ok waking up an old thread but i intend to use the phosphoric acid to clean rust of the car body but the problem is i might not have an propper garage to do it in i even might have to do it outside on my pourch at the sea side of iceland is that going to work or should i ask a frend if he can borough me his garage .
I have used ospho for 30 plus years. It has been used under laquer and single stage and two stage, ppg, nason you name it. I strip panels to bare spray it on with a pump sparyer like you might get with simple green. I then scuff it with scotchbright pads and wipe the excess off with clean coton rags. Let it sit and dry 24 hours and it is ready for primer. If it makes you feel better do a light scuffing sanding and cleaning before paint. I even used it on a bare fender and tossed it outside in the weather in Houston texas and for many months ..no rust..it stained but no rust. Turns the rust from an oxcide to a prosphate. Rust turns black...won't work on the big chunks..those you need to wire brush first.
Been using Phosphoric acid for rust since the mid 60's. Was taught by one of my shop teachers. Have never had a problem when used for such. If you are worried about your concrete, spray it with water first. As long as it is wet I have not had a problem with BLEACHING. Got some on your skin, Walk over and wash it off. PROTECT your eyes and use in a well ventilated area. I have used a brush, Hand held sprayer and a pump style bug sprayer to apply. Clean and dry, wipe with thinner. Then spray with a etching primer. I get it at Home Depot in the paint section. Klean-strip phosphoric prep & etch. Around $15.00 a gallon.
Yes....I know it's an old thread. All you thread nazis can go pound sand. I'm a chemist, so just for everyone's edification, here's what's happening when you use phosphoric acid to treat rust: The phosphoric acid converts iron oxide, Fe2O3 (rust) to ferric phosphate, FePO4 which is typically a black color. Ferric phosphate (aka Iron III Phosphate) actually used to be used as a dietary supplement to aid in blood clotting. It was given to people who were hemorrhaging, etc. And....believe it or not...if you scrape off the powder after a rust treatment, you can use the ferric phosphate to kill snails in your garden. It's safe for your pets or other critters that you don't want to harm if they tend to get into your garden. It is fairly non-reactive and can be painted over if it is adhering nicely to the surface metal. I've been using it since I was a teenager to stop rust....with good success.
It should be common sense....but I'll add this anyway.... ANY acid has the potential to be harmful, so use protection when you use it....gloves, good ventilation, protect your eyes, etc. If you get it on you or the driveway....don't freak out....just rinse with a ton of water....quickly....the sooner the better.
I have been using some driveway cleaner that is all phosphoric acid...I cut it with water...after I wipe it dry it sometimes leaves a sticky residue thats really difficult to get off...any idea how to not have this happen? What I have been doing lately is : soak the panel and scrub with stainless steel wool, keep it wet foor 10-30 mins, wipe dry and immediately wipe with lacquer thinner...but I am wondering if I am wiping away the protection with the thinner...your thoughts appreciated!
so it would be beter if i could do this inside an garage not outside in the moist ocean air the phosphate acid wont dry if it is to much humidity or does that not have any affect
I have also been using it for 20 years or more in restorations. It is best if keep wet while its working, then wiped off. Don't let it dry on panels you intend to paint, unless you re-wet and do it again. IMO, do not wash off with water as some suggest. It just allows flash rust. I also keep some in a container that I drop hardware into. leave it in 1-2 days, bring it out and dry it off. It leaves a nice Ferris phosphate finish, very similar to many factory finishes. It's a good way to save old hardware.
ok now i did a test on three types of phosphor acid .first is rustremower propower it turnes the rust whiteish . the second is 60% pho and it turned the rust black the third wich is intended for lime and rust removal has done nothing so far so if the rust turnes black is it ok or is it the 60% pho to strong or simply wrong for this use
I have derusted using phosphoric acid in different forms many times. -naval jelly stays in place and works without running off. -ospho seems to cost less. -blue lightning is strong and works quickly. Apply the acid and, if possible, scrub the area with a wire brush to help it work down into the rust. When the rust is gone, I rinse it with clean water, force dry it immediately and prime it. The acid etches steel lightly and helps paint stick. I have not been happy with the phosphoric acid solutions which you don't wash off. Body work I did 40 years ago is still rust free under the paint so it works. more recently I've used electrolysis to remove rust. It is messy and requires a big tub and heated baking soda and water. The plus lead ofthe charger goes to the sacrificial steel anode the minus to the rusty part.
do you mean to tell me that someone would complain thats this is a old thread? i seem like every day somebody's saying "do a search"! this is some good info here. i just cleaned my 30 coupe visor, getting in ready for primer and i'm doing this exact thing. it made my 82 year old visor look like a reproduction part it came out so clean.
