Oxalic Acid (2 Pack, 4lbs Total) 99.6% Pure - Metal & Wood Cleaning and Bleaching, Rust Removal (C2H2O4) - HDPE Container w/Resealable Child Resistant Cap

This is a good value item to make an Oxalic acid solution for rust removal. It has much less odor than the pre-made solutions that I have purchased in the past. It is a cheaper substitute to "On-Off" boat rust remover. You still need to use rubber gloves and eye protection. This powder is easily dissolved in plain water. It can be applied with a sprayer, brush or roller. Leave it on for about 15 minutes, scrub, then apply again until rust is gone. Mix carefully in larger container and apply warning labels. Only mix what you need at one time as the liquid solution loses effectiveness over long storage.

works really good

Had long streaks of rust stains from fertilizer iron dissolving into driveway. Had been there for a while. Researched how to remove the rust stains. Seemed like using oxalic acid was the most effective means to get rid of them.Diluted and dissolved in hot water per instructions and worked into the stains using broom that had very stiff bristles. The stains don't go away immediately, but after a while of soaking the stains do disappear. Make sure to completely rinse off the driveway afterwards. Stubborn stains may take repeated application. It is an acid so be careful.

When you buy this product for beekeeping you are getting a pure enough product to use in the control of Varoa Mites (a parasitic mite that effects honey bees). Though there are other uses for this, including the cleaning of aged and molded wood on homes and decks it is commercially viable for use for honey bee Verona mite control. Using a heating device that reaches over 400F very quickly turns this Oxalic Acid powder into Formic Acid Vapor which, when expanded into beehives, reduces the population of mites on your bees. Used as recommended (FDA recommends 1 gram per application) it does a mediocre to poor job. However when used in the dose that has been observed by the University of Florida’s beekeeping program, 4 grams for a large hive, it has been observed by scientists to have a more effective range in controlling up to 70% of Verona mites attached to honey bees. I would not recommend this dose as it is not recommended by the FDA but has been observed in broad spectrum scientific experiments to be the most effective dose for mite control. Use your best judgement according to the laws of your state.For application I recommend the best applicator you can afford. I made my own with 1” pipe capsule, drilling and tapping in two Diesel engine glow plugs and using a 12V Truck battery to operate it at temperature. The resulting Formic Acid Vapor is emitted from a small copper pipe into the bees hive within seconds. IF YOU DO THIS: PLEASE USE a Chemical Vapor Mask to protect your eyes and lungs. Make sure you cover both eyes, nose and mouth…Formic Acid is dangerous to breath in or to have blow back into your eyes and can cause chemical burns!

I have 3 bee hives. The bees suffer from mites. The best treatment for mites is to gas them with Oxalic vapor. The bees are unaffected by the gas, but the mites fall off. Since some of the mites are on the pupa in the closed cells, treatment has to be on-going. The Oxalic crystals vaporize nicely. Oxalic treatment is "organic" as the acid is found in nature, Rhubarb and spinach both contain it. There is no effect on the honey

It is supposed to be a strong cleaner for toilet, but meh, not working well me. I doubt the purity of it. It doesn't disolvde well even in hot water. I left it in the toilet overnight. No visible effect the following morning.

Cleaned stains from wooden steps after 2 washes. Very good

Great product, I've used it with great success many time. Only order it here if you have ample time to wait for it's artival.