[prairiewelder]

At work I currently use the stock 200/300 amp 15 ft gun that came on the lincoln mp350. I would like to buy a 25 footer because I always seam to be rolling the welder back and forth (burning time not wire) when building platforms and structures. When i'm welding heavy base plates/knife plates (spray arc) my nozzle insulators detach (unglue) from the nozzle.

So the question is. What are the new problems i would have if i bought the longer/heaver gun? or other solutions to the problems stated above.

thank you for any imput
Levi R

[PeteM]

Feeding seems to become a problem after 12-15 feet. The only thing I've seen that works consistently beyond that is a push-pull gun system like the cobra-matic, and boom systems if that is feasible.
The heavier duty guns don't break down under the heat as badly either. Tregasakiss/Bernard toughgun was the type of gun I used running 1/16 flux core at around 400+ ipm, and around 30V, but that was with a less than 15ft. run. The lower rated guns I've used would run into problems like you described with the insulator and melting nozzles.

Putting a long feed and high deposition together reliably seems to be a real trick though. Any claims by a sales rep need to be put to the test under the expected duty conditions. Hard wire, if you're running that, may feed better over distance, but tube wires either crush in the drive rollers, birdnest, sputter, or all three.

Or, since the MP 350 is a roll around model, switching to a suitcase wire drive system might help with portability. You have a work lead to deal with, but the portability when you have to move around in or on a large weldment is great.

[Poland308]

Wish I had a picture but when I worked production they mounted the feed box up on a swivel hanging from a boom. It was like an engine hoist except you could hand crank the whole stand up and down as well as crank the boom in and out. Plus it swiveled on the base and at the feed box. It was mounted to a heavy duty frame that the welder sat on and then your wire spool sat on top of the welder. We ran anything from 30-400 lb spools of wire.

[Oscar]

Speaking of feeding problems, do those Lube-Matic pads work as advertised? Anyone tried them out?

[PeteM]

I have never used them or seen them in use. I was told that dry crud in the liner is better than gooey crud, and the oil makes it gooey crud.

[prairiewelder]

I don't know if I used the pads wrong but when in tried them the welding quality went way down.

[PeteM]

Another reason I've been told that they are not good is that they directly introduce flourocarbon contamination to the weld pool.

[Poland308]

They offered them to us when I was working production. I had the best luck with just the wool pads that clip on. I avoided the liquid stuff it didn't seam to benefit anything and in some cases appeared to create a goo inside the liner.

[MFleet]

How do you have the machine set up while melting insulators? Wire type, wire size, amperage?

Lincoln did support and sell the MK python with the MP350 at some point. There is high current, water cooled version of this gun. It reads as possibly supporting your situation if you can't go with a separate power source and remote feeder.

I do use the python but it is in a completely different scenario than what you are dealing with. Al, air cooled, 25ft. for personal prototyping. The literature claims that it will run a large variety wire. The gun itself is very long and there are are individual runs for everything. Four total for wire conduit, power, gas, multi-pin connector. This adds up to a noticeable weight behind me. MK does offer an optional "super flexible" power lead that I have no experience with. It does balance well and easily controlled once I have the leads carefully positioned.

http://www.mkprod.com/Prod_CobraSys_python.htm

[prairiewelder]

I run mostly 045 70s-6
the nozzle comes unglued when I'm spray arcing above 25 volts

[Otto Nobedder]

Speaking of feeding problems, do those Lube-Matic pads work as advertised? Anyone tried them out?

I only use the dry "wiper" pads (available from lubematic), to keep dust and grit from entering the liner. These are a great help. I've never found a positive value in either the lube pads, or the lubematic liquid they sell to douche your pads with.

Steve S

[MFleet]

The potential to cook things makes sense. You should be ~300+amps at that point. The gun Lincoln ships is 200A 60% for mixed gas and 300/60 for co2.

I looked at the gun I use for steel on the comparable 350P out of curiosity. It is rated for 400A 100% with co2.

I agree with everyone on the wiper pads. I only use the dry red type from lubematic or a piece of scotchbrite clipped on.

[Superiorwelding]

Levi,
I have ran 25' guns for years with no real problems, except the obvious when you have it kinked. No matter which gun you get, you should step up to Lincoln's higher amperage consumables. They will fit on your factory gun and will allow you to weld longer. I don't know all the numbers off hand but you will need the diffuser, nozzle, isolator and contact tips that handle the 450 amp range. The contact tips are KP2745 series while the factory diffuser uses the KP2744 series tips. You will notice a difference for sure. The only drawback is they are physically larger in size but no big deal. That Magnum gun is heavy anyway.

I recommend that anyone having trouble burning up contact tips and/or nozzles to seriously look into water cooled guns. Once I tried them I don't want to go back. My consumable life had well over quadrupled just switching to water cooled. I use Abicor Binzel if I am purchasing new guns but choose whichever you like best and makes sense for you.
-Jonathan

[cherwolf]

In the beginning...I had water cooled gun. After just a week of heavy welding and having little finger under constant weight of a hose and trying to hold a gun through thick welding gauntlet, a joint between finger and palm was in pain. I immediately switched gloves to thin ones and got uncooled gun. Welder mate didn`t and had surgery in a month of welding. He still has health related problems with that finger.

Longer gun is handy, especially if you have a portable feeder, just grab and drag it for 5 meters.