Kyle's 77 Cutlass

Has any one used phosphoric acid to clean rusty parts? I have been looking into this, first started with molasses which you have to soak for 2 to 3 weeks. Then I found muriatic acid which people say it works well but have to use caution when using. So now we are at phosphoric acid, is their a mixture ratio with water or you just use pure? I have looked and I can't find anything with ratio's or procedures to clean parts.Any one done this before? Advice is very welcome

TripDeuces

Coca-Cola contains phosphoric acid and I know it removes rust.

In fact many sodas do

1969w3155

Why not use Evapo Rust?

dancutlass

Coca Cola can remove a little rust, but as far as I know it only contains about 0,05% phosphoric acid. So the ability to derust with Cola is very limited. There are also some ready-made products containing Phosphoric acid. I used Pelox RE on my engine, but I don't know if it's available in the US. Also heard of some, that they bought 85% phosphoric acid in the drugstore, mixed it fifty-fifty with water and used it as a rust remover. Just haven't tried that myself.

MDchanic

All of the common "MetalPrep," "MetalReady," etc. surface treatments are essentially phosphoric acid solutions +/- a bit of one thing (like hydrochloric acid) or another.

- Eric

Lady72nRob71

And also these are rather weak for removing rust. They also etch your parts for painting - their primary use.

Evaporust is an widely available, economical rust remover, about 10 bucks a gallon. It works, but requires the parts to be soaked anywhere from a day for light rust to a week for heavier rust.

There is another industrial version called LIGHTNING, for about 40 a gallon and will derust in minutes! Light rust gone in 5-10 minutes, heavier rust in a few hours. This is a more concentrated acid and MUST be washed off well afterwards.

Whichever you use, the stuff will get dirty but can be filtered and reused, as long as it is kept covered to prevent evaporation.

Run to Rund

Keep baking soda and water in case you get the phosphoric acid solution on you. Also, baking soda is good for neutralizing the acid left on the metal.

70Post

I think you may find that these acids will act more as a rust convertor than a rust remover. Iron oxide turns to iron phosphate....but you still have the "converted rust" laying on the metal.

You're better off spending a bit more and using something like EvapoRust as already mentioned(more like $20-22/gallon at places like O'Reillys Auto Parts)...it seems to actually remove the stuff as opposed to convert it. It's not perfect but you don't have the concerns about eating away the metal itself (you do need to fully submerge the parts in it), etc.

TripDeuces

http://www.theruststore.com/Rust-Rem...art-W22C2.aspx

Article on common rust removers

oldsguybry

ahhhhhhhh , good to know

Kyle's 77 Cutlass

K,thanks for the info

66-3X2 442

I do a lot of phosphate plating and have since 1993. I've tried everything,blasting,all kinds of acid etc. I use muriatic acid for derusting parts prior to plating. I tried using a baking soda solution to neutralize the acid but it left a film on the parts. I finally started just taking the parts straight out of the acid and quickly washing them with high pressure water and going straight to the phosphate tank. This works very well with hood hinges because it's really the only way to clean the rust. You can blast a hinge till you're blue in the face and you still can't get down between or behind the overlapping arms clean of rust.If you just blast the hinge,the grease will turn loose and streak when it goes into the hot phosphate tank. The acid will get in there and do the job. When I do any parts,I clean/degrease them in a cleaner,carb cleaner works great or I take them to the machine shop and hot tank them. Once the grease is gone,the acid process begins,then the plating process is completed. Remember when using muiatic acid,use only plastic containers,that's why muriatic acid comes in plastic jugs. DO NOT leave muriatic acid in an open container indoors,it will rust any and everything exposed to it. I use a five gallon plastic bucket with a lid on it for storing the acid and I leave it OUTSIDE. Another note about using muriatic acid,do not leave parts in it for long periods of time,it will etch it. It just takes time experimenting with using it and you don't need new acid every time. The older it gets,the longer it takes to clean parts and it easier to control the more diluted it gets. New acid cleans very fast,so keep a check on the cleaning process and you will get a feel for how it works. You can get large plastic pans or containers to do the hinges and large parts. I use a smaller 2 gallon bucket with drain holes drilled in it for small parts like bolts,washers,hood latches,brackets stc. Just put the 2 gallon bucket inside the 5 gallon bucket and let them soak.

Run to Rund

As a chemist, I have a healthy respect for these mineral acids like phosphoric and hydrochloric (muriatic). Wear good eye protection, gloves, and keep a hose with water flowing ready when using them.

