Cleaning aluminum for spool gun welding

[farmshop]

Hey everyone I am curious what everyone does to clean aluminum prior to welding with a spoolgun. Most of the aluminum welding I do is repair work on aluminum dump trailers and tanker trailers. I try to go at it with a carbide burr or grinding wheel or wire brush depending on the situation. The problem comes from the crap coming out of the crack or from between layers of material. Machine is a miller 252 with a 30a spool gun. 100% argon. Using .035 wire. Any help would be appreciated thanks

[djd775]

That’s always a tough situation. I often try to heat it up with a torch to boil out the water and other crap before welding.


Sent from my iPhone using Tapatalk

[Dodgediesel2]

Make sure your wire brush is stainless steel...

[albrightree]

X2 on the above mentioned. Goof off works well on removing road tar, stickers, grease/oil.

[Bistineau]

Make sure your wire brush is stainless steel...

And has NOT been used on any other material except aluminum. Any other use can imbed contaminates into the brush which then can be transferred to the aluminum and contaminate it.

[CrookedRoads]

http://www.streamlinesupply.com/Prod...ate__1500.aspx

[Hobbytime]

http://www.streamlinesupply.com/Prod...ate__1500.aspx

Streamline's Aluma Brite Concentrate (Concentrated Aluminum Brightener)

This item is a corrosive material and can only ship in 55-gallon drums outside of Utah and Idaho. so how do you buy a gallon outside of those 2 states????

[CrookedRoads]

That was just a brand that popped up, all the truckers use this on their trucks. I've been getting this Power Brite at my welding supply down at the port, next week thay may have some other brand.

[SaskWelder]

I have found that on old aluminum, (despite doing all that you can do to clean and prep it) the end result often is to grind out the first (and usually second) weld passes. The puddle will "float out" the crap and rise to the top. Grind out 80% of the weld and weld again. Grind the top 50% off the second pass and the third pass will be okay.

Its extra work, expense and heat input but often its the only way.

[farmshop]

I have been doing what saskwelder says. It has been working but is slow. I was hoping someone had a miracle cure all

[albrightree]

Thats the challenge of repair welding vs. new fabrication. So many times I'm given something "ready to weld", and half way through the weld it erupts like a volcano(silicone, grease, who knows what?). It happens a lot on stainless(people like to sneak silver solder, or braze in lap joints that were previously spot welded), as well as Aluminum jobs. Sometimes its easier to remove a brace or bracket completely and fully prep area , then weld a new piece in , if thats an option. Most of the time on trailers you try and grind real deep before welding, and hope for the best. The different types of road salts really do a number on the aluminum. What kind of grinding/flap wheels do you use on your aluminum?

[Yofish]

I have found that on old aluminum, (despite doing all that you can do to clean and prep it) the end result often is to grind out the first (and usually second) weld passes. The puddle will "float out" the crap and rise to the top. Grind out 80% of the weld and weld again. Grind the top 50% off the second pass and the third pass will be okay.

Its extra work, expense and heat input but often its the only way.

What this man said. Along with heat that can evap some of the goo. If you have a nice laboratory setting, caustic soda is the BEST degreaser known to man but it also turns AL into hydrogen gas and white residue over time. Throw a chunk of say, 3/16" AL into a concentrated solution and in hours only some residue will be left. Nonetheless, if you have the space and can be cautious as it is extremely noxious to work with, and must be flushed thoroughly with water, it is a wonder.