OiltoDiesel
04-28-2006, 05:24 PM
http://www.oiltodiesel.com/oiltodiesel/Image5.JPG
FLUE AND BURNER BLOCK ALTERNATIVES
FLUE
Standard brick size soft firebrick can be shaped like this #1 using very simple tools i.e. old wood drills, hacksaw blades, and a woodworker's rasp, (cut the hole as near to a slot as you can, this helps to keep the heat in by acting as a passive baffle.)
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image6.JPG
The brick fits into the kiln lid like so #2 and is held in place with Nichrome wire through the holes shown.
Drilling soft firebrick does not require an electric drill, quite often the bit can be used just held in the fingers! I usually use an old bicycle spoke for small holes. Remember that soft firebrick will break easily so carry out all operations on it with great care, however once in place it resists abrasion better than fibre, and means you can alter the size of the vent easily and accurately without damage.
BURNER BLOCK
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image7.JPG
As can be seen from the drawing, the burner block is a more complex shape, but it can be done with care, and its benefits outweigh the fiddle involved in making it. As with the flue brick, it is fitted with the "flange" on the inside, and is held in place by stitching it with Nichrome wire. Keep any off-cuts of brick, as they will be useful for controlling the size of the flue opening during early stages of the firing (economy) and during reduction (if any).
Note 1: When pushing either of these bricks into place, use another brick or a piece of wood as a pusher to prevent breakage as they will be relatively frail once they have been cut to shape
Note 2: If the kiln is going to be used for high temperatures on a regular basis, it is worth cutting a shallow groove where the Nichrome wire crosses the hot face, and burying the wire under a thin layer of fire cement to protect it.
TOOLS,
Standard tools:
Small Angle Grinder-to cut the drum.
Electric Drill and bits -to drill holes in same.
small nosed Pliers.
Hacksaw blade.
Old Tenon Saw.
Wood Rasp.
Old but sharp Carving Knife-to cut blanket.
Small Garden Hand Spray.
1 yard straight edge.
Non standard tools
Bicycle spoke drill.
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image8.JPG [IMG]
Tube borer: Made from a short length of steel tube with teeth cut into one end. Makes the job of boring holes in brick for the flue or burner a bit simpler.
Ceramic button threader
-For this you need a piece of wood or metal rod about 8" long sharpened at one end, and a short length of plastic tube, the sort used to protect the ends of fine paint brushes. The rod is pushed from the outside of the kiln through the fibre to the inside, the piece of tube is then pushed over then end, the ceramic button with its piece of wire attached is offered up on the inside, the wire ends tucked into the tube, and the whole lot pulled back through to the outside. It saves a lot of time (and temper). The size of the piece of plastic tube will dictate the size of the holes you drill in the drum of the "outside in" kiln.
Tips
When laying fiber inside a drum, I find it helps to use a rolling pin or piece of plastic pipe in a stroking rather than rolling fashion to compress the blanket against the wall
If you are building a kiln using a cut down drum, keep the bit you cut out of the middle of the drum; with the edges cleaned up, it makes an excellent cutter for the discs of fiber for the top and bottom.
If the inside of the kiln becomes damaged during use, repairs can be made by spraying the damaged bit with Rigidiser, and while it's still wet pushing a scrap of fiber into the hole and spraying over it again.
SETTING UP ETC.
With your kiln built, the inside rigidised you'll need a base shelf to go on the kiln floor, three props between 3" and 4" long, and the first shelf of your setting. As far as the latter is concerned I have found that contrary to what you might expect, round batts are the last thing you want in a kiln of this type, especially if you are proposing to use it for firings other than Raku. Square batts, the corners of which miss the kiln wall by about 1/2" seem to be the most effective. The fire circulating round the kiln hits the corners and is deflected into the setting, rather than skating round the outside as would be the case with round batts.
FIRING
Place the kiln in a well ventilated area with no overhanging material within 5 feet of the flue vent.
