I have a DEVIL FORGE that was just not getting quite hot enough to forge weld. I noticed that it only had about an inch of insulation so I increased the insulation by another inch, used rigidizer and refractory cement. Now it's barely getting hot enough to forge steel. I've obviously done something wrong. Can anyone give some advice?

Pictures of your setup will help, tank, regulator, fittings,forge opening (doors). The refractory cement may be a problem. Knowing where in the world you are located will also help. Different countries have different LPG (propane).

Welcome aboard Martn, glad to have you. If  you'll put your general location in the header you'll have a chance of hooking up with members living within visiting distance.

Have you calculated how much you reduced the volume of the forge by adding another 1"+?

I'm betting the much smaller forge volume is causing so much back pressure the burner just can't work properly.

Frosty The Lucky.

I am brand new to this as well and bought a double burner Devils Forge. The refractory it comes with is a joke so I followed the advice given here and purchased plenty of kastolite 30 and relined it with that over the factory 1" of kaowool. I only made a layer about 3/8" thick. The volume of the forge is too small by my eye to have it thicker and place a sacrificial brick in there as well. It would put the project material right in the blue flame and from my handling of a torch this is not a good thing nor where the heat is. I am going to make my own thin sacrificial brick from left over kastolite. I also will be closing off 90% of one end to conserve heat and have better control of it. Is yours open on both ends or does it have the doors?

 

3/8" of Kastolite on the floor is all you need. If you want a flat floor level it but don't get too carried away, a couple inches of flat is usually plenty.

Frosty The Lucky.

16 hours ago, Blackcloud said:

. I am going to make my own thin sacrificial brick from left over kastolite.

Good choice there!