Source for Phosphoric Acid or similar compound for acid dipping?

[LOGDOG]

Guys and Gals,

   I'm looking for a source for Phosphoric Acid or a similar type compound to be used for acid dipping and rust removal. I wondered if any of you have used this method and maybe had luck finding a local source for it from say one of the big box stores or chain type hardware stores? I've found plenty of sources online but thought maybe a local source could be found. Time to clean some tools and the like that moisture has gotten to here in the south.  : All help appreciated. 

LOGDOG

[Left Coast Chris]

I used muratic (not sure of the spelling) acid to remove rust................ got it from one of the paint chain stores.   Any painting store should have diluted acid to clean steel.... unless some regulation has prohibited it in the last few years.

If you can't find any acid......... I believe the automotive stores still cary navel jelly.....I used it to clean out the inside of a rusted gas tank....it worked great but for a big job it might be a little spendy since they seem to sell it in small amounts.

[tcsmpsi]

All the time and for many, many years.  

I get mine (OSPHO) from one of the local lumber stores, for what I use on 'rough' work.  Not what I use in the shop for firearms.

Usually in the paint section.  I posted something about this earlier in some thread or other.

It turns iron oxide (rust) into an inert iron phosphate.  Poof!  No more rust.  

**just brushes on with a paint brush, or you can dilute it a bit and immerse smaller items**

[LOGDOG]

Great ...thanks guys. I had read that muriatic acid can actually encourage rust and turn the metal black. I'd like to avoid that. I'll check the lumber stores here and see what I can find. I'll post my results for anyone else interested.

Thanks again!

LOGDOG

[Bro. Noble]

We use an acid in our rinse water in the dairy barn.  It's supposed to 'put a shine' on stainless steel and glass.  I believe it is phosphoric acid,  but I'm not sure.  I'll look in the morning.  It is available at any store that sells dairy supplies,  but it may be too dilute for what you want.  We get it in five gallon buckets,  but it is also available in gallon jugs.  It's not very expensive.

[Raphael]

  Ammonia is an acid, has anyone tried it on steel?

[Beweller]

Ammonia is not an acid.  It is an alkali.  It will not remove rust or form a protective coating on steel.

Hydrochloric acid (muriatic acid [spelling?])is good for removing rust, but the cleaned item must be washed thoroughly to remove all traces of chloride--which promotes rust.  For this reason, sulfuric acid (dilute) is often preferred.  There are "inhibitors" for these acids that reduce the attack on the base metal.

Glycolic acid is used in many commercial rust removers, and is less agressive towards the base metal than the mineral acids.

[brdmkr]

I have a homemade electronic bore cleaner that uses a mixture of white vinegar and ammonia in solution with an electrically charged rod in the bore (a 9 v AC/DC power supply).  It really works well to clean up old militrary rifles.  I don't know what your intended use for the phosphoric acid is (how big your tools are), but you might be able to rig up a reverse electroplating rig to remove rust similar to the bore cleaner.  I know that archeologists use a similar setup when restoring iron artifacts.  If you are interested, the negative charge would go to a sacrficial piece of metal in solution with your tool (I use a 1/8"steel rod, not stainless).  This metal should not touch the tool.  The positive charge would go to the tool.  You have to use DC current as I have been told that AC current removes and then replaces the rust .  I don't know if that is so, but it seems possible.

If it is working, the solution will bubble when the electric is on.  If you decide to do this, post or PM me because I would really like double check on where you attach the electrodes (+ - configuration)

[LOGDOG]

Nope ...haven't tried ammonia. Let me tell you though ... today I found some Phosphoric acid at the big box store that sports the orange letters. Found it in the paint section with the alcohol and other solvents. It was about $13.00 a gallon. I bought 4 gallons and a new 5 gallon bucket to make a little dip tank. I had some long bicycle chains that had gotten corroded. I had used a wire wheel trying to clean them but even that wasn't able to get into all the nooks and crannys. The chains are about 80 feet long each +/-. I dropped the first one into the bucket, let 10 minutes go by and pulled it out onto my blacktop drive. I hit it with the water hose and it blasted the solvent and the majority of the rust off. It nearly looked brand new after just that first dip. I dipped one chain twice, the other three times and they're as good as new. After the dipping and rinsing was over I put about 2.5 gallons of diesel fuel and 1/2 gallon of oil in another bucket and dropped the chains down inside to soak overnight and let the oil get in everywhere it needs to penetrate.

