pulse weld bead vs constant bead

Im sure the debate has arose here before. Just wanna stir up some fun whats your preference? In my opinin both have tjeir place and also size of the metal on the project, size of the welder, power output of tphe machine.and wire size all play a big part in what structuraly is best for the situatuion.

My most common projects include welding tubing together most commonly D.O.M. ancd mild steal. I jave my tig for cromo and alum. I use a miller 252 with .035 wire normal voltagke range between 16.5-19.0 volts. My personal preference is pulse welding without letting.the cherry cool commonly each pulse is 2 seconds ontime less ,than a secon off. Thus still creating a constant bead on the metal internally at the base of the weld the nicei stacked dimes look on top with consistant 40-60 percent overlap.

Now if im welding 5/16 or larger metal plating or any other with same or higher voltage settings i prefer to do one constant bead and not pulse weld as i beleive then the metal needsk that constant arc to maintain heat and penetration on the work piece.

It's been proven over and over through testing that this on/off style of MIG welding creates porosity at the start since even though you may think the puddle is still hot, you have a cold wire disturbing it. There fore you end up with poor fusion at the start and then you also have porosity under the bead.

What you are doing isn't really pulse welding, as by definition, pulse welding is a regular variance between two different amperage or voltage levels while the welding arc is maintained.

True. I build/Modify trailers and trailer hitches and accessories with MIG, but for the critical weld points, like the tongue mounting and axle mouting points, I like to TIG them. Cannot be too careful when working on trailers. Rule number one applies (not sure-don't do it). On aluminum horse trailers, I usually MIG with the Spoolgun for all but the critical stress points or cosmetic attachment points, then I TIG.

There's no reason you should HAVE to tig a trailer tongue. I live in a trailer manufacturing town. Many of your name brand cargo trailers are built right here. These guys are only using MIGs, and they don't have any issues...if they did, they wouldn't be around long. Penetration is penetration. You can make just as bad of weld with TIG as you can with MIG. When both are done correctly, both are fine.

We have done many trailer and the tongues, all MIG. Just did one for a guy that moved to Il. With his life and tools all loaded on it. I talked to him a couple days after he left, he made it no problem.

I have two name brand trailers build 2.3 hours away, also all MIG welded. Like Mark said, if it is a good weld, either will work, TIG just takes longer :D

Where does the Everlast 250P unit fall into line in this topic? I like the idea of pulsed MIG for filling gaps and thin materials, but it seems it's a DC only unit. How well could it weld Aluminum with a Spoolgun? Is there no cleaning action since no AC? Would a guy be better off with the 250 S Synergic MIG? I am looking to upgrade from my tiny MIG units and like the looks and fill and thin part of the 250P unit, but wonder why there seems to be no talk of it, even after a few years out.

There's a few misconceptions we need to clear up.
Pulse has nothing to do with the ability to weld aluminum with MIG. Pulse for MIG is completely different and works different than pulse for TIG. For MIG you are pulsing voltage not amps. Pulse for MIG is intended for axial spray (axial spray is indeed how you weld aluminum) mode to drop the voltage into the globular transfer range long enough to cool the weld so that spray welding can go out of position (vertical, overhead, horizontal)...but not transfer metal.

There's NO such a thing as AC MIG, unless it is some sort of cheap, junko HF 90 amp mig or something. DC+ is what provides the cleaning. MIG is typically done with DC+ anyway, so you get all the cleaning you want.

We've sold a good many 250P....they quietly work and keep plugging along. Who has time to stop and complain or compliment about something that works and keeps them busy? These guys are busy making money with them for the most part...and don't drop by often to say hi. Pulsed MIG is more for heavy materials than thin. It does allow you to weld a little thinner, but setting up a pulse manually requires in depth understanding of the process.

We have the i MIG 250 now, which has better features in my opinion with a built in spot and stitch timer.

We aren't offering a synergic 250S migs except in the MTS units which only carry a maximum roll diameter of 8".

However if you are using a spool gun, that won't matter on any machine.
For the best and easiest use of aluminum with a spool gun in MIG, the MTS is a good unit choice...since the synergic makes things a little less complicated.

Mark, Thanks so much for your quick, brief, to the point response! I've been turning this question over and over in my mind and it's such a relief to have the facts laid out simply.

Mark,

I cannot find any specs, nor manual for the iMig 250 , even the iMig 250p has no manual on your site. Where can I find the specs/manual about the iMig 250 vs. iMig 250p?

Quote:

---

Originally Posted by John71a

Mark,

I cannot find any specs, nor manual for the iMig 250 , even the iMig 250p has no manual on your site. Where can I find the specs/manual about the iMig 250 vs. iMig 250p?

---

I think you would love the 250P. The advertised specs aren't exactly correct... it has a little more range. Volt range is 14.5 to 28.5 and wire speed is barely moving to around 400 ipm.
I replaced my mig gun and ground to better suit my needs and added a lead hanger. http://www.everlastgenerators.com/fo...On-Lead-Hanger

Thanks, Zoama. I was worried that the posted 26 Volt max was right on the bottom edge for spray on 1/2" aluminum per the Miller guide.

Do you think the mig pulse would make a cleaner weld on slightly rusted or mill scale steel?

Quote:

---

Originally Posted by John71a

Thanks, Zoama. I was worried that the posted 26 Volt max was right on the bottom edge for spray on 1/2" aluminum per the Miller guide.

Do you think the mig pulse would make a cleaner weld on slightly rusted or mill scale steel?

---

The 250P will spray with ease. In testing on steel, I turned the volts and wire speed to maximum and it sprayed cleanly using 75/25 argon/c02.
I can't answer many questions on pulse due to limited experience and no formal training, but I can say that without pulse you can get clean welds through mill scale and light rust using s6 wire.
The only time I've used pulse was to weld a flowmaster muffler back together filling a gap.