Why not just buy a reusable half-mask? Keep in mind that you would need to wipe it down with diluted bleach after use.

This is the one I bought. (Price has gone up in the last couple weeks)

https://www.amazon.com/GVS-SPR456-Elipse-Nuisance-Respirator/dp/B01663XTM0/ref=sr_1_44?crid=3OBCKEEO5S54F&keywords=p100+mask&qid=1582227075&sprefix=p100%2Caps%2C168&sr=8-44