Simple protection for decarb?

[Bo T]

I am going to make some hot cuts and punches from S7. I am not to concerned with the shaft but would like to protect the cutting edge and bevels from decarb. Can I just use some furnace grout?

 

[samuraistuart]

Seems like the satanite does indeed offer a level of decarb protection! It needs to be only a thin "wash", not too thick. IIRC, someone had asked about different available decarb protections, and I want to say Mr Hanson III mentioned that satanite for decarb protection was a good option. It may not have been him, but another knifemaker. The thin layer tends to blow off during quenching, even air cooling will "blow" it off. So if you're doing thermal cycles, it will need to be re-applied.

 

[James Hall]

I was just suggested in another thread that brazing flux will help to prevent decarb, although it shouldn't be used during final hardening because it can be an insulator.

 

[Bo T]

S7 is air hardening up to 2.5". So it can be brushed off when pulled from the furnace.

 

[Stacy E. Apelt - Bladesmith]

Just a note:
Welding/brazing Flux may prevent decarb, but it also may also etch the steel. The ingredients in the flux are designed to eat a bit into the steel to clean it....This may be OK for punches, but not what you want in blade HT.

 

[Willie71]

Just a note:
Welding/brazing Flux may prevent decarb, but it also may also etch the steel. The ingredients in the flux are designed to eat a bit into the steel to clean it....This may be OK for punches, but not what you want in blade HT.

That's a good point I hadn't considered.