Classic & Vintage - Oxalic acid question

I went to the local Sherwin-Williams store this afternoon and left ten bucks lighter clutching a 12 ounce tub of oxalic acid. The label has lots on instructions on mixing it up as a wood bleach, but what's the dope on making it a rust remover?
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Depends on how much water you're using.

I use a very scientific method - I fill a metal pie tin with hot water, and add pinch or two (literally - a thumb/forefinger pinch). Stir it a bit to dissolve, and add the rusty bits. Then let it sit and occasionally check it for progress. I've done soaks for a couple of hours for lightly rusted stuff, and for a couple of days to take care of really rusty stuff. I tend to err on the weak side, just because.....

I had some cable clips with light surface rust that came out gleaming after about a 2 hour soak. Conversely, I had a chain that was dry and bright orange - after a 2 day soak it looked and worked like new.

It can be a lot less strong. Maybe start at 1/5 the amount of acid to water as is on the instructions.

Mix it in warm water until the solution is saturated (Crystals no longer dissolve). If you want it weaker, add water from there. Always use warm water.

FWIW I pay about $6/lb at Rockler woodworking for Oxalic acid.

Mix it in warm water until the solution is saturated (Crystals no longer dissolve). If you want it weaker, add water from there. Always use warm water.


Wow - you mix it way stronger than I do. How's that work for you? Does the rust dissolve really quickly?

Does anyone have experience with oxalic acid and plated parts? I'm thinking about nickel and chrome plating, primarily.

I own a band instrument repair shop, and my 79 year old repair tech dips some parts in Lysol Toilet Bowl Cleaner. I'm wondering if oxalic acid is the active ingredient in that. Does anyone know?

Wow - you mix it way stronger than I do. How's that work for you? Does the rust dissolve really quickly?I don't need a 2 hour soak. YMMV

Does anyone have experience with oxalic acid and plated parts? I'm thinking about nickel and chrome plating, primarily.


Almost all the parts I've done have been chrome plated - cable clips, chain ring bolts, binder bolts, headset cups, etc. Works great.

You do have to clean/degrease the parts first, though. Oxalic acid needs to touch the bare surface, and will not work though grime or grease.

There are two sets of instructions on the container: 3 oz per quart to BLEACH wood and 3 oz per gallon for BRIGHTING wood decking. Do I use either of these or some other dilution?
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There are two sets of instructions on the container: 3 oz per quart to BLEACH wood and 3 oz per gallon for BRIGHTING wood decking. Do I use either of these or some other dilution?
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Lets put it this way: It sounds like Old Fat Guy is using way more that 3oz per quart, and bigbossman is using way less than 3oz per gallon. My own mix is somewhere in between the two extremes. It all depends on how fast you want it done and how often you want to restock the OA.

Oxalic acid is a very mild organic acid. It has long been used to remove rust stains from fabric and will not damage fabrics. It is poisonous so wash your hands after using it or use gloves. I'll bet if you read the ingredients in your Tidy Bowl, you will probably see EDTA (ethylenediaminetetraacetic acid or one of its salts). EDTA is non-toxic and is also used in foods like salad dressing. It's great for dissolving soap scum and dried minerals like calcium and magnesium but I'm not sure about removing rust (iron oxide) from parts. 10 bucks for less than a pound seems like a Tidy profit for the store.

Vegas Triker, chemist

It's great for dissolving soap scum and dried minerals like calcium and magnesium but I'm not sure about removing rust (iron oxide) from parts. 10 bucks for less than a pound seems like a Tidy profit for the store.
Vegas Triker, chemist

Give it a try, you'll be amazed. Here's (http://www.chemistrystore.com/oxalic_acid.htm) where I buy mine.

I actually make a paste of Zud cleanser and oxalic acid for larger things, like forks , fenders and wheels. Works great.

You could also do the electrolysis thing with borax, water, a battery charger and sacrificial piece of steel.

There are two sets of instructions on the container: 3 oz per quart to BLEACH wood and 3 oz per gallon for BRIGHTING wood decking. Do I use either of these or some other dilution?
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Brightening. The mix to bleach wood is much stronger than you'll need. Just give it a shot with the brightening ratio and see how it goes.

