I bought a shaver for full retail (around $700)for a job I did. It paid for itself on the first job. When I found a second one in a pawn shop for $150,00, I jumped on it. They are what they say they are in terms of paint removal. When running mine I always run off a vacuum (otherwise the motor will burn up). I hook my vacuum to a Dust Deputy cyclone, which removes about ninety percent of the debris before it gets to my vac filters. For $70.00/$200.00, it's an investment you'll use over and again. Team this with a HEPA filter and you have a winning combo. When I'm done with the shaver, if I don't like the rough surface. I blow over the siding with my Porter Cable siding sander and as fine a disk as I can get. I can fine sand the entire side of an average house in one day. Another option I've used for find detail is my Porter Cable variable speed, random orbit sander with hook and loop disks. This may make more sense for most, since you can use it in your shop to polish and sand other things. I've even used it for edge work on hard wood floors. It only takes a bit longer than the very expensive edge sanders.

Calcimine ( also kalsomine or distemper paint) is a calcium carbonate product that, mixed with water and sometimes pigments and glue, formed an opaque, easy to use and fast-drying coating used mostly for ceilings. I assume you know for sure that the coating is a calcimine paint. The usual test is to rub a damp finger over the paint. If it feels "chalky" it's calcimine. The only way I know of to remove it is lots of soap, water, elbow grease and patience. It's messy and wet and not at all fun to remove. To avoid discouragement, don't get over-ambitious. Do one wall at a time. Also, be sure to protect your floors. with 3-mil PVC sheets. This will catch dripping and any lead paint. When you are done, role it up, tuck it in a contractor bag and remove it outside. It can go out with the regular trash as long as it is tied securely. Scrape off all the loose paint using a 6" taping knife or carbinde paint scraper. Keep a 2" putty knife in your back pocket for tight areas. Some of the paint is probably lead paint, so wear a dust mask and try not to track it all over the house. If there are several coats of oil-based or latex paint, we use a gel-type water-based paint remover on the wall. Follow the manufacturer's directions, but generally it's paint it on, let it sit, then wash it off. Using a very wet sponge, wet the wall. Some calcimine will dissolve and lift from the surface. Then using a sudsing cleaner (Spic 'n Span or Dawn) and a scrubbing pad, wash the wall vigorously until all the Calcimine is gone and you are down to the hard final coat of plaster. We then use a rubber window washing blade to remove as much of the suds/water mixture as possible followed by a rinse with a wet sponge. Some of my colleagues add 10% vinegar to the rinse water. We tried it and did not see any difference, but maybe your experience will be different. Thid does not remove all of the calcimine, but does remove all of the loose and chalky calcimine. Once the wall is dry, inspect it carefully. Use the damp finger test in any suspicious spots to check for remaining chalky calcimine. Paint with a good calcimine-ccoating primer such as Benajmine Moore's Super-Spec Alkyd Calcimine Recoater. There are other brands, but we have had good success with this one, so we have not tried any other. Do one room at a time. Remove the old paint; prep, prime and paint the walls. Start with the room you like the least. Practice on that room. As you get better, move to rooms you like better. Good luck with the project.

Wow, that is a stumper then. I really have no other suggestions. Myself, I'd be leery of putting poly over it to hold it down, I'd be thinking the poly would lift up too, or crack and craze? Dunno. Had a similar experience recently. Freebie little lamp I got, perfect shape for a bedside but it was black and I wanted it cream. Did everything right and there was one tiny spot that the primer and paint just kept curling up and cracking off of and I just can not get it fixed. Guess you could always try the poly, if you can get the topcoat to cling long enough to apply it?

^^Well said. All LBP requires in order to be safe is proper management. OP is doing that and so are millions of other homeowners. It's generally not something that should keep a person from buying a house, unless the paint is peeling off or otherwise damaged, in which case abatement can take care of it. BTW there are plenty of ways for lead paint dust to be released besides chewing which is probably less common but does happen. The two big risks are friction and impact. Friction from shoes (on painted floors), windows sliding up and down, doors opening and closing. The other is impact - something hitting something else. It does not take much to create a lead dust hazard, but it usually doesn't take much to prevent it either. Same with many other hazards we protect our children from. Windowmaster, I do hope you are handing out the HUD pamplets to homeowners when doing remodeling work in lead painted homes, as required by law. Even if you think it's dumb, it's not worth the fines.