I'm very new to sheet metal working and I'm having trouble understanding how I can keep this patch from bending up like this when I put the 'ribs' in. So far I'm following instructions from a great thread on Retro Rides forum from a few years ago and using a piece of 6mm plate and a chisel to replicate the shape, but when I'm doing this it's bending the whole piece around. Now, I've followed a couple of instructional videos and forum posts and tried either stretching out the top edge with a cross pein hammer to get it straight again, or using a torch to heat up the 'long' edge and then hammering and quenching it to shrink it back. Neither technique has really worked for me and I don't know if I'm doing the right thing because I've only seen it done for uneven-ness in panels, or if the 'ribs' are preventing the shape from going back the other way because I'm doing a lot of hammering and heating with no movement at all and it just feels like I'm thinning out the metal too much or heating it too much and making it brittle. I've made three or so of the little strips I'm trying to do and they've all curved the same way.
- Thread starter Max36
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That's what I've ended up doing for this thin bit, but I have a larger section to do with longer ribs and I'd like to know how to do it properly.
I haven't welded it in yet but it's in the right area and lines up okay; not having the straight edge from the guillotine cut on the sheet just means having another side to straighten up as well.
I haven't got a great photo but this is the larger piece I'm trying to make. The rust goes up a bit further underneath that foam material so the piece will be a lot wider than this strip.
steveo3002
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^ pick ups dont have seat belts in the bed
steveo3002
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some thing that rough i would just bend the L shape and weld it where it touches , then give it a tap with a hammer and chisel so it meets those shapes
It’s a 1996 Land Rover Discovery, the wheel arch and quarter panel create a gap that’s difficult to clean out properly. I’ve taken the other side rear quarter off which was much worse, but whether or not cleaning has caused me the issue, I still don’t know how to stop the repair patch from bending.
Okay so make the lip at the bottom first and welding to the floor, and then form the ribs in situ?
droopsnoot
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I think the issue is that when you form the rib, instead of stretching the metal you're just shaping it, so you've now taken a section of metal that's, say, 2" wide, and want it to form a rib that's 2" wide but also has sides that are, say, 1/4" tall. That extra 1/2" of metal has to come from somewhere, and at the moment it's coming from the surrounding steel. I would think you'd either need to pre-stretch the area of the rib before you form the rib, or stretch the rib after you've formed it. When I put ribs in a floor section it becomes quite distorted, then I stretch the bottom of the rib and that gets it flat enough.
You could also try clamping the piece to something solid before you form the rib, so that when you start hammering there's some resistance to it pulling in. A decent clamp perhaps an inch either side, then form the rib between the clamps, and that might force the metal to stretch for the rib sides rather than just pulling in. What thickness steel is this?
You could also try clamping the piece to something solid before you form the rib, so that when you start hammering there's some resistance to it pulling in. A decent clamp perhaps an inch either side, then form the rib between the clamps, and that might force the metal to stretch for the rib sides rather than just pulling in. What thickness steel is this?
steveo3002
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yeah tap it into place as you go, doesnt look like it needs a perfect repair
Onthespotwelding
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Both of those quotes send shivers down my spine.
Plenty of welding to be done
Morris
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Perfect stormBoth of those quotes send shivers down my spine.
Plenty of welding to be done
It's just 1mm mild. I had it clamped but just with quick clamps so I'll try some G clamps instead. I wondered about pre stretching but I didn't know if that would create more complex distortions I would have to get rid of at some point, but I'll try it out! I've tried stretching the bottom of the rib but I must be doing it wrong, I guess just more practice needed! Thank you for the advice.
Haha, I bought it as a bit of a welding practice project as I'd done a lot of welding classes but not really put any of learning to much use, but bodywork is a whole different animal to the chassis stuff!Both of those quotes send shivers down my spine.
Plenty of welding to be done
MattF
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Slight understatement there, methinks.
Stop using the cross pein on flat surfaces, it just makes a mess.
When they bang out the panels in the factory it can take 3 strikes with the monster press and the finished result has a seriously frilly 6" edge that gets cut off.
Heat and quench shrinking works best on flat panels like doors that someone has kicked in, you push the dent out from behind and it looks great till you touch it and it flips back in again because it stretched.
Make the G clamps very tight.
When they bang out the panels in the factory it can take 3 strikes with the monster press and the finished result has a seriously frilly 6" edge that gets cut off.
Heat and quench shrinking works best on flat panels like doors that someone has kicked in, you push the dent out from behind and it looks great till you touch it and it flips back in again because it stretched.
Make the G clamps very tight.
Tinbasherdan
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I’ve done plenty of these, just buy the repair panels from froggatts and be done with it
