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Full Version: Oxalic Acid. Removing rust from Chrome the very best way! > VintageBMX Talk > Restoration Tips & Tricks
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Ted Carl
After trying some of the New School techniques listed here at VBMX and other forums, I can say without a doubt, that when it comes to rust removal, that I am going back to the Old School method I have used since I was about 10 years old cleaning beer cans. Aluminum wool, AC-500, Zep toilet bowl cleaner, Evaporust, and others all work, but all pale to the simplicity of this technique.

I have given Evapo-rust a fair shake, and fair share of parts. The stuff works good for some things, but is much slower, and much less effective than Oxalic Acid. Again proof is in the pudding. I have a Sting that I am working on, and here are some interesting results for you guys. This is an 18 hour soak.

Clamp Before


Bars Before


Forks Before


Dropouts before

Ted Carl
Headset before

Headset after. (Ok there is something fishy about this one! lol)

Frame before (original paint)

Original paint after polish

The biggest problem with Evaporust, and other products, is the quantity, and price, of the amount needed to do the job. It has to be soaked, and soaked for a long period of time. Therefore, gallons of the stuff are needed and that is very expensive, and it has to be filtered to be reused, and stored.

Oxalic acid is typically marketed as a wood bleach in hardware stores. It costs less than 10 bucks. All you need to do is mix a few ounces of Oxalic acid in a large tub of water, and soak the parts for 12-36 hours. You simply wipe the parts free of the rust occasionally with a white (soft, non-abrasive) scotch-brite pad, and you are done.

Rinse the parts off, and coat the insides of the tubing with LPS-3 rust proofing. Done. On to polishing...

The pitting will never go away, but you have not added any steel wool scratches, or scotch brite scratches, or any other damage. In fact, it will often leave the decals in tact! Especially if you cover them with tape first!

These parts above look completely unusable, but they are now perfectly show-able! Polish-able, paint-able, or ready for use, as is.

I have not decided whether I am going to powder the forks, and bars, black for a unique look, or polish and show chrome them, or use them as it.

I think I will still strip, polish and show chrome them, but I wanted to give you a really good answer to the popular question. "How do I remove rust from chrome?"

Oxalic acid, White scotch-brite, and a tooth brush. Nothing more, nothing less. A couple of dollars, soak it, wipe it, pull the drain plug, and rustproof the parts. Polish to taste, Done.

The results from Evapo-rust are not as good as this, and it does some funny things, like turning steel black, and removing black oxide coatings.

OXALIC Acid. AKA Wood Bleach. Powder form, hardware store.

[ April 01, 2006, 01:35 PM: Message edited by: Ted Carl ]
Next time I go to Home Depot I'm picking some up. Wood bleach you say? Which department would I look for that in? Paints and Stains??
Ted Carl

Dont forget to pick up WHITE Scotch brite pads. NOT the Meanie Greenies, or Radical Reds! Wimpy Whites are what you want!

[ April 01, 2006, 01:58 PM: Message edited by: Ted Carl ]
How do you dispose of it when your done?? I have a couple items I would love to use it on.
Ted Carl
Pull the plug in the laundry room sink! It cleans the pipes on it's way out! lol

It is just an Oxidizer. Spray it on your deck, rinse it off. It is not a hazardous material to the best of my knowledge. The container says nothing about it being environmentally unsafe.

Dont drink it, dont wash your eyes out with it, etc...
Jet Black
I'll have a look at thru one of our local Hardware stores & see if they stock it & what it's equivalent name is here if it's not the same. I have to agree with you the results are stunning , the price sounds right , especially compared to that Evapo rust snake oil.
What instructions does it give if you ingest it ? Drink milk or induce vomiting.
It says harmful to skin on the bottle , whats the burn factor like if you get splashed with it , it's obviously going to be proportional to the mixture....speaking of which "a few ounces in a large tub of water" is a bit of a vague mixture ratio

Looks awesome , a slow non abrasive rust (or anything) removal method over large surface areas is always preferable to a fast concentrated cleaning , makes for an even lift over the entire piece.


