It used to be sold in cardboard tubes of just crystal powder but now I can only find it as a part of something (sold as a tinted wood bleach or in a liquid form mixed in with something like Thompson's Deck Seal.

I should have said I'd like to be able to soak a half a bike frame at a time. I want to buy 4-5 pounds without breaking the bank so looking for bulk source.

Wondering if anyone knows a good source?

I got mine at my local Tru-value hardware store -Dalys Oxalic acid bleaching powder.

Ebay

https://www.ebay.com/itm/Oxalic-Acid...8AAOSwcBhWY4yO

...are you sure you need 4-5 pounds ? Check out how much youi will need to mix with water, in order to fill your backyard tub of it. Then if you have the space and can cover your soaking tank (which I recommend), you can simply leave the stuff over in a corner somewhere with a poison hazard label on it.

I think I only bought maybe 8 or 12 ounces of the dry stuff in a package at the hardware/paint place, and I only used maybe half a cup of the stuff to mix up a huge plastic storage bin full of it for a soaking tub. You buy those at the Home Depot with a good, tight cover. Ask for "wood bleach" as you call around. The more of the stuff you mix up, the more you need to neutralize and properly dispose of afterward. The stuff is toxic, highly acidic when mixed for soaking, , and not at all benign. Neutralize with large amounts of baking soda or another alkaline agent before disposal.

^+1 to [MENTION=209177]3alarmer[/MENTION] above. I buy a small 12-oz. tub of Savogran Wood Bleach at Ace Hardware, then mix about 1 tablespoon per gallon of water. Cost is ~$10. It goes a long way.

Barkeepers Friend, widely available, is primarily oxalic acid.

Ya know, that is an intriguing idea because the Oxalic Acid I have bought from ebay, is very granular. Barkeeepers Friend is very powdery, and would likely dissolve in water much easier.

Rockler's wood working, or any wood working place is a source. Rockler's has retail stores in big cities.

It has a place on bikes, but not like it does with wood bleaching, toilet bowl cleaning, or removing sweat stains from your straw hat.

It's a last resort on a bike, IMHO, though there is a time and place.

I'm glad I'm done with those times and places.

I've never sure if Niagara region is US or Canada.
Lab grade OA is available in Canada at Bebbington in NS and perhaps in your neighbourhood.

I'll order some through eBay. I appreciate the tip. I just didn't think of the 'bay for some reason. I want to get a kiddie pool for frame and forks sets to soak in.

Thanks all.

Just make sure it's not an inflatable one.

They're in the US, and go by a different name these days.

I don't see why the solution can't be soaked into the dirt outside. The acid will react with the dirt and it will become neutralized over time.

Small amounts I mix in a bowl I just wash down the drain.

Use vinegar if concerned about handling and environmental impact.

I bought my powder from an online Taxidermy outfit. The powder may be regulated in some transactions because of it's possible use in illegal drug manufacture.

Surprised no-one mentioned Amazon: 10# for $26.70, smaller amounts also avail, but price goes up pretty fast...5# is about $19.00 Don https://www.amazon.com/OXALIC-Crysta...NsaWNrPXRydWU=

Exactly. For acids and alkalis, the solution to pollution really is dilution. We're not talking hydrocarbons, pesticides, or heavy metals here.....or even, <gasp>, the dreaded carbon dioxide.
But do protect your skin and your eyes while it's still concentrated.

Material Safety Data Sheet
Oxalic acid, anhydrous, p.a