Step 2Inlet air hole
iImage Information

I cut the inlet air hole and welded 2.5" pipe in an angle so the air will swivel and create more heat in the center. I kept the pipe 2" inside that will be the thickness of the refractory in the furnace. I found my welding magnets very usefull for holding the pipe in place. After getting all my welding gear ready the pipe was perfectly welded into place. Small tip: when placing the cylinder on the side place 2 wood battens under it to prevent it from rolling aside when using the grinder on it.
How long is the inlet pipe ?
Is the length critical ?
Is the flange important ?
Great job.....Roger
Another simple option is using card board or plastic cylinder to form the inlet hole, after refractory is set take the cylinder out.
In my image I drew blue line that represent metal angle brackets and the red dots arepresent metal screws.
Hope this will be useful to you.
DANGER:
Cadmium is extremely toxic even in low concentrations. The fumes given off by zinc is toxic also when heated.
Lots of materials around that we need to be careful we don't breath the fumes it makes when we are heating it.
Once it is burned off, you are probably okay. Just remember to not breath any of the white smoke/fumes. They are toxic/poison. If they never get heated hot enough to smoke/cause fumes, there shouldn't be any problems from using cad plated parts.
Great instructable!
Ken
102410 2029
Is there any way to know when melting coated object if the paint contains cadmium?
Or the best thing is just to melt clean parts such as car pistons act' ?