  The acid dip was a life saver for the chains. I took a wide flat file that had rusted so bad that the ridges in the file had filled up with rust (thought it was ruined) and dropped it in the solvent for about 15 minutes. It came out clean as a whistle. Same thing with a wrench that had some rust.  

  I'm thinking I might have a new addiction. You can really pick up some neat stuff at the flea markets down here for pocket change. Knowing that I can clean metal this easily makes some of those antique trinkets even more appealing. I think I want a big dip tank now.  ;D

  One question I do have ... how do I get rid of the phosphoric acid in an environmentally friendly way when I'm done with it?

Thanks for the tips guys!

LOGDOG

[beenthere]

............onto my blacktop drive. I hit it with the water hose and it blasted the solvent and the majority of the rust off. ........   One question I do have ... how do I get rid of the phosphoric acid in an environmentally friendly way when I'm done with it?
......

When will you be done with it?  When you run out of rusty things to clean up?  When you stop buying those neat rusty things?    Or when the solution doesn't have any punch left?  I think keeping it on hand would be the best idea.

Either way, seems diluting it would be the way to dispense with it..slowly.  Same as what you did when rinsing the chain off in the driveway......as I would say that was enviromentally friendly.

[LOGDOG]

Uhhhhh ....errrrrr.....ummmmm ...  : Since you put it like that I'd have to agree. ;D

Actually I read an article that said after Phosphoric acid loses it's punch it's safe to use as a liquid fertilizer if you can believe that. I mentioned that to a chemical salesman today though and he said he had never heard of it. I'm sure his grade of phosphoric acid is much stronger than what I used today though. I'm curious, how long does the stuff keep it's heat? I have no probelm keeping it around for a while until everything is shiny. I can always run it down to the city dept that handles that I guess. At least to get rid of the bulk of it.

LOGDOG

[Bro. Noble]

I checked on the acid we use at the dairy----it is Phosphoric acid.  I'm not sure what the concentration is but it is specifically for use in cleaning milk lines and bulk tanks.  It (as all chemicals used in milk lines and tanks) is approved by the FDA and I'm pretty sure,  must be bio-degradable.  I think the gunk that gets disolved in the acid would be more of a problem.  If it were me,  I wouldn't lose any sleep over it.

[tcsmpsi]

Logdog, neither the phosphoric acid, nor its residual iron phosphate is detrimental to the environment.  Now, a high concentration of it in a particular area might keep rutebegas from growing, but I'm not convinced that is a detriment.

I am glad you found some.  If I would have had any smidge of doubt you would, I certainly would have offered to ship you some.  I've been using it on tools and equipment and metal roofs for about 25 yrs.  I've had it all over me, and am sure I have ingested some. 

Though some might could argue that may have contributed to some mental deficiency, any of that was certainly a more natural process.   ;D

[jkj]

If you dilute acid with water before disposal, be sure to add the acid to the water.  Mixing acid and water releases heat.  Adding acid to water creates a very dilute solution initiallly and allows the heat to be released slowly.

If you pour water into a container of concentrated acid, the thermal reaction can explosively boil the solution and throw the acid into your face.  This may be undesirable.

[LOGDOG]

Thanks Bro. Noble, Tcsmpsi, and JKJ (everyone else too).

   I have to say, having the forum as a resource is like having the "phone a friend and ask the audience lifeline" on "Who wants to be a millionaire''. It's great to have such a collective wealth of experience close at hand - especially for a young guy like myself.

Thanks again.

LOGDOG

[tcsmpsi]

Logdog,

As far as how long it will keep, I've not actually found a 'cut off' time.  Only when the solution gets 'dirty' enough, do I change it out.  You can tell when that happens, as the process will slow considerably, and 'dirty' enough, will stop altogether.

It does put a whole new light on steel stuff, doesn't it?   ;)

I originally found it for refurbishing metal roofs.  Works well on new galvanized steel to paint, also.  In fact, it should be used on any of one's steel stuff before painting.  Makes certain there are no oxides underneath the paint and allows it to make an 'airtight' bond to the metal.

