Thanks! I will look into that. What about using a plain old wood planer? It may make some dust but I don't imagine it is much worse than scraping.

A hand plane will still generate some small particles...probably about the same as hand scraping, but you may hit nail heads with the planer blade and also have wood tearout on the siding. You also won't be able to get into corners, and any "dry" method means cleanup will be more work. Finally, I don't know where you live, but, in my area, you also need a permit for that amount of lead paint removal.

Also, be careful of all the lead paint on the ground, or your yard will be contaminated.

I have done a lot of paint stripping on my old house. I use a heat gun and wear an N-95 mask and glasses, and I shower after I finish for the day. I've been tested for lead in my system and I am fine. If I had children in the home, I might feel differently about this, but I believe a one time project like this has little effect on adults. If I did this for a living I would feel differently.

The government didn't require that lead be removed from paint until 1978, so there are lots of people who are working with lead paint who have no clue.

There are no lead paint restrictions that I know of where I live.

An N95 mask is inadequate to filter all particles from lead paint removal. You need a mask specifically designated for this purpose, typically an N100 or P100. And, as I mentioned above, standard heat guns release lead fumes, which is a further hazard.

https://pksafety.com/blog/lead-and-paint-fumes

https://www.beaconjournal.com/story/lifestyle/home-garden/2012/04/07/paint-stripper-makes-lead-paint/10485417007/

Thanks. I had to fire the guy who was previously doing the work for various reasons so now I guess now I just have to find a contractor who will do it properly. But I do see that wet sanding with a HEPA filter vacuum (not DIY), chemical stripping, and infared (not heat) guns are all options for removing the paint from these boards safely, with the proper safety procedures.

Daughter has a 1753 house and had lead painted clapboards scraped and repainted. Is it smooth- nope? But the other choice was full scale lead abatement down to total bare wood everywhere at an astronomical price. New paint has been well adhered for six years. Can recommend that you embrace the imperfections that come with an old house.

Replacing old clapboards are way more expensive than you may think. A tree fell on end of daughter’s house. The original clapboards were 1 1/2” thick cedar- the reason the house was not more damaged than it was. The area that had to be replaced required custom milled 1 1/2” cedar boards- $$$$.