66-3X2 442

You're a chemist? wow,that's neat,never knew what you did for a living.

oldsonharmont

It sounds low tech, but I like vinegar to gently remove rust from steel parts. The trick is to let 'em soak over night in the garage because the wife gets mad when I leave parts soaking in the kitchen.

Lady72nRob71

I heard the apple-cider variety works even better. I bet it tastes better, too!

Rickman48

In my experience with Metalprep, we only used it, in a 50/50 mix, to kill surface rust that may have formed on bare metal while sitting in the shop, prior to priming the vehicle, or after grinding out a rust spot in the middle of the panel, before filler.
Never used it on like a rusty frame - still must be ground out - the rust isn't gonna fall off.

citcapp

Apple Cider vinegar works very well for rusted nuts, bolts and small parts. Cheap fix. Never used it on any thing larger

Kyle's 77 Cutlass

Thanks for the great explanation. One thing you said,do not leave parts in it for long periods of time,it will etch. Some guys say it is a good thing to etch,helps the paint stick better.True or false?

66-3X2 442

I do not paint parts that I acid clean,I only plate them. The problem is,if you acid them,they will rust if you don't put a rust protector on the parts. If you put a rust protector,they are hard to paint. If I was painting the parts,I would just blast them.

Bernhard

Sand blasting is the way I like to clean/remove rust from parts, surface is ready for paint or plating after a good blow off with clean air from the air hose.

jdana24

I'm not sure what you are removing rust from, but I thought I would show you the before and after shots of removing the rust from my metal top rails using electrolysis. Also, attached is a photo of my makeshift container (kiddie wadding pool). I put in 12 gallons of water, 12 tablespoons of washing soda, and bought a $1.75 piece of scrap steel to act as the anode. I used a regular battery cable and attached the positive cable to the scrap metal piece, and the negative cable to the rusted top rail. I left it in the solution for 24 hours, took it out, and hosed it off, and all of the rust was gone, and had attached itself to the scrap piece of steel. I then sprayed it with some degreaser, rubbed it with some scotchbrite, and hosed it off again since it had a black scum on it. Then I lightly hit it with my wire wheel on a drill and it came out looking pretty good. Other than letting it sit in the solution, it only took about 10 minutes of my time to get this looking like it does. You should try it if you ever need to remove rust from an item, as it is very simple and you don't have to use any potentially dangerous chemicals.

oldsguybry

I think that maybe sandblasting is the best way to go if feasable . I know that certain parts are too big , and hard to get into all the nooks and crannys . It also has it's own set of dangers , like breathing in the dust from blasting . I like to blast outside .... I use a large piece of plastic to cover the part or parts so the sand dont go everywhere , and have an old piece of glass from a decrative round table to see through . My sandblaster is fairly weak , so I'm not worried about it breaking the glass or anything . I still wear safety glasses , and you still need a mask even though your outside . The only places I found that need some kind of acid or other method like mentioned above , are like areas where two pieces of metal are welded together like the rear wheel wells on a car .

RetroRanger

that looks pretty good Jdana...Ilike letting the battery do the work.

before anyone (else besides me) asks where can i get washing soda

here you go

washing soda from baking soda

arodenhiser

Or... for about $4 from Walmart you can buy this.....




I too have use the battery charge to clean parts and have been amazed by the results.

I gave it a try on my bumper brackets.

Before...



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During...

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018_zpsf5be026b.jpg

After a 48 hour soak and scrubing with a kitchen plastic scouring pad...

May082012005_zps881550e5.jpg

May082012006_zps3b77b8dd.jpg

Two days wait with a ten minute cleanup. I was shocked, and not by the battery charger. I used an old rotor from my Grand Am as the sacrificial electrode. I have done several other parts too.

Adam

Bernhard

I used to use a shop blaster untill I killed my DV compressor.I found it cheeper to use a sandblasting shop once I found one that I could work with. Now I save both time and money as well as my lungs. Not to be negative but the bumper brackets are still not ready for paint.What do you do with that nasty looking water?

coppercutlass

This is where i clean my stuff. i get to do it for free since my dad has worked there 30 years and i have shop pirvleges. I just thought i would share. Nothing can beat what this place does and it does not etch or weaken the metal.
http://www.redistripco.com/

pete324rocket

What 66-3x2+442 said about Muratic Acid is good information. Cheap and fast and an excellent rust remover, it beats all methods available to the home restorer. I tried the electrolysis, neat to try but a serious waste of time for less than perfect results, although a full scale plating operation will make it work.I've never had Muriatic Acid ruin a part by eating too much of it, but pot metal and aluminum is a different story and will be obvious with the instant foaming/eating of the part, once it is immersed.

