Leslie Stain Remover (Ascorbic acid)

[Denniswiseman]

Will acsorbic acid work on concrete paviors

[waterbob]

You're probably best off using vinegar or muriatic acid as ascorbic acid can get real costly.

Is there a particular reason you want to try ascorbic?

If you have rust stains try oxalic acid instead.

Bob

[Denniswiseman]

Hi Bob

Thanks for that
I Just have some rust and didn't think I could eliminate it
I have vinegar and muriatic acid and I can get oxalic acid, what is best and what dilution should I use
Also will it remove the colour from the pavior

[Larry]

Hi Dennis

Good to have you back at the forum.

In my experience with rust I have found the muriatic acid to be too aggressive and it etches the surface too quickly to be an effective rust remover. It is a very effective scale remover though.

I have never tried vinegar (weak acetic acid).

I generally use and recommend oxalic acid because it seems to do the least "collateral damage" for the amount of rust it removes. Being an acid, it will lighten the color of old concrete but doesn't eat it away like muriatic acid does.

The way we use oxalic acid is:

• for localised dark spots (from wire, nails, welding flux, ...) we mix enough water to the oxalic acid to make a thin paste and apply the paste liberally. When the paste starts to dry (usually at least 45 minutes) we scrub the stain with a hard plastic brush or abrasive pad and a little water. Rinse and repeat.
• for large light rust stains we mix 5%-10% oxalic acid by weight to warm water and spray liberally on the stained area. We keep the surface wet for at least an hour, reapplying as it begins to dry. We scrub the surface intermittently and the final scrub with fresh water usually removes most of the stain. We spot-treat any remaining stubborn spots.

As with any chemical treatment, test a small spot to see what effect the acid has on the surface before applying to the whole area.

Larry

[Denniswiseman]

Thanks Larry

It's good to see the forum back to it's old self

I will purchase some Oxalic acid and do as you suggest
I was beginning to think the rust stains were going to be there for ever

Dennis

[Larry]

No problem Dennis

[RLP1950]

Thanks chem geek
My pool is 15,000gal so I ordered the 5lb bag. $30 is not too bad if it works
So I guess I add about a pound at first and see how things go.

I have a 20,000 Gl Pool,all of the sudden it started showing stains that look like rust,i purchased a 2 LB bottle of Stain Remover {ascorbic} from Leslies Pool supply,pretty expensive ,but it worked like magic,the minute the powder hit the floor of the pool the stains were gone...AMAZING.Just lower the ph to about 7.2,mave a low amount of Chlorine,and run the pump for 24hrs,in my case runing the pump wasant even necessary,the stains were gone instantly,the price for the 2lb was expensive at $48.99 plus tax,were did you get the large amount so cheap,pls let me know,like to keep some on hand

[Denniswiseman]

I get mine on Ebay just search for Ascorbic Acid (vitamin C)
You will find it's hard to get a decent FC reading for a while because the AA will stop it untill the FC uses the AA up
Just keep testing and adding chlorine slowly, not to much at once
You will also need a sequestrant to hold the iron in suspension