This is intresting. i use a off the shelf solfatizer often, but it seems to only work well at a cetain temperature, like if i pass the torch lightly just to evaporate the humidity but if i warm it a little more it doesnt work as well and of course if i apply it on cold steel is the same. I kno cause i did some tests. The part that i warmed lightly lasted under the weather for a whole year b4 filler n paint w/out the slightliest sign of rust. The others, both the one aplied on cold steel or on hot steel lasted the 1st rain and then rusted. nerdless to say its hard to get the right temp. I have phosphoric acid at work as i work on a lab, and its super tuff, if a drop gets on your hand it burns it off. im guesin you guys dont have this type, also cause if you drop water in it it kinda "explodes" it needs to be mixed/diluted in a certain way.
found this one just in time, lots of good information i will need to use in the next few weeks on the Nomad.
Okay, so I applied a heavy coat of OSPHO to my surface-rusty 1951 Chevy coupe body shell a couple years ago, right after it was sandblasted. I did not scrub or wipe the OSPHO off afterward and it has left a shell of black that can be taken off with a wire brush. Do I need to get that all off before I can prime the body? Or just sand it enough to scuff it? I have heard both and I'm hoping someone with real experience can tell me for sure. (It's going to be messy and perhaps a bit dangerous to get all of that surface stuff back off so I'm hoping I can leave it!)
That's the biggest problem with a thread like this, everyone is all gung ho on the rust removal process and often getting the paint to stick is rarely mentioned. Someone else comes along, reads all the rave reviews on how easy the rust came off, and does exactly what you did. Just as it's difficult to get scale out of pits, removing acid residue from the pits is equally challenging. So someone unknowingly will paint over leftover residue in the pits and have paint lifting issues down the road. Good thing you checked first, paint materials are rather pricey. Some epoxy primers are not compatible. (House of Kolor, SPI, others?) You're spraying an acid on the metal surface, and in some cases given acid residue they will indeed react months after paint application, causing lifting/delamination issues. I would suggest to figure out what primer you intend to use and then see if it is compatible with these conversion coatings. If not, you'll need to re-think your strategy. The reason I suggest starting with identifying the paint first, is that Ospho, Picklex, etc are less forthcoming in putting out any info about compatibility issues. Paint manufacturer's will be more up front about what their products are not compatible with. Nothing against using the processes described in this thread, but you need to insure you have cross link compatibility from start to finish on your paint job. Better to find out before buying products that won't work together.
Thank you, MP&C. Good advice. It's not that I hadn't thought of this before, it's that I had a bare metal body with surface rust rapidly reappearing and no time to do anything else with it. Fortunately it's only the basic shell. The hood, fenders, doors, trunk, etc. are all still in original paint. I'll head to my local paint guy and start quizzing him on compatibility issues. I may end up choosing my paint brand based on that alone.
