Mm 251 & 350p

[RIVERRAT]

As I have stated before I am some time in the future hoping to build an aluminum boat. Material thickness will range from 1/8" - 3/16 with some 1/4" stuff. My question is, would the pulse mode on the 350p be that great of a benifit for my use. I am hearing to many different opinions on this. Which is making it hard for me to decide.

I can be set up to weld aluminum with a 251 with spool gun for less than the cost of just the 350p unit by itself...HELP!

[backuproller]

i weld 1/2" ali on dump bodies all the time, they do come back, but the cracks are usually new ones, right in the creases of the tailgates, where the c-channel is welded to the plate. thats the common fix on our dumps, the drivers love to slam the tailgates.

[RIVERRAT]

Can any one add anything on whether or not the pulse mode on the 350p would be a benefit ? Such as out of position joints? The reason I am wondering is because spray transfer welding is not supposed to work that well when in out of position work. Just hoping some one can tell me where my thinking might be wrong or offer advice.

[JohnnyWeld]

Fyi , you can spray transfer with the 251 also . Its a matter of setting your wire speed out your spoolgun just right. I have the 350 p too. The benefit in my mind would be the quantity of wire you can use if you have a push-pull gun with it- which again is even more money....

[RIVERRAT]

JonnyWeld, OK my lack of understanding is bringing me up short here.

I understand you can achieve spray transfer with a 251. But are you saying the pulse mode on the 350p would not be much of a benefit for my use?

[lotechman]

The pulse mode for aluminum has some distinct advantages. Vertical up welds are easier to do and there is no spatter. With practice and adjusting one can weld 1/8 sheet aluminum with a MIG gun on pulse.
When I worked in a shipyard my lunch buddy had to qualify in all positiion using this method for the Coast Guard. It took him the better part of a week to get his settings right. With conventional current it would be next to impossible. His joints were required to be full penetration.
It is a lot of money but the quality of the welds is better. Most yards in the world that build aluminum vessels are using pulse. Conventional current is doable but it is more difficult to produce a nice looking weld.
They built quality aluminum boats for many years before pulse became common. The question is more about money and skill level.