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The Ospho Solution..(rust removal)

353K views 664 replies 61 participants last post by  Lizer 
#1 ·
This is the start of a thread dedicated to successful rust removal using ospho,a water based phosphric acid product I've been using professionally for many years.
Ospho has some advantages over other methods, mainly a DIY can do it at home inexpensively with little mess,fairly easily.
I'll try to answer any questions and offer some advice on the successful use of this product.
.....First,I'll start with the most common use : To remove surface rust That has accumulated on unprotected steel....Then heavly rusted and pitted metal,and using it to prevent surface rust of freshly stripped steel...
...
The pics below show the trunk floor and wheel wells I made for my old car.After making the pieces and screwing them together ,it got cold out and I put the car up for a couple months and the steel got pretty rusty.
In the interest of time I'll just do a spot to show how its done and what Materials you'll need.Bare with me I'm a newbie with the computer.
 

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#441 ·
Brian, have you done any research on rust converters ?? They chemically change rust into an inert material that stops the rust process and is paintable. I have been doing this for several years on my projects with good success. From what I've seen of your rust issue, it's minar and would be done in 10 minutes with a converter. I'm not dismissing your dilligence or desire to be "rust free" but even blasting will leave small particles of rust in pits that WILL return over time. The converter eliminates that.
 
#444 ·
Of course there are a lot of factors in why things rust, why they fail, and so on. Hell, I have all the sheetmetal to this truck out in the back yard. It was primed in lacquer primer and painted in lacquer paint back in 1979! It's been sitting in the back yard for 20 years un-covered and there isn't a single bubble or rust spot showing! The chrome grille, it's all rusted but I don't believe there is a single spot of rust other than along an edge or something where the primer and paint got thin. The moulding down the center of the hood has rusted through for some reason, but the rest of the hood looks good, just seriously faded lacquer paint.

For that matter, I have an old vintage gas pump out back that was sandblasted and primed in urethane "Tint Prime" from S-W 20 years ago, 20 years in the weather, again, not a spec of rust or failure showing other than the primer loosing color and turning to chalk. :drunk:

When I strip the paint off am I going to find the metal all rusted, I sure as heck don't think so, if it was after all this time it certainly would be bubbling or something.

Brian
 
#445 ·
Climate has a lot to do with it. The older primers had components not available today. Move your truck to Webster Florida at the end of two years you probably wouldn't recognize it. I would put out displays with old pitted rust, that had not rerusted in years. I would leave them out overnight and be there be a new layer of rust the next morning. For me if all the major paint companies recommend metal prep,with all their experience ,and technical know-how, and research and development I'll go with their recommendations.
 
#449 ·
You must not know how things are in in LOUISIANA.. I don't have to put that truck in FL to test what I test.. By air here,, I can spit in the Gulf of Mexico.. I'm 55 miles north from all the salt water I need... So it's been well tested my friend... We used PPG back then and ALL body filler was done With RAGE...

As far as rust goes... We watch it happen within Hrs here..
You won't sell me any acid, So no need wasting your time trying..Have a good day..
 
#448 ·
For the hundredth time follow the data sheet ,damp rag in one hand, dry rag in the other. In 30 years I never had a problem with metal prep. About 15 years side-by-side with Capt Lee in a booth that I don't remember any issues with metal prep or Rust away.
 
#450 ·
Well if PPG worked so great why would you consider changing? Let's get one thing straight you and I'll never agree on anything as for selling you anything I don't sell stuff anymore the rest of family does. I couldn't care less if you use acid or not. Have a great day:)
 
#456 ·
LOL... I changed because times have changed,,:mwink:

Some things isn't made anymore... You should know about that...

I have nothing to agree with you on..That's all.. Nothing between us..:nono:
And if your family is still selling it,,Your a part of it no matter how you look at it..:D
 
#451 ·
from your own web site .

U Reapply Metal Prep, dry with paper towel or lint-free cloth, and allow 2-3 hours for Metal Prep to cure. Prime and paint .



i have no problem with your product . just your instructions.
 
#452 ·
You can rest assured that if there was a problem here we would be right on it.I may no longer be involved in the sales aspect but this was my baby and I keep an eye on what goes in and what goes out. I don't think I can remember if there's ever been an adhesion problem with the use of our metal preps. Rest assured there will always be someone who can screw up a peanut butter sandwich by not following directions. My wife and I always commented how lucky we were there we received very few complaints about our products, pretty difficult today in the paint business. Everybody has their own way of doing things, and we certainly wouldn't try to sell a Chevy to a Ford guy.
 
#453 ·
pat, believe me . i have used drums of metal prep over the years. i started with nitrocellulose lacquer and have used everything since. in the 70's we discovered that chemstrip on vettes was killing us . thus began the dawn soap and water . in the 80's we discovered metal prep was biting use on the ***. the problem was traced down to just not rinsing well enough. the methods i use are not " my way ". it is how paint techs have designed this stuff to work. they develop a new product , we use it , we screw it up or they screw it up doesn't matter. if you are a professional in this trade you do it right and that is doing it the way the techs say to . i have to go by ppg -dupont- spi or whoever's tech sheets. and every one of them caution about not neutralizing the metal prep right . you can do everything right but once you pick up that gun a 100 things can blow up on you.
 
#454 ·
There seems to be a little too much perceived toe stepping on, and animosity growing in this thread. Maybe the hot summer days, or just anger at rust, I do not know. We are all trying to come up with the easy no work solution to getting rid of it, but I really do not think it exists. Rust removal is just plain hard, time consuming, dirty work.
I have tried electrolysis, that seems to work pretty good, but you need a waterproof non metallic container to do that. Cattle water tub, or a neighbors swimming pool for a whole cab?
I also has some success with molasses, and small parts, in an old crock pot. Both of these processes need some final clean up, sandblasting, sanding, or other work.
Wire wheels have been discussed. No need to rehash that.

I have found these abrasive impregnated rotary nylon brushes can be useful.
 

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#455 ·
Shine I agree with you, preps and rust removers that contain even small amounts of hydrochloric acid require a water rinse. The mastercoat de scaler we suggest rinsing it three times. We then recommend the prep to prevent flash rusting. As for paint and body it can be quite aggravating I'm happy not to have to do it every day.generally they are using the Mastercoat Primer over our prep and we haven't had any problems. Perhaps as a side note when using epoxy a quick rinse might be in order. What your take on that?
 
#460 ·
Glad to see this thread back on the upswing.

See area I discovered on the inside of my door last night. I wiped it down with a dripping paper towel of metal prep, then smoothed dripping wet paper towels over it, let sit all night. Peeled them off tonight. Took me all but 15 minutes. No scrubbing, no grinding. There looks to be some scale left, or maybe it's remnant of the sound deadener.

One thing, once those paper towels dried, they stuck like a ***** and I had to scrape parts of them off with a putty knife. I can see how a real towel would definitely be better.
 

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#464 · (Edited)
tell me about it I had set some used up towels on the fender next to what I was working on and they glued themselves down also... I rewetted them and they came right off.
I did try the wet sweat shirt also but it didnt work so well for me.when I came in the next day the towels were still soaking wet but they seemed to seperate from the surface which was dry and almost untouched when I peeled them back...so I went to work with the wire wheel...when I soaked the flannel it was dripping wet I placed it over the rusted area and using a paint brush I ran the brush over it pushing out all the air trapped between the two. I dont know what happend but I didnt get much when I tried a soaked paper towel at the start of the the first fender when I was just playing around either...mabee some saran wrap is a good idea. unfortunately it took a lot of the rust remover to soak the flanneland I'm worried that I wont have enough to finish this fender,so I put the flannel in an old coffee can and put the top on so if I do run out I can squeeze the liquid out of them and use it over again.
 

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#463 ·
ospho

I can't belive you people are arguing like this, everyone does things different, some right some wrong. But I can assure you when using Ospho brand acid just spray it on with pump bottle let COMPLETLY dry!!! no water rinse .Sand it a little or a lot , prime it any kind of primer and paint, you're done.It won't come back to bite you. If you don't belive it, try it your self and you will see ,quit telling people it won't work because it will. I'm not arguing just making a statement and I'm done. Thanks Steve
 
#465 ·
I did rewet the paper towels but it only took me so far.

I stripped my ENTIRE mustang using a wirewheel. However, the metal was not rusted and I was just stripping paint, it came out nice and shiny like Randy's picture.

My pitted roof on the other hand....it was sandblasted which did not get down into the pits, and the wirewheel wasn't getting down in those pits well either.
 
#466 · (Edited)
heres something you can try Liz,Brian this is for you too....first off that stiff braded wheel is great for the hevey stuff but a little too stiff to get down into deep pits especially if the speed is to high so you want to use the big cup wheel,its abit softer...
get some play sand or whatever blasting media you have laying around...put about a 1/4 cup on the rusted surface and using Ospho or uncle pats MS pour the solution over the sand making a paste (kinda like a buffing compound but very rough) ,then spread it around with a bondo squeegie evenly,then rewet the whole area and using the red scuff pad simply scrub that paste in good,all the sand will settle down in the bottom of the pits and scub that strubburnd rust out,after you've scrubbed it then rewet it again and use an old DA with a velcro pad and stick a scuff pad to it and run it over that area again then finally,using the softer cup wheel and go over again further grinding the sand into the pits...after all that just use the bondo squeegie to scrape the pasty mixture off and into something rince ithe area with fresh stuff utill all the sand is gone and let it dry....it sounds like a lot of work but its really not......I'm have really good results using uncle Pats MS when I use it the same way I use the Ospho....I've got to work on the wet flannel method some more its just not working that well for me for some reason...The flannel is stayin wet but the rusted surface is drying out.:confused:
 

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#468 ·
Thank you DBM for the technique of using play sand , great idea. At the moment I'm having some Rust remover/Descaler made up for further evaluation. This is a combination of acids and does require a good water rinse follow by the prep or Ospho. I will also have them address the wetting issue to see if we can improve on that.
 