Motor City Mongoose
I used that stuff BITD to clean rusty beer cans for my collection. It would remove the rust and leave the paint on the cans, even as thin as that paint is. Of course, that was before most cans were aluminum! You can also get Oxalic Acid at a pharmacy. If they don't have it in stock they can order it for you-I had to do this BITD. You get some pretty strange looks from the Pharmacist when you are 10 years old and ask for Oxalic Acid......
Jet Black
I would have been about the same age when I was asking for Potassium Permangenate to make Salamanders evolve into land lizards (they don't evolve anymore using this method now what I've read) & change the colour of swimming pools. In all my searching on rust removal Oxalic Oxide has never turned up , Molassis & water was the only clean/green "soaker" method that showed up to remove the iron oxide from chrome.
I'll punch Oxalic Oxide into google , some other internet archive search engines & maybe even look through the hidden internet....pending on how interesting it looks & have a read up on what ppl have been doing with it over the years. It's obviously not a new technique or method , just another conviently forgotten method/technique in a world where brand names / hype / glitter & advertising
continue to dumb down the population into knowing what a wide variety of simple cheap OTC products can be used for.

I'll ask at the hardware store for Oxylic Acid first & see what sort of reaction I get , then I'll ask for "wood bleach" , blank stares are usually the norm for questions like this , hopefully I'll find a chemically minded person in the paint section , but I'll probably end up having to read the content labels on a lot of bottles before I find what I want.Failing that the local Pharmacy should be able to supply me with some primo grade Oxylic Acid , fortunately the staff are used to me asking for stuff by name & if they don't know of it they will ask the Chemist there direct for guidance....
I think I still have some old rusty beer cans here that still have the enamal paint & rust spots on them too No ring pull tabs on these ones , just 2 screwdriver holes punched into the top of most of them.....

i have a nickle frame to clean some light rust & oxidation off of, will this stuff work for it?? (Oxalic acid)
Ted Carl
It will work like a charm on Nickel....

What instructions does it give if you ingest it ? Drink milk or induce vomiting.
It says harmful to skin on the bottle , whats the burn factor like if you get splashed with it , it's obviously going to be proportional to the mixture....speaking of which "a few ounces in a large tub of water" is a bit of a vague mixture ratio

Funny you should ask. One bottle says Milk of magnesia, and DO induce, the other says large doses of water and Do NOT.

The mixure is by experimentaion. I filled the laundry room sink about 2 inches deep to cover the forks and most of the handlebars, and plunked the clump of what was left of the bottle from 1990 into there. Not quite up to the barcode on the bottle is all that I had left in that bigger bottle.

It doesn;t take much.

I splash around in it without gloves. leaves your hands kinda stinky and orange (rust in the water) colored for a bit, but it doesnt burn you at that concentration....

[ April 01, 2006, 08:02 PM: Message edited by: Ted Carl ]
Those before pictures make you want to slap whoever owned that bike.

Almost looks like it fell in a vat of cocoa powder.

Well done Ted!
Thank you for posting this! Probably the most usefull & informative post I have ever seen on this site, or any other site. Thank you, thank you, thank you!!!

How did you polish the paint- it looks great.
Yeah what a great post Ted, and great pics as always - thx man, I'll be trying this.
Jet Black
My expedition to the local Bunnings , was interesting but fruitless , the guy knew what I was after , but couldn't find it , as I wandered past the thinners section pricing 20 liter Xylene & Tolulene drums (octance/anti detonation additives) to compare against 200liter drums , I found a 1 litre bottle of liquid Oxalic Acid & cut down to 10% purity & $14 !!!

The instructions said you could step on it further to make 5 liters in total , I never buy product that far down the line , it's always expensicve & heavily stepped no matter what you are buying , so I'll have to go to the Pharmacy for the good stuff, BP.
It did give me a reasonable "working guide" on how to cut & dilute the pure crystal.
I missed reading the safety instructions , they are usually a good guide as to what you are dealing with , Ted seems to be dealing with confused manufacturers ....

Great stuff Ted, Maybe theres hope for some of my bits yet.
Ted Carl
Randy, the saddest part of this one, is when you take a look at the parts closely.

Look at the fork dropouts. You can see that the front wheel was removed once, and replaced once with a different washer.

The rear wheel was not adjusted more than 4-6 times.

The scratches were from storage only.

This would have been one clean 79 if the guy's parents would not have tossed it out of the garage and into the weather a couple of years ago.

In fact, it was used so lightly, the only real damage is from water.

Sad, in a way. But I have it now, so it has a happy ending , and his kid got a new Trek MTB out of the deal.
rick kast
i clicked over from the vintage side, when i saw the heading, i said, " obviously ted collected beer cans when he was young." lol
i still have whats left of my container from 78, and yes they wanted to know what the hell an 11 yr old kid wanted with that stuff.
Ted Carl
I thought I would clarify that I am not knocking the Evapo-rust. That stuff really does work, and has some great potential for certain tasks.

