Removing paint from control joints

[Okolowicz]

Any recommendation as to the best way to remove paint from the control joints in preparation for epoxy?

I grinded the floor with the diamabrush and used an angle grinder for the edges. The only area left to prep is the joints. Is a steel brush sufficient? Sandpaper? Or, is a chemical stripper the preferred method.

Thanks

 

[Edger]

Oh boy, that is a difficult question.

If you need to remove the paint from the joints I think a diamond blade would be best. Try to rent a dry saw if possible with vacuum or use an angle grinder with a diamond blade. Run this up and down gently rubbing the blade against the side of the joints.

If you are not careful you will make the joints more ugly.

 

[pauls_workshop]

Depending on the width of these joints and the height of the diamond blade, using an angle grinder could be extremely dangerous for the non-professional. If the blade gets "hung up" or "caught" between the front and rear walls of the joint, this could very easy jump out of the joint and be hard to control. I would not recommend this at all. Maybe a pro could do it but still very very dangerous. A saw based approach would be much safer I would think. - Paul

 

[Edger]

"If the blade gets "hung up" or "caught" between the front and rear walls of the joint, this could very easy jump out of the joint and be hard to control."

I think that only happens with a steel cutting blade. I never had a diamond blade react like that in concrete.

I wish someone would offer a better solution, but I cannot think of one because wire brushes do not get down into the joints and they tend to rub and polish rather than clean.

 

[mayday0017]

Honestly I doubt you need to be worried about it, you probably won't ever have any problems with it regardess of what you do.

 

[Okolowicz]

OK. It's done. Turned into a complete debacle.

Plan A was the angle grinder but it was incredibly difficult to get just the paint off without making the joints look terrible. So, I scrapped that and went to plan B. Plan B was an assortment of wire wheels on the drill. That worked pretty well to remove the top coat of paint but did not get down enough to get the bottom coat of paint. So, it was on to Plan C: paint stripper.

Paint stripper and a steel brush worked extremely well. However, removing the stripper/paint residue goo was a nightmare. I had ground the floor last weekend and I think the resulting texture is what made it made it extremely difficult to remove the residue. I went through a gallon of Xylene and every curse word I know and there was still residue.

Before I started the joints on Saturday the floor was otherwise completely ready to go. By the time I gave up on scrubbing I now had water beading on the area around the joints. Maybe more scrubbing would have worked but after all the prep already invested I was not going to leave anything to chance. So, I rented the Diamabrush on Sunday (again) and reground the floor.

So, word of advice to anyone else getting ready to do there floor with a similar issue, learn from my mistake and: remove the paint from the joints before you grind the floor!

Needless to say, I am glad it's over.

 

[Edger]

Great post, thanks for your honest comments.