Welding without warping
 

Not sure quite which section to put this in, but since the idea behind the question is based in frame tables and frame assembly I figured the chassis section would be a good start.

Alright, during my research for frame tables I've seen, repeatedly, that fully welding is frowned upon to keep the warping down. Completely understand, makes a ton of sense.

Next, I see Roadster Shop build their frames out of plasma cut sections welded together and ground smooth to look as if it was made out of mandrel tubing. Obviously they are on another level compared to me... or a completely different building! However, I have to wonder....

How do they keep their frames from warping at all?

I picked up an issue of Street Rodder (Kindle be damned, I love paper magazines) and inside they showed the Roadster Shop's build of a frame for their car. The had pics where the frame was marked every 5" or so and numbered repeatedly. 1, 2, 3, 4, 5, 1, 2, 3, 4, 5.... you get the idea. It looked as if they would weld all the 1's, then 2's, so on and so forth.

I do have access to a plasma table large enough to handle frame sections, but I'm not sure I trust myself to weld such a frame without warping.



Cliff Notes - How does Roadster Shop (or any others) manage to weld together an entire frame from 4 (or more) sections of steel without warping?

Link (Couldn't find the pic with numbered sections) http://www.hotrod.com/events/coverag...ad-tour-chevy/

I can't answer for The Roadster Shop.... but I will say there are several things to take into consideration when welding almost anything. CLAMPING is critical... and all welding EXPANDS first - then shrinks / moves as it cools.... if you know this then you can weld in such a way as to pull the metal back into shape. Take a T weld -- you weld on one side - it pulls - you weld on the other side - it pulls back... Obviously this is oversimplification. CLAMPING - Then Tacking - Then skipping around so that you have counter forces working to help you.

practice practice practice.

Get a bunch of scrap and try different techniques and weld sequences. A tight fit also makes it easier.

I wish I could watch Roadster shop do what they do. I understand welding expands and shrinks metal, it's a constant fight when I weld in patch panels, but to try and keep a roughly 16 foot long frame from warping over the entire course? WOW....

That's part of the reason they use jigs....

When you are basically making a box with .120 wall material it isn't too hard to control temperature. Now sheet metal on the other hand. No matter what you do it still needs hammer and dolly to get flat. Huge difference between frames and sheetmetal.

Try it and you will see.

They tac every 3" the fill between and alternate locations.

I would love to try this, seems like the best way to get lots of nice looking contours.

As far as jigs go, I do believe that, if you put enough heat into something to severely warp it, it would show up as soon as your removed the jig. Granted, that would probably take welding a huge length without ever stopping, but I just wouldn't want a jig to give me false confidence. Obviously a jig is necessary for repeatable results, but I don't think it would stop warping entirely.

I've been wanting to build a go-car from an old 3-wheeler engine I have... could be some good practice on a smaller scale. Cheaper to learn the hard way ;)

No a jig will not eliminate warping - it helps - but first you have to know what you're doing.

Start watching videos - you'll need 'em!! LOL

I have a decent amount of experience with a MIG, just starting practice with TIG. I've been doing tons of sheetmetal welding lately, body repairs. I'm confident with a MIG, no worries there. I've always been amazed by RS builds and wondered how they could keep everything so nice. While I'm sure I could probably weld one up without too many problems, I always try to learn as much as possible first. This means asking a lot of questions that I already have an idea about, but it's more about trying to hear others opinions.

I recently found out I will deploy to Kuwait in August so I created a small bucket list of things to do before. Some household things I'd like to get inline, some fun things with friends, some work related things, and, of course, some car project things. I'd like to have a frame table built and it'd be amazing if I could get my C10 on a rolling chassis before I leave. With any luck (and a good tax return) I should be able to start building. Since it'll be a month or two before the materials will be purchase, I'm spending this time researching things that will pertain to both frame tables and frame building.

I've searched here and Pro-Touring quite a bit and I'm just trying to clear up the cloudy areas. Things I have an idea about but would like more opinions. Hope I haven't bored too many with my questions!

You'll love TIG welding over MIG... I don't MIG anything any more unless I'm just building something to tear apart. LOL


TIG on the chassis - will allow you to smooth your welds with ease compared to MIG. The fill is far easier to grind - and the weld just generally starts out looking better to begin with.