.Make sure all the welding to the door is done before the bodywork process starts though.From that point, you could finish the door anyway you like, applying rockergaurd will hide all the little imperfections, or you could finish it with proper primers and then finish off with automotive/truck paint, your finish would then be like that on your vehicle, any color you choose.Applying rockergaurd to the inside of the door to clean up the welded areas would work very well.  Clean off any weld spatter etc first.  You can also paint over the rockergaurd as well to match the color of the outer side of the door.  Space out your welds so that they are all even looking, you know so many inches aparts and the weld say one inch long.Whole process is actually very simple, and the cabinet would not be subject to the elements either.There's a method to the madness, disregard the method and the madness begins!!Since I no longer do safes for the local "expert" in his mind, I'll let the feline out of the bag.Most "repaired" safes leave the shop with an undercoating of trunk paint, and topcoat of whatever color the customer wants. Generally a safe, even new, is so full of wows you wouldn't believe it, so the factory paints them with stuff that hides the defects.Appreciation Gains You Recognition-