vertical GMAW part II

Date 07-03-2002 00:52

Thanks for the response fellas on my previous post.

One last question... (Ok, two)

What diamter wire should I be using for 3/16" and 1/4" (and up to 3/8") mild steel? I was thinking of using .035 wire?

Lastly, what wire should I be using...ER70S-6? or -3 (in the past I've always used -6 due to the local supply house recomendation)? The one page I read on Lincolns site is they say the -6 has a "more fluid puddle and an excellent bead profile". Would this possibly aggrivate the bead "running" in a vert down weld situation?

Do I need to use a quicker hand motion/feed rate in vert down to minimize the bead running down and over the arc/puddle?

Thanks for any input
Todd
http://www.malibumotorsports.cjb.net

By welder_guy2001 (***)

Date 07-03-2002 01:31

.035 dia. wire is actually the thickest you can go for all position welding w/ GMAW. i've tried .045 uphill and downhill, and it just runs all over w/o any kinda control.

what they actually mean by a more fluid puddle is, the puddle spreads out more w/o you having to weave it so much. ER70S-6 is so popular for a good reason...it's versatile. it won't tend to run all over the place, but it will flow easily. meaning you'll have less undercutting and a smoother bead.

depending on how you have your machine set up, your downhill motion can be about twice to 3 times as fast as uphill motion.

By Goose

Date 07-03-2002 01:49

Thanks for the quick reply. Should I consider using the .030 wire instead of the .035?

I don't do much verticle welding, so this is why all the questions. How would the vert down speed compare to a flat horizontal weld (could be a butt joint or a inside corner fillet)?

By welder_guy2001 (***)

Date 07-03-2002 02:27

no, .035 is useful for all positions/applications. .030 tends to be rather slow, and you can't pump as much amperage through it either.

vert down is about the same speed as flat. but all you have to do is watch the puddle. if the arc starts riding up in the back of the puddle, you better speed up. if the arc is sputtering and the wire is sporadically pushing your gun away from the bead, you better slow down. just stay ahead of the bead that's forming behind the arc and you'll be ok. that's all you have to remember w/ any kind of GMAW when trying to determine travel speed.

By overthehill (*)

Date 07-03-2002 04:06

I agree with Welder Guy. .035 wire is extremely versitile, and economical. Although .045 will produce higher deposit rates, it's a bit much to handle and takes all the fun out of it. I think .030 is used mainly on sheet metal. Go with ER70S6 wire. (Although I'm not sure you could tell the difference between 6 and 3). The problem with GMAW low voltage (short circuit) all position welding (especially on the metal thicknesses that your working with) is lack of fusion along the sides of the weld. Don't try to carry too much metal. In many situations, your better off running 2 or 3 passes instead of trying to make the weld in one pass. The travel speed is relative to the voltage and amperage settings. More wire and heat, faster travel. Less wire and heat, slower travel. Got to say it one more time, always keep the wire squirting on the leading edge of the puddle, that's the important thing.