Phosphoric acid

[Jeffrey S.]

Hello all and a very happy new year to you! Can anyone tell me where to go to buy phosphoric acid-not a product that contains phosphoric acid like naval jelly or "Ospho"(?) but pure acid? I would like to be able to make up about a gallon of this so i can soak some larger pieces to remove rust. I am in the Detroit area but perhaps if you can tell me the type of store that would carry this I can find one here. Thanks for your help.
Jeff

[Dick W.]

Re: Phosphoric acid

Find a part store that sells truck washing chemicals. Get aluminum brightner. Delute to suit. Wear goggles and gloves. Use in a well ventilated area. Will clean rust asap

[Duke W.]

Re: Phosphoric acid

Or any auto paint supplier.

Duke

[Dick W.]

Re: Phosphoric acid

As Duke said any paint store. The product that you purchase at a paint store can be used full strength. I do not think that I would want to use the aluminum brightner full strength

[Tom P.]

Re: Phosphoric acid

If you are wanting to remove rust (which is only on ferrous metals) use Muratic (HCL) acid (all oil, grease, crud, paint must first be removed before placing in acid). That is what is most commonly used in chrome plating shops to disolve rust. You can buy Muratic in ANY hardware store (Lowes, Home Depot, etc). It's about $5-6./gal. I bought one of the BIG (about 33 gal) plastic tubs with a snap on lid from Walmart and filled it about 2/3 with Muratic diluted 1:3 with water. So, with 5gal Muratic and 15 gal water, which is 20 gal total, there is enough in the tub to submerge most parts completely except big items such as rear axle housings and front cross memebers. When I put those kind of parts in acid, I put in one end for about 30min, switch ends, and continue to switch until all rust is gone. Then rinse with my power washer, bead blast and paint.
Muratic is also good for cleaning up tarnished coppor/brass parts.
I use Phosphoric acid for brightening alum parts. I dilute it about 1:3 or maybe 1:4. DO NOT LEAVE ALUM PARTS IN MORE THAT JUST A VERY FEW MINUTES. Rinse with hi-press hot water. There is an auto detail supplier in Okla City that I buy Phosphoric from, 5gal at a time. Its dirt cheap.

[Jeffrey S.]

Re: Phosphoric acid

Thank you all for your quick responses. I will try the suggested retailers tomorrow. I have tried muriatic acid and while it does work, it also gives off some pretty obnoxios odors. I have used it also to remove plating from fasteners and other small items (zinc, cadmium, even chrome). I like the way phosphoic acid works in naval jelly but to buy the quantity I want would be very expensive. Thanks again!
Jeff