The fact that the part has to remain submerged, and that it costs like (?) 700 dollars for a 55 gallon drum of it leads me right back to this technique for anything that wont fit in a tupperware dish.....
I picked up a spray bottle of pre-mixed Oxalyic Acid solution from Home Depot the other day. It worked a charm! I found it in the plumbing department in a white spray bottle, with an orange label and sprayer under a brand name like Rust-b-Gone (or something, it's down in the garage). I went specifically looking for Oxalyic Acid, and they didn't have 'wood bleach' or anything like it, so I went hunting. I found this stuff, tried it and took a heap of rust off an old Haro. Not done yet, but certainly underway! I think the spray bottle type is great for surface rust on chrome bikes especially. It's easy to use, and the bottle was like $5, so minimal investment. Check it out.

Looks like a trip to Holmes Depot is in order. Hey ettsn, how did you go about using the pre-mixed stuff? Spray it on and just let it sit overnight?
Yep, just sprayed it on. Bottle says to let it sit for 30 seconds! I let it sit for more like 30 minutes, and it ate the rust up something fierce. I picked up a brass brush today to get down into the welds. Full report coming!

Ted Carl
I have gotten quite a few emails from people braving the technique, that is very cool! I hope to see some good results pix here in the future!

To help answer some more questions....

I am guessing an ounce or 2 per gallon will do it. I have never been that scientific with it, if it isn't working, I add more....

The stronger you mix it, the faster it works. Even in lower concentrations it will work over time. I mixed a pretty "Hot" batch in a tupper-ware container for my headset, and it didn't hurt the plating at all, even in stronger concentrations.

My best advice would be to reduce the amount of water as best as possible. Maybe lay a frame flat in the bath tub? Or line a small frame box with a plastic bag?

Minimizing the water makes it cheaper. Less acid needed.

When it is right, you should see some light bubbling going on, and off-white powdery stuff gathering on the frame, especially on the rust within about 6 hours. And the orange rust turns pastel yellow. That is the stuff that will brush right off with a tooth brush! Below is the actual headset shown earlier (in fairness, lol),


...and the dish mentioned above showing what came off of the hardware I put in there. This is the yellowy powder that collected in the bottom that I was speaking of.
Ted Carl

I am not ignoring you....Maybe I will do something on polishing paint in another thread?

Right now I am still goofing off with those Graphite Tuff wheel "hub caps" (making 5 more sets, lol), and I have a few other truly pressing matters going as well. All in time...
hi mate

i bought my self a 500 gram tube of crysltals and i was wondering how much to put in a 40 ltr bucket. i put the whole lot in but i am unsure if that was enough crysltals for 40 ltrs.
Ted Carl
I am guessing an ounce or 2 per gallon will do it. I have never been that scientific with it, if it isn't working, I add more....

i bought my self a 500 gram tube of crysltals and i was wondering how much to put in a 40 ltr bucket.
You are kidding right? lol

I haven't done the math in English, leave alone convert it to Metric!

I did, however, just measure off 2 and 3 gallons, and dump it in the sink I used to do the bars and forx in the pix. There was about 2 1/2 gallons in my sink, just enought to cover the parts. I could not have had more than 4 ounces left in the jar I dumped in.

My best advice is to find a container that barely fits the parts, and barely cover them with water, and THEN add the crystals. Forks and handlebars can lay flat in a sink, and only a couple of inches of water is required. DONT fill the sink, and then drop the parts in....Too much water.

However, I have been informed that the new can of "wood Bleach" says to use 12 ounces per gallon. That is for bleaching wood. I guarantee that is at least 6 times stronger than you need for what we are doing with it.

I am not a chemist by any stretch. However.

CO is Carbon Monoxide. O3 is Ozone. If you put Ozone and Carbon Monoxide in the same room together, they will get together and relax, and "Socialize". The 03 will gladly give up one of it's Os and the O3 becomes O2 or Oxygen, and the CO will take the O and become Carbon Dioxide CO2. Everybody is happy, and both the Ozone, and the Carbon Monoxide are no more. Used up. Gone. Global warming. Ozone thinning. Are you with me so far?

