Welded Roll Cage

[ksayuk]

Andy

In the article entitled Welder Basics - The Right Techniques For Putting The Peices Together a picture was shown of a welded roll cage. It looked like it was Mig welded and all the welds looked like "rows of dimes". I was wondering how this look was accomplished. Was the mig torch trigger turned on and off so as to overlap the individual weld puddles or was it done with the torch motion and if so what type of torch motion. Thank you very much.

[ASKANDY]

Great question!
It's all technique of the torch. Swirling the torch in small circles will give you that look. Also some people move the torch forward then back over the puddle for an instant then back forward again. It kind of depends on the joint type and what the operator is comfortable with. Some people do trigger the weld to get that "look" but that is the worst way to do this as all you are doing is putting a bunch of "tack" welds down with little penetration. In otherwords, looks good but won't hold sh--. Practice torch movements on fillet welds until you find what you are looking for.

[10secBu]

Hey Andy (or anyone willing to elaborate more),

I'd like to get more info on this "stacked dimes" bead appearance.

I currently have a car in the shop where I work part time that just had a back-half completed (tubbed street rod). I spent some time looking over what work I needed to do myself and also was admiring the welding work of the chassis shop that did the frame/tin work.

He Tig welded the roll bar, but Mig welded the frame & 4 link. I was very impressed with the clean appearance of his mig welds as they had that distinctive and attractive "stacked dimes" look.

I have a great machine to work with (251 Millermatic...thanks Andy), and would like to learn how to duplicate this weld appearance myself. I will have to try the methods you mentioned above...don't know the chassis builder, so I can't ask him on his technique.

My question is, is it possible that this weld bead appearance could be attributed to using a "pusle" mig machine/setting?

I find that such weld appearance is quite attractive and is many times the calling card of a chassis shop/fabricator/welder. I would like to explore this for myself and see if I can duplicate such weld results.

Any other ideas on accomplishing this task would be greatly appreciated.

thanks
Todd G

http://www.malibumotorsports.cjb.net

[chub380]

Mig welding

Just wandering if any of you had a link to look at this mig welding bead that you are talking about? Picture,Website,attachment? Thanks I would like to see it also. Thanks CHUB380

[10secBu]

I could not find any real good photo's to give a good example. This is the best I could find...



Basically, the Mig bead appears like what a Tig bead would be on aluminum where there appears to be overlapping distinctive round beads or spot welds forming one continious long chain.

[10secBu]

lets try this a different way.

[chub380]

Thanks for the picture. It does look almost exactly like a weld on aluminium. That is hard to believe one could make it look like that just by gun technique. It looks like he would have had to pulse the current some how to get that big of spaces between the beads. I am going to have to see if I can do that with my Millermatic 250x. I think that is just an older version of your 251. Thanks again for the photo. CHUB380

[10secBu]

I spent some time in the shop this evening trying to duplicate this weld appearance. I first tried to make small circles and then the forward/back method that Andy mentioned above. Neither technique gave the results I was looking for. I even tried a "C" torch movement similar to what you would do to fill a gap, and again, no luck.

I'm beginiing to think that this weld appearance might just be the result of a pulse Mig...either that or I just don't have the torch technique exactly right.

I guess I'll have to stick to my boring, smooth Mig bead appearance.

[Sean Brown]

Honestly,

I'd do whatever produces the strongest weld! There is a guy here locally who uses the "tack weld technique" as Andy called it. It not only raises the question of weld integrity, but it looks like crap to boot. And God only knows how much time the guy would save if he just learned to weld properly...

If you're really hung up on it, you might try a different wire alloy. I've noticed the S6 seems to "flow out" more than S2 does. Also, you might find that wire diameter affects the look of the bead. I.E. .049 may give a better look with proper technique than .030 does.

Sean