Uses for Oxalic acid?

[thinwater]

If you google "passivate stainless" you will find that citric acid is your best DIY choice. Keep it on there a long time (soak a rag with 10% and wait). Spotless Stainless is citric acid.

Oxalic acid has generally disappeared from hardware store shelves in the US, due to toxicity and because either lactic acid or citric acid work better (depending on the problem) for less money. The only application I know of where oxalic works better is wood. lactic acid is better for scale removal and citric acid is better for rust stains (although lactic acid is very good too).

 

[Seajet]

Be very careful with Oxalic Acid cleaners - years ago I used it to degrease my boats' topsides before painting - it said on the bottle ' to halt action, rinse with fresh water ' so I foolishly thought it must be feeble stuff.

It ran down my arms - soon I was in real agony, luckily a club member is an ex matron and she saved me - rather than rinsing my arms under a tap - doesn't work - she had me fill a basin and keep my arms submerged for 40 minutes.

I was very nearly an ambulance job.

If using this stuff for gods' sake use eye, face and arm protection and watch out for anyone passing.

 

[Little Dorrit]

I have used the crystals but they did not dissolve...is there a trick to using them? I have gone back to using Y10 which seems to be easier to use and although appears expensive it goes a long way and lasts me a couple of years. I simply paint the gel on with a brush. The crystals didn't work for me.

 

[Mikedefieslife]

In France oxalic acid is readily available in supermarkets and bricolage stores, even in towns away from the coast, which suggests it is widely used for domestic purposes as well as cleaning boats

I'm in France (in a way) Oxalic acid is €25 a kilo compared to about €5 in Greece.

Phosphoric acid is popular here. Much faster acting and IMO better than Oxalic acid. It's €15 a 1l bottle and can be diluted 80% with water. Pretty much instantly obliterates rust, yet I've not found it to damage even single component paint if removed in a timely manner.

 

[Slowtack]

5% solution by weight is adequate for cleaning Hull and stainless steel. I wear a full face plastic visor and gloves. I use a small roller to apply it as it generates less splash than spraying. Apply. Rinse with water. 2 or 3 repetitions removes most hull stains.