First up, hi all I'm new here. I dabble in a bit of everything but mostly knife making. I'm currently at the stage where I need to heat treat a knife that I've made from s90v (1150-1175°c) and I've decided to try the salt pot method.
I've made the usual rookie mistake of building a propane forge and not really knowing what I was getting myself into and I can't seem to get above around 890°c - though it's time for a propane refill.
I have a burner that I bought to save a bit of time, frosty style and with a 1" flare iirc, 6" pipe but I'm not sure what size jet. I'm at 30ft above sea level.
The flame looks quite good to me, I'll get pictures next time I run it. I'm using a converted propane cylinder in the upright position with approx 11" tall by 7" internal chamber, 2.25" refractory cement lining and 4.5" exhaust. The burner is at the very bottom and arranged to create a swirl (like the devil forges).
I get an orange flame out of the exhaust, not like unburned fuel to my mind - more like super hot fumes, of course I may be talking rubbish there though. I've had the regulator everywhere between 5psi and around 20psi - to get the very highest temperature, I need the pressure as high as it will go. The cylinder freezes in around 15mins at any pressure but it did start out around 1/2 full and we're 6-10°c outside at the moment.
Any thoughts about what I might have wrong? Just from gut feeling and working on similar projects, I'm tempted to blame the refractory cement (looks a lot like mortar) but could do with you guys' more experienced opinion before I start throwing money at the problem.
Any help would be much appreciated
20201201_131136.mp4
Inside the lid, showing the refractory that I used (Still not quite dry at that point)