wrk101

Thought I would post a few pictures from my current oxalic acid rust campaign. I saved up about six bikes, so I will be treating parts for the next couple of weeks. The campaign starts with my kiddie pool, direct from the local Xmart store. Added almost 20 oz of Oxalic crystals from Sherwin Williams (they come in 12 oz tubs, so I used a little over 1 1/2 tubs). The first pic shows the pool in action. I have a homemade dam in the pool, as it is a little bigger than I need. I then have a few pictures of steel/chrome rims from a recent garage sale purchase, a 1971 Schwinn Racer. I think the transformation speaks for itself. One thing I really like about oxalic is that it does all the work for you. You just set it in the bath, leave it, pull it out later, neutralize with baking soda, rinse it off and wax it.

Be sure to read all of the safety warnings on oxalic, and be sure to protect your hands and eyes!

But no scrubbing, rubbing, no abrasives, no nothing, just time. This wheel sat in the bath for 2 days.

poutine

How did the frame cope? Any effect on the paint?

wrk101

I have never had paint or decals affected in any way. It will attack aluminum, so you need to strip the bike down. You will notice I pulled the axle and bearings on the wheel. Don't want to mix acid with your bearings.

I have used oxalic on several bikes, this will be my largest single campaign (more efficient than doing piecemeal).

mkeller234

I soaked this frame in oxalic acid for 1.5 days, The paint and decals came out beautiful after a baking soda path, polish and wax.

gerv 

What happens to your bath water when you are finished? I'm assuming you can't throw it down the sink.

Oldpeddaller

That wheel came out near perfect. Does the acid (adversely) affect the zinc finish on non-stainless spokes? How do you neutralise the oxalic solution inside frame tubes and especially stays ad fork legs? -Or do you plug up those little expansion holes with cocktail sticks?

I tried this out on a micro scale on a rusty steel seat binder clamp and bolt in a small plastic tub. It came out totally rust free with a clean, completely rust free but dull finish that polished up like chrome. I'm hoping to try bigger projects as soon as I can buy some Oxalic crystals in bulk. Does the solution corrode aluminium?

Would appreciate the benefit of oyhers experience to avoid costly and disappointing mistakes!

wrk101

I don't plug any holes. I want the solution to go inside these tubes, to deal with any rust there as well. I make up a bucket/trash can of baking soda/water, and immerse the fork in that (first draining the acid out into the acid bath). For the frame, I pour baking soda solution down all the tubes, draining it into the same bucket. You are just neutralizing it, so it is real quick. Then rinse it, blow it out with air, and frame save it immediately.

The oxalic helped clean up the spokes as well, as they had some rust too.

Without the oxalic, I would be tossing these rims for sure. The fenders turned out even better, ditto the Schwinn cranks.

Oldpeddaller

Thanks Bill, that's really helped to clarify how to do it. Much obliged.

jonwvara 

After pulling the axle and the bearings, did you immerse the wheel hub and all, or did you just immerse the rim and rotate it periodically to treat the whole circumference? What would you do about an aluminum headbadge? If it's a nice one and original it's a shame to have to drill out the original rivets. Perhaps you could cover it with grease or liquid mask?
jv

wrk101

I immersed the whole wheel after pulling the axle and bearings of course. Note, this wheel has a steel hub.

On the headbadge, I leave them in place. I am not recommending it, as over time, the oxalic will eat the aluminum.

If you look at the pic of my kiddie pool, you will notice a small plastic container to the right of the pool. I use that for small parts, easier to keep track of them.

RobbieTunes

OK, I'm hooked. My stealth Velo Cheapo project is getting the Oxy treatment.

And now we know what happens to the moonshine that doesn't cook right in them thar hills.

Banzai

Wow. Nicely done.

gerv 

This notice from a British source seems to say that even in heavy solutions, it should be biodegradable.
https://www.chem-distribution.com/MSDS/OXALIC%20ACID%20MSDS.pdf


So maybe you can throw it down the drain. Or use it to water your lawn.

Does anyone know any different?

JohnDThompson 

Oxalic acid is biodegradable.

sunstealth

is oxalic acid effective in below freezing temperature ? will it freeze ? I have a frame and 6 wheels that could REALLY use that treatment! (plus 99.9% of the parts of an old italian iron!)

robatsu

+1. I've become a big believer in oxalic acid for parts large and small. Watch the aluminum and zinc coated steel, though. Oxalic acid occurs naturally in the environment, even in some veggies you eat, I wouldn't worry a whole lot about pouring it out. As for paint/decals, just seems to clean them up. Use in a well-ventilated area.

Acids, like many chemical reactions, tend to work faster w/heat. Conversely, they work slower in cold. Just about anything will freeze given a low enough temperature, and this applies to oxalic acid solution. The exact freezing point will be determined by the strength of your solution.

gr23932

Do you guys ever re-use the mixture?? Just wondering. Because of this thread, I'm going to have to keep a bike I was initially going to toss and try this out.

mkeller234

yeah, I have an old coffee can with some oxalic acid that has been around for a while.

operator

Cool - but how does that affect the steel? Does it make it weaker?

cds

hello,

this is a great thread, im wondering how the baking soda solution is done? do you just mix the baking soda with water to make a thick solution, or do you go quite thin with it?


thank you

DavidW56

I also was wondering exactly what proportion of baking soda to water is correct for neutralizing the oxalic acid solution. I had my gears, RD, chain and other miscellaneous parts sitting in a bucket of acid solution for over a week. It did not neutralize all the rust, and worse, I think there is a greasy residue over everything, probably lifted by the acid from the gears and spread all over everything.

Earlier this winter I did attempt to use the oxalic acid solution outdoors in my garage and it did begin to freeze at temps around 20 F or under. The solution turned to a gel. I brought it indoors before it froze over completely.

sbsplease

HOLY shnikes I'm defintely going to use this for my px10 project

Panthers007

To neutralize an acid - including oxalic - the use of baking soda (sodium bicarbonate) makes it simple. you see: It fizzes. When you sprinkle some in to the acid, it gives off carbon dioxide gas - causing it to 'fizz.' Like an Alka-Seltzer tablet. After you add some, stir it around. Add more and watch it fizz - stir. Ad more. Fizz. Stir.

When you get no more fizz, she is done. But be careful still - you now have a solution containing sodium oxalate - which is also very poisonous to people and pets. Pour down the drain with plenty of water to chase it. It will biodegrade harmlessly. Rinse everything several times.

wrk101

One comment on disposal: the oxalic acid you buy is commonly sold as deck wash. If you wash your deck, where does the solution go?

As far as reusing the solution, I will be reusing it at least six times, doing six different bikes, misc parts, etc. In the past, I have kept a couple of gallons that I reused dozens of times treating small parts. I will probably keep a gallon or two of this solution as well. Its good for those miscellanous fasteners, or an occasional chrome fork. I have used a tall kitchen trash can to treat a fork, it is pretty much the perfect height.

On the baking soda, I just make a solution of it, buy baking soda by the pound at Walmart. Since almost all of the oxalic acid has been drained off the part prior to neutralization, its not like you are neutralizing the entire kiddie pool. I immerse small parts in a bucket of baking soda solution, I also pour it down frame tubes and over the bike frame in general. I then give the part a quick rinse, and wax chrome parts, and framesave the forks and frame.

sbsplease

So if your vintage bike has a aluminum headbadge with rivets you wouldn't recommend using this acid solution right?