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JRSutton 03-07-2012 10:57:27 75.130.109.233 Report to Moderator	Temps are coming up into painting territory where I live - I've got a question on phosphoric acid washes - Pricing is all over the map on various brands. There's the astonomically priced stuff at like 30 per quard that I can't even think about, then I see 60 per gallon for ppg stuff - better, but not cheap. But then I see stuff at Home Depot like klean- strip phosphoric prep and etch for $15 per gallon... And that's cheap enough to make me question why I'd need anything more. Thoughts? [Reply]   [No Email]
redman88 03-18-2012 12:27:14 198.228.201.151 Report to Moderator	Re: Acid wash in reply to JRSutton, 03-07-2012 10:57:27   I just noticed that I posted my post about 3 times. Sorry about that. I was thinking about this film that is left behind and I'm just not sure what to do about it. I don't know if I should wire wheel it clean or if that will cause flash rust again. Any help would be appreciated. [Reply]  [No Email]
showcrop 03-18-2012 14:31:21 75.67.231.80 Report to Moderator	Re: Acid wash in reply to redman88, 03-18-2012 12:27:14   I use the stuff a lot. I use the cheap stuff but follow the directions on the expensive stuff that says to keep it wet for ten minutes so that it has time to penetrate then to wash it off. You must not have washed it. I would reapply the acid then get after it with brush and pressure washer after ten minutes. I have not gotten the white if I have rinsed it off. [Reply]  [No Email]
showcrop 03-07-2012 18:49:32 75.67.231.80 Report to Moderator	Re: Acid wash in reply to El Toro, 03-07-2012 10:57:27   Go down 3 posts to the one on preparing for primer. There have been many threads on acid wash. [Reply]  [No Email]
CNKS 03-07-2012 18:44:17 216.144.104.128 Report to Moderator	Re: Acid wash in reply to JRSutton, 03-07-2012 10:57:27   All phosphoric acids are not the same. The safest you can buy is Picklex20. $40 for 1 pt. You might do a search and find it cheaper. That is not expensive because you can do several tractors. Use it as a rust preventative after removing the rust. I do not consider it to be a true rust converter, but it will kill the rust in pits if you can't get to it. You DO NOT wash it off, thus it is not an "acid wash" as described on this forum and elsewhere. Simply put it on clean sheet metal and keep it dry, it will last for months. When ready to paint simply rub off the white residue with a scotchbrite pad and then use wax and grease remover. I have used it on cast once, but I do not recommend that because I think it might get stuck in the pores and lift the paint later. Picklex20 is a relatively mild H3PO4 and Zn combination. I wouldn't use anything else. Picklex20 [Reply]  [No Email]
ShadetreeRet 03-07-2012 18:33:00 184.3.41.120 Report to Moderator	Re: Acid wash in reply to JRSutton, 03-07-2012 10:57:27   To be honest, I don't know that much about the stuff. But I would check the label to see just what else may be in the stuff from Home Depot, 'cause that is awful cheap compared to the others. But if there is enough phosphoric acid in it to get the job done, then I would go for it. Kinda like buying a car or truck, when you pass a certain price you are just paying for the name. Just my thoughts. [Reply]  [No Email]
redman88 03-18-2012 09:24:42 198.228.201.149 Report to Moderator	Re: Acid wash in reply to ShadetreeRet, 03-07-2012 18:33:00   I bought the same stuff from home depot( klean strip) ( phosphoric prep and etch). I use in on my tractor because I had a lot of rust on it before I sand blasted it. I blasted then took the klean strip and applied on tractor with a small brush like it said in the directions. The thing I noticed after letting it dry was spots that were like a white crusty film left on the top. I am a little concerened about this because if you try to wipe it off with a dry shop towel it kind of gets imbedded into the cast like writing with a piece of chaulk. This is my first time using this product and the first tractor restore. I am planning on just wiping it done with a wax and geese cleaner and then maybe mineral spirits right before paint day. [Reply]  [No Email]
redman88 03-18-2012 09:31:16 198.228.201.149 Report to Moderator	Re: Acid wash in reply to redman88, 03-18-2012 09:24:42   I will show a picture of the tractor after treating it with klean strip phosphoric and you can see all the white film on it and the blues and greens in the metal. I think the discoloration I'd due to the chemical reaction between the metal, rust and klean strip. [Reply]  [No Email]
redman88 03-18-2012 09:24:00 198.228.201.149 Report to Moderator	Re: Acid wash in reply to ShadetreeRet, 03-07-2012 18:33:00   I bought the same stuff from home depot( klean strip) ( phosphoric prep and etch). I use in on my tractor because I had a lot of rust on it before I sand blasted it. I blasted then took the klean strip and applied on tractor with a small brush like it said in the directions. The thing I noticed after letting it dry was spots that were like a white crusty film left on the top. I am a little concerened about this because if you try to wipe it off with a dry shop towel it kind of gets imbedded into the cast like writing with a piece of chaulk. This is my first time using this product and the first tractor restore. I am planning on just wiping it done with a wax and geese cleaner and then maybe mineral spirits right before paint day. [Reply]  [No Email]
CNKS 03-18-2012 14:56:10 216.144.104.128 Report to Moderator	Re: Acid wash in reply to redman88, 03-18-2012 09:24:00   Use wax and grease remover as the final step, not mineral spirits. Ok to use mineral spirits before wax and grease remover. As to your acid, although I have done it once, I do not recommend H3PO4 on any kind on cast, it may get in the pores and lift the paint later. The one time I did it with Picklex 20, it did not lift. If you insist on it, repeatedly use about any cleaner to try to get it out of the pores followed by wax and grease remover. Looking at your picture, you used far too much acid. It does not take much. The "dirtier" the cast, the more white residue you will have. On clean sheet metal, for example, there is very little. Using a product such as Picklex 20, which is a mild version of H3PO4 the white residue can be mostly removed with a scotchbrite pad, followed by wax and grease remover. After I had painted my 1st tractor, it dawned on me that I do not need any form of H3PO4, because I live in a dry climate, and I simply do not get rust on bare metal inside my shop. [Reply]  [No Email]
redman88 03-18-2012 09:22:20 198.228.201.149 Report to Moderator	Re: Acid wash in reply to ShadetreeRet, 03-07-2012 18:33:00   I bought the same stuff from home depot( klean strip) ( phosphoric prep and etch). I use in on my tractor because I had a lot of rust on it before I sand blasted it. I blasted then took the klean strip and applied on tractor with a small brush like it said in the directions. The thing I noticed after letting it dry was spots that were like a white crusty film left on the top. I am a little concerened about this because if you try to wipe it off with a dry shop towel it kind of gets imbedded into the cast like writing with a piece of chaulk. This is my first time using this product and the first tractor restore. I am planning on just wiping it done with a wax and geese cleaner and then maybe mineral spirits right before paint day. [Reply]  [No Email]