Rookie needs help

[sizzlebrain]

I've just got a spolgun and tried my hand at aluminum welding. I cannot get a decent bead for nothing. I'm an avid stick and mig welder in ss and mild steel and this is really driving me nuts..I know tig would produce better results but I'm building a boat and would like to finish before I retire.My setup is a Miller 251 with the 30A spoolgun. Running a positive electrode with 100% Argon. Any advice,suggestions, or tips would be greatly appreciated. I've done a lot of practicing and have buried my practice pieces 4 feet deep so they cannot be found with a metal detector. Not too proud of them. Is that deep enough?

[jeffscarstrucks]

Hi, I have run the same gun on a 251 as well as my xmt304 with great results on both spray and SS modes. If you give some more detailes as well as your settings and wire types I am sure you will get all the feedback you need to make sound welds. Good Luck, JEFF

[sizzlebrain]

More Details

Originally posted by jeffscarstrucks
Hi, I have run the same gun on a 251 as well as my xmt304 with great results on both spray and SS modes. If you give some more detailes as well as your settings and wire types I am sure you will get all the feedback you need to make sound welds. Good Luck, JEFF

I'm running 4043 filler (.035") and welding alloys 5052 and 5086 that range from 1/8"-3/16". I use the recommended settings for heat and wire sapeeds and have tried varying that by about 20% in the wire speeds and heat. I have also varied the gun position. Guess I just havent found the right combination. Any more info you need let me know. Thanks!!

[Andy249]

Definately try changing the wire you are using to a 5000 series wire. Marine grade aluminium is an aluminium/magnesium alloy, as opposed to the aluminium/silicon based alloy you are currently trying to use to weld with. I saw a guy run this setup on a pulsed MIG and the welds were very poor to say the least! You can forget about any kind of positional welding whilst using this combination! Try changing your wire to marine grade and try again.

A stainless steel wire brush and acetone are the best way to clean your aluminium before you weld. Don't use anything but a stainless wire brush as the others leave impurities on the ally which will result in a poor finish.

[timw]

Just to cover the basics, with Alum it has to be clean. The worst Alum that I ever had to weld was refrigerated semi trailer floors. Always seemed to be animal or vegetable fat on it. And the insulation would outgas when heated and ruin the welds. If your weld turns out black you have a contamination problem or your gas is being blown away. Another thought, did you purge your hose? If you had air or previous mix gas it would be rough. Aluminum settings are more sensitive because the metal melts differently but once you get the hang of it you will love it. And with Alum it reflects the arc way more than steel so cover up, you burn much quicker.

[sizzlebrain]

Types of wire

Originally posted by Andy249
Definately try changing the wire you are using to a 5000 series wire. Marine grade aluminium is an aluminium/magnesium alloy, as opposed to the aluminium/silicon based alloy you are currently trying to use to weld with. I saw a guy run this setup on a pulsed MIG and the welds were very poor to say the least! You can forget about any kind of positional welding whilst using this combination! Try changing your wire to marine grade and try again.

A stainless steel wire brush and acetone are the best way to clean your aluminium before you weld. Don't use anything but a stainless wire brush as the others leave impurities on the ally which will result in a poor finish.

Thanks a bunch, that makes perfect sense. I guess I can't listen to my welding supply guy.Would the wire speeds and heat recommendations on the welder still come pretty close with other types of wire? Do you know of any charts or good books that would have the proper wire/ alloy type combintions? Thanks again Sizzlebrain.

[Andy249]

I use 5356 series wire on all my marine grade aluminium welding. Aluminium is a fantastic conductor, and as such you need to weld with a fair bit higher amperage and wire speed to compensate. Generally spray arc is the way to go with this stuff! This of course means that your travel speed increases alot as well!! I far prefer fabbing with aluminium as it is so much faster to weld and cut for that matter.

I just found this site which puts welding aluminium in a nutshell pretty much.

http://www.twi.co.uk/j32k/protected/band_3/jk21.html

I have gained my aluminium welding experience from doing quite a few years of it in the workshop and also doing my certification courses.

Good luck with it and keep us informed!

[Paul Seaman]

Sizzle:
Cool name, Andy 249 nailed most of the stuff pretty well. My advise would be you have to push the weld,{forehand} as they say. I had some trouble at first and it was poor cleaning, now I use a 3M roloc disc in a diegrinder then wipe with acetone, wipe dry and weld it up.

Weld well,

[Canuck]

Andy249 is on the ball with the 5356 wire. It lays in different but welds almost any AL. I work in an Aluminum shop and all we mostly use is 3/64 5356 wire. I would recomend .035 wire because you may need to go into short arc. Also set your gas flow rate to about 40 cfh this will help keep in cleaner.

[sizzlebrain]

Thanks a bunch

Thanks to all for all the advice. I'll get a few pounds of wire, use all the tips and go for it!!!