I used it on a freewheel and it went from this:

http://i46.photobucket.com/albums/f106/RabidKoala/IMG_0536.jpg

To this:

http://i46.photobucket.com/albums/f106/RabidKoala/IMG_0542.jpg

I did disassemble it first, though.

Does anyone have experience with oxalic acid and plated parts? I'm thinking about nickel and chrome plating, primarily.



Chrome is fine, I don't know about nickel.

DON"T use it on zinc or cad plating, the acid will eat the plating and leave you with dull metal. The tiny bubbles coming off the plating during the process are pretty cool though.:)

Here are before and after pictures of the fork on a Rossin I picked up:
http://www.gallery.unvoiced.com/main.php

Give it a try, you'll be amazed. Here's (http://www.chemistrystore.com/oxalic_acid.htm) where I buy mine.

I am going to have to find a local source. The Chemistry Store would cost $32 for a minimum order and S&H.

I am going to have to find a local source. The Chemistry Store would cost $32 for a minimum order and S&H.
Yeah it ended up costing me $29 for a 7lb pail delivered to Texas but I'm so far out in the sticks I don't have any other options. That's why I don't mix it as strong as Old Fat Guy does, and at the rate I'm using it it should last a couple or three years.

Yeah it ended up costing me $29 for a 7lb pail delivered to Texas but I'm so far out in the sticks I don't have any other options. That's why I don't mix it as strong as Old Fat Guy does, and at the rate I'm using it it should last a couple or three years.

I found out that there is a chemical supply house here in town that is supposed to stock it. I had been to home depot and they just had the deck wash that was a weak solution for $10/gal. If I can find a cheap supply, I figure I won't have to worry about using it so sparingly. OFG's Rossin fork did turn out nice.

Here is the directions off my box of OA:
Directions: Rust Stain Remover
Wet the stain and sprinkle PURE OXALIC ACID on it. Rub with a wet cloth, sponge or brush until stain has vanished. Rinse thoroughly and wipe dry. For more stubborn stains, make a paste of PURE OXALIC ACID and water, apply to the stain and allow to stand a minute or two before rubbing. Rinse and wipe dry. To whiten iron stained clothes, presoak using 4 tablespoons of PURE OXALIC ACID in 2 gallons of water. PURE OXALIC ACID can also be sprinkled in the toilet bowl and other porcelain surfaces to clean embedded rust and hard water stains.
Source:
http://www.empireblended.com/engineered/specialtysundry-pureoxalicacid.html


Like I said above, a paste made with Zud cleanser and OA, rubbed or steel wooled onto the surface works in a few minutes.

Borax will neutralize the OA, if needed.

I thought the fork on the Rossin was junk, but as you can see in my earlier post, a bit of elbow grease and OA works wonders.

If I can find a cheap supply, I figure I won't have to worry about using it so sparingly. Note: Even using it fairly sparingly doesn't reduce it's effectiveness. It just takes longer to do it's job.

OFG brings up a good point - using Borax to neutralize the acid when finished treating. I had a case where treating cheap shorty fenders the acid seemed to continue working even after I rinsed and polished. I noticed a couple weeks later that it left dull specks down to the steel where the rust spots had been. I now rotate the old box of Baking Soda out of the fridge into my OA rinse baths to ensure the acid stops working.

What works on aluminum? I have a pair of shorty Weinnman fenders which need to be cleaned of corrosion spots. I have used mag/alum wheel polish but it does't get it all.

I am going to have to find a local source. The Chemistry Store would cost $32 for a minimum order and S&H.

I found a small tub of it labelled Wood Bleach at a True Value store. Ace may have it as well. Cost less than $10 if I remember correctly.

Have any Canucks found Oxalic acid? I have asked at a couple of different Home Depots and local hardware stores and they have never heard of it, is it labeled as something different here in Canada? Thanks.

Not a Canuck but try a drugstore or you can purchase it online. It is also really good at removing rust stains from sinks, tubs, dishwashers etc. http://www.cheap-chemicals.com/chemicals.asp?Sort=O

does home depot have any of this product?

does home depot have any of this product?

