Miller Maxstar 150 Tig

[ducktapeguy]

Anyone else using one of these? I haven't seen much talk about it, but it seems perfect for the amateur welder. 110/220 auto-voltage select, weighs 13 lbs, and relatively cheap.

I finally couldn't resist anymore and bought one. I couldn't pass up the deal, got the package deal including the carrying case and gas regulator and all tig accessories and hoses for $700, and it's basically brand new.

The only thing is it came with fingertip control, which I have no experience with, I've always used a foot pedal. Is there an advantages or disadvantages to the finger control? I was debating selling it while it's still new, and put the money torwards a footpedal.

 

[John Smith]

I would keep the thumb control and buy a foot control also. Think about welding under the truck or in a position where the foot pedal won't work, you will be happy your have the thumb control. For $700 you got one hell of a deal. Let us know how it welds once you get a chance to use it.

 

[kulangot]

If I could only have one, I'd get the fingertip control. For doing roll cages and rust repair, it's the way to go. Like John said, you can always get a pedal.

Nice to have both.

Good little machine but you'll find that most 110 outlets don't have enough juice unless they are 20 amp and those are rare. You see them a lot in commercial buildings, but most home garages have 15 amp. You can use it on 15 amp but not turned up very far.

 

[ducktapeguy]

I've been practicing with the fingertip control, I'm probably gonna keep it for the reasons you mentioned. I'm just gonna need to get used to it.

I wanted a 220 machine, but none of the places I would use the welder at (home, parents, gf) at has 220 outlets, so I settled on dual voltage. I know the 110's gonna limit me, but most of the stuff I'll be doing is small. If I've got a large project, I usually have access to a shop with the 3 phase machines.

What kind of tig rod are people using? Right now I'm looking at doing body panels and general purpose welding, I'm looking at 1/16" ER-70S rod, any other recommendations? Another dumb question, but can you use stainless rod to weld non-stainless?

 

[kulangot]

Because that machine uses an inverter and not a rectifier or transformer, you need to use red tipped 2 percent thoriated tungsten which is mildly radioactive .

Wire size depends on what you are welding. I like to use thin wire for most tasks.
Use ER70S-6 1/16 filler rod for steel 1/8 (11g) and thinner and 3/32 rod for steel 1/8 and thicker.

You can use stainless wire, on non stainless but it costs a lot more.

Here is a great FAQ:

Miller - TIG Welding Tips - Troubleshooting

Ron Covel offers a great Tig welding DVD and Miller has some great student info packs. I also really like the weldtalk board over at Hobart Welders

-Stumbaugh

 

[Pin_Head]

For welding body panels, you could even use coat hangers for filler as long as you cleaned off the paint. TIG can put a fair amount of heat into the weld compared to faster processes, so do a lot of tack welds spaced 1 inch apart and cool the metal completely with a wet rag before doing the next weld. Otherwise, you will get a lot of heat distortion.

Lanthanum, zirconium or cerium containing tungsten is also available if you don't like the idea of thorium. Thorium containing electrodes are also used in DC applications on transformer type boat anchor machines.

 

[ducktapeguy]

Thanks for all the info. I've been playing around with it a bit over the weekend, and the machine itself works great, it'll lay a nice beads on the scrap metal I've been playing with. I've been running around the house just looking for things to weld together, it's starting to look like an abstract metal sculpture garden in my backyard. I've been using coat hangers just for practice until I need to weld for real.

One slight problem I've been having is getting used to the fingertip control. Like I mentioned, I've always used the foot pedal, so it's probably just a matter of more practice. Any advice, tips, or techniques that make it easier? Do most people use their thumb or forefinger to adjust the rotary dial? I just can't seem to get the hang of adjusting that dial on the fly while I'm welding. Part of the problem might be my gloves are too thick, I need to get some better tig gloves. But I'm also left-handed, I don't know how much of a difference that makes, other than the dial "feels" backwards to me. I'm almost tempted to put the dial on the underside of the torch and use my middle finger to adjust it.

 

[kulangot]

The right gloves are key and keep them very clean...

You'll get used to it, but it will never be as good as a foot pedal. In the last few years, I've seen a lot new machines that come with a finger control and pulsers as well. It's a lot easier to use a finger control if you have a pulser as well as the pulser takes a lot of skill and timing out of the situation. If you get a machine setup and dialed in correctly with a pulser, nearly anyone can lay down some nice beads.

