I'm repainting my porch and need to remove the old paint. A lot of the paint was flaking but some is stuck really good. I pressure washed the porch and got some off but there is still a lot that didn't. The porch is concrete and some of the paint is 50 years old. I tried some paint stripper and that seemed to work ok. It will take forever to scrape the whole porch. My dad suggested I use a sander on the stuck paint but that will also take forever.

I'm thinking about using paint stripper and pressure washing instead of scraping and seeing how that does. Anyone have any ideas of a simpler way to get stuck paint off a concrete porch?

Beware of lead exposure.

If the concrete isn't too rough maybe an orbital floor sander would work

Wear a proper respirator and follow precautions. Since you probably shoot firearms you do not need to increase your lead blood levels.

My experience is with steel, not concrete. Try the pressure washer to remove the loose material. With metal, any old paint that remains would seem to have excellent adhesion, I'd just paint over it.

When we used paint stripper, we'd apply as directed & then cover with plastic sheeting to keep the chemicals from evaporating, keeping the stripper on the substrate as long as possible, then used a scraper to remove what came up.
More power washing to clean up surface.

my ideas have already been mentioned.

I'd start first with a strong paint remover. Something N-Mp (N-Methylpyrrolidone) or stronger (like Methylene Chloride based). You'll sometimes find it called "Aircraft remover".

That should work on everything but the most stubborn stuff.

I'd use a diamond floor sander as last resort, only because I'm cheap and they're often costly to rent.

As was also mentioned. If the paint has been on there for 50 years, it should probably be considered lead-based, and respirator should definitely be used if any dust will be generated.

Over the years, I've become a paint removal pro...my family owns a 115 year old Victorian bed and breakfast at the NJ shore...imagine the amount of paint on the place...layer upon layer in some places.

In my experience, carefully using a blow torch and scraper to remove the layers from all the ornate wood has been my go to paint removal method.

Now your surface material is concrete...if I were you, I'd give it a few passes with a blow torch...should peel right up.

If the paint that's left is not too many coats and thick. Feather sand the edges so not to have abrupt transitions. Prime everything then repaint. Make sure the primer is one that's designed to be walked on. You'd be surprised how many aren't. An example.... kilz 2 is not for that purpose. Kilz Premium is.

Do not use oil on concrete

If it's adhered this long, chances are it will stay stuck for many more years

I'm doing the same thing on my side porch. It has stone which is/was/kinda attached to the concrete slab. The previous owner painted it with tan/earth-colored epoxy paint about five years ago, and I have to get it off at least on most of the stones before I can clean and re-mortar them.

I tried both pressure washing and an orbital grinder. The best results came from the pressure washer, although it was a somewhat messy cleanup as chips and pieces of paint went everywhere. The grinder was less messy, but it took three times as long, and hard on the back.

Rent a sand blaster?

I've seen these used in LA on grafitee.

Rent a hot water pressure washer. Steam better yet. Be careful of the steam it'll burn the shit outta you.

I washed significant amounts of paint off a ag sprayer one day not knowing what I was doing. The heat will soften the paint like a blowtorch and the pressure wash does the rest.

It may not be perfect but it'll be better than hours of chemical fumes and a scraper.

I have tried most methods listed.

Sand blasting was the most effective.

Don't use a torch. Heating concrete can cause an explosion due to the trapped moisture it may contain.

Thanks for the torch tip. One of those things I would have never known.

quote:

Originally posted by cparktd:
Don't use a torch. Heating concrete can cause an explosion due to the trapped moisture it may contain.

Oh give me a break. He'd just heat the paint on the surface until it peels. The concrete won't explode.

Torch will make quick work of that job.

If it is a small porch an angle grinder with a wire wheel cup will get all the loose stuff off. I would then just repaint whatever is left on there.

I would use a torch, wire brush on a grinder and even a hammer and chisel for heavy stuff.
If its real heavy over a large area, there is a tool that grinds down concrete level when edges wind up lifting. This tool would be a .last ditch effort though. I think its called a scupper.

Perfect is the enemy of the good. I'd use that metal cup brush in the drill. Clean and sweep good and put good coat of paint on it. Try and let the paint cure a couple extra days and it will wear longer.

quote:

Originally posted by TXJIM:
Beware of lead exposure.

I'd like to echo this. Lead paint was banned in 1977. If it was painted before 1977 then purchase an EPA recognized lead test kit.

In oil & gas, we used to use a red primer that had lead in it so we can't just test the surface paint.

The reason I mention this is that a lot of the methods posted would make the lead airborne. If lead is not present, they're good methods.

Are you sure you want to re-paint? I have concrete steps and porch that had multiple layers of paint. Went through the process of getting rid of it several years ago. Used everything mentioned here and maybe more (don't neglect the idea of a hammer and chisel; it took off the most the fastest where it was thick. Used a sacrificial 2" wood chisel with metal cap, because it needed to be fairly sharp to work). Much prefer the look of natural, and it is no maintenance. And, yes, it took forever, and a lot of work. But that's why I did it; I don't want to do it again (i.e., every time it needs painting).