I couldn't find it there - had to go to Orchard Supply.

I can't believe Home Depot wouldn't have it; you'd probably have to ask for it as 'wood bleach' though.

I struck out at Lowes and Home Depot here in Oregon. However Ace Hardware carries Oxalic acid as a 'wood bleach'. $7.99 as I recall.

No help for our Canadian friends, but Rockler Woodworking stocks it:
http://www.rockler.com/retail/retail.cfm

Just about any woodworking store should have it. I have also been able to get it through my local pharmacy when I lived off the beaten path.

I had been to home depot and they just had the deck wash that was a weak solution for $10/gal.

It is stocked in the paint dept. with other wood finishing products.

Home Depot in Phoenix does not carry oxalic acid. They do have a 'wood bleach', but is not 100% OA.

In So Cal, Home Depot didn't stock it, but Lowes did.

Anybody have any luck taking off the rust from spoke nipples? Do you just dip the whole rim into the oxalic acid bath? Would it discolor the aluminum rim? I'm assuming anodized rims are a no-no.

If the nipple isn't too rusty, but beyond steel wool, I would take the Dremel (thanks for the advice guys) to it. You should be able to do that will little fuss and no chemicals.

Anyone ever tried electrolysis and oxalic acid? Many years ago I worked in a museum restoring antique equipment and when we had stuck parts we would mix up some chemicals and connect the parts backwards from normal plating causing rust partials to be drawn off the stuck parts to a peace of old copper pipe. Normal plating battery connections have the parts to be plated connected to the negative post of the battery and the plating material connected to the positive post of the battery. We used an old 6-volt car battery that was supplying about 3 volts and we connected the positive battery post to the stuck part like a piston and the negative post to the old copper pipe. I just wonder if using about 3 volts DC in addition to oxalic acid would speed the process, as the rust would be drawn away from the part as the oxalic acid works on it.

http://www.amazon.com/Wood-Brightener-Oxalic-Acid/dp/B000FGLRRO Dont know if this is the same but is says mix with water and its one lb.

What works on aluminum? I have a pair of shorty Weinnman fenders which need to be cleaned of corrosion spots. I have used mag/alum wheel polish but it does't get it all.

Simichrome and super fine sandpaper 1500+ always work well for me.

Here are before and after pictures of the fork on a Rossin I picked up:
http://www.gallery.unvoiced.com/main.php

So how did you keep the corrosion from coming back? What about pitting?

Sorry, I'm really impressed with this whole thing, I would almost want to go find something rusty just so I can try it.

I never tried oxalic acid but use phosphoric acid frequently

It can be found at Lowes in liquid form (green stuff).
Works quite well

So how did you keep the corrosion from coming back? What about pitting?

Sorry, I'm really impressed with this whole thing, I would almost want to go find something rusty just so I can try it.
I apply a good coating of automotive wax. I polish and coat all my chrome parts with wax. This seals the chrome surface from the elements so the chrome will stay bright, shiny, and rust free for months at a time. As for pitting, you just got to live with that or have it re-chromed. For some vintage bikes the pitting provides a bit of patina enhancing the vintage bike visual effect.
http://en.wikipedia.org/wiki/Patina
In effect it allows the vintage bike to tell everyone that looks its way; I'm old, proud, and cyclists love me!

So how did you keep the corrosion from coming back? What about pitting?

Sorry, I'm really impressed with this whole thing, I would almost want to go find something rusty just so I can try it.I haven't really addressed the corrosion issue yet. I just finished the other half of the fork and decided I can live with it the way it is. The fork is Columbus SL, I presume, and it polished up nicely by hand. I'll post pictures tomorrow in a different thread.

I'm thinking that I could just throw a coat of wax on it, or maybe screw around with a rattle can clear coat. I'm open to ideas after I post better pictures and get everyone's feedback.

There is still evidence of pitting visible, but no rust. The frame it belongs to is in good shape (pics tomorrow), but the decals are ON TOP of everything, and a bit brittle, so I am hesitant to be too aggressive with it. A short bit of easy buffing on decal-less surfaces with a light rubbing compound produced no noticeable results. It's never gonna shine like bigbossman's Palo Alto, that's for sure!