?? warpage/shrinkage - butt welding 1/8" sheets together ??

[123weld]

I seldomly mig, and asking for some advice. I have a flatbed pickup, thats wood. I'm planning on leaving the wood there, and lay some partial sheets of 1/8" sheets I got laying around over the wood, and weld them together and to peremiter of the bed. When finished I'd like the metal skin flat as reasonably possible. I'm not sure best way to go about it. I plan on notching out a narrow shallow valley across the wood, the length of the welds to prevent weld-wood contamination
Not sure whether to just open root the square butt weld (id be happy w/ 80% pen), or if laying a flatbar backing strip into the wooden valleys at the seems, would give me a flatter end result.

Not sure what wire size, how much I should gap, or if I stitch/jump around, whether gaps will start to close/tighten on me, or thickness of flat bar backing if used.
I'm looking to keep experminting to a minimum, so any thoughts/suggestions would be appreciated.

[M J D]

I would use the backer and gap the sheet about 1/8". Tack about every 6" starting in on direction and working to the other. Leave some gap on perimeter, 1/16"-1/8" and same deal tack from one corner, outward both ways. Leave the opposite corner alone, then tack and weld into that direction. If the gap closes up, you may need to open it up with a cutting wheel. Set your welder fairly hot and travel as fast as possible to reduce heat input.

[Bonzoo]

Trash the wood. Build a bed frame from 3" channel.

[123weld]

I would use the backer and gap the sheet about 1/8". Tack about every 6" starting in on direction and working to the other. Leave some gap on perimeter, 1/16"-1/8" and same deal tack from one corner, outward both ways. Leave the opposite corner alone, then tack and weld into that direction. If the gap closes up, you may need to open it up with a cutting wheel. Set your welder fairly hot and travel as fast as possible to reduce heat input.

gotcha, thank you

[123weld]

Trash the wood. Build a bed frame from 3" channel.

lol, no thanks. my energy/time is limited

[n00b]

I seldomly mig, and asking for some advice. I have a flatbed pickup, thats wood. I'm planning on leaving the wood there, and lay some partial sheets of 1/8" sheets I got laying around over the wood, and weld them together and to peremiter of the bed. When finished I'd like the metal skin flat as reasonably possible. I'm not sure best way to go about it. I plan on notching out a narrow shallow valley across the wood, the length of the welds to prevent weld-wood contamination
Not sure whether to just open root the square butt weld (id be happy w/ 80% pen), or if laying a flatbar backing strip into the wooden valleys at the seems, would give me a flatter end result.

Not sure what wire size, how much I should gap, or if I stitch/jump around, whether gaps will start to close/tighten on me, or thickness of flat bar backing if used.
I'm looking to keep experminting to a minimum, so any thoughts/suggestions would be appreciated.

if it was up to me i would just drill holes in through the metal, counter sink them and then screw the plate down. im too lazy to not keep things simple, xcept when its my project, im to lazy to make it simple lol. This way u dont have to worry about this warpage thing if u want it dead flat to whatevr tolerance 1/100"

[outdoort]

If u can clamp it down it would be best. And if u can do that reasonably id feel comfortable butt welding two sheets of 1/8” together without significant wapage. U prob will have a little to be honest so idk how picky you will be.

[123weld]

i'm not that picky, ill tack/weld both ends or something, then do it. maybe even lay some heavy stuff on it. ill play it by ear, thanks