Baldor Grinder Water Pot Residue

Years ago, when faced with the same problem, I coated the inside of mine with POR15. It has held up great. POR15 is a combo rust treatment/ paint that is used alot in the classic car restoration field. Do a web search for it

Don't use any sort of base on aluminum - the base will attack it.

I'm glad you brought up this topic, Bob. Every time I enounter this powdery effect on aluminum, I think "the RCM'ers would know what causes this, and what to do about it", but then I forget.

Since Mike H said not to use any sort of base on aluminum, I thought I'd look for some examples of common compounds will cause the erosion reaction.

Some soaps, ammonia, lime and possibly some other products like lye. I recall seeing cautions on some household products stating; not for use on aluminum, or do not use on aluminum.

I'm also interested in knowing what to do about areas that are affected, such as removing any active contamination and stopping the erosion.

Toilet cleaner (lye) and aluminum foil in a sealed pop bottle makes for a bang. Hard on eyes and lawn.

Wes

Yep, and those two materials make up a drain cleaner product, Wes. Nasty stuff, and dangerous in the hands of the average doofus.

I heard of an incident from my cousin where his landlord lit a match to look down the sink drain to see what was happening after putting drain cleaner in it. The fumes ignited, but he was lucky, and didn't cause serious eye injuries.

WB et al

Thanks for the input. It is appreciated.

It has been 50+ yars since any chemistry training so I will have to think what bases are and what the opposite is. I think it is acids.

So after looking over the replies I think I will mount the cup in my lathe and attempt to polish off the inside cruddy finish and then use the POR15 stuff. Will have to look for it. Not sure where to find it but a Google search should get things started.

Eagerly anticipating more RCM input. Bob AZ

I've heard of great results from the use of Por15 products, Bob, although I haven't tried them yet.

My experience with coatings on aluminum have been related to prep and finishing with older conventional automotive finishes/paints.

Diluted phosphoric acid is a common treatment for bare aluminum, where it's applied for about 20 minutes (and kept wet during that time), then rinsed off with clean water and dried quickly, to be followed by primer within a short time. There are numerous phosphoric acid prep products sold at autobody supply places, which would include the dilution instructions for treating and etching various metals. These products are typically relatively weak solutions of phosphoric acid, which are then further diluted by the user, in different ratios for different metals.

Safety precautions will usually be included with the dilution instructions. Eye protection should always be used for handling any chemicals, but getting diluted phosphoric acid in a cut on a finger (for example) will sting like you'd expect lemon juice to sting, so it's not something that one should risk getting into their eyes.

A reliable primer for aluminum is zinc chromate if the paints are conventional enamels or lacquers.

Your application of a water bowl may be different than the usual refinishing applications where metal parts wouldn't be required to withstand being submerged in water.

If coatings don't appear to be the solution to the erosion taking place in the water bowl, maybe you could find a stainless steel vessel that would fit in the existing bowl, or it could be used to replace the existing bowl.

Acids would be at the opposite side of the pH scale from bases, with distilled water (for example) being neutral in the center with a pH of 7. The pH of bases would be greater than 7.

Normal aluminum behavior is to form an oxide film after cutting/ polishing/sanding, usually it's so thin you can't see it. The white stuff is oxidized aluminum, for some reason, it's not forming a film. Acids will eat the base metal, ditto bases. The anodizing process I oversaw started with a hot caustic dip to remove any oxide, it also etched the metal. It will produce hydrogen, not a good idea in enclosed spaces. Best idea is to clean off what you can, then immediately coat it with paint/lacquer/powder coat. Start with some dishwashing soap, to remove whatever it can, then sand it. I say dishwashing soap because I know it won't react with aluminum, otherwise pots and pans would be disappearing in the dishwasher all the time.

Stan

Bob AZ wrote in rec.crafts.metalworking:

If your water supply is "rich" in Calcium [mine is] then try using some vinegar to remove the buildup of Calcium resulting from the evaporation of water in the pot.

I go through this periodically (about once a lustrum).

RAM *3

I did this and I think it is what got me to where I currently am. I also admit to taking the time to be fussy about this Water Pot, when I should perhaps be doing something more useful for myself and others.

However I am currently planning to put this pot in a fixture of sorts in my lathe and polish the inside clean and fresh right down to the bare metal. Then I will go the POR15 route. I also will clean it all again with some Phosphoric acid as others have recommended.

On a side note: I had a coffee maker, Farmer Brothers type that had an enormous build up in the water heater area that was causing it to malfunction. I did a 24 hour soak with straight vinegar and now it is clean as new.

Thanks to all for the inputs. It is appreciated. Bob AZ

CLR is a good product as well.

Mart>> If your water supply is "rich" in Calcium [mine is] then try using some

"Martin H. Eastburn" wrote in rec.crafts.metalworking:

Dilute Phosphoric, IIRC.

You're right: it works very well.