MIG ALUMINUM advice

By Lawrence (*****)

Date 03-10-2011 21:24

Levi

The things you don't know are most of the things folks need to know in order to give you advice.

Is this a surprise test?

Why diddn't you find out about it before and bring your questions??????

Not to be too hard on the Beaver.... But,,,,,,, your job as a student is to read your chapters and know about your assignments... Our job... oh wait... we don't get paid to answer your questions... Our pleasure.. Thats better.. Is to help motivated folks with their problems on the JOB... Students need to do a little more footwork to get answers, because they have the time to and have been provided with all the answers in their assignment.. your job is to STUDY.. :)

Ok out of the woodshed :)

Also find out if you are running GMAWP or traditional spray transfer.

By weldstudent (**)

Date 03-10-2011 22:24

i did ask all of the questions that i dont have the information to. durring my education i did do all of the required studying, and some. for reasions unknown to me we did not do alot of aluminum MIG. because i know a book cant weld i am trying to get any help i can from those smarter than myself. i know what the book said and i can rember some basics from the few hours i had to work with the aluminum MIG process.

thanks for your assistance.

By Lawrence (*****)

Date 03-10-2011 22:39

Oh I see... This is not a school test.. Its a Job test.

Here are golden nuggets of tips!

http://content.lincolnelectric.com/pdfs/products/literature/c8100.pdf

Print this out and put it in your toolbox.

Take notes of the parameters for Spray transfer voltage and wire feed speeds for your test tommorrow.

My Apologies for assuming you were still in school!

Go get the job

By weldstudent (**)

Date 03-11-2011 00:11

understood, i should have been more clear.

By welderbrent (*****)

Date 03-10-2011 22:53

I don't do enough Alum GMAW to offer any tips...

Just thought I would wish you luck. Problem is... if you only pass on 'LUCK' maybe you shouldn't have the job. Hopefully it will be something that you can handle with out risk to the life and safety of others and will include some training as well as experience gained for the future.

This is not meant to be a negative criticism. Just be careful about applying for jobs you are not really qualified for. At least they have a test and if you can pass then you should be qualified enough to do what they need done and can add to your skills as you go.

Do your best. Learn all you can even from a test. About the welding and how to present yourself. SSSOOO...Good Luck.

Have a Great Day, Brent

By weldstudent (**)

Date 03-11-2011 00:14

thanks, i hope to get the job but if im not skilled enough so be it. the company builds ambulances so i really dont want to screw up, if i get the job and do poorly people will die.

By DaveBoyer (*****)

Date 03-11-2011 01:45

Be sure to use a "push" angle to keep the argon out in front of the puddle. If You are using 3/64 [.047] wire, You will have to move pretty fast. Much of aluminum MIG is done in spray transfer, it makes a "swooooosh" sound when it sprays. I use about 40 CFM on the argon. Pay attention to the back step at the end of the bead as mentioned in the Lincoln article. Good luck, it isn't impossible.

By Tommyjoking (****)

Date 03-11-2011 04:25

if they have a nice pulse setup just aim for the joint and let the machine do it its job..it will weld and fill fast and seem hot..if it is a spool gun, use a good push angle like Dave was talking about....that will really help keep it clean looking. If it is very thin materials you might have to back step as you go..... I know that is not much help but read the Lincoln article and good luck with it.

By Blaster (***)

Date 03-11-2011 05:56 Edited 03-11-2011 06:08

Hey Levi

Can't do a lot of everything in only 1,600 hours of training, and aluminum mig is cake if you have a solid grasp of wire fundamentals. You have to think back to about a year and a half ago, to your second quarter in school. You should do fine.

Just remember the basics... wire is amps, voltage is arc length, DCEP, CV for spray or short circuit. Spray if you can, short circuit if the metal is too thin to allow it. If you spray, use the minimum arc length necessary to achieve it - start your dial in in a short, and add just enough voltage to transition to spray. Excessive voltage loses root penetration and gives a lot of very small stuck spatter in the "etched" area on either side of the weld.

You can't dial in on hot aluminum (after having run a couple of beads on it) and then expect the parameters to work on cold pieces or pieces of a different thickness or ona different joint configuration. Dial in on exactly the conditions you will test on, or do production on.

If you have pulse spray, use it if you can. You will probably be operating in CC if using something like an Miller Optima pulse unit. Don't get confused - a pulsed spray machine will probably show a "trim" number for arc length instead of a voltage value. If it is a trim number you may need to set it at 50 or whatever, which obviously would seem like too much if you thought you were looking at a voltage value.

If you have adjustable run in, try about 50% to help prevent stubbing and LOF on your starts. Use run off tabs if allowed.

You wll probably be using 3/64 5XXX or 4XXX. If you are using a machine with programmed software, be sure you enter the right series of wire as the the burn off rate between the two is quite different.

As mentioned, 40 CFM or so with slight push. Stick out doesn't have a dramatic effect like it does with steel wires. Travel speed is really critical though. You must be very consistant.

If you are making oramental welds on material that will not see paint, such as on shiney tread plate, they almost certainly won't want to see you scratch it up with a wire brush to remove oxides. Best to ask if not sure.

And leave no craters!!!!

Good luck and keep in touch!

By weldstudent (**)

Date 03-12-2011 18:23

thanks for the info.

well the weld test was designed to fail. 1/6" aluminum 3/64 wire, no pulser. had to build a box, not so hard. was told to run fill length welds on two of the lower outside edges, "dont stop when u start" is what i was told. "on the inside make 2" intermetent welds on the other two edges and only tack the risers in the center" i was only allowed to use a spray.

well i built a box. the wire was too big for the metal. didnt blow any holes but because i was not allowed to clean the aluminum there was a lot of burn-through.

i got a chance to see some of the other boxes that people had made and mine looked good compared to them.

By Lawrence (*****)

Date 03-12-2011 19:37

Aluminum GMAW travel speeds are frighteningly fast for the operator who is beginning to use it. You really need to zip along. Forget about pretty whipped ripples and lay it in like high speed caulking.

But small fillets in material down to .063 (1/16th") can be done with spray GMAW without pulse... But it takes alot of practice.

By welderbrent (*****)

Date 03-13-2011 00:26

One more point to what Lawrence said,

Lots of people try to run too cold when doing thin material. Rather it is steel or alum. Often it is better to run hotter and faster. When you run cold you have to slow down to get it to warm up enough to fuse, then you get too much heat in too short of an area. Burn through.

Keep practicing. You'll get it.

Have a Great Day, Brent

By DaveBoyer (*****)

Date 03-14-2011 02:28

It will take a lot of practice for anybody to do a nice job of that.

By bozaktwo1 (***)

Date 03-14-2011 16:58

All I have to say, in addition to the fine commentary above, is CLEAN. Clean, clean, and then when you think it's clean, clean it again. There shouldn't be so much as a gnat's leg hair within 2 inches of your weld.

Good luck.