i know this subject has already been done to death, but i'v been trawling various forums still struggling to find the information i need. first of i have an rac helmet shell, post-war, or so i've been told, without liner. i have the para leather chinstrap and liner, and fixing bolts. As for tools, my dads an engineer so i have a whole factory of tools to play with. Anyway i want to know anything and everything, especially measurements of wear to put the bolt holes. Pictures would also be greatly appreciated, even if they're photos of originals, so at least i could look at them and try to work it out what to do.
cheers
liz
If the shell is made of hardened steel then drilling holes is almost impossible. Even cobalt bits won't do the job. The "approved" method involves heating the metal red and then drilling which isn't something to do on the kitchen table 
Cheers, but the drilling shudnt be a problem. I could always turn an industrial sized blow torch on it. That shud do the trick.
I recall Gadge doing something clever that didn't involve drilling. If he doesn't pipe up maybe drop him a PM?
I recall Gadge doing something clever that didn't involve drilling. If he doesn't pipe up maybe drop him a PM?
We've done a couple (including my own) by just riveting the leather chinstrap to the liner, rather than the shell.
With the right industrial equipment, it's possible to drill though the shell, Nige recently had some work in a foundry, and he got one done there.
My helmet doesnt have a liner tho. Its just the shell. I have a repo para liner. But even so i dont even know how that attaches. 
My helmet doesnt have a liner tho. Its just the shell. I have a repo para liner. But even so i dont even know how that attaches.
Ah right. inside the RAC shell you should see a small pin sticking down in the crown, that's what the post-war liner attaches to. To use it with the para liner, you'll need to drill the shell.
If you do get it drilled, you might want to grind down that pin, it's bloody lethal without the liner attached!
Yeah it does look nasty. So i need to know where to stick the bolt holes.