First timer and need advice

[flyguy68]

Brand new to welding and I just received my Multimatic 200. I watched many many videos on mig welding and figured for my first project I would weld up a cart for my welder and plasma cutter. I am using 1" sq 16 ga and did miter cuts with my dry saw. Squared it, tack and welded. I did have some burn through a little and turned it down a little. I am guessing because I put two edges together. I welded up the base of the frame and it came out perfectly square. I welded some tubing upright, held it in place with a string 90 degree magnet, tacked it and according to my protractor 90 degrees all around. I did another on the opposite side the same way. 90 degress where the welds are. Now I measured the distance between the upright tubing and measure at the top. There is about a 1/2" plus distanceweld1.jpgweld2.jpg between the two. Shows 90 degrees at the weld but it bows outward as you go up. My question... how do I fix it and how do I keep it from happening?

Any help is much appreciated!

[Cgotto6]

Pictures would help understanding what your talking about.

[shovelon]

Unfortunately distortion is the name of the game. The good news is that with study it is predictable.

I build on the premise that I will have to do some adjustment after the fact. If I can adjust my fitup during the build on a production run, I can come pretty close to print.

Find a way to adjust the angle after weld. A nice polyurethane mallet works wonders.

[bob_e95482]

Part of the learning curve. Welding tubing can be tricky. Tubing is prone to 'pull', especially on the corners. Always tack, check, etc.

[flyguy68]

Pictures would help understanding what your talking about.

There are two pics in the original post. The embedded in the second to last sentence for some reason. Click on the links for the two photos. If you need additional I can take some more.

[tackit]

I use a pipe clamp to bring things into plumb or square. If you don't have a torch try running another bead over the weld on the side you want to move the riser towards and working fast crank the handle of the clamp until you get the riser squared up with the other one. The best way to build is tack the whole project up if possible then weld it out by jumping around welds to avoid warping. A solid flat welding table with a vise, plenty of clamps and thinking out of the box are needed too. if you have a vise try putting the straight riser in the vise leaving 6" stand proud of the vises jaws and pull off it.

[flyguy68]

Unfortunately distortion is the name of the game. The good news is that with study it is predictable.

I build on the premise that I will have to do some adjustment after the fact. If I can adjust my fitup during the build on a production run, I can come pretty close to print.

Find a way to adjust the angle after weld. A nice polyurethane mallet works wonders.

Thanks, I have to weld a top bar on and was thinking of pulling them together with a tie down strap and weld it.

[flyguy68]

I use a pipe clamp to bring things into plumb or square. If you don't have a torch try running another bead over the weld on the side you want to move the riser towards and working fast crank the handle of the clamp until you get the riser squared up with the other one. The best way to build is tack the whole project up if possible then weld it out by jumping around welds to avoid warping. A solid flat welding table with a vise, plenty of clamps and thinking out of the box are needed too.

Sounds good. I guess I am learning the hard way.. tack it all then weld it up. Thanks again for the advice. I guess I will be learning how to use my 4 1/2 grinder pretty well as I go to.

[tackit]

flyguy68 you'll do fine, just expect to become frustrated at times... it's all part of the fun....

If you don't have experience with a grinder leave the guard on even if it seems to get in the way.... they'll tear ya up quick. Being you're new if I were you I would wear welding gloves while grinding, they could save you from getting skinned alive.

Good luck, remember to think about where the sparks are going, be sure there are no flammables around.

By your name are you a Vietnam chopper pilot? I was there 67/68.

[MR.57]

Quick rule of thumb: The metal is always going to pull towards the weld. How much it's going to pull depends on a lot of variables.

Lots of different ways to deal with it:
- Change weld sequence
- Clamp/Fixture the heck out of part to be welded.
- Leave part unfixtured and compensate for it beforehand (Example: weld the inside of a 90 degree corner with the part positioned a few degrees over 90 so when cool the part is at an exact 90 degree angle)
- Preheat everything as much as practical so there's less temperature differential
- Creative use of heat sinks
- Postheat, and/or avoiding quick cooling (even just a cool breeze over a hot weld will add to warp)
- Weld hotter and faster (less heat goes into base material)
- Let it warp and flame straighten to final dimensions afterwards (use torch to flame shink warped areas back to straight)
- Cold bending after welding
- Normalizing to relieve stresses and mechanically straightening after welding

What method/s you choose to use depend on the part to be welded. equipment available, and your level of skill.