PJames Posted January 7, 2012 Share Posted January 7, 2012 I did not get an answer back yet on anther thread about whether or not to fire my forge before applying plisix, so I went out and lit it anyway. I guess I cannot post pictures directly from my computer. But the flame I got was blue and sounded like a torch kind of a steady roar. Then the blue would go out and I could not see any flame at all and the pitch would increase. It would go back and forth like this. I pulled the burner in an out a few times and adjusted gas flow. My main question is what am I looking for? I wanted to use a firebrick(1.25" thick) in the bottom but it is wide enough that I have alot of space under the brick. I did not have a brick available when I built the forge to see how it would sit. The space above the brick is about 5 inches or so wide and 3.5 tall. I lit it at first without the brick but did not do any adjusting until i put the brick in. Then it was too hot to remove the brick and attempt to adjust empty. I am planning on trimming that brick so it sits deeper in the forge body. Quote Link to comment Share on other sites More sharing options...
Venison Posted January 10, 2012 Share Posted January 10, 2012 not fully clear on your question, but hope these help:http://images.tribe.net/tribe/upload/photo/c63/38e/c6338e12-10fc-48b2-a48b-4b823690f20bhttp://ronreil.abana.org/design1.shtml Quote Link to comment Share on other sites More sharing options...
kraythe Posted January 10, 2012 Share Posted January 10, 2012 I did not get an answer back yet on anther thread about whether or not to fire my forge before applying plisix, so I went out and lit it anyway. Takes a while sometimes. Poeple do have lives you know. However you can fire the forge before or after the plistix, either way works. You will need to fire it after though to make the plistix cure. I guess I cannot post pictures directly from my computer. But the flame I got was blue and sounded like a torch kind of a steady roar. Then the blue would go out and I could not see any flame at all and the pitch would increase. It would go back and forth like this. I pulled the burner in an out a few times and adjusted gas flow. After a forge is up to heat it would be normal to sometimes not be able to see the blue flame in the forge. That depends on the light in the forge. The glowing bricks will make it tough to see sometimes. If you adjust the burner properly when the forge is cold, be patient. The forge will come up to temperature then a lot of the unburnt propane will get ignited by the atmosphere. As for the pitch, that depends on the burner and the forge. If the flame for the burner is retreating into the burner then the back pressure is overcoming the venturi effect and the forge, ironically, needs more openings to breathe properly. If the flame is leaping off the end of the burner and going out then the gas velocity is too high and you need to use a bigger jet. A smaller jet might also help against back pressure. Adjusting venturi burners is tricky. It takes a lot of trial and error. My main question is what am I looking for? Steady sound, good flame characteristics, 6 to 8 inches of dragon's breath. Flame should be anchored right on the top of the flare and not off it or inside it. I wanted to use a firebrick(1.25" thick) in the bottom but it is wide enough that I have alot of space under the brick. I did not have a brick available when I built the forge to see how it would sit. The space above the brick is about 5 inches or so wide and 3.5 tall. If its a hard firebrick, Id stuff some insulation underneath. If it is a soft brick than get a hard brick. I lit it at first without the brick but did not do any adjusting until i put the brick in. Then it was too hot to remove the brick and attempt to adjust empty. I am planning on trimming that brick so it sits deeper in the forge body. Ahh be careful. Hard firebricks when glowing are in excess of 1500 degrees. Do not touch them even with gloves. However, venturi burners have to be adjusted exactly to the size of the forge and when you change the volume of the forge significantly by putting in a brick, especially if that brick chord's the surface of a can forge, the volume has been drastically reduced and a tuned burner may now suffer from back pressure problems. This is why blown burners are easier, you can just crank up the air a bit if you need to. However, venture's have their advantages. I would say you probably are having back pressure issues with the burner and need to adjust the jet's position in the burner, size and jet tip. Without being on hand, that is the best I can do. You might try uploading a video to youtube and I can help you further. Quote Link to comment Share on other sites More sharing options...
PJames Posted January 12, 2012 Author Share Posted January 12, 2012 The pics help. I actually had a pretty lean fire. I thought the increase in orange/red and the lighter blue flame meant it was too rich so I actually increased my openings. I had to choke it back a ways and it started burning fine. I am using a burner with slits so a simple band made from folded aluminum foil works well. I do not have a guage. I thiought I was buying one since the package label on the propane line said 0 to 20 psi. It just has a needle valve and the forge seems to fire best at a little over 1/4 turn from off. I doubt I will get welding temp with this burner, but I can a bright red/ almost orange and the rebar and RR spikes I played with got fairly maleable. Thanks for the pics and comments. Quote Link to comment Share on other sites More sharing options...
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