Test your floor for sealer by mixing equal parts muriatic acid and water in your glass measuring cup.
How to remove water from garage floor.
Thoroughly rinse the floor with a hose if possible or buckets of water.
Mix the ingredients and apply to the surface of the floor where the rust stain appears.
If it puddles then you have to strip it off.
Scrub the area with a stiff brush and rinse thoroughly with clean water.
Use a squeegee or push broom to remove as much water as possible from the floor.
To remove stubborn rust stains from your concrete garage floor you can create a paste out of laundry detergent and baking soda.
Mix about one third cup powdered laundry detergent in a gallon of warm water and scrub with a nylon bristle brush.
It is not unusual especially with old concrete stains to have to clean the surface several times.
Finally dry mop the floor.
You will be using a fair amount of water and anything left in the area will get wet.
As mentioned the cleaner cannot dry and the contact time of cleaner with the floor must me be kept minimal or etching can occur with some cleaners.
Break the floor into sections that are easily managed.
Don t underestimate the power of warm soapy water to keep your floors clean and remove minor stains.
Leave the baking soda paste on the stain for about an hour keeping it wet so that it doesn t harden.
If the acid bubbles up it means the floor wasn t sealed so you won t have to strip it with acid.
Work in sections that keeps things under control.
Pour a small amount on the floor in an area that has been covered by stuff for a long time.
New garages don t have floor drains that would eliminate the problem.