MIG Aluminum

[matkins]

I would like some advice on using the Hobart 135 for welding aluminum.
My problem seems to be that the wire ***** up and sticks to the end of the gun upon the initial arc. When this occurs, the drive wheel bird nests the wire. I'll bet I've got almost 200 ft of 10 ft sections wasted on the shop floor due to the bird nests. When it works like it should I have no problem actually welding aluminum.
Are there any tricks to getting the wire flowing like it should?
Here's my setup. ER4043 wire size .030", .035" tip, Argon gas - pressure gage=20, heat setting = 4, speed = 90.

I've also had the liner as close to the drive wheel as possible. That still doesn't help. I've tried wire stick out from 1/4" to about 3/4". Speeds from about 80 - 100.

Very Frustrated!

Thanks

[RawkRash]

I'm no expert, but a few things to try are:

Let up on the drive roll tension so the rolls can slip if the wire sticks. This should help get rid of the birdnesting.

I'm suspecting that you need a little more stickout on your wire. Aluminum sprays rather than short circuits and spraying requires a little more room between the gun and the work. Sounds like your wire is burning back into the tip.

It's not typically recommended to use a larger tip than the wire size, but I'm no aluminum expert so maybe someone else can give some advice there.

[matkins]

Thanks for the comments RawkRash.

I have tried the tension backed off all of the way...it still bird nest the wire. (Book suggest 2.5 for .030" wire) I wish it would slip, then I wouldn't be wasting so much wire.
I will try more wire stick out and back the tip away from the metal some more.

Thanks

[Fla Jim]

I've never had good luck trying to push aluminum with a mig, I use a spool gun. But saying that. there is a couple of things that will help.
Change to 5356 wire. 4043 is very soft. How old is your 135, if you've been using it for steel your liner is probably dirty causing friction. Make sure your tip is clean with no build up, and finally set your feed roller pressure so it barly pushes without chewing up the wire, and try to keep your lead straight.

Jim

[Roger]

What kind of drive roll is in the welder? Some HH175 have V knurled drive roller which is no good for aluminum. U groove is best (.030 U groove not available for HH). V groove is ok but high drive roll pressure deforms aluminum wire causing feed problems.

Make sure you have wire reel drag set at minimum required to prevent backlash and birdnesting when feed stops and no more.

Page 18 of Hobart Handler manual shows how to set drive roll pressure feeding wire from gun's contact tip into board. Start adjustmet so wire slips as it hits (stubs) board and tighten just enough to get a little gun rebound without birdnest.

Hold 1/2" stickout while welding aluminum with your welder not the 1/4" to 1/2" used welding steel. This will help prevent burn back to tip. If you try holding much more can have shielding gas problems. Extended nozzel helps hold shielding gas with 1/2" stickout by recessing the contact tip 1/4". Aluminum really needs good shielding while welding.

Aluminum is such a good conductor that changing stickout length has no effect on welding heat before loosing shielding.

5356 wire is stiffer than 4043 wire less feed problems.

Manufactures (not hobart handler) use lots of little tricks on conntact tips for aluminum wire, larger size bore, grooves in bore for cooling gas, counter bored larger at tip end. This is because aluminum expands more than steel when hot. Try correct size tip and over size tip then use what works.

Very fine line between puddle and burn through welding aluminum. Called hot short. To deal with that problem MIG welding use higher settings with faster travel rate. Travel about twice as fast compared to steel MIG welding.

You can use steel liner but it should be clean, not used for steel wire, and correct size. Pushing wire through over sized liner causes more drag results in more feed problems. Teflon liners are used for aluminum wire because less friction and don't contaminate aluminum wire.

[Thomas Harris]

You should be able to at least solve the problem of spool overrun by slightly increasing the tension. Keep that whip really straight. Clean liner of correct size for wire. Oversize tip. Clean the piece thouroughly before welding. Straight argon gas. fairly high voltage/wire speed. Rabbits foot in pocket. Start welding. I welded a couple of pieces with my Millermatic 172.Although it worked , the beads looked of "poo poo", and the puddle was wild and uncontrollable. Have fun.

[JeramyK]

This link has some good info as well :

http://millerwelds.com/education/tech_articles/articles10.php

-Jeramy

[ventureline]

It's the limp noodle through a straw senario, keep the gun as straight as possible, use 030 1 knurled drive roll ( bottom), 1 V groove (top), very light drive roll pressure, 1/2" stick out and 1 035" tip. and presto your an accomplished Al welder.

Welder Tech

[matkins]

Thanks for all of the good information !

I think several of the replies cover my problem.

I have a liner that is about 1.5 years old and has been used exclusively for steel. I now notice in the manual that Hobart offers an AL liner with nylon in it.

My drive roller is V grooved. Will see if my dealer can come up with a U groove so I can get some slippage.

If these don't cure the problem I'll go to the stiffer wire.

Thanks Again for everyones feedback ! It is greatly appreciated.

[Roger]

If you can't get slippage with your V groove drive roller your wire reel drag is set too tight. Back off the knob or nut pushing aginst spring that holds the wire reel on shaft. Reel drag must be tight enough to stop reel before bird nesting wire on reel when wire feed stops.

[Mowjunk]

Originally posted by Thomas Harris
Rabbits foot in pocket. Have fun.

Ain't that the truth!

[ventureline]

Ummm, you really don't want the slippage.that's why it's nessarry to use a knurled drive roll to push the wire through the gun. With 1 slip of the wheel, the wire will birdnest, as you've now made a nice curl on the wire surface.

With the wire tightend to the point that it readily slips, there is no way of pushing it through the liner. Heaven forbid that the gun cable is snaked in some way, because with the wire drive loose, thats all it will do is slip.

A single knurled drive roll is all you need. Thats all I would recommend as it does not flatten or damage the wire.

Make sure you use a 1/2" of stick out. I've been asked this question and demonstrate to customers for years. I perfer a spoolgun, but for a cheap way out, this system works fine!

[bjdenommee]

The best way to do that is SPOOLGUN

[axehind]

This post should help you out. It's for 220V machines but should help with the 110v too.

Google Welding

Basically

1. Use a teflon liner in the gun.
2. Use a smooth drive roller.
3. Use only 5356 alloy wire .
4. Use a helium / argon mix (at least 75% argon / 25% helium).
5. Each time you let go of the trigger, pull the wire slack out, and
snip it off flush with the tip.
6. Clean the metal thoroughly.
7. V-grind all welds on materiel thicker than 1/16"
8. Let the machine cool down between welds.
9. Preheat the area to above 500 deg.F for thicker sections.

[Alden Pruett]

mig aluminum

I have never tried welding aluminum with anything other than a spool gun or a push-pull set -up but you might try running a little wire out maybe 3" and before you pull the trigger bend the wire back with your hand. This seems to help when you first strike the arc a little trick an old-timer showed me once.