Stripping paint?

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Not strictly speaking a welding question, but who has a good recipe for a home made paint stripper?I need to strip some paint off a concrete slab - outdoor.There are about 4 layers of paint, and the bottom one would be lead based.So sanding is out.Burning wouldn't be great either.Conventional strippers are okay, but they're expensive - I need to strip about 40 sqm.Then there are those infra red ones that I can hire, but that's a hassle.So who has a recipe for a stripper? I heard a recipe made from a mixture of a cleaning solution and hypochlorite acid. Is that swimming pool chlorine? And yes, I know that I need to take all sorts of precautions. Scott
Reply:Is this all nice and flat/smooth?? There's a stripping machine out there, that looks exactly like the big commercial floor buffers. In fact it might be. On the bottom they put a plate that has carbide blades and as it slowly rotates it grinds the whatever off.  I've seen them use it several times to grind that nasty glue off after they've peeled the old floor tile and/or linoleum up. A round pad can't do sqaure corners naturally.  Sure there was dust, but a respirator would probably work since you would be making a short job out of it instead of lengthy sanding. Could be a critter like this is a rental item. Never looked like a duty I wanted any part of so I always stayed back a good distance.
Reply:Hi Sandy. Yep, it's flat. Problem with lead based paint is that when it turns to dust (from sanding) it contaminates the soil etc. Very bad for kids and pets. I need to lift it off and dispose of it.
Reply:Agreed about the need to control lead paint during stripping.  However, you may be overestimating the airborne dust generated by these mechanical impact-type paint strippers.  They do not abrade the paint into dust - they impact it with a multitude of sharp points on hardened wheels that look like the wheels on a rotary grinding wheel dresser.  I haven't used the rotary, "floor buffer" style, but I did acquire and use a heavy duty navy surplus devices that does the same thing with spiked wheels mounted on three axles that rotated as a unit.  It handles somewhat like a belt sander except that there is no belt, just the three axles carrying the spiked wheels rotating around a central axle.  Since the spiked wheels are loose on the axles (especially after extended use), they do not scrape the paint, they impact it vertically with the spikes on the wheels.  They were used shipboard for scaling paint and rust off the hull.  Black and Decker, I believe.They work best on thick layers of paint like you described and produce flakes and granular paint waste rather than dust.  Worked great on about 1000 square feet of concrete  garage roof, stairs, and porches.  I can't guarantee absence of dust, but they definitely do not create clouds of dust to be blown around like a sander would.By the way, are you assuming that lead is present or have you had it tested?  I collected samples myself at ten suspected locations and had them tested at a local lab for a little more than $100.  They did the tests for me on samples I collected myself because it was not a formal certification test requiring complete control of the sampling procedure and a chain of control of the samples.  Turned out that the paint chips off my old apartment building and my home, both about 80 years old, were negative for lead.awrightLast edited by awright; 02-28-2007 at 05:07 AM.
Reply:Thanks Awright. I'll see if I can find something like an 'impact type' stripper. I know hire shops round me rent out machines for griding down concrete slabs - exposed concrete is pretty popular these days.I'm in an older part of Sydney. My house would be 100 years old. Lead paint was used up until the 70s in Sydney. There are lots of soil contamination issues round the older parts of Sydney because of the layers and layers of lead paint that have been slapped on over the years.Hardware stores sell single use test kits because it is a problem. Admittedly, they wouldn't be 100% accurate. The top two layers of paint on the courtyard came up negative for lead. The older layer came up positive. A homemade stripper recipe would still be great for the fiddly bits if anybody has one.Scott
Reply:Originally Posted by scott brunsdonHi Sandy. Yep, it's flat. Problem with lead based paint is that when it turns to dust (from sanding) it contaminates the soil etc. Very bad for kids and pets. I need to lift it off and dispose of it.
Reply:Originally Posted by scott brunsdonHi Sandy. Yep, it's flat. Problem with lead based paint is that when it turns to dust (from sanding) it contaminates the soil etc. Very bad for kids and pets. I need to lift it off and dispose of it.
Reply:By sheer coincidence I ran across the file folder containing the manual for the B&D 727G1 Chipper-Cleaner today as I was looking for a completely unrelated file on a roofing contract.  Although I think I understand that you are really looking for a chemical way of stripping the lead-bearing paint, I'm going to try to post an image of the center pages showing the chipper and the cutter wheel as an exercise in posting images.  I've never succeeded in posting an image before, so let's see what happens.Well, nothing happened except that I wasted half an hour trying to scan (ok), insert as attachment (failed - too many pixels) and resize (failed miserably).  How do you guys do that?Well, back to the cave.awright
Reply:Actually, when you consider all the ramifications, is it possible that it might be less hazardous using a chipper with a HEPA vacuum rigged up with a hood at the tool to suck up the chips as they are generated, rather than having a large area of concrete covered with gooey chemical residue scraped off the concrete and tracked around on your shoes?My experience is that the effective paint strippers contain very strong chemicals, the most hazardous of which is Methylene Chloride.  Methylene Chloride is a powerful solvent that softens most paints but the fumes of which can induce heart attacks in the elderly or those with heart issues.  Check out the MSDS(?) (or whatever the the hazard data sheet is called) on the chemicals you intend to use.  An additional factor is that Methylene Chloride and many other powerful solvents will easily penetrate and/or dissolve many types of "rubber" or vinyl gloves.  Be sure to use gloves that resist penetration and dissolution.  I think Neoprene or Nitrile gloves may be most resistant.  Absorption through the skin can be as hazardous as breathing the vapors on a big job.Things may have change since the last time I used chemical strippers, but I found that the low-hazard enzyme-based (?) strippers were simply ineffective.No simple answers, but I think that, with care and a well designed vacuum hood around the chipper, you might end up with less hazard and only bags of dry paint granules to dispose of rather than a chemical mess.  Both will have to be disposed of in accordance with hazardous material regulations.  Remember that you will end up rinsing the chemically stripped concrete with a hose at the end of the job, washing the residue and the chemicals into the garden.Good luck.awright
Reply:I think I might have found a solution. I taked to a hire shop about what sort of machines they had for doing the job. They had the big grinding machines similar to what Sandy suggested. I explained the lead paint dilemma. He said he could fit it with a wheel that would work with water. So I wet the surface - not enough to cause any runoff - and then grind it. I just have to mop up the sludge. I figure I can put it in buckets, let the water evaporate, and then get rid of it properly.Thanks for the suggestions,Scott