phosphoric acid

[Mike Aylward]

I have been having a terrible time finding some phosphoric acid to treat metal. I used to get it at Menard's but they have stopped carrying it. I also asked at Lowe's but nobody seems to even know what I am looking for, even when I mention "Ospho" or some such brand name. Can anyone give me some other brand names or help in any way? Thanks. Mike

 

[PBrowning]

WalMart will carry either EXTEND or RUST CONVERTER - both in aerosol form (rattle cans).

Home Depot and/or Lowes paint departments should carry something along these lines as well.

Ace Hdwe has been known to carry OSPHO. There's many others I'm sure. (PatB)

 

[Mike Aylward]

Pat, the trouble I'm having is the "junior cadets" at these stores. It it's not on the computer they have no idea what you are talking about. The product I was using was "concrete etching compound" but was phosphoric acid. I've checked Lowe's and they do not have it (or at least the one store didn't). I'll keep looking. Thanks. Mike

 

[JoeM(GA)]

Asking in a place like that doesn't help. They don't even know what the chemicals they sell do. You've got to read your own labels. I haven't seen any in our Lows lately. Home Depot sells it as "Must for Rust" it is with the paint thinners and such. Any auto body paint store will also have it. Eastwood sells it online too.

 

[Anonymous-0]

i purchased some lastnite at lowes here in upstate SC . there"s goes by the name Prep & Prime made by Jesco... $6.48 per qt

 

[Dave H]

give up on the junior cadets. Always go to the paint prep section and look for metal prep. Ospho has disappeared in my part of he country but the stores now stock the same stuff marketed by Kleen Strip. Just bought a gallon from Home Depot.

Like said, any automotive paint place will have (should have it) marketed under their label, but it will cost X2 there. I have gone that route when desperate.

 

[Butch GA.]

I just bought a quart from my local ACE Hardware store 9.00 dollars for the quart. I live in So East Ga.

 

[Anonymous-0]

Mike,
First of the month Illinois minimum wage is now $7.75, now I know you will get better help at the Box stores. Two local hardware stores, Ace and Do-it both have employees that know what's in the store (even the jr. cadets) or ask someone, maybe even the owner. They will both get my business even if I wait a day or so for them to order for me.

 

[alabamafrog]

I bought some a month or two ago at Home Depot, it was the kleenstrip phosphoric prep & etch, it was around $15 for a gallon. I was looking for it on one of the paint department aisles when one of the “paint experts” ask if they could help, long story short, both employees had no idea what I was talking about and said they did not carry anything like that. While they were talking I pushed my way between them and got it off the shelf and showed it to them as I walked off. It’s not their fault, they were young women who probably had never even seen rusty tractors. Moral of the story is you gotta do-it-yourself if you want it done right.

 

[F-I-T]

Mike:

I have found Phosphoric Acid most recently at my local Home Depot in the paint prep chemicals section, and the name of the product was "PH-OSPHO-RIC PLUS+”. I have also purchased a product called "Metal-Prep" at a car show, and it is now carried at my local Bumper to Bumper dealer. "OSPHO" is a brand that is carried at many automotive paint supply stores (like your local DuPont retailer). I bought another product called “THE RIGHT STUFF METAL DE-RUSTER” at the local Discount Auto Parts. They have since been purchased by Advance Auto Parts, and now they only to carry it at some stores in quarts. “THE RIGHT STUFF METAL DE-RUSTER” is manufactured by CLI, and they have a web site : http://www.cli-rightstuff.com. I just saw it in quarts at my local Advance Auto Parts. I recently saw a product in the paint thinner section of Lowe's called Jasco - Prime and Paint. It's Phosphoric Acid, too.

Look for it in the concrete cleaning products section or the paint prep chemical section.

Frank

 

[nylon4020]

If you need HPO4 then get it at redimix supplier if you cant get it at box / hardware stores. Industrial paint stores also. Anyone who deals with etching concrete to paint, seal or resurface has it. It comes as many product names, but as fit said...it is phosphoric acid. It will be listed as the ingredient on either the label or a MSDS.

 

[alabamafrog]

While we are on the topic of phosphoric acid,
I had a problem with it the first time I tried to use it. After sanding my tractor to the point I thought I was ready to prime it I sprayed the acid on real heavy one night and went to bed planning to paint the next day. That next day the whole tractor was covered in a thick black substance and had drips and runs all over it almost like it has clear paint poured over it. I had to go back and sand the whole thing again. The first time I mixed it 60/40 or maybe a little stronger with water so I decided to try it again and mixed it much weaker, like 40/60, and sprayed less on, and pressure washed it off after about an hour. The day after I finished the paint job it decided to rain for a couple days. After all the rain I had black spots all over my new paint job. It took many hours to clean it all back up and it still does not look 100%. All I can figure is some acid was trapped inside nooks and crannies and behind or under stuff and the long slow rain brought it all out. I’m not sure if the acid is worth the trouble or not?

 

[Anonymous-0]

Frog

I have never experienced that. It sounds like you put that stuff on areas that were already painted? Maybe that is the clue. I have never applied it to anything but bare and sometimes pitted metal.

 

[F-I-T]

Did you apply a primer/sealer? Sounds as if it was never truly dry when you scuffed off the flaky deposits and applied paint.

 

[Mike Aylward]

That sounds like a very strong mixture to me. It doesn't take a lot of phos acid in water to work. In fact, less is more. It actually seems to work better if it is diluted more. If it is concentrated enough to make "bubbles" when it dries it needs diluted. Mike

 

[wilamayb]

I too had the problem with the black sludge when spraying it on with a garden sprayer. The trick is to wipe the excess off with a rag within a few minutes. After figuring this out I am very happy with the results.