Leif Svendsen

It's not fully choked down, but pretty close. When I open it up more the flames lift of the block and it can even extinguish itself. I've decided to leave it like this for now and and time it once it's mounted on the forge.

It's ALIVE! Melting out the wax on the barbecue worked really well This running at 15 psi with a 1.0 mm mig tip.

This has to be the weirdest thing I've ever barbequed. What do you think? Low and slow on indirect heat to cure the refractory and melt out the wax?

So I finally cast the burner. Our two week family holiday in Italy delayed the process. I ended up doing 132 holes. Even though the sprue wax said 4.0 mm on the package, it was actually a lot closer to 4.5 mm. Here's what it looked like with all the pins in place. The mold is 240 mm by 90 mm and 70 mm deep. I've never really used Kast-o-lite 30 before and I had to go on YouTube to find some visual aid on what it should look like when mixed correctly. It really funny how it well it flows when vibrated. My power drill has a high pitched hammer function and this was the perfect tool for the job. I got the mold completely full. Here's a look at the new forge I'm building. The shell is only 1.2 mm thick so I need to make an external fram to support the burner. I don't think the shell will be able to support it in the long run.

My thoughts, exactly

Alas, had I only had a 3D-printer! I've ordered some sprue wax from China that I'll try to make sense. That's one of the reasons I'm using 4 mm holes, I think 3 mm wax will be too bendy. I'll try to go as thick as possible. Hopefully I'm have enough refractory to get close to 3".

Thank you, Frosty! I have some Kastolite 30 that I bought years and years ago with this intended purpose. Never got around to it before now, though. Thanks to this thread I've understood that it most likely will need some tuning when I mount it in the forge and I have built the burner with this in mind. I'm also playing with the idea of putting even more holes in the plinth and plug a few if I have too many. It seems easier than drilling into it or casting a new one if I have too few.

First of all I want to say thank you to Frosty and all the other contributors for the amazing well of information that this thread is. I'm going with a NARB for the new forge I'm planning and I feel that I've ready to move out of the testing phase and start building the mold for the refractory. I'm using a 1" burner with 0.8 mm mig tip and the wooden test block has 142 4mm holes. I've tested it up to 25 psi and It is burning really stable over the whole pressure range. No back firing or other issues at all. I feal that I've gotten as far as I can without a proper forge to play with, so that's next on the agenda. This is testing at 15 psi. What do you guys think?