arodenhiser

The was step one. The black you see is old paint that is still bonded on. These got wire brushed and a light sanding. This was a early test. With regards to the ugly water, if you remove you parts and let the water set for a day, all of the rust settles to the bottom. I would syphon of the clear solution into another container for future use. The bottom inch of scum can be washed down the drian because it is simply iron oxide and laundry detergent. the soda is actually just a catalyst and does not become any more harmful from this process.

The great thing about using this method is workes everywhere. I dida test with a set of bucket seat sliders that were so rusty I could get them to slide. After a few rounds of soaking the levers and roller all move freely. Better than the ones I planned on using. I would never have been able to blast the seat sliders clean.

Sorry I could not find pictures quickly. I agree that blasting is great, but without access to a large enough compressor/equipment the electric battery charger method is very useful and not harmful to you or any non conductive parts. It is also extremely cheap.

kitfoxdave

here are clead up bumper brackets... about 30 minutes in acid bath, rinse with water, then soak in baking soda and rinse again and dry. painted with POR 15 they look brand new!

Kyle's 77 Cutlass

That looks pretty Sharp

oldsguybry

I wonder if I had a container big enough I could turn my car on it's side and dip the rear QTR's in it for a while

tndrtgr

Here is how my husband did his Fury Convertible. It is from another site and a little long, but he has great pictures of the system he used.

http://www.forwardlook.net/forums/fo...=31027&start=1

oldsguybry

Whoa ! Now that's a project ! I love it .... He's very brave for taking on that restoration .... and I guess what I said could be done

Delmont 88 PA

I used Rust-B-Gone on my '67 Delmont 88 that had light rust covering the entire body. The method we used is on a previous post--if I find it I'll send it to you. It costs $26/gallon and seems to work well. The company suggest drying the part with air and rubbing it down right away with a solvent to prevent flash rusting. For small parts I put about a quart or so in a plastic coffee container and soaked them for 15 minutes to a couple of hours.

This is the link for Rust-B-Gone. http://www.envirotechcoating.com/Rust-B-Gone/

It's no miracle cure for rust but it does remove it instead of converting it. For large areas, like the hood, I soaked a towel to keep it wet for an extended period of time.

Next time I do this, if there is a next time, I'm going to try muriatic acid first since it is probably a little bit stronger.

Delmont 88 PA

Shown below is my post from March. Basically, you remove as much rust as possible through mechanical methods and the rust remover digs into the pits, etc. Oh yeah, sometimes you have to repeat the process but the end result is pretty good.

March post:
We are attempting to remove surface rust from the trunk lid of my 1967 Olds Delmont 88. So far the best process seems to be--strip, strip, wire wheel, 40 grit sand (DA), Rust-B-Gone and 40 grit again. Then it's ready for regular 80 grit and primer.

Just wanted to post this in case anyone else has a similar challenge. It's a pain but there doesn't seem to be an easier way....

Kyle's 77 Cutlass

Are you kidding me???? Wow that worked awesome

Kyle's 77 Cutlass

Where did he get the big holding tank?

Chesrown 67 OAI

You guys are a hoot!! I wish i know only about 1/4 of what the two of you know combined!!
Joes still working his chemical R&D to come up with the correct formula that will turn non-believers into Olds nutz!!

brddg

Exactly. I use muratic acid on large body panels that blasting can work-harden and warp with blasting. The rust will actually come up through the checks and cracks in the original lacquer paint. After you remove the paint ( I use an electric buffer and a 3M 9" soft pad with 80 grit at about 1200 rpm) pour the acid on and spread it around with an old push broom or similar. This process will actually get into the pits the rust creates. It will turn yellow as it works, rinse it off with a hose (not high pressure as you don't want to splash this on anything) dry and repeat. Then I use dish soap and a scuff pad to clean thoroughly and dry and blow off, ready for primer now. Wear two pair of gloves and a respirator and a long sleeve sweatshirt and treat this stuff like it will kill you. For smaller parts a blasting cabinet is just far easier and faster but they do need a large compressor to run. For the frame/radiator support etc you need a pressure pot blaster and the room associated with doing this. Wear a respirator when using the cabinet and sand blaster also.