*One other little tidbit.  For immersing longer items, I use a long section of 4" pvc pipe, capped off on each end, and top of the pipe cut out lengthwise the length of the pipe.  I cut out boards for a base for the pipe to sit in (front, back and middle), and then cut a pipe lengthwise in half to use for a cover. 'Snaps' in place when you push it over the pipe in the stand.*

[Kcwoodbutcher]

Normally phosphoric acid does not degrade over time, only when it reacts with the items you are trying to clean.  Concentrated phsphoric acid (85%) will burn your skin due to the exothermic reaction with the water in your skin. As far as ingesting it- take a look at the ingredient label on a can of coke or pepsi.

[Larry]

LOGDOG, ya could try this method.

https://forestryforum.com/board/index.php?topic=6915.0

Cheap and effective.  Lota guys use the method to clean up old planes.

[SwampDonkey]

I've always heard that phosphates in fertilizer and laundry soap was bad for the environment, especially when it gets in streams and ponds promoting pond scum that robs oxygen from the water needed by aquatic life.

http://www.ec.gc.ca/WATER/en/manage/poll/e_plant.htm

[tcsmpsi]

The inert iron phosphate is a wholly different critter than the type and intent of phosphates used in fertilizer and detergents.   ;)

Been herbal and organic since long before I started using the solution and had studied it before applying it.  Been so long, I don't remember all the detail, but do remember that the iron phosphate was one of the few things approved for organic farming (which requires being environmentally beneficial).

Good for everything except rutebegas, of course.   :D

[LOGDOG]

I'm not sure if you read that thread that you linked SwampDonkey. Notice the comment it makes:

"But today, in many places, this process is tremendously accelerated by high concentrations of phosphorus and nitrogen (from fertilizer, for example) which enrich the water with nutrients, causing the aquatic plants to bloom."

   So in actuality the the phosphorous promotes growth in this case rather that hindering it. The reason that particular study wasn't crazy about it was because it was making algae in bodies of water grow out of control. If you've ever been around a lake that's overcome with weeds you can understand why. Plant growth out of balance is many times an undesireable thing.

  Tcsmpsi ...I'm glad  to hear you mention rutabagas. I thought only yankees like me knew what those were. Don't hear of many folks down hear using them.  One of these days I'd like to take a roadtrip over your way and see how you're coming along with your mill. ;D

LOGDOG

[SwampDonkey]

Here's a result of some Googling. Looks quite benign.

Here's a USEPA Fact Sheet on iron phosphate

USEPA Technical Document

Metal Finishes

[SwampDonkey]

I'm not sure if you read that thread that you linked SwampDonkey. Notice the comment it makes:

"But today, in many places, this process is tremendously accelerated by high concentrations of phosphorus and nitrogen (from fertilizer, for example) which enrich the water with nutrients, causing the aquatic plants to bloom."

Yeah I did and it states what I said earlier if you read on. Not sure what point your making.

'As the plant growth explodes, it chokes off the oxygen supply normally shared with other organisms living in the water. When the plants die, their decomposition uses up even more oxygen. As a result, fish suffocate and die, and bacterial activity decreases.'

I've seen what fertilizer runoff does to brook trout in fish ponds. When algae scum grows, robs oxygen and your trout croke. Brook trout are more sensitive than rainbows.

[DanG]

  Tcsmpsi ...I'm glad  to hear you mention rutabagas. I thought only yankees like me knew what those were. Don't hear of many folks down hear using them. 
LOGDOG

Logdog, I grow a batch of'em every fall down here in Fla.  Rooterbeggers is one of my favorite veggies.  Fresh ones are better than those big ol' waxed ones in the store, though I like them too.  Ya ever try the greens?  They're great when mixed with turnip tops or mustards. ;D 8) 8)

[tcsmpsi]

Yep.  Rootbeggers are just rusty turnips, for which I've always had a great appreciation.  ;)

Well, LOGDOG, you've got the talking part of the roadtrip done.  Look forward to it anytime.  Though, I am pretty much constrained to Sunday (ones I don't have class on) sawing at the present.  One never knows what tomorrow may bring, though.