Silver still won’t melt!

I’ve searched previous posts to find help in melting my 925 silver, approx 12g new from Cookson. I bought the setup suggested before, with the sievert 3941 burner and am still struggling. I don’t think even this burner is getting hot enough, but it should do from everything I’ve read. It took ages to prepare the crucible with borax, although eventually that worked.
The silver is moving around and looking like mercury but it takes about 20 mins to get to that stage, and cools before it pours even though I’m heating the lip. I’m outside but under cover and it’s not windy and I’m using a barbecue cover for protection, and some firebricks next to it. Could the burner or regulator be partly blocked somehow? How would I check? I know the hottest part of the flame is just at the end of the blue zone, but the only way I can get any melting is by having the burner tip almost inside the crucible.
Any suggestions are welcome!
Thanks

I took advice from Hamilton Gas on which burner to use on my own Sievert for this

They recommended the 8179 which fits on the same neck as the jewellers tip but has 8x the heat output. It's not as powerful as the one you are using though!

What pressure is your regulator at, and any chance you could upload a video to Youtube?

Im not familiar with this torch but can you adjust the nozzle on the torch to get more air into it ? the slots at the bottom of the nozzle. this will make it burn hotter

Nah, the Sieverts entrain air according to the gas flow, no other adjustment. A 3941 is the standard nozzle and is plenty to melt reasonable quantities of metal with enough propane driving it, but a hearth also helps.

A few issues I know of that can occur … Sievert tortures run on propane and not butane … mostly running with a hose failure valve and not a small regulator … a jet inside the burner controls the gas flow and can sometimes get partly blocked or corroded.

A common mistake I’ve seen is using a crucible too large for the torch. A 2” Square Crucible/Scorifier is plenty big enough for most jobs and can hold 20-30g of silver. Larger crucibles are much harder to heat properly and mostly need oxygen mixed torches. I have a large variety of nozzles for my Sievert torch and before getting an Oxy/propane set up my go to nozzle for this small size crucible was the 2941 burner I also had to include creating a small reflective ceramic cave surrounding the crucible.

One last suggestion if all else fails, I used to sometimes use pieces of barbecue charcoal placed on top of the crucible and silver. It all ignites and starts to glow radiating heat down towards the silver creating a mass of radiant heat on top of the crucible. When ready to pour it can be flicked off or simply held back as the silver will flow from beneath the charcoal embers … good luck with it … Nick