SICK of my Denver Kiln's element hanging system
Moderators: Brad Walker, Tony Smith
SICK of my Denver Kiln's element hanging system
Has anyone seen/heard of/imagined a good hanging system for a fiber-lidded kiln? The Denver system uses mullite tubes (which break all the time) that hook onto steel pegs. There are two separate racks (one for each side) and the system is unwieldy at best, horrible terrible cussing & swearing at worst. I am desperate. Who has ideas for me???
"Every artist was first an amateur."
--Ralph Waldo Emerson
--Ralph Waldo Emerson
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Kevin Midgley
- Posts: 773
- Joined: Mon Mar 10, 2003 11:36 am
- Location: Tofino, British Columbia, Canada
Re: SICK of my Denver Kiln's element hanging system
not trying to defend Denver but why are your rods breaking? Are you thermally shocking them by crash venting in order to get production happening? Mullite is the same stuff kiln shelves are made out of and extremely durable .....unless you have been treating them roughly by crash cooling etc. Another system may be to use quartz glass tubing with the elements inside the tubes but all your firing schedules would need to be redone in some ways with the change in thermal mass and the difference in the elements radiating heat differently.
Or is it the elements that are breaking? If that is the case ask why they are not using Kanthal A1 elements that develop an oxidization coating on them that stops them degrading further, that is unless you are burning a lot of organics in the kiln with each firing of say a load of paint or fibre paper requiring an empty heat up to temperature to rebuild the element coating.
Kanthal A1 should last decades.
Also are you letting your kilns absorb atmospheric moisture as I note you are in Florida, by leaving them open when not in use? The mullite may be sucking it up out of the air and when you rapidly fire it up may not have enough time to allow the water to escape before the water inside explodes into steam with a resultant break in the mullite.
If I want a successful firing in Tofino in an unused for a while kiln, I always warm it up to drive off the water. Perhaps heat yours up to say 150F, open the kiln for a few seconds of venting and close it to finish drying out. I usually take mine up several hundred degrees, open them to vent and you can smell the moisture, close them, let them cool to a loading temperature..... but I don't have the mullite rods.
Does this help you any?
Oh and if you are physically hitting these rods while loading or unloading your kiln and breaking them that way, my only suggestion would to hire a smaller bull elephant to do the loading and unloading for you. Maybe one without the pesky ivory tusks that hit everything.
As for rebuilding your current lid with just new elements and hangers, I would not do it. I would rebuild with new fibre as the old fibre will have had enough heating to now be forming more crystobalite, the not good to breathe ****. Just getting a new lid to fit the hinges of the old kiln lid can be a major pita.
There are problems or potential problems with any system.
Cheers, Kevin
Or is it the elements that are breaking? If that is the case ask why they are not using Kanthal A1 elements that develop an oxidization coating on them that stops them degrading further, that is unless you are burning a lot of organics in the kiln with each firing of say a load of paint or fibre paper requiring an empty heat up to temperature to rebuild the element coating.
Kanthal A1 should last decades.
Also are you letting your kilns absorb atmospheric moisture as I note you are in Florida, by leaving them open when not in use? The mullite may be sucking it up out of the air and when you rapidly fire it up may not have enough time to allow the water to escape before the water inside explodes into steam with a resultant break in the mullite.
If I want a successful firing in Tofino in an unused for a while kiln, I always warm it up to drive off the water. Perhaps heat yours up to say 150F, open the kiln for a few seconds of venting and close it to finish drying out. I usually take mine up several hundred degrees, open them to vent and you can smell the moisture, close them, let them cool to a loading temperature..... but I don't have the mullite rods.
Does this help you any?
Oh and if you are physically hitting these rods while loading or unloading your kiln and breaking them that way, my only suggestion would to hire a smaller bull elephant to do the loading and unloading for you. Maybe one without the pesky ivory tusks that hit everything.
As for rebuilding your current lid with just new elements and hangers, I would not do it. I would rebuild with new fibre as the old fibre will have had enough heating to now be forming more crystobalite, the not good to breathe ****. Just getting a new lid to fit the hinges of the old kiln lid can be a major pita.
There are problems or potential problems with any system.
Cheers, Kevin
Re: SICK of my Denver Kiln's element hanging system
That hanging system is bogus, makeshift and impossible to fix well. The nuts holding it in place rust solid. Furthermore, Denver packs the lid (behind the thin fiberboard) with scraps of board and blanket so once the thing starts sagging it's a total loss. But wait, there's more- the sheet metal on top is prone to rusting on the underside and the flakes work their way to the edges and fall on one's work.
On my "free" KL60 I took the lid apart, replaced the top rusted sheet metal with stainless steel, put serious fiber board in, and installed new elements in quartz tubes. They're supported by nichrome wire ties that go around the tubes, through the board, and tie off on top of the stainless. It's an interesting look but it works well.
Kevin- yes it's the same mullite but those rods are relatively fragile and they do break, sometimes on their own with no one looking. I think it has more to do with the steel support system's expansion and contraction than with accidental tagging.
On my "free" KL60 I took the lid apart, replaced the top rusted sheet metal with stainless steel, put serious fiber board in, and installed new elements in quartz tubes. They're supported by nichrome wire ties that go around the tubes, through the board, and tie off on top of the stainless. It's an interesting look but it works well.
Kevin- yes it's the same mullite but those rods are relatively fragile and they do break, sometimes on their own with no one looking. I think it has more to do with the steel support system's expansion and contraction than with accidental tagging.
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Kevin Midgley
- Posts: 773
- Joined: Mon Mar 10, 2003 11:36 am
- Location: Tofino, British Columbia, Canada
Re: SICK of my Denver Kiln's element hanging system
build a new lid if that is what is happening.
It will be cheaper than having failed firings, repair time and repair costs.
It will be cheaper than having failed firings, repair time and repair costs.