Cleaning aluminum

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I want to get the groups input on using aluminum brightener to clean pieces of aluminum before fit-up of pieces to be welded.I can buy aluminum cheap from a local steel supplier but all the stuff I can get cheap has what they call water marks. Alot of times I just work around the bad spots.I found whats called aluminum brightner from O'Reilly auto parts. It consist of hydrofluoric , hydrochloric , and phosphoric acids. I thought of getting a Rubbermaid tub or something to pour some of the brightner in and soaking my pieces so they would have a consistent finish prior to welding. Thought I'd ask if anyone has done what I'm thinking about and the downside if any to doing this. Will this affect any structural integrity ? I plan on using rubber gloves etc and doing this in a well ventilated area btw and completely cleaning all cleaner before welding. I am aware of the deadly effects of using clorinated solvents and tig welding but haven't heard much about this stuff. Thanks
Reply:I just use Acetone to clean and a stainless "toothbrush" to go over where the weld area is..Don't forget the clean rags.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:If it is cast especially something engine related that has absorbed oil, coolant, carbon etc, I scrub with PPG metal prep. (phosphoric acid), available at auto refinishing suppliers. Fairly cheap stuff. Cuts down on contaminants bubbling up in the puddle
Reply:Originally Posted by zapsterI just use Acetone to clean and a stainless "toothbrush" to go over where the weld area is..Don't forget the clean rags.....zap!
Reply:Showdog,I would not recommend cleaning the aluminum in the manner you propose.  I'd be very concerned about how you "neutralized" those acids after the cleaning occured.I think you best bet would be to weld it up and polish post weld.Aluminum is really very easy to "polish" depending on the finish you wish to achieve.  There is an assortment of abrasives available and a fine scotch bright pad works wonders if you're looking for a "brushed" finish.I hope you've read some of the hazards of using "brake clean" prior to welding.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Showdog75,the white chalk will come off with acid/aluminum wash and scrubbing with a ScotchBrite(tm) pad while the sheet is wet, so will rust unless there's serious penetration then the pits remain.I'd use latex disposable gloves covered by elbow length parts washer rubber gloves and wear you rain suit and rubber boots.  I make our shop guys wear half face North air purifying respirators with the black/grey activated charcoal filters and glasses covered by face shield. Correct PPE is important with aluminum etching solutions.  We have Aluma-Brite, Zep-a-Lume and the PPG products in our area, and they all do the same thing at different rates due to the different concentrations of the solutions.We lay the sheet on horses and flood some area with acid mixed 2:1 in warmed water [the acid works more actively if warm and we live in Alaska] and scrub away.   ON cold days we'll heat the sheet using propane weed burner "until the dew drys off." The acid will foam for a few minutes then start to dry up, we flood that area with a water hose and let the dilute run off into the gravel, not a problem as it dilutes millions/billions to one.If the area needs another go, repeat until the sheet is descaled of mill scale (shiny junk that has corroded to form the water mark) and the white areas are gone.  The pattern of the ScotchBrite will remain.In some cases where we had to have a nice, uniform brushed looking sheet for the project we clamped 1x4's to the sheet and used sanding blocks with the ScotchBrite to guide long uniform strips that ended up with a uniform abrasion pattern on the cleaned sheet.  I've also done this with a belt sander and ScotchBrite belts to attain a uniform set of brush lines.Now, years later we have a 50" wide roll/drum sander that has a wrap around strip of scotchbrite-like hook and loop backed abrasive and we feed the sheets through it to get the mill scale off faster and still have a nice uniform look to the sheets.Sheet on the left is cleaned with power sander sheet on the right has mill scale.closer view of sheets aboveCheers,Kevin Morin
Reply:Great Post Kevin - all the answers, the experience and the proof are there.Rick V 1 Airco Heliwelder 3A/DDR3 CTC 70/90 amp Stick/Tig Inverters in Parallel1 Lincoln MIG PAK 151 Oxy-Acet
Reply:Thanks guys.