A few decades ago a painter taught me about using Rustmort as a pre paint rust preventative/treatment. When I learned it was essentially phophoric acid, diluted, with a dye, I just went to using straight (various concentrations, 80-90%) and doing my own dilution based on perceived need. Many folks are using phosphoric acid without knowing it due to their preference for a trade name such as Naval Jelly. Over years of use I've made some mistakes and seen some different outcomes, pictures to follow. Yes, use eye protection, well ventilated area, gloves. Water is good to have around for quick dilution if spilled, whether on you or other surfaces. Drops on concrete will end up etching the surface and leaving a white powdery spot if not neutralized. I don't find it as good on existing rust that's more than the flash variety without some form of removing the accumulated rust; brush, blast, DA, whatever. The sticky, somewhat lumpy residue some have mentioned is a result of not washing off the reactive material soon enough before it dries. Depending on ambient conditions and the amount of rust working on, I'll wash off the working acid coating anywhere from 1-4 hrs, but definately before it dries. If it dries, you'll need to sand off the residue (yes, use some form of repirator, no sense attacking your lungs.....you'll probably live longer than you think and will some day say, "I shoulda........") Here are a couple pics of some different outcomes. The model a coupe body I stripped the paint with stripping discs, and applied the acid with a brush within the first couple hours after stripping a side. A few hours later washed with straight, hot water, then dried. The blackish/grayish color is the norm. The deuce chassis the body is sitting on was treated about 3 years ago. When I got it it was covered with a moderate layer of flash rust so I applied the acid with a red scotchbrite pad. Yep, work fast, the acid eats the pad eventually (may have to switch to that stainless pad mentioned above for longer service). In our somewhat humid climate here in western Wa. St. it's remained rust free for the whole time. The splash panels were interesting to me. They are all from a '65 Dodge but are apparently of a differing alloy from one another. All three peices were run through the glass bead cabinet to depaint/derust, then coated with the acid, washed/neutralized after about an hour. As you can see, the fender panels got a goldish tone, the under rad panel more of a rainbow gray/red/blue. Similar looking to some plating processes that also use acid.
I just used this method yesterday on a pickup hood. I had painted this truck in High School, 31 years ago, and am redoing it for my dad now. Of course I used lacquer primer back then. because lacquer primer doesn't keep out moisture, especially after that long, this hood was covered in rust spots. After alot of thinking, I used a grinder and #40 grit to carefully remove as much as I could, then a D/A sander and worked it all good. Visually, I removed 95% of the visible rust, but I knew there were a few faint spots still. I was unable to find anyone around here that sold Phosphoric Acid, but alot of stores sell NAVEL JELLY. Same thing, only thicker. I applied it and let sit for 10 minutes, then washed off with water and a rag. left a nice coating on the metal. The little bit of rust showed up as dark spots which I hit with a wire brush on a drill. I then reapplied JELLY to those bare spots again. Hood looks great and I feel like I have done all I can to make sure this lasts. I am going to D/A entire hood to bare metal, just to be sure that I have no compatibility issues and apply an epoxy primer tomorrow. Should last my lifetime.
I was following along with BugGuts saying "yeah, that's how" right up to the reapplied part with no further mention of washing it off again. The acid (which ever variety) needs to still be active as in 'wet' when washed of with ample water. If allowed to dry, washing even after sanding still leaves the problem down in the pits and pores. Blow dry with the shop vac then begin the 'normal paint prep procedure' i.e W&G etc... In Full Disclosure: This from a novice who asked the guy who manufacture's the epoxy I chose to use.
Always add Acid into water. To remember, what you did to the old car batteries, adding water to your battery is wrong for safety. Ago
Sorry. In my earlier post, I neglected to add that after I reapplied the jelly to the wire brushed spots, that I did wash off the panel again with water and a rag. Sorry if it was misleading. I was in a hurry and did'nt have time to proof my writing.
Yeah, always add acid to water. Im talkin 95/96% solphoric acid thou. Slightly stronger than the one/s you guys are using, i even question it might be too much. Solphatizer? well, maybe it doesnt translate this way. The label reads - Ferox "Soluzione solfatizzante" - (italian) Its a solphoric acid based solution, very mellow, so much it doesnt burn and once a drop flied into my eye n nuthin happened. Im positive that what solph. acid does to oxidized metal is solfatizing, or solphatizing? but again, it might translate diffrently. Id like to know if its the wrong word of course. Again, thanx for the tips everyone. Real handy thread.
I bought some Ospho to use on the inside of one of my fenders but the directions seemed different from what you guys are doing. Am I missing something??? Here's how they say to use it: RUSTED METALS - OSPHO is a rust-inhibiting coating - NOT A PAINT You do not have to remove tight rust. Merely remove loose paint and rust scale, dirt, oil, grease and other accumulations with a wire brush - apply a coat of OSPHO as it comes in the container - let dry overnight, then apply whatever paint system you desire. When applied to rusted surfaces, OSPHO causes iron oxide (rust) to chemically change to iron phosphate - an inert, hard substance that turns the metal black. Where rust is exceedingly heavy, two coats of OSPHO may be necessary to thoroughly penetrate and blacken the surface to be painted. A dry, powdery, grayish-white surface usually develops; this is normal - brush off any loose powder before paint application.
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