What is the brown lining inside a cajon 316 T fitting?

[Effcap]

I was at a surplus place here in LA and came across some Cajon brand 1/4" stainless steel 316 T fittings, perfect for a project I was working on. When I got them home I noticed they were lined inside with a very hard brown material. It almost seems like bushing material. Does anyone know what this lining is and if properly cleaned, would this fitting be safe for passing water through?

Thanks

 

[MikeHalloran]

The only brown 'coating' that came to mind is heat tint from welding, but that seems unlikely.

How about just buying brand new, clean fittings from your Cajon dealer?
At that size, they can't be terribly expensive.



Mike Halloran
Pembroke Pines, FL, USA

 

[Effcap]

Hi Mike.. I was just wondering if and why some fittings are lined with ceramic or whatever it is for a reason. It's a very hard substance and yet I can scratch it. It's not weld residual but more like a sleeve inside that covers all surface area until it gets near the threads and then it stops and the fitting is perfectly shiny new beyond it. i noticed it because I have been inserting bushings into these for other reasons and the bushings would not fit since there was already a sleeve end at each opening.

Just curious.

Frank

 

[MikeHalloran]

I'm aware of a few substances that can be specified as 'lining' for things like fittings, but they are mostly either not hard or not brown.

You might ask your Cajon dealer if an option matching your description is available from Cajon, or if he knows of one from a third party.

The coating that comes to mind now is one of the PTFE-infused conversion coatings offered by the Magnaplate company, but I remember it as more gold/purple than brown. There may be variants of which I am unaware.

Can you section one and photograph it?



Mike Halloran
Pembroke Pines, FL, USA