welding question

[mustardfj40]

Hi,

I am playing with the MIG welder and would like to have a question, I can easily weld 2 pieces of metal when they are in contact but if there an 1/8" gap in between how do you it? The metal sheets are about 1/4" thick.

Thanks.

 

[2badfjs]

go light on the voltage and fill the gap
run a pass, clean it
run a pass, clean it
run a pass, clean it
untill the gap i filled
with the last pass you can sometimes make it look like you only did one pass

keep practicing

 

[brian]

11 GA is'nt really suited to open butt joints. it's possible but not pretty. small wire low heat and turn the wire speed down.
with heavier metal you can get away with open butts and mig, you just turn the wire back a bit.

depending how long a joint you're dealing with, it could end up looking like a pretzel. i would look for a better fit.

 

[Pin_Head]

It is all about joint design. For 1/4 inch, V grind both pieces (60 degrees, total) and fit up and tack weld with a 1/16 root gap. Start the puddle so that a "keyhole" forms at the root and then use a "C" weave to move the keyhole along the joint. For a 110V welder, it may be best to make 3 passes to completely fill it. Pipe welding 101.

 

[cruiserhead]

You can use a backing plate(ie-copper is best).If your going for a weld test,look at the specifications for 1/4 inch.It will tell you the spacing and the thickness of backing(same as parent material)plate to use.Good luck and remember,practice,practice,practice.

 

[cruiserhead]

It is all about joint design. For 1/4 inch, V grind both pieces (60 degrees, total) and fit up and tack weld with a 1/16 root gap. Start the puddle so that a "keyhole" forms at the root and then use a "C" weave to move the keyhole along the joint. For a 110V welder, it may be best to make 3 passes to completely fill it. Pipe welding 101.

Yea,thanks Pinhead.30 degree bevel on each piece,2/3rds deep.

 

[El Cazador]

Good welding advice. I'd only add, be patient. No way you can make that weld in a single pass. At least I wouldn't try it. Related observation: I'm picking up a new tig machine this weekend. Can't wait.
Vic
Redlands, CA.

 

[FJ40fiji]

Best class I have taken so far in college was a welding class. Awsome instructor, great experiance, and I am using it tons more than the calculus or political science or. . .

 

[Steve C]

Ditto all the above. Plus remember that when initially tacking, you will need to start on side of the joint and end on the other. and you need to secure the metal very securly while tacking so that it dosn't suck in the gap due to thermal "de-expansion" while cooling.

An interesting exercize is to jig everything up, then make marks on each side of the joint at specific distances apart. Then weld the joint and measure how much closer the marks are. Ideally, you want to keep shrinkage to a minimum.

 

[Mark W]

1/4 inch thick material? That should be just a little larger than a perfect gap to join them. You may need to back the heat off a kittle or turn the wire up a bit. If it is a vertical weld, work from top to bottom and slow the pass a little. No need to bevel the edges with this size gap. The only reason for a bevel it to ensure penetration when you are using a heat level which will not push all the way through the material quickly and easily. With this gap you are applying your heat to the edges of the welded peices, not the face, so this isn't a problem.

If the location is apropriate a piece of backing behind the gap will make it even easier.


Mark...

 

[Adventure Teq]

The C weave works for me, just do it and see what you need to adjust. It's all about experimentation and finding out what works for you.