Welders ?!? (Aluminum)

[Jack D Davis]

I have used my Lincoln SP170 with the standard push setup and no problems, YET. Did not use any special lubricants. I'm told I shouldn't have any problems if I use .045 wire, but smaller wires are troublesome. If it's a small job, I wouldn't worry about a spoolgun or push/pull gun. But if you're going to use it a lot, by all means, get the push/pull or spoolgun.

[Gerard Kennedy]

I have a Lincoln Cobramatic Inverter MIG with seperate wire feed and push pull gun. It is computer driven and can be driven pretty well by a fool.

Not cheap but small light and has 100% duty cycle.

Gerard

[BillyDoc]

MIG welding has a lot of problems with wire feeding, as you can see from the posts above. TIG requires you to coordinate the feed stock with one hand (the welding rod) and the arc with the other --- similar to welding with oxy-acetylene. This double-hand thing sounds like it would be a lot of trouble to learn and get good with, but actually it’s much easier than trying to compensate for a wire feed rate that is almost NEVER right for the arc heat, heat conduction of the work piece, etc. Need more time in a particular area so the “puddle” forms better? No problem with TIG, just take the time. Want to dab in just the right amount of welding rod for whatever reason? Again, no problem with TIG.

A really good MIG welder will probably say that MIG is better, but that is because he is really good at it. For those of us that only weld occasionally, then I certainly feel that TIG is better. Oh, and most people agree that the final product produced with TIG is far better than MIG as well. You can usually recognize a MIG v. TIG weld because it will have too much weld-bead, or the weld will have not been properly melted into the substrate.

Many dealers will take you “out back” and let you try their welders, so give TIG a try before you buy. It does look like it might be difficult, but it really isn’t. I use a Miller Synchrowave 350 LX and I love it.

Oh, and one other thing, I assume you will be welding marine grade aluminum of some sort - - - so you will want to weld it with the SAME grade of aluminum for best results. TIG uses simple rods of material and (as far as I know) just about any grade is available as a welding rod. And if it isn’t, you can just buy some form of the same material you are welding that you can feed into the puddle and use that. I had to weld some titanium recently and didn’t have any rod, so I just cut some thin strips of the same material and used that. It worked fine! Titanium is dead easy to TIG weld, by the way, I sure wish I could afford to make a boat out of it.

[kmorin]

BillyDoc, On this topic bud1000 wrote that you get what you pay for and I agree; that's the final word. He advises to check the amount of work to be done and spend accordingly and I agree. Also with those two points go the obvious training and learning to weld. Without enough effort to train the most expensive equipment will yield poor results, and with good practice and weld prep old poorly made equipment can produce satisfactory results.

Of the several push pull MIG guns I've run for the most of my 5k+ hours under the hood on aluminum they're the most useful. I used mostly Cobramatics by MK Products, who now make the Pythons for both Miller and Lincoln. This gun like all complex motorized devices requires adjustment and maintenance and without them will appear poorly designed and of little use. On the other hand, correctly adjusted and controlled they will deliver more wire than spool guns with less fatique. I've had more than a year's use without any feed problems off a single adjustment of this brand. Again as bud1000 says its what you pay for. In this use of his phrase the "pay" is total effort to learn the tool, adjust the tool, and maintain the tool- not limited to the amount of the initial expenditure for that tool.

I don't think the discussion of Mig vs Tig is justified since they're both important to use to build boats. I'd never want to sail with MIG'ed tanks (well maybe pulsed Mig welded) and would not want to pay for the week's wages it would take a manual TIG hand to weld out a single hull seam.

The two processes each have their place in my mind and I wouldn't think of have one OR the other. Long double sided welds, hull stiffening and many other seams are much faster and good enough quality in MIG. But aluminum MIG is accepted as a porous weld that I don't like to rely on for corners, brackets, tanks, and other areas where the appearance of the weld needs to be high.

I personally use the OTC Dahien Tig Gun which is a 300 Amp water cooled head and a cold .5lb roll fed pistol style welding torch. I keep both a Cobra and the Tig gun on the skiff or hull of the boat I'm building and use which ever one is appropriate for the joint being welded or tacked. I power this with a nearly 30 year old Lincoln 300/300 power supply.