Hydrogen Peroxide is water with "Extra" Os, Oxides. The Oxides react with anything it can, and it kills the oxygen thirsty bugs by ODing them. Swish it in your mouth, and it foams up and kills germs.

Bleach....same deal.

Oxalic Acid, has something that resembles Oxygen in the name. It is placarded as an Oxydizer (makes fires worse). Somehow, the acidic nature of it disolves the rust, and the Oxidizing action reacts with the softened Iron (Iron likes reacting with Oxygen and making rust), however, it must like the Oxalic Acid, and it react with it quickly, and makes it into a powder that can be brushed off, and sinks to the bottom of the water.

Point(s) being, it gets used up in the process of attracting and removing the rust. So, if it is working very slow, it needs more crystals. If it is working great, and then stops working, then it is getting used up, and needs more crystals.

Therefore, the mixture needs to be strong enough to create an acid strong enough to get the rust loose, and enough stuff to react with it.

Whew....Did I make any sense at all?

As for the "One can per gallon" that is says on the bottle. When bleaching wood, I would think that there is SO MUCH stuff in the wood for it to react with, that it will use itself up very quickly, hence the potent mixture. With a pair of Chrome-moly handlebars in an inert bucket. The only thing for it to react with, is the rust on the bars, the grease you forgot to wipe off, and whatever bacteria were in the water. So if you mix it so strong that it is still good when you are done, you wasted it, or need to find more rusty parts. OR, you want it done fast.

[ April 05, 2006, 02:01 PM: Message edited by: Ted Carl ]
Spanish Fly
just don't freak out when your fingers come up missing
Sounds like a good product. I still prefer a $1.50 can of "Bar Keepers Friend" and 00 Steel wool. Works like a charm for me.
Has anyone tried this concoction with black oxide parts, like Ashtabula cranks and stems? Will it ruin the black finish?
Ted, Thanks for the work-words-and pics you did for this post....I will be saving this info for future projects!
Z-man, yes it most likely will remove the oxide finish from Ashtabulas or the like. That finish is in nature basically an engineered 'rust' (oxidation) on purpose.

Any more test results from those of you who've tried Oxalic acid?
Ted Carl
I have gotten some Emails touting great results.

I agree, If you guys are liking it, we need some pix here!...
Motor City Mongoose
It turned my Ashtabula stem green, but removed the red rust, so I ended up blasting it anyway.
I've had great results for anodized parts and just need to know Ted's polishing secrets, haven't polished yet.
Joe P.
Would these bars be a good candidate? There doesn't appear to be any breaks in the finish,just plenty of pitting...Great work Ted!
Ted Carl
Ted Carl
Bead blasting is always best for bare metal. The acid dip is the really cool way to do Chrome.

You dont want to bead blast chrome, or scotch brite it, or sand it, or even steel wool it. I am sure it will do a number on Black oxide finishes.

Chrome or nickel plated stuff with this technique is truly the intent here.
Motor City Mongoose
Yep, I agree. I planned on blasting the stem anyway, I just wanted to see what the acid would do since I had a batch mixed up already.
great thread - thanks!

i have a frame i am about to give the rust removal treatment to, thinking about wither the spray bottle method or lining a frame box w/plastic and soak. its been 20 some odd years the frame has been sitting, so i'm thinkng the soak is the way to go.
Stopped by a hardware store on the way home from work.... got a couple parts soaking. pics tomorrow!
$7.30 for 1 lb. of powder... not bad.
Joe P.
PICS PAUL!! I'm dropping those SE cruiser bars in tomorrow,and I'm scared outta my pants,I'll go to take them out,and all that will be left is the end hangin out! With all those "other" SE bars around,I want to keep these!! Thanks again Ted,I'll press forward and post my results as well!
Sorry, didn't have time to take pics. It's a slowwww process. I left a couple bits in for 24 hours. The chrome cleaned up pretty well for the most part, but I think I'll have to do another treatment to get all the rust out of the welds. Some ugly pitting is left. I guess there's no cure for that though.
I also did a set of profile crank arms that had peeling chrome and rust underneath. The acid doesn't make the chrome peeled areas any prettier, but it cleaned up the surface rust on the chrome itself nicely. pics next week... I'm heading to sunny Nebraska for the weekend. woohoo!
I got 2 frames soaking in the bathtub now, Home depot didn't have it and when I asked they said they don't carry it anymore cause there is not enough demand, but a small hardware store did have it. I put about half the container in and I have to let the water trickle cause the drain is slowly leaking. I'm hoping for those great results cause I got a lot of parts I can do this to.
Ted Carl
Polishing will help a lot.