Stand the kiln on three bricks to allow air to circulate beneath it.
Ensure the burner is down wind, as cool air blowing into the burner port can adversely affect the quality and controllability of the firing.
DO NOT stick the end of the Burner inside the kiln. It needs to draw in as much, or more air, than is already available through the primary air holes in the Burner Head to achieve complete combustion. Putting the Burner into the kiln will starve it of air and ultimately destroy it. Ensure that there is a gap equal to the thickness of your hand between the Burner and the kiln
IMPORTANT:
ALWAYS place the gas supply to one side and downwind of the kiln.
ALWAYS protect the hose with some sort of cover to prevent it being tripped over or trodden on.
ALWAYS INSPECT THE HOSE FOR DAMAGE OR AGEING BEFORE FIRING
Only increase gas pressure in very small amounts, the same applies to changing the size of the flue opening with your brick off-cuts. These kilns are scaled down versions of large kilns, so a damper movement in the latter of 1" would scale down to approximately 1/16".
MATERIALS
Below I have listed the materials you will need to line a cut down 55 gallon drum to 2 ?? thickness. This kiln should be capable of reaching and sustaining temperatures to 2300 deg F, if you do not need the extra heating then 1 ?? thickness should be ok for our application.
Ceramic Fiber Blanket, 8lb density (128KgM), 2300 deg F grade, 1? X 2? X 16.5?
Ceramic Fiber Blanket, 8lb density (128KgM), 2300 deg F grade, .5? X 2? X 8.5?
Bisc. buttons (home made) X 18; 10 or 12 top, 8 bottom
2 ea 10' coils Nichrome wire,
2 ea Insulating Bricks
32 oz Rigidiser/Hardener (SWAG on amount)
Scrap 55 gallon drum
Assorted self tapping screws
1 ea 7' X 1/2"X 1/8" mild steel strap
You should be able to get all the supplies at any good online or local ceramic supply house. Let me know if you are having problems.
GOOD LUCK, HAVE FUN.
Gary
FLUE AND BURNER BLOCK ALTERNATIVES
FLUE
Standard brick size soft firebrick can be shaped like this #1 using very simple tools i.e. old wood drills, hacksaw blades, and a woodworker's rasp, (cut the hole as near to a slot as you can, this helps to keep the heat in by acting as a passive baffle.)
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image6.JPG
The brick fits into the kiln lid like so #2 and is held in place with Nichrome wire through the holes shown.
Drilling soft firebrick does not require an electric drill, quite often the bit can be used just held in the fingers! I usually use an old bicycle spoke for small holes. Remember that soft firebrick will break easily so carry out all operations on it with great care, however once in place it resists abrasion better than fibre, and means you can alter the size of the vent easily and accurately without damage.
BURNER BLOCK
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image7.JPG
As can be seen from the drawing, the burner block is a more complex shape, but it can be done with care, and its benefits outweigh the fiddle involved in making it. As with the flue brick, it is fitted with the "flange" on the inside, and is held in place by stitching it with Nichrome wire. Keep any off-cuts of brick, as they will be useful for controlling the size of the flue opening during early stages of the firing (economy) and during reduction (if any).
Note 1: When pushing either of these bricks into place, use another brick or a piece of wood as a pusher to prevent breakage as they will be relatively frail once they have been cut to shape
Note 2: If the kiln is going to be used for high temperatures on a regular basis, it is worth cutting a shallow groove where the Nichrome wire crosses the hot face, and burying the wire under a thin layer of fire cement to protect it.
TOOLS,
Standard tools:
Small Angle Grinder-to cut the drum.
Electric Drill and bits -to drill holes in same.
small nosed Pliers.
Hacksaw blade.
Old Tenon Saw.
Wood Rasp.
Old but sharp Carving Knife-to cut blanket.
Small Garden Hand Spray.
1 yard straight edge.
Non standard tools
Bicycle spoke drill.
