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Pre-weld cleaning of cast aluminim

Posted: Thu Jul 26, 2012 11:13 am
by weino
Hello,
First off, I love this web site. Piles of info here.
My question is -
What is a good product for cleaning cast aluminum prior to welding?
I am welding a transmission housing and it has plenty of dirt on it.
After wire brushing and prepping the weld area, I was wondering if anyone has a cleaning product they like to use.
Thanks for any advice.

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Jul 26, 2012 4:23 pm
by nickn372
Brake cleaner or simple green (1:1 solution) and a hot water pressure washer. Outside of that make sure you use a flap disc for aluminum and/or a stainless steel wire brush/wheel.

Re: Pre-weld cleaning of cast aluminim

Posted: Tue Jul 31, 2012 9:01 pm
by pro mod steve
Acetone. NO BRAKE CLEANER do a search for PHOSGENE POISONING.

Re: Pre-weld cleaning of cast aluminim

Posted: Tue Jul 31, 2012 9:23 pm
by weldin mike 27
Hey,

I second Steves imput. That stuff scares the shit out of me.

Mick

Re: Pre-weld cleaning of cast aluminim

Posted: Wed Aug 01, 2012 5:44 pm
by Otto Nobedder
Brake cleaner made in the USA and Kyoto Protocol countries are "SUPPOSED" to be free of the chloroflourocarbons that form phosgene, but why take a chance? I use brake cleaner occasionally on stainless (where I can be sure of complete evaporation), but on a porous casting I wouldn't risk it.

Steve

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Aug 02, 2012 11:35 pm
by pro mod steve
I have a can of CRC Brakleen right here from a 9 case shipment I just got at the shop. " WITH SKULL AND CROSS BONES Cannot be made non poisonous. Contains methanol,acetone,toluene,heptane,and co2. DON'T USE THIS STUFF PRIOR TO WELDING PLEASE.

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Aug 02, 2012 11:40 pm
by pro mod steve
There is no specific antidote for phosgene poisoning. Care is supportive with oxygen administered upon appearance of respiratory problems, in particular chest tightness or dyspnea (labored respiration). The patient is kept dry, warm and calm (no exertion). An antibiotic might be administered as a precaution against developing a secondary bacterial infection. Ventilators are required for patients with severe pulmonary edema. Any person that might be exposed to phosgene should be transported to a medical facility for evaluation for a period (minimum 6 hours, some specialists recommend 12 or 24 hours) even if the person feels fine because of the latent period before onset of symptoms. The evaluated person should be symptom-free, normal oxygen saturation, normal chest radiograph, and have normal respiration before discharge. More details are at http://emedicine.medscape.com/article/832454-print.

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Aug 02, 2012 11:43 pm
by pro mod steve
People please don't get me wrong. I am NOT trying to be a downer I just want everyone to be safe and go home to loved ones after a hard day of earning a dollar or enjoying thier sparking hobby.

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 1:04 am
by mr 32
my engine builder was talking about this the other day said he can hot tank most cast items maybe thats the way to go?
ive also been told sand blasting works well

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 2:25 am
by weldin mike 27
Hey there,

Theres a link on the main page to welding safety, with a story about a guy who got Phosgene poisoning from brake cleaner/ welding. Nasty stuff. Steve, telling someone about safety is not a downer. It should be talked about more. Especially this sort of thing because it is the secondary reaction between the argon/heat and chemical which causes it to break down into the phosgene and people dont realise that.

Mick

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 10:01 am
by nickn372
Yeah including me... never heard of that before. Sorry for the misinformation. I just remember when i worked on sprint cars our crew chief blasting an oil pan with brake cleaner so he could weld a crack in it. Question though... would it make a difference if it was non chlorinated? Cuz i know they sell it as chlorinated ed or not chlorinated.

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 5:34 pm
by Otto Nobedder
"Chlorinated" means it contains the solvent Methylene Chloride Not a factor in phosgene production. The CFCs that used to be the propellent for almost any aerosol (until that pesky hole in the ozone layer) are the culprits.

