I hope this isn't a question which is too broad to answer. I'm an amateur novice welder. Most of what little welding I do is short circuit MIG, for drive train, frame, and chassis work on my race car, ( drag racing). I'm interested in hearing/reading some experienced based reviews about any advantages, or disadvantages of using Spray or Pulsed MIG welding. For instance: is either one easier to produce consistent welds with, or perhaps more forgiving of less than optimal welding technique than Short Circuit MIG can be? I fully understand that practice makes perfect, but since I only have some experience in the more common Short Circuit MIG, I'm curious if there really is noticeable and significant advantages to Spray and/or Pulsed. Please explain why, or why not if you can. I'm also curious if spray or pulsed is any easier, or more difficult to use for overhead and vertical welds than short circuit MIG is. Thanks in advance.
BTW, my question is in regard to welding 1/8", 3/16" and 1/4" thick mild steel, ( if that matters) and NOT to sheet metal body work welding, nor aluminum.
i do very little mig, i've only once done spray mig with steel.
i think the biggest downside for a lot of people is the gas requirements. you need high argon gas mix like 90/10. (our standard gas here is tri mix co2/o2/ar that you can use for it)
also you need pulse for multi positions, which means you need a larger machine. it appears to be a lot more common outside of usa as aluminum mig is common rather than spool gun.
i've really only heard of spray being used on thick material, but again its not something i normally do.
i think the biggest downside for a lot of people is the gas requirements. you need high argon gas mix like 90/10. (our standard gas here is tri mix co2/o2/ar that you can use for it)
also you need pulse for multi positions, which means you need a larger machine. it appears to be a lot more common outside of usa as aluminum mig is common rather than spool gun.
i've really only heard of spray being used on thick material, but again its not something i normally do.
tweak it until it breaks
If you’re building a frame for drag racing, you need to check the Regulations carefully. Yes, mild steel is accepted and MIG can be an appropriate technique for mild steel. Spray transfer is not well suited for the material thicknesses or small diameter tubing (less than 4” Sch80).
Pulse MIG could be an option for you though. No special gas, just a decent machine. 0.035 wire with pulse welding around tubing can be very manageable. You really need to dial in your settings so that the appearance matches the strength! Good looking welds aren’t a guarantee of strength. Strong welds don’t always look great. But the latter matters far more than the former.
Do some sample pieces and then perform some destructive tests, dye penetrant tests, and cut and etch to verify you’re getting the weld deep enough into the tubing.
Pulse MIG could be an option for you though. No special gas, just a decent machine. 0.035 wire with pulse welding around tubing can be very manageable. You really need to dial in your settings so that the appearance matches the strength! Good looking welds aren’t a guarantee of strength. Strong welds don’t always look great. But the latter matters far more than the former.
Do some sample pieces and then perform some destructive tests, dye penetrant tests, and cut and etch to verify you’re getting the weld deep enough into the tubing.
Jack Ryan
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Yes, rather often but mostly oriented to thinner material. Biggest issue with spray mode is position dependence. I can’t envision welding a roll cage with spray transfer for steel. Every regulations book I’ve seen for racing restricts short circuit for mild steel, TIG for chrome moly.
Well his question was about pulse or spray, not pulsed spray. And again, I’ve never seen anyone weld a roll cage with spray transfer (pulsed or otherwise).
Jack Ryan
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I think we are going in circles here. As I wrote earlier:
When most people talk about "pulse MIG" they are referring to "spray pulse".
Spray pulse is the most common form of pulse (I think) by a large margin.
Spray pulse can be used on thin metal as it can be used to control heat input. On the other hand, short circuit transfer was developed as a "cold" process for thin metals. I can't think of a good reason to use spray pulse (usually with added expense) instead of short circuit transfer on thin metals.
Some are MIG braze welding on vehicles using pulse but I don't know the details.
Jack
You’re right. The relevant information the OP stated are: novice welder, race car is the project (frame, roll cage, drive train). Too frequently contributors stray from answering the specific question with details, options or “also cans” which cause confusion and don’t help address the needs of poster.
Specifically, if he wants to do spray mode MIG, he must use 80/20 or better gas, have a machine suitable of it, then further get a machine that might also do pulsed MIG. And finally, the rule books must allow the process on the material. On a race track, EVERYTHING is decided by the regulations.