Prepping for sealer

[Dragster Racer]

Here is the history. 40x40 shop. 4 years old or so. Used seal and cure when the concrete was new....which was great for a while. Now it is dirty and has accepted some stains. This is what I would call a working shop. I have the motohome in there and the dragster and any of the daily drivers on the lift. There is welding and grinding and other fabrication.
I have tried cleaning the surface, and it is just not coming clean.
What is the best way to prep for a new sealer if grinding is not an option for me? I would love something that I could do half the floor at a time. Methanol seems to lift the sealer until the methanol evaporates. But even then I don't know how to get it off the surface short of scraping it. How do you go about starting over? I would like to do half of the shop at a time.

 

[Shea]

Unfortunately the only other option to grinding is to chemically strip the sealer from your floor. A solvent based stripper would probably be your best bet though they do make some more eco-friendly strippers that are not as aggressive. It's still a lot of work but it will remove your old sealer.

After removal of the old sealer I would recommend using a floor buffer with a nylon brush attachment made for concrete to degrease and clean the floor to prepare it for new sealer and remove any remaining residue from the stripper. I don't see why you couldn't do your shop in sections this way. Just work along the contraction joints. It's still going to be a lot of work no matter how you look at it.

 

[trbomax]

Dayton Superior makes 3 different chemical strippers for concrete.They remove most brads of cure and seal as well as oil and stains. Google is your friend.