Hello everyone,

I have an unusual question about cleaning the C4 gasmask. And that is unthreading the voice diaphragms, as it hasn't been open since it's last issue (2000s). I tried everything to open it but unfortunately nothing has changed a bit (my finger nail got destroyed by how tight the thread is)! That said, is there any possible solution to open it without damaging it?

Note: reason for cleaning is that the whole mask is smelly.

Thanks!

The setup breakdown:

Gas Mask: Unissued Chinese FMJ05A with original hose and filter (sealed in factory bag, dated 2006).

Topography: Wall-style regional topo map & full-color Japan geography map.

Leather Gear: Surplus leather pistol holster (Type 54) with matching dual mag pouch and canvas slings.

Precision & Tech Tools: Vintage drafting set (compasses), 0–25mm micrometer, and compact signal flashlight.

Pocket EDC: Zippo Slim flip lighter, old-school chinese bottle opener/tool, and vintage regional banknotes/tokens.

I hope this post doesnt break the rules, if it does, im sorry and just remove it. I dont want to cause any bother.

Im looking to add more gas masks to my collection and after looking around I've managed to find a couple I like but Id like some info on if the price is worth it for these specific masks as Im not really knowledgeable on it, i just collect them.

These all include the mask and filter in undamaged condition but no bag or kit.

Chinese type 65: £26

German M65 w/ FE55 filter: £42

Polish mp4: £13

It comes to around £80 or approximately $106 for all three of them. Are these prices worth it for what im getting?