I have started puting mine together. I am still deciding whether to show chrome them or not.

Polishing takes all the bumps off. The pits leave a little pucker around each pit. Polishing gets rid of all that.

I will try and take some good pix of mine after polishing in some sunlight. Unfortunately, it may take a few days before I can get to it.

Mine were pretty badly rusted. They are really nice looking until you get about 6 inches to a foot away from them. Right on the edge of a survivor, and show chrome decision.

Remember, if it is tooooo slow, don't be affraid to give er a little sprinkle, and kick er up a notch....But you definately don't want to watch it. It's about as amusing as watching grass grow. However, think of it more like X-mas. You get to wake up and see what you got!.....

I'll share some chrome polishing tricks as well.....
Im getting ready to use some of this stuff and I was wondering about letting it drain down the bath tub? Does it affect PVC piping?? From what Ive been reading so far, it seems like it is harmless to anything but rust! Thanks!!!
Ted Carl
Nothing hurts PVC. Especially not this stuff....
TedCarl, I am thinking about using this tech. on 3 of my MCS Magnums.I read that if you tape the decals it wont hurt them.Everyone knows how hard it is to get decals for these bikes.Do you use masking tape and will it stay on in the soaking process? This thread kicks butt and I really want to try it but like I said I don't want anything to happen to the decals.
Your black frame looks awesome,did you replace the decals on it afterwards?

[ April 24, 2006, 12:51 AM: Message edited by: jpbmxoskul ]
Quote from Joe P.
PICS PAUL!! I'm dropping those SE cruiser bars in tomorrow,and I'm scared outta my pants,I'll go to take them out,and all that will be left is the end hangin out! With all those "other" SE bars around,I want to keep these!! Thanks again Ted,I'll press forward and post my results as well!

How did it do?

Ted Carl
Here's the deal on decals.

There are so many different kinds of decals and decal inks used that you aren't going to get me to tell anyone that if you use method x, then no decal will be damaged.

However, it is just a water based oxidizer. Anything waterproof will prevent the solution from getting to it.

I tend to use creative solutions. But often when I suggest them to people, I find that many don't have the technical skills and insights to make them work like it did for me. Addtionally, if you tell someone plan "A" works great on aluminum, someone will use it on magnesium and say the idea sucks.

1. There are many kinds of decals. Metallic, paper backed, vinyl, etc...

2. There are many different brands of tape. Not to mention different kinds of tape. The tape I use, is likely to be different from the tape you use, even if it is called the same thing.

3. Tape sticks to different things, and to things differently. One may leave the glue behind on one decal, and not on the other.

So, If you want to keep the decals on;

First, I would study the decal. Looking ahead in the project. Will the decal absorb water? Will the color rub off if you need to rub glue off of it? Etc....

Second, I would look at creative solutions to keeping it dry during the bath. Some ideas are;

Candle wax. Light a candle and drip the wax on the decal, overlaping the edges a little bit. remove the wax with a heat gun, or iron, and a paper towell afterwards. Lay the paper towell on the decal and warm it up, and soak up the wax. Again, there are a lot of variables here. A paper decal might not like this at all, and may turn to the same color as the wax.

Cling wrap. Saran wrap. Etc. Wrap the area of the decal with Saran wrap a few times around. If a little bit of water gets to it, so what? It gets wet in the rain right? There shouldn't be enough Oxalic acid that gets past it to do any damage.

Waterproof tape. Too many to list. Again, will peeling tape off pull the ink off with it like it would on a "Schwinn Sparkle" decal?

Personally, I like candle wax, and saran wrap.

However.....I make no implicit guarantees or otherwise. It is a creative process. There are no guarantees, only rewards for the most creative thinking, which yields the best results.

And one more thing. DON'T skimp or forget about rustproofing the insides as soon as it comes out of the bath! You are removing a piece of raw metal with an oxygen rich surface on it. Use crummy old WD-40 if you have to for now, but get something on the raw metal as soon as it comes out of the bath. LPS-3 is my choice for availability, and longivity. I am talking about the insides, not the chrome plated side here.

The stuff is tested on plates of metal in salt water ocean surfs. The 2 year rating is when exposed to the elements. It will last forever inside a BMX frame. But can be degreased out if needed.
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