Help, heat distorted my frame

I have nothing of value to say, except to ask you to post your findings when you find out. Very nice looking welds.

You can make the heat do what you want, I have long way to go to take advantage to this proceedure, but it might be easyier if the whole project was clamped tightly or tacked to a heavy metal table. will listen to others suggestions. Ed ke6bnl

Grant Erw> Bend it straight. Good applicati>

Yep, you warped it! All welds will tend to shrink in the direction of the heated part. While it's hot it is soft, expands outward. As it cools it shrinks, the strength returns before the shrinking so it curls up. You can clamp everything flat but it usually has some residual stress: you still have some distortion.

to keep it from going out of plane you will need to do the same short welds but on both sides (flipping it over)

3) Never quench welds in water. It doesn't hurt if the steel is indeed mild steel but if there is any carbon content, you can wind up with very brittle weld areas. You used black iron pipe which has unknown but usually moderate carbon content. Assume it will be brittle if you quench.

Tacking bracing across your legs before welding would help. Since you have TIG I would have duplicated the welding heat on the outside of the tubes just using the TIG arc and no filler. That would take care of the kinks on the long lengths of pipe. When you are heat shrinking remember that the red side will become the short side. You apply the water spray or wet rags to the side opposite to where you are heating. Quenching a red hot area will do nothing. Keeping the opposite side and area surrounding the red area cool increases the shrinkage in the red area. Once there is no red showing you can cool the whole assembly or let it cool in the air. When a pipe frame such as yours distorts out of plane it is a problem. If the frame does not flatten out after taking the kinks out my first choice is the jumping method. Set the frame on a concrete floor and rock it back and forth to find the two high corners. Take two pieces of 2 by 4 wood and set them under the two low corners. Have someone stand on one high corner then you jump on the opposite high corner. If you bent it too far, which is likely, then change corners and bend the other way. As an aside: When your frame is something like four inch square tubing quarter inch wall jumping just does not cut it. You have to set the frame on steel horses tacking the high corners then using com-a-longs pull down to the floor on the other corners using the steel imbed plates installed in the concrete floor. Don't tell me that you forgot to put imbed plates in your concrete floor :'))) ... Better get a couple of vehicles and drive over it :'))) Randy

"Tom" wrote in message news: snipped-for-privacy@g49g2000cwa.googlegroups.com... Hello, I'm working on building a frame for an electrathon, which is basically an electric go-kart. I used cheap black pipe for the prototype, and had a simple design: two long pipes, and two short ones. Pics here:

Some questions:

1. How do I avoid this next time?
2. Can this be straightened by heating the 4 joints with an oxyacetylene torch?
3. Do I let it cool slowly or quench it with water?
4. Will this weaken the welds?

Thanks, Tom.

Hi,

Thanks for all the answers. I've summarized other people's emails and posts from other newsgroups here: