Hot Rod Forum banner
Status
Not open for further replies.

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.
 

Attachments

See less See more
4
#52 ·
crashtech said:
The MSDS for Ospho does not mention any dichromate compounds, but their literature does, so it's not clear to me if it actually contains dichromate. But for the curious, here is a link to the sodium dichromate wiki page, as well as a link to the hexavalent chromium page (sodium dichromate is a member of the hexavalent chrome family). It's sobering reading.
20 + years ago I routinely worked in conversion coat process tanks and literally would be soaked to the skin with wash product containing hexavalent chromium. Wasn't until years later did I learn of the health risks of the compound.
Every time I hear or see the name I think of Silkwood.

If ospho is self neutralizing, I wonder why the MSDS says to use soda ash to neutralize in case of a spill?
 
#53 ·
Old Fool said:
20 + years ago I routinely worked in conversion coat process tanks and literally would be soaked to the skin with wash product containing hexavalent chromium. Wasn't until years later did I learn of the health risks of the compound.
Every time I hear or see the name I think of Silkwood.

If ospho is self neutralizing, I wonder why the MSDS says to use soda ash to neutralize in case of a spill?
Luckily for you, skin absorption of Cr(VI) compounds is apparently minimal, but inhalation is a severe hazard, as lungs are particularly vulnerable.

This could be a serious problem for anyone dry-sanding a residue containing sodium dichromate. I question whether it is even present in Ospho anymore, but until we can confirm its presence or absence, people should be warned against dry sanding the dry Ospho film.
 
#54 ·
a simple phone call to the tech line is all that is needed . call your paint mfg for info. DO NOT go by any info here. always consider the source and look for proof of claims made on the internet . the only opinion that counts is the mfg that will void your warranty . spi has told you time and time again not to use it unless completely neutralized and is the same answer you'll get from any of them. and drying overnight is not neutralizing anything.
 
#55 ·
crashtech said:
The MSDS for Ospho does not mention any dichromate compounds, but their literature does, so it's not clear to me if it actually contains dichromate. But for the curious, here is a link to the sodium dichromate wiki page, as well as a link to the hexavalent chromium page (sodium dichromate is a member of the hexavalent chrome family). It's sobering reading.
Its always good to knowthe risks of using automotive paint products...We've lost many old timers before their time...Wear proper protection when using all paint related products..

I have a bottle in front of me and right at the top it dosent list the ingredients but it does say: A balanced formula of,Phosphoric,bichromate,wetting agents,and extenders...What I dont understand is why a company would send someone out to use a hazardous material without proper protection ...sounds like a good case for a lawsuit....
Even the guy at the body shop that taught me how to use it told me to wear gloves and a mask when applying it and you always wear a mask when sanding even sanding wood can be dangerous Any kind of dust is bad for your lungs....and your skin will suck up any type of solvent or even handling lead is bad without gloves...Everything in this business is dangorous so read the precautions...
I dont care what paint manufacturer you call but if you tell them you used any other kind of product but their's they'll say we wont guarantee it ....Any one thats been in this business know thats all BS andwe all mix and match whatever product we like best for that particular job .... For instance epoxy primer is epoxy primer but I like SPI best so thats what I use. when it comes to paint were very particular about our favorite brands but if you use SPI epoxy under dupont and have a problem (I never did ) Dupont will blame it on the SPI epoxy and might even call it crap.dosent anyone find it funny that HOK says using any metal prep but theirs will give you trouble? no wonder their underpreforming materials are so expensive...they think we're all chumps...
The whole purpose of this thread was to explain how I use Ospho successfully because until I talked to SPI I didnt know anyone that had trouble with it .I never had it bubble up ,or had any type of adhesion problems and if anyone ever does , contact me and I'll help them achieve the same success as I do...To those that still argue about how it doesn't work I say show me, because I KNOW it works and works well and I showed it ...That should end the debate right there ..... Consider who is saying it wont work and their agenda or do they work with rusty cars for a living ....Sure there are other ways to strip paint and fix rust but not for me. Blasting and priming all in one day is a lot work even for a pro.if it can be done at all ,I wont do it and no one would blast a fender,prime it then blast another fender and prime that what a mess that would make. NOT only that we should all know by now how much damage a sand blaster can do to sheetmetal in the hands of a newbie ...blasting should be done by a pro and thats expensive and still no garuntee it wont be warped ...
So to anyone that says it wont work like I say it does ,I say: show (us) the proof ....I've already proved my side,so put up or shut up ,this is getting old...comments like consider the source go both ways and take much less time than I've put into this subject.... Or this one post for that matter...
 
#56 ·
I believe where at least some of the problem arises, is how the ospho is supposed to "self neutralize", w/o going back and neutralizing it w/at least a water rinse along w/scuffing it w/something.

I would think that trusting that ospho will completely neutralize- by just allowing it to dry overnight- would be an invitation to problems w/acid residue.

I'd be curious to see how litmus paper would react by applying it to a re-wetted section of overnight-dried ospho-treated metal, or dipping it into the rinse water after an ospho treatment.
 
#57 ·
cobalt327 said:
I believe where at least some of the problem arises, is how the ospho is supposed to "self neutralize", w/o going back and neutralizing it w/at least a water rinse along w/scuffing it w/something.

I would think that trusting that ospho will completely neutralize- by just allowing it to dry overnight- would be an invitation to problems w/acid residue.

I'd be curious to see how litmus paper would react by dipping it into the rinse water after an ospho treatment.
====================================================

Se this is the whole issue here that I don't want to be involved with at all.

Like I told mike two years ago, YES the way he uses it and the part setting for 6 months it will self neutralize enough that a DA and wax and grease remover will work under an automotive product.
It neutralise's with deteriorating age, not in 24 hours.

Flash rust is the painters best friend, IF using epoxy.

By the way where or what happened to the expert that was going to come on here and explain how this film will not affect an amines, polyol or polyester the three common things used in the auto refinish business.??????

Remember and here is why he is not here, this market does not pay their light bill, it is industrial that supports them, oil based, latex's, acid etches, etc.
Those products could care less about an acid film.
 
#58 · (Edited)
Everybody screws up

deadbodyman said:
Roger,
Skip foose is also famous and I see him screwing up a lot.....
I've seen two guys on tv suggest putting tranny fluid on your car to protect the bare metal also...
My point is follow my instrutions on its application... it works under any primer I dont care whos name is on it ....If someone had a problem ,they did something wrong ...Pros screw up on a daily basis just ask one if they ever forgot to add hardner to primer or paint and we use mix the stuff every day..
After all if you want to know how something works wouldnt you want to ask someone that uses it without any problems.
If you wanted to build a guided missle who you going to ask ? Hamas or the americans..
For 15.00 its a cheap way to find out for yourself, try it my way and let us know right here....
When I reread this I sill dont understand how you think I attacted you or the pro whos opinion you respect so much..It was not my intent...Everybody screws up.I'm no writer and sometimes I'm misunderstood.Nor was it ever my intent to get on a soap box or try my hand at grandstanding ... I'm simply tring to explain how to use it without problems..The directions on the bottle are a little vague and I use it a little differntly (example :some guys applied it with a rag ,thats a waste of time)whether you try it or not ,its not my concern... but many will ,whether I wrote this thread or not and have trouble ,this is for those that do try it...
I could'nt find that post in that thread so I dont know what he said about it or if it was the first time he used Ospho... Phosphoric acid is the main ingredient in Ospho, navel jelly and etch primer... Ospho out preforms all of them...but I've never used straight Phosphoric acid and I dont use any other rust treatments (they just havent worked for me)...all my comments are strickly concerning Ospho...
I did however read a lot of posts by a lot of pros stating that laying down epoxy then doing body work is the wrong approch and will create adhesion problems...so I say they're wrong about that too...I also saw one of our most respected members posts (under another name) that confirm this so I feel better about that...I thought I might have been screwing that up too ,all these years....
This thread and the videos were posted as a request by other members and moderators,it was never my intent to be anything else but to help them... I'll ignore all other comments from here on, that arnt related to how to use it or to help with any problems that might occur using it...To all the hundreds of members that have PM'd me that tried it sucessfully ....Thank you for the nice comments.....and not getting involved in the debate like I asked...Mike O.
 
#59 ·
If I were to use ospho, I know I'd be flushing it w/copious amounts of water to be darned sure there was no acidic residue. Overnight or after a week or a month. Whether or not that's actually necessary- for ME- is a moot point, I'm just too anal to do otherwise.

But the bottom line would seem to be, that as long as there's no residue- of ANY type- left after a treatment w/ospho, there should be no problems w/adhesion from having used the ospho in the first place.

I realize that rinsing/scuffing negates at least a portion of the convenience of using ospho in the first place. But to assure there was nothing left behind, I personally would be using a scotch pad w/a lot of water to be as sure as I could.
 
#60 ·
Also ,When its done its job of protecting bare steel from surface rust and your ready tp prime,it can easily be sanded off with 180 ,so you can sand it completly off if you want ,there's never been any doubt that it does protect against surface rust...So you just sand it off one panel at a time,prep and prime .and not worry about any kind of reaction with the primer... sometimes I get carried away sanding because it looks better and better the more you sand and sand it off( it'll actually start shinning)..but I also remove the black from the heavyrust with a wire wheel and reapply until the rust spot stops turning black...so I'm removing the rust not converting it...it dosent say anything about that in the directions either....But keep in mind the automotive industry only accounts for 1% of it total sales its mostly use for big projects like metal roofing and those big water towers ,mostly people buy it 200 gallon s at a time...its been around forever...As faras neutralizing with water goes ,all I can say is I never did it like that, I just sand or scuff then dewax...
Gentlemen, I gotta go visit my new grandson born saturday ....
 
#61 ·
Great Post! I've used diluted phosphoric acid (concrete etcher sold at lowes ) to treat rust but always neutralize post treatment going over the area with a water wet shop towel first to get the heavy stuff (i will not use a scuff pad once i have neutralized since i believe that would rub in traces of acid into the metal. I wire brush and then use denatured alchohol over the clean raw metal, then I prime.

never used ospho but now I'm curious as to the content...I know that alot of acid treatments like ppg dx579 use phosphoric acid and light detergents in their mix, however the white phosphate film that is left MUST be rinsed off or you will HAVE adhesion issues.
 
#62 ·
Welcome aboard, racer_inboston05!

I'm sure you know the difference, but for those who might not- Be REAL sure that you are using dilute phosphoric acid and NOT muriatic acid (aka hydrochloric acid)- which is also sold as a concrete treatment/cleaner.

I'd even go as far as to say it's probably better to just use ospho instead of diluting your own phosphoric acid.
 
#63 ·
I believe thats where people get messed up,by spraying over the coating without any prep it looks like clean bare steel .... I dont know about what you are using but when I'm ready to prime I just sand with 180 then wipe with a wax & grease remover ,its how I was taught years ago I was skeptical back then but that first car is still around after 25yrs and it really looks good...the next time I run down to Fla I'll have to snap a shot of it ,The guy and I became pretty good friends durring and after I did that car.
I've never used water...Does the stuff you use protect against surface rust for months ?
The phosphoric acid content in Ospho is 45% I'm not exactly sure what percentanges are of the rest of the ingredients...
Have you ever had any adheasion problems with what your using ???
I'm sure there are other products out there that work just as well but its like bondo ,when you find one that works just the way you want it you never switch unless you have too...
BTW,I was talking to a member on the phone this morning and when I said something about using wax & grease remover properly and I explained you dont just wipe it on ,he didnt know that ...it needs to be wiped off while its still wet or it does nothing ....I'm sure glad I caught that ...sometimes the simple things can be the cause of a failure or a problem....and easily overlooked when troubleshooting....
 
#64 ·
cobalt327 said:
Welcome aboard, racer_inboston05!

I'm sure you know the difference, but for those who might not- Be REAL sure that you are using dilute phosphoric acid and NOT muriatic acid (aka hydrochloric acid)- which is also sold as a concrete treatment/cleaner.

I'd even go as far as to say it's probably better to just use ospho instead of diluting your own phosphoric acid.
OMG YES !!!!!! :sweat: theres are many kinds of acid and I dont play around with any of them except citric (not to be confussed with nitric) ....It tastes pretty good....
 
#68 ·
cobalt327 said:
Welcome aboard, racer_inboston05!

I'm sure you know the difference, but for those who might not- Be REAL sure that you are using dilute phosphoric acid and NOT muriatic acid (aka hydrochloric acid)- which is also sold as a concrete treatment/cleaner.

I'd even go as far as to say it's probably better to just use ospho instead of diluting your own phosphoric acid.
oh my, Thank you very much for having me in this wonderful place everyone!!!!

OMG yes, only PHOSPHORIC acid please! and I'm not sure what the content is of the top of my head but the instructions say to dilute 50% with water and water does neautralize it. and yes stick to brands that you like...
 
#71 ·
Chopper ,
The only products I use on metal is Ospho and epoxy primer..I never liked rust encapsulaters and theres just no need for etching primer,the ospho etches the metal.I'm not sure what lizard skin is..
Sorry to leave you guys hanging with the heavy rust vids I've been busy with a bunch of other projects and havnt even touched the plymouth for months but I'll make a special effort and get a vid posted in the next two weeks. I really need to get these front fenders done anyways.
 
#73 ·
Thanks for the reply deadbodyman. Is the epoxy similar to a high build in that it seals of the metal to prevent any contamination/humidity? The Lizard Skin is a (2) part sound and heat control that comes in a kit with a spray gun to do the interior/firewall/trunk etc. have'nt used it yet but seems like a good idea with many of the cars that I work on....that is they leak...and regular sound deadener and heat stuff is like a sponge
 
#76 ·
I just read the wiki on lizad skin. I thought it sounded like a two part. Has anyone used it? I've always used 3M body shultz (rubberized,paintable undercoating) But I'm always open to any recomendations that'll get the monkeys off my back (3M Dupont etc...).I have seen some shops use truck bed liner, it looks good and paintable but I havent tried it myself.
As for epoxy primer.
Nobody disputes that using epoxy isnt a good idea.It's been discribed as putting a condom on your car.I'm very particular to what brand I use and found SPI has the absolute very best as a matter of fact I wont use any other epoxy and I dont dare use any other phorphric acid solution...One of the things I like best about SPI is that you can build it and it sands fairly well. personally I always do my metal work first then start out with 2wet coats of epoxy and let it cure for a few days,then I sand it with 180 and do my filler work on top of the epoxy then a few more coats of epoxy to seal everything up (like an epoxy sandwich) Theres really no need for any other primers but a good 2k (over epoxy)would be much faster and even more buildable if your filler talents arnt quite professional enough I've used The SPI 2k primer and found it was also excellent...
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top