If you can prove the can in your hand was made in the USA, or the E.U, you can be pretty confidant it's CFC-free. If it's origin is questionable, I do not trust China, India, or any of the second- and third-world countries not to use them because they are cheap, easy, and effective. The solvents in brake/carburetor/engine cleaners will dissolve some of the CFC's, and unless you bake the part dry, it's hard to be sure they're gone.

A note on Methylene Chloride-- It's a great solvent, but has raised some health concerns and is becoming less common. It's also "Known to the State of California" to cause cancer, so for God's sake, don't use it there :lol: .

Steve

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 7:09 pm
by weldin mike 27
Hey,

I unfortunately this falls under the category of "Pfffffftttt, I do it like that all the time" when it really should be "you've just be lucky" Pays to research and pay attention to warnings and also find and read the Material Safety Data Sheet MSDS on any new product. or any for that matter. In Australia workplace laws require Msds to be accessable for all products used.

Mick

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 8:18 pm
by Otto Nobedder
MSDS access is required here.

I still won't trust the ones from China. They put lead and mercury in toothpaste, cadmium in toys and paint on cribs.

I smell conspiracy, but haven't the evidence to shout it from the rooftops. Ever read "The Art of War"?

BUY LOCAL!

Steve

Re: Pre-weld cleaning of cast aluminim

Posted: Fri Aug 03, 2012 10:41 pm
by nickn372
Haha it seems like a lot things can cause cancer in california. Nowhere else just california. Lol jk

Re: Pre-weld cleaning of cast aluminim

Posted: Sat Aug 04, 2012 8:10 pm
by pro mod steve
Not to high jack the thread but you will love this. I own a automotive repair shop and just read the state of California says there is too much copper in brake dust contaminating rain water run off. They are pushing to mandate automakers implement filters on car wheels to capture brake dust. NO BS.

Re: Pre-weld cleaning of cast aluminim

Posted: Sat Aug 04, 2012 10:37 pm
by WerkSpace
pro mod steve wrote:Not to high jack the thread but you will love this. I own a automotive repair shop and just read the state of California says there is too much copper in brake dust contaminating rain water run off. They are pushing to mandate automakers implement filters on car wheels to capture brake dust. NO BS.
My solution to this problem is different. I suggest that we all drive hybrid electric vehicles that do not use brakes but regenerative braking via the electric drive motors. The motors are brushless, there are no brake pads and the regenerative braking system simply puts power back into the system. Braking is very inefficient anyway. Too much lost energy that is converted to heat. http://www.brakeandfrontend.com/issue/a ... tid=102757

Re: Pre-weld cleaning of cast aluminim

Posted: Tue Dec 11, 2012 8:58 pm
by ajlskater1
Hot tank works great if it the same thing I am things of. One thing on cast al especially oil soaked casting they are almost impossible to get to weld perfectly clean. Baking them in a old grill works really well to burn out a lot of the oils in the pores of the metal. Do it outside it will stink and don't cook with it after. Also of you fixing a crack grind a large bevel don't try to penetrate through the crack doesn't work well.

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Dec 13, 2012 9:36 am
by vr6swap
ajlskater1 wrote:Hot tank works great if it the same thing I am things of. One thing on cast al especially oil soaked casting they are almost impossible to get to weld perfectly clean. Baking them in a old grill works really well to burn out a lot of the oils in the pores of the metal. Do it outside it will stink and don't cook with it after. Also of you fixing a crack grind a large bevel don't try to penetrate through the crack doesn't work well.
Baking stuff may help - I used to do powder coating and would always preheat aluminum castings for at least 30 - 45min @ 400 F to get all (most of?) the oil and contaminants out onto the surface where you could clean it off.

Also, undiluted Simple Green will do a lot if you soak the parts down and let it sit for a while before rinsing.

Re: Pre-weld cleaning of cast aluminim

Posted: Thu Dec 13, 2012 6:00 pm
by ajlskater1
Ya Simple green is good stuff. Just a side note not sure if any of you guys fish but simple works great for restoring cork handles on fishing rods.