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  1. 12 Inch Club

    i guess collaring would count as a pull, eh?
  2. Regardless of the type of burner you use you must have enough space at the inlet port to allow it to draw sufficient secondary air for efficient combustion. if your burner is 2.5" in diameter make the port 4.5", or 1" all around. This will allow plenty of area. Since you are bringing in cold propane and relatively cool air you must also allow for an exit flue of at least that area, since the exhaust gases have expanded in combustion.This means that the exhausted fuel requires more area to flow out of the kiln.You can't really force the exhaust out by putting more fuel/air in. if you were using a blower or if you had a chimney that would help, but with your set up you need a flue opening of say 5'5". Then use a piece of fiber tied to some wire mesh for a damper. I have a little kiln made with soft brick sides and a fiber top that reaches temp just fine and the burner port is roughly twice the size of the burner and he exit flue is roughly twice the size of the burner port. I use the fiber/wire mesh as a damper so I can reduce if I want to. is, The point is, imho, you need to get more air in and more exhaust out for your kiln to work properly. Hope this makes sense, good luck with it, Bill
  3. I've used hand held airless sprayers that work ok, but they are noisy, at least they were back when I tried them. That may be what OffCenter is talking about. For the TCP global guns what you need is a compressor that meets the specs of the guns; "Operating Pressures of 29-50 PSI, Air Consumption 3.5-7.1 CFM", from the website. The cubic feet per minute requirement is what is most important, almost any compressor will deliver 50 psi, but if it were a tankless one and couldn't provide that much air you would get a pulsating effect; very aggravating. If I am going to spray, which means clean up afterwards, I usually wait until I have a good number of pieces. That means I will be spraying for a while, so I want to have a compressor that can keep up. The one I use at home has a ten gallon tank and it works fine. On the subject of spattering: in an earlier incarnation as a scenic artist on movies, I used to take the air cap (that's the first part to come off when you cleanup) off of the spray gun to spatter paint. Having been reminded of this I think I'll try it with glaze. We used to use a pressure pot but it should work with a gravity feed gun as well. Bill
  4. 48Cuf Gas Kiln Help

    Your answer ---- and not: Your answer Cheers! Didn't know there was a rule. Seen others do it, so I figured I'd just keep my reply next to what i was responding to. Sorry to have annoyed you so. Hope you have a good evening even though.
  5. 48Cuf Gas Kiln Help

    on the previous page, "...if the kiln is under constant reduction and will not climb in temperature easily, the portholes can be widened to provide more secondary air for combustion. at the same time make sure that the exit flue is not too small. However, most of the time the burners will have oversixed orifices, thus throwing off the air/gas ratio for proper combustion.To solve this problem, replace the orifices with smaller ones. (Normal orifices for low pressure burners are between ..... 38 and 42 for propane"
  6. 48Cuf Gas Kiln Help

    Hey there, based on all i've read here and in "the kiln book" 3rd edition by F. Olson it seems like you're choking the kiln. you've gone from 27cf to 36 cf and 2 burners to 4 burners, respectively, so i would think that lack of fuel is not the problem. From page 201 of said book: "Exit flues. There are 3 methods of determining exit flue sizes: 1. Add the total inlet flue areas (ports) to find the exit flue area. 2. A rule of thumb for exit flues is 2 1/2 sq. in. per cf kiln space. 3. I find that 7,000 btu burner input requires 1 sq. in. exit flue area, regardless of the burner system used A kiln requiring 1,000,000 btu burner input will need an exit flue of143 sq.in., or 12"x12". It is always better to have flues on the large side than to have them small and choke the kiln. When the flues are too big they can be made smaller easily. Of the three methods, I use No. 1 and 3 and build the flue accordingly." I also suspect that your inlet ports are too small, not allowing enough secondary air, but this is just a guess based on the size of the flue indicated by your required btu input for that size kiln. Again, good luck with it, Bill
  7. 48Cuf Gas Kiln Help

    I am anything but a kiln expert, but I do recall that the area of a circle is pi times the radius squared. that would give an area of 28,28 sq.inches for your 4 burner ports and I think you said your exit flue was around 28 sq. inches. If you consider that the volume of hot air coming out is greater than that of the cool air going in then I suspect that the problem is possibly that you cannot exhaust enough spent fuel. Making the burner ports bigger or the burner orifices larger will not fix the problem, if this is true. Sure am curious to know how you eventually fix the problem, as I am creeping up on building a larger kiln myself. Best of luck, Bill
  8. I have used copper foil with good results. Thin walled vessels with a glossy glaze so the adhesive on the foil will stick while you're building. If you are doing glass inside an opening in your vessel, there is no chance of it coming loose if you fold the foil over the perimeter of the opening. It is then captive in the opening after soldering. If you want to do a lidded vessel, in order for the foil to remain in place, you need to create a small groove along both sides of the edge so that the foil is not depending on the adhesive to remain in place, but rather is formed over the edge and into the groove a bit to hold it in placeafter soldering. Best to use a wide foil for the perimeter and narrower foil for the glass.