This brings up a subject that came up often in welding school, better to learn right the first time around as old habits good or bad are hard to break. If your used to the foot pedal it will just take you some time to get used to it, but I don't think you'll ever feel like you can float the finger control like a foot pedal (but you can't do that while your under a car...so you need both).

With all due respect, I don't agree with the almighty pinhead about cooling the welds. To put a finer point on that, you should never cool red hot welds with a wet rag as it causes shrinkage and cracking. However, once it's cooled down to where you can almost touch it, at that point it's OK to use a rag. However, I prefer to just take time and do one little tack a time. You'll have less trouble with warpage if you take more time and just air cooling do the work. You can use this time to decide if you need to hammer on the welds to flatten on the panel as the welding process itself shrinks the metal as you weld the patch in. By hammering on the weld, you flatten the area and make the panel larger and flatter.

Tig also CAN put more heat into the weld if you linger and go slow it will warp as Pinhead said, but if your fast and just put down a small BB sized tack it will not. The point being that you can in theory hold a tig weld in stasis where the mig process just keeps putting down more material as long as you pull the trigger. I prefer TIG as I like the postflow of gas and I like to keep the heat very low. Covell covers this debate as well. For the beginner, I have to agree, Mig is certainly easier. (The new MM252 Mig has gas postflow - I'd like to try that)

I do use a wet clotch to shrink metal where you have an oil can dent, and in this case, you have to heat the area up to cherry red and then shrink a few spots a time.

Ron Covell Welcome To Covell.biz has some great videos on this and a great Tig video as well.

You can rent them here: http://smartflix.com/store/video/15/Basic-Techniques-For-Working-With-Steel

-Stumbaugh

 

[RHINO]

about the only thing i could expand on is size of machine and material working.. aluminum is a pretty common material for all of us and a 150 amp machine is going to get small, i run between 140-170 amps on 1/8th" alu. so i prefer a bigger machine for a better duty cycle.

 

[Pin_Head]

To put a finer point on that, you should never cool red hot welds with a wet rag as it causes shrinkage and cracking. However, once it's cooled down to where you can almost touch it, at that point it's OK to use a rag. However, I prefer to just take time and do one little tack a time. You'll have less trouble with warpage if you take more time and just air cooling do the work. You can use this time to decide if you need to hammer on the welds to flatten on the panel as the welding process itself shrinks the metal as you weld the patch in. By hammering on the weld, you flatten the area and make the panel larger and flatter.


-Stumbaugh

I agree and I didn't mean to imply to quench red hot metal. The sheet metal cools pretty quickly, but the point is to cool it to ambient temp before your next tack or the distortion will propagate.

 

[ducktapeguy]

Thanks for the input. One of my first welding projects was patching up a rusted gas tank, so I learned my lesson about letting the welds cool down. Part of it looked like a ruffles potato chip. I like to think I've gotten a little bit better since then, but most likely I just move a lot slower now.

I've watched the Covell vids, that guy is good. Especially the one about metal forming and the one with the english wheel. I made part of a hot rod nose cone with the English wheel, but that's something that really requires a whole lot of practice, it's almost like a black art. What takes him a few passes on the english wheel took me a few hours to copy.

Still getting used to the damn finger control. Now that I got a new welder, I gotta get a new helmet. I'm eyeing a new speedglas. Might as well cry now, since I'll probably buy it eventually.

 

[kulangot]

I agree and I didn't mean to imply to quench red hot metal. The sheet metal cools pretty quickly, but the point is to cool it to ambient temp before your next tack or the distortion will propagate.

We are on the same page Pinhead. I usually do metal fab in the colder months and the ambient air temperate does it for me. In fact, I often have to preheat because the steel in freezing and that causes cracks as well. Not because of how cold the steel is but because how rapidly the weldment cools because the heat is drawn into the area around it that is still freezing causes it too cool to rapidly very much like a wet rag. Very interesting stuff.

You going to that OC swap meet mid august? I am going to try and go before I head back east for good.

Ducktapeguy: I'd have to say be a Luddite and stick to your old helmet. I am not a fan of auto darkening, especially when doing tack welds. You might want to get a different, slightly darker shade and just use your old MIG helmet. If you do buy an autodarkening one, make sure it's approved for repetitive tack welds. I learned this from Clive Lugmayer, my welding instructor, who said they were for non weldors and that any real weldor would use a real old fashioned helmet and that was all there was to it...he probably has one now.

-Stumbaugh