SJX426 

Before OA:

After OA:


Lost some paint on the chrome. The paint is Italian an probably a weak bond. I have debated removing all the paint on the fork as I have seen many with all chrome forks and don't know if they came from the factory that way or not. 2% OA in a 24 hour soak.

sekaijin

Wow, long memories around here ... I see I won't get to slink away on this one!

Fact is I have not taken the "after" pics yet. I hoped to finish that build (a 1969 AMF Hercules) last winter but didn't. Now it's my upcoming winter project. The chromed parts did respond nicely to the OA. Painted parts, less so. Stainless parts, soaking them in OA was a mistake.

Grand Bois

Was that supposed to answer his questions? I must be missing something.

I have the same question about the wheels.

ftwelder

As do I, I have a pair of 80 year old Raleigh wheels that I am going to OA treat. The second step will be a soak in a base then a kerosene soak and agitation cycle.

Grand Bois

I plan to use a plastic concrete mixing boat to soak parts in. I'll cover it since oxalic acid is poisonous.

bigbossman 

I cannot address how he did his but I can tell you how I did one, with similar good results. I used a plastic wallpaper trough that I bought at Home Depot for a buck or two. I just stuck the wheel into the solution, and rotated it to do a section at a time.

nlerner

I don't know what the question was either, but I did a bunch of wheel soaking in OA last winter and had good results. I built a soaking tub out of a large, shallow heavy duty cardboard box (the kind of thing furniture gets shipped in) lined w/ heavy gauge plastic. I used a fairly dilute mixture of OA (maybe a gallon of OA and at least 10 gallons of water). I made this chamber for frames, but while I was doing frames, I treated wheels, too. I stood the wheels up and rotated every couple of days for complete coverage. I rinsed with hot water before rotating. None of these wheels had SS spokes, so once the wheels were done, I had to clean up those spokes separately.

Neal

Grand Bois

If the acid won't hurt the zinc plated spokes I should be able to dunk the entire wheel. The hubs are steel and rusty. It's a '58 Schwinn middleweight.

noglider 

I have OA in powder form. What recipe would you recommend? The most helpful expression would be something like "one teaspoon of OA per gallon of water" but I can also deal with "20 grams of OA per liter of water" because I have a nice shipping scale that has decent resolution.

Grand Bois

I just read 1 percent in another thread.

southpawboston

i thought OA attacks zinc, causing a chalky white layer to form... but i could be wrong.

Grand Bois

I thought that I remembered reading something like that.

BluesDaddy

My local general store has a pretty good paint department, and I found oxalic acid there in the form of a gallon of Cabot Problem Solver Wood Cleaner for $20. I realize there are probably cheaper ways to get OA, but I went the easy route. The gallon is intended to be mixed with 4 gallons of water to make a solution to clean tannin stains and nail rust from decks. I poured some of it straight into a baby food jar and then added all the bits from a very rusty pair of quick-release skewers (except the rods) and let it sit overnight. When I came back to it, the parts were covered in a pale green film which fell off with agitation. I pulled out the parts and rinsed them in the sink and they gleamed! The instructions said that the cleaner can be rinsed off the deck, so I had no qualms about dumping my undiluted spent OA down the drain. The only downside, which can not be helped, is that the chrome was still pitted, but that had nothing to do with the treatment process.

ColonelJLloyd 

I treated the rusty steel rims and galvanized spokes on my '73 recently to great results. The spokes developed a chalky, white layer, but it comes off easily with a nylon brush. It's easier if you brush the white layer off every few hours. I will try and update this post with pics.

I use wood bleach crystals with hot water. I don't measure the crystals as I have not found it necessary.

sekaijin

OK OK, here's one before-and-after set ...

southpawboston

after some googling, i've learned that that chalky white layer is zinc oxide; the oxalic acid is oxidizing the zinc. if you scrub that oxide layer away, you're essentially removing the zinc plating. i wouldn't recommend this for things like spokes, as they will probably be more susceptible to rusting afterward.

ColonelJLloyd 

Oops. Too late! Eh, you can't keep a good Sports down.

southpawboston

ah, now that's being a sport(s) about it!

Iowegian

I've had the same experience with galvanized spokes and don't put zinc into OA anymore. I've also learned that grease is a great mask for OA treatment and must be removed beforehand.

Come to think of it, I suppose a coating of waterproof grease on the spokes would protect them. Hmmm...

RookieXL

I have a heavily rusted chromed fork I'd like to soak in OA. I wonder if the acid might damage the alloy it was brazed with?

sekaijin

Here's another before-and-after:

DRietz

Who wants to see an extreme citric acid test?

This mass of oxidized molecules that's now held together by paint (See left chainstay in the middle of the picture) was a custom mountain bike frame that was left in Citric Acid for probably 2.5months now:

bigbossman 

My Ciocc fork was surface rusted, and I soaked it for a couple of days in a weak solution. Came out bright and shiny, and hasn't fallen apart on me yet.

sailorbenjamin

How would that have been if you hadn't left it in for so long? Was there any good metal taken away?