#469 ·
pat, back in the 80's i attended a class that was being taught by one of ppg's techs. he normally did not do them but got stuck with it. unlike most that just promoted product he got into the failure side of it pretty heavy.
there were several painters there that had no clue and made every mistake you could . first and foremost was washing steel with lacquer thinner. this alone doomed the job. another was the way they used both dx440 and dx520 . both good products but if abused would destroy the job. the dx440 cleaner had to have a long flash time as it would not evap very fast off metal . the dx520 was a very good metal etch but was a little difficult to get rinsed off. people would rush it and not spend the time rinsing it.
in the old days you could almost get away with it but with todays top coats and primers you cant. they removed the sp from products and this made the prep process even more important. many cases of solvent pop is in reality blistering from the corrosive battery taking place .
like i said i have no problem with your product but i do believe it should be noted that if used under epoxy or polyester it should be well rinsed while wet .
 
#473 · (Edited)
pat, back in the 80's...
there were several painters there that had no clue and made every mistake you could . first and foremost was washing steel with lacquer thinner. this alone doomed the job.
I have a question about laquer thinner, Can I use it as part of the cleaning process as long as I use a quality wax and grease remover before applying epoxy? Of course I would allow adequate time for the flash to happen.

Did that make sense?

Thanks Jerry
 
#471 ·
Wow, since it looks like we may be done with all the BS, maybe I can explain in short why the confusion.
Not sure why I want to bother after seeing BS like I will do a ph test or half statements like it say it will help adhesion, with out pointing out that every one of PPG tech sheets on their acids say water, water and water.
Zinc rich epoxy in automotive refinish??, No such thing and you can figure it out after reading what I try to say.

First like I said many times, the automotive refinish is a very small market compared to the industrial market and products are different for a reason!!!!!

So when mail order companies buy acid mixes and slap their label on them, the industrial company that makes this product big business is industrial, remember Dead body man saying Ospho telling him, auto refinish would not pay their electric bill a year ago??

Now epoxy or urethane can be made 100’s of ways and this is why with the purchase of ameron seven years ago by PPG, (Ameron made only epoxies and the best in the world.)
I bet PPG has over 30 different epoxies but only one in auto refinish, why? The industrial grade will not work.

Neutralizing: If you are selling to stationary objects, or 3 MPH dozers you do not need to neutralize as a 30-50 % adhesion rate and a ton of zinc is perfect for the job but on a car or truck doing 70 mph if he hit a bug or stone a nice big chip is going to happen.
Zinc is a formulators dream but in automotive there is a most important factor that trumps everything, “co-adhesion this is not a concern or most likely not even measured in industrial, in automotive, if this is wrong you are in deep chit!
Zinc positive is rust and its weak point if too much is used you start to lose adhesion and or co-adhesion depending how it is used, 1percent to much mixed in auto refinish and you can really cause a mess.

I would bet from old knowledge, some of the Ameron epoxies for the oil stations may be in the 50% range, yet automotive epoxies may be 1-10% depending on they type of epoxy resin that is used in the formula.

So bottom line is both sides are right, depending on applications, I posted on a forum a while back about how I get over a 100 calls a year from metal treatment products that fail because they were not neutralized, like they are suppose to be.
The best one was the PPG shop in another post who wanted my opinion if ppg epoxy was bad, thirty minutes of questions, I said sir, you did everything perfect, and I asked you a lot of trick questions and can tell you the LF and K36 were just fine and with what you said as to how you did everything, the car cannot peel like you said.
Then he said what if I used this metal treatment the customer brought me and said use after blasting? I said we could have saved 30 minutes of me interrogating you. Oh that is one of those private label miracle metal prep sold by a mail order company that attacks do-it-yourself market because they don’t know any better.

Bottom, line, follow TECH SHEETS, or call me when the paint has a problem, if you give me the straight scoop on size, location of bubble and where, I can tell you, if you washed the metal with lacquer thinner, or did not neutralize the Ospho, or if you used merratic acid and can tell you if you used hydrochloric, as they all cause a different reaction.
 
