DIYChemicals Phosphoric Acid 85% – Rust Remover, Wood Stain Remover, pH Control, High Purity Orthophosphoric Acid for Metal, Fertilizers - Made in USA - Half Gallon (64 fl oz)

I dilute this to a 5% solution to use as a rust remover on steel Hardware and parts. Works great!

I needed a strong rust remover and this does a fantastic job of it. I used it on old rusted tools and machine parts. The rust was removed fully and quickly. Follow all safety warnings especially wearing gloves, eye protection, face shield and long sleeves. I mixed it with silica powder from Amazon to create a paste/gel and that works well for verticle surfaces

Perfect for mixing as a rust converter to the proper concentration

Muy bueno para soldar con estaño incluso para inoxidable

When they had arrived, acid had leaked all over the bottles.

excellent product for cleaning concrete and rust removal

Got two smaller sizes instead of one 64 oz bottle. The plastic seal doesn't actually keep the cap from opening. Somehow one bottle ended up twisting open in the box, spilled a bit, and started to eat away at the shipping box. Would potentially order again, but hoping for improved handling and product info.

DIYChemicals Phosphoric Acid 85% is excellent for hydroponics. It effectively lowers pH levels and is highly concentrated, so a little goes a long way. The packaging is secure, and the quality is consistent. A great value for growers who need reliable pH control in nutrient solutions. Highly recommended!