I have remote controls on all my welding equipment as I don't want to go back and forth to the machine. Now remotes are often built in- but they're easy to rig on older equipment. I believe in direct wirefeed speed control in MIG (and with the TIG GUN too) so I've modified my cobra speed control to allow hand operation; slow wire to start and stop, and with the heat/power control near the wire speed its easy to start 'too' hot with less than enough wire- which delivers a nice 'wetting' in long arc spay mode; then add wire and trim the heat for the puddle conformation you want as you make the weld and end by slowing the wire then dropping the heat to reduce crating when you either back lap one puddle or 'wipe' out of the weld as you drop off the heat. That way I reduce cold starts, cold laps, overly large stacking at initiation and crater cracks at the ends of the welds. These are just about the same things a TIG welded does with the pedal or barrel switch and slider when you weld w/TIG and they make a better weld.
I consider it important-critical- to my weld quality to be able to control the MIG process almost exactly like the TIG process so I added controls to do that, and anyone could do these simple add-ons.

If you're building one boat, maybe two eventually- the spool gun will do fine and I'd add a manual TIG torch before I moved to push-pull like a cobra or python. If you're going to build full-time I'd go for the push pull and manual TIG and add the TIG gun as soon as you can. There are plenty of multipurpose machines but one MIG power supply and one TIG power supply make more sense as the TIG must be AC to weld aluminum.

Cheers,
kmorin

[myles king]

The best mig system on the market to weld aluminum with is the Lincoln Electric Power Mig 350MP with the Python Plus Push Pull Gun. The machine is easy to set up and weld with it has two pulse programs for Aluminum regular pulse and pulse on pulse. No other manufacturer of welding equipment has pulse on pulse except Lincoln. When you are making a weld in the pulse on pulse mode you do not have to weave the gun at all just hold the gun in the joint and push along and your weld will stack up like dimes. You will be able to get a tig like weld with this machine. Log on www.lincolnelectric.com go to product search and type in Power Mig 350MP.

[myles king]

A 115V welder is made for small jobs like repairing your lawnmower deck that is carbon steel. A115V welder will only weld aluminum with .030 diameter wire correctly. A good welder is the Lincoln Power Mig 215 with a spool gun you can weld steel with .035 and.045 diameter wire and aluminum with .035 and 3/64 diameter wire with no problem. If you buy a 115V welder you are throwing your money away.

[Big-A]

best thing to do for ya would to be able to buy a machine that is capabile of welding a range of metals and process out of one power sourse u can go the high road or low road.

miller xmt 304/350 does it all - its a power sourse that does mig/tig/stick
u will have to buy what ever kind of wips you will need to do your job

or you can buy a
miller matic 210/251/300pulser that can mig weld steel and aluminum and stainless
but only mig. hooked up with a 30a spool gun with a long wip is a exellent idea i would go for that for a first machine set up

[Bob Mott]

I have as above and have no problems - no wire jams as the remote feed is set up so that if there is burnout at the tip the wire stops feeding. Simply take of the nozzle tip and cut the wire and slip it on again. The Cobramatic does stainless TIG and handles rod with a flick of a switch. Computer controlled with speed and amps set from the gun. I can carry the feed and the main unit around myself one at a time. The unit has a 100% duty cycle and is capable of doing as many hours as you like without rest. I purchased it as a demo from Lincoln Singapore. Great unit and great company support.

A TIG is to slow to build a 15.4 metre performance sailing cat with.

Anyone interested we are soon to build 3 of these in Thailand followed by about 5 others. Custom - new design - quick - pratical - without the production cat price tag - out of the latest Sealium alloy from Alcan/Pechinery France. Welders are Lloyds certified.

Check out www.langkawiregatta.com for race results 2005 Chameleon and Multihulls magazine USA July edition for complete race story. The new cats are a upgrade of Chameleon. They are Naval Architect designed with my imput and my partners input based on many years either sailing or building cats.

Alloy is soon to be ordered from France - with construction starting around September in Phuket or Pattaya Thailand if all goes well.

