Charl. Crossforge

I might be a bit late here, but I have a 2 burner forced air forge done with verokast 1600. It works well. I used mig tips as jets but drilled them out to 3mm. If your jets are too small they act like regulators themselves and no matter how much you open up your regulator, you can only force so much gas through those small jets. If you go too big on the jets you pick up another problem in that you get no back pressure from them, causing your pressure gauges not to show any pressure, thus making adjustments in pressure difficult as you can not really judge the pressure from your gauge. That said, I have found that most times, guys using forced air have too much air blowing into the forge. I use a blower from a car's aircon system which does not give a lot of pressure, and still I have my "gate valves" open only about a 5th of the way. (Flexible pool hose connected to the blower and the feeder pipe for the air with the gate valves is about the same size.) The more air you have, the deeper in the burners your gas will burn, but keep in mind that the air you blow into the forge also cools it down, thus, with too much air you will have roaring burners but in the process you are cooling the forge with too much air preventing it from reaching proper temp. You want most of your flame outside the front of the burner where you want the heat, with only a little flame exiting the mouth of the forge. From here, if you need more heat, increase gas pressure and then increase air flow slowly to reduce the ammount of flame at the mouth of the forge. Repeat till you get the right temp. Also keep in mind that verokast will initially have trapped water and also contains particles that need to burn off initially so you will need to run it a couple of hours to burn in properly. After that it will start to function a lot better. You will also find that as the temperature in the forge starts to increase you will need to adjust gas and air settings. When mine gets up to operating temp I drop my gas pressure by about a third and reduce the airflow to get a little bit of flame at the mouth and that is enough to keep it at the right temp. The trick is really to get the ratio between jet size, gas pressure and airsupply figured out and your forge should work like a charm. Hope that helps.

I agree with NuViking. I have even welded and brased stuff onto the tang after heat treatment with no ill effect. I simply submerge the whole blade into a tin of water leaving about 15mm exposed from the point of welding. NuViking's idea of freezing the water will aid ease of handling but just plain water is good enough for cooling. Water in liquid form will not exceed 100 degrees celcius unless it is under presure so hardening will not be affected.

Kaowool is in fact a ceramic fibre blanket. You will be able to obtain it from any company that build kitchen ovens as this is used for the insulation of the oven.

Fritz. Do yourself a favour. There is stuff on the market called mouldable ceramic fibre. Basically it is chopped ceramic fibre mixed into a sticky mois clay base (White). After finishing your furnace, coat it with this. It will need to air dry for about 2 days (when packed 1 1/2 cm thick. It becomes hard and insulates very well. this causes the furnace to heat and cool at a slower rate largely reducing cracking caused by temperature fluctuations.