#497 · (Edited)
Wow, since it looks like we may be done with all the BS, maybe I can explain in short why the confusion.
Not sure why I want to bother after seeing BS like I will do a ph test or half statements like it say it will help adhesion, with out pointing out that every one of PPG tech sheets on their acids say water, water and water.
Zinc rich epoxy in automotive refinish??, No such thing and you can figure it out after reading what I try to say.
-----------------------------------------------------response:
Pats zinc rich rust remover works pretty well. You dont rince it off while wet either...Like Ospho you want that coating so the bare metal dosent start rusting again after you've finished removing the heavier rust or after stripping paint.That zinc coating MUST be removed BEFORE priming.Think about it,the zinc disolves in the acid ,when the acid drys or evaporates the zinc remains,its stuck on there like the paper towel that was left to dry.theres no resins gluing it down so its not stuck on there very well...it needs to be sanded off and preped properly for good adheasion...Ospho doesnt have zinc but still needs be sanded to get the coating off and properly prepped before priming
------------------------------------------------------

First like I said many times, the automotive refinish is a very small market compared to the industrial market and products are different for a reason!!!!!

So when mail order companies buy acid mixes and slap their label on them, the industrial company that makes this product big business is industrial, remember Dead body man saying Ospho telling him, auto refinish would not pay their electric bill a year ago??
-----------------------------------------------response:
I have no idea what thier elec bill is I dontthink they do either I never talked to any accontants ....What I stated was automotive industry accounts for only 1% of their total sales.....Thats a LOT...
------------------------------------------------------------------------
Now epoxy or urethane can be made 100’s of ways and this is why with the purchase of ameron seven years ago by PPG, (Ameron made only epoxies and the best in the world.)
I bet PPG has over 30 different epoxies but only one in auto refinish, why? The industrial grade will not work.
----------------------------------response:
LOL,ILMAO..They're automotive grade dont work very well either....:mwink:
--------------------------------------------------------------

Neutralizing: If you are selling to stationary objects, or 3 MPH dozers you do not need to neutralize as a 30-50 % adhesion rate and a ton of zinc is perfect for the job but on a car or truck doing 70 mph if he hit a bug or stone a nice big chip is going to happen.
Zinc is a formulators dream but in automotive there is a most important factor that trumps everything, “co-adhesion this is not a concern or most likely not even measured in industrial, in automotive, if this is wrong you are in deep chit!
Zinc positive is rust and its weak point if too much is used you start to lose adhesion and or co-adhesion depending how it is used, 1percent to much mixed in auto refinish and you can really cause a mess.
------------------------------------------------------Response:
I'm not crazy about the zinc coating either its just one more thing to get off.
-------------------------------------------------------------------------------

I would bet from old knowledge, some of the Ameron epoxies for the oil stations may be in the 50% range, yet automotive epoxies may be 1-10% depending on they type of epoxy resin that is used in the formula.

So bottom line is both sides are right, depending on applications, I posted on a forum a while back about how I get over a 100 calls a year from metal treatment products that fail because they were not neutralized, like they are suppose to be
--------------------------------------------response:Thats usually the case when theres an arguement

_________________________________________________________________
The best one was the PPG shop in another post who wanted my opinion if ppg epoxy was bad, thirty minutes of questions, I said sir, you did everything perfect, and I asked you a lot of trick questions and can tell you the LF and K36 were just fine and with what you said as to how you did everything, the car cannot peel like you said.
Then he said what if I used this metal treatment the customer brought me and said use after blasting? I said we could have saved 30 minutes of me interrogating you. Oh that is one of those private label miracle metal prep sold by a mail order company that attacks do-it-yourself market because they don’t know any better.
----------------------------------------------response:
sounds about right...but if he was a pro he never would have used any of that crap in the first place.....that customer might have said it was media blasted but if the media was sodablasted it would have done the same thing, peel off...soda blasted metal is prepped differently....unfortunately sandblasted is a general term used that shouldnt be...
_________________________________________________________________

Bottom, line, follow TECH SHEETS, or call me when the paint has a problem, if you give me the straight scoop on size, location of bubble and where, I can tell you, if you washed the metal with lacquer thinner, or did not neutralize the Ospho, or if you used merratic acid and can tell you if you used hydrochloric, as they all cause a different reaction.
_______________________________
I agree completely.......Read the sheets.... They state very clearly let Ospho dry.
if you rince it off you might as well not use it at all....We want that coating...for now anyways...

I think that puts the "apply and let dry" thing to bed for good now...You cant really argue with the tech sheets.....
 
#474 ·
not only do we not know what is in that thinner today even worse is solvent will " set " anything biodegradable . this means you will have very little chance of cleaning it. first thing is soap and water. this will remove all of it. then a quality cleaning solvent. BUT lacquer thinner is not a cleaning solvent , never has been.
 
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