[kmorin]

Bob, it took a few readings of the post to confirm that you're discussing the MK Cobramatic welding power supply and I've referred to the Cobramatic which is the old name for a MIG wire feeder.

What got me really excited, but proved to be another example my poor reading was my inference that MK had made a TIG wire feed. Since this is my favorite welding tool, I was ready to find one, however the MK site shows the name Cobramatic for power supplies while I have a few large roll wire feed cabinets and MIG guns in my shop with name and the snake logo printed on them.

Save us from the ad-men. If the p.s. is as reliable as the MIG wire feed I think they'd be great welding power supplies. They don't seem to offer an AC TIG power supply?

Regarding speed of weld in aluminum TIG I'd say you could sustain 2'/minute with the OTC (Dahien) cold wire feed TIG gun using a 5/32" electrode and 0.035" wire on 3/16" to 1/4" aluminum at 240-265 amps AC. (20cm weld in 15sec on 6mm plate) Slow compared to MIG, but, considering the control and composition (alloy elements, don't vaporize and are still in the molten puddle in 'proper' percentages) this is an economically useful deposition rate.

Cheers,
kmorin

[ETEE]

I contracted for 15 years to this Aluminum Shipyard................Engineering Systems design and installation.

http://www.geoshipyard.com/shipyard/new_page_2.htm

You won't find a MIG, TIG or Plasma Machine that doesn't have the Miller logo.

90% of the Aluminum Crew- Supply Boats used in Offshore Oil Production in the world are made in a corridor of shops from Lafayette, La thru Morgan City. About 75 miles. You almost never see anything but Millers in their shops.

[Bob Mott]

I have a Lincoln and am happy with it. I also have a Miller TIG and Miller plasma cutter. I go to other shops in Asia and I see heaps of WIA welders that are made in Australia. They are extemly common over here.


So Miller isnt dominent everywhere.

Bob

[Bob Mott]

Hello kmorin,

Sorry to say I am not to technical. I just plugged the Lincoln in and followed the instructions. It worked and that is good enough for me.

The guys at Lincoln singapore gave me great backup by email and again later they bought some alloy bar for me and sent it up to Thailand for a repair I needed - freight charge only.

With service like that little wonder I am sold on Lincoln units - not matter how many Millers are reported to be around.

The first time I used the Lincoln I had it set up at a building yard in Langkawi Malaysia by professionals. They had a go and liked it and I did my first weld every - and it was a good one per the professional guys comments. Thats the sort of machine I like - forgiving and easy to use.

I gather most of you guys are from the US?? I am a Aussie - Australian.

Will be off racing my ALLOY 48 foot cat end of this month - www.phuketraceweek.com

Theres more to alloy that just welding it up. You need to have some fun with it later. I won the www.langkawiregatta.com in Chameleon in March Racing division 2005. So much for all the propagand about alloy being heavy. So far Chameleon - my cat has been up to 19.5 knots - with room for improvement.

CU

Bob

[peter northaus]

Bob, any info on the boats you are building would be appreciated. You can e-mail me at dozeringram@hotmail.com. cheers Peter

[neald101]

hi,
i am very interested in your boat building stories, it must be fun to do so in asia.
i live in north dublin, ireland and sail a mermaid, its a small timber boat, i admit i am a novice and am only learning the ropes.
what really interests me though is the construction of alloy boats as i am a fabricater ( i make electric golf trolleys ). i have a number of mig plants, miller 304 multiprocess inverter, kemppi 400 kempoweld and fronius tps 2700 ( the best for alloy, machine only 35 kg, 100 % digital ). you should check fronius out, their from austria, their new CMT mig process will weld aluminium to stainless steel 316, welded alu side, braised steel side. distortion is minimal due to very low temp, no hardening of joint and no splatter, machine costs about same as small suv.
i find the american machines no nonsense robust workhorses but if you want that bit extra buy fronius, their tig plants are also world class plant.
anyway please keep forum infomed of your building in asia and ckeck out fronius, its the best.
neal

[Wellydeckhand]

Try Mixed gas for better aluminium weld result..... Ar + CO2........ Argon act the shield and Carbon dioxide cool the job........................ aluminium cant be too hot.........I think..........