[IMG]http://www.oiltodiesel.com/oiltodiesel/Image8.JPG [IMG]
Tube borer: Made from a short length of steel tube with teeth cut into one end. Makes the job of boring holes in brick for the flue or burner a bit simpler.
Ceramic button threader
-For this you need a piece of wood or metal rod about 8" long sharpened at one end, and a short length of plastic tube, the sort used to protect the ends of fine paint brushes. The rod is pushed from the outside of the kiln through the fibre to the inside, the piece of tube is then pushed over then end, the ceramic button with its piece of wire attached is offered up on the inside, the wire ends tucked into the tube, and the whole lot pulled back through to the outside. It saves a lot of time (and temper). The size of the piece of plastic tube will dictate the size of the holes you drill in the drum of the "outside in" kiln.
Tips
When laying fiber inside a drum, I find it helps to use a rolling pin or piece of plastic pipe in a stroking rather than rolling fashion to compress the blanket against the wall
If you are building a kiln using a cut down drum, keep the bit you cut out of the middle of the drum; with the edges cleaned up, it makes an excellent cutter for the discs of fiber for the top and bottom.
If the inside of the kiln becomes damaged during use, repairs can be made by spraying the damaged bit with Rigidiser, and while it's still wet pushing a scrap of fiber into the hole and spraying over it again.
SETTING UP ETC.
With your kiln built, the inside rigidised you'll need a base shelf to go on the kiln floor, three props between 3" and 4" long, and the first shelf of your setting. As far as the latter is concerned I have found that contrary to what you might expect, round batts are the last thing you want in a kiln of this type, especially if you are proposing to use it for firings other than Raku. Square batts, the corners of which miss the kiln wall by about 1/2" seem to be the most effective. The fire circulating round the kiln hits the corners and is deflected into the setting, rather than skating round the outside as would be the case with round batts.
FIRING
Place the kiln in a well ventilated area with no overhanging material within 5 feet of the flue vent.
Stand the kiln on three bricks to allow air to circulate beneath it.
Ensure the burner is down wind, as cool air blowing into the burner port can adversely affect the quality and controllability of the firing.
DO NOT stick the end of the Burner inside the kiln. It needs to draw in as much, or more air, than is already available through the primary air holes in the Burner Head to achieve complete combustion. Putting the Burner into the kiln will starve it of air and ultimately destroy it. Ensure that there is a gap equal to the thickness of your hand between the Burner and the kiln
IMPORTANT:
ALWAYS place the gas supply to one side and downwind of the kiln.
ALWAYS protect the hose with some sort of cover to prevent it being tripped over or trodden on.
ALWAYS INSPECT THE HOSE FOR DAMAGE OR AGEING BEFORE FIRING
Only increase gas pressure in very small amounts, the same applies to changing the size of the flue opening with your brick off-cuts. These kilns are scaled down versions of large kilns, so a damper movement in the latter of 1" would scale down to approximately 1/16".
MATERIALS
Below I have listed the materials you will need to line a cut down 55 gallon drum to 2 ?? thickness. This kiln should be capable of reaching and sustaining temperatures to 2300 deg F, if you do not need the extra heating then 1 ?? thickness should be ok for our application.
Ceramic Fiber Blanket, 8lb density (128KgM), 2300 deg F grade, 1? X 2? X 16.5?
Ceramic Fiber Blanket, 8lb density (128KgM), 2300 deg F grade, .5? X 2? X 8.5?
Bisc. buttons (home made) X 18; 10 or 12 top, 8 bottom
2 ea 10' coils Nichrome wire,
2 ea Insulating Bricks
32 oz Rigidiser/Hardener (SWAG on amount)
Scrap 55 gallon drum
Assorted self tapping screws
1 ea 7' X 1/2"X 1/8" mild steel strap
You should be able to get all the supplies at any good online or local ceramic supply house. Let me know if you are having problems.
GOOD LUCK, HAVE FUN.
Gary