I bought one of those small propane furnaces and the air came in two separate locations, through an opening in the opposite side of the furnace and also where the fuel and air mix in a 3/4 pipe tube with 11/4 bell reducer. The real problem was when the fuel needed to be turned up to get the heat needed,the furnace lacked air at the proper opening.
This furnace was originally designeed to use ambient air . The way it came from the manufacturer it would either waffle, or go out. The mix in the crucibles wouldnt get hot enough to make the contents run and drop the gold,. or pour into a mold. The crucible and furnace got up a little higher than orange red heat, I realize having worked in a refinery of late we can judge from a distance if the furnace temps are getting close. I know that more borax helps,but I believe the primary problem is the furnace Im using.
I enquired some advice from a fellow with many years in refining and assaying etc. Well I closed up the hole on the opposite side with refactory cement,and now I have a single air/ propane opening in the same entry as the original. So I built an inner compressed air tube with a small bell reducer to cone around and bring the compressed air to mix with the propane orfice opening.This propane opening is located in a small brass tube located in a larger 1 1/4 inch bell reducer. Its still hard to adjust the mixure but works well like a jet.But it isnt easy to use,or adjust the flame jet because its got very fine adjustment which is difficult without the thing going out or flames scaring me!!.Keep door open leave window cracked or partly open, as fuel valves can leak without you knowing it!
I exspermented with drilling one hole to bring ambient air at that location from out side the tube with a the larger bell reducer,it helped but did make it easyier to adjust the fuel to air ratio.Also brings me to question,because the fuel can lite inside the drilled opening.I was trying to copy the design that I saw online that were for sale,but couldnt see the entire fuel tube and internal part.I have a large propane shut of close to the furnace,I believe its too big to adjust fine increases. Any thing I"m missing here? The openings I drilled in the 1 1/4 bell reducer? Skip
This furnace was originally designeed to use ambient air . The way it came from the manufacturer it would either waffle, or go out. The mix in the crucibles wouldnt get hot enough to make the contents run and drop the gold,. or pour into a mold. The crucible and furnace got up a little higher than orange red heat, I realize having worked in a refinery of late we can judge from a distance if the furnace temps are getting close. I know that more borax helps,but I believe the primary problem is the furnace Im using.
I enquired some advice from a fellow with many years in refining and assaying etc. Well I closed up the hole on the opposite side with refactory cement,and now I have a single air/ propane opening in the same entry as the original. So I built an inner compressed air tube with a small bell reducer to cone around and bring the compressed air to mix with the propane orfice opening.This propane opening is located in a small brass tube located in a larger 1 1/4 inch bell reducer. Its still hard to adjust the mixure but works well like a jet.But it isnt easy to use,or adjust the flame jet because its got very fine adjustment which is difficult without the thing going out or flames scaring me!!.Keep door open leave window cracked or partly open, as fuel valves can leak without you knowing it!
I exspermented with drilling one hole to bring ambient air at that location from out side the tube with a the larger bell reducer,it helped but did make it easyier to adjust the fuel to air ratio.Also brings me to question,because the fuel can lite inside the drilled opening.I was trying to copy the design that I saw online that were for sale,but couldnt see the entire fuel tube and internal part.I have a large propane shut of close to the furnace,I believe its too big to adjust fine increases. Any thing I"m missing here? The openings I drilled in the 1 1/4 bell reducer? Skip
