need help deciding on which large kiln

[cbrandt]

I have been doing my research and have learned so much from this forum but now I need feedback and opinions. I am currently looking at the Paragon Pearl 44 which is 44x22x13 and the Olympic GF8 clamshell which is 48 x 24 x 12. Since I often build my long pieces inside the kiln I like the clamshell design. Both can come with fiber tops and mercury relays.

Pro Paragon pearl 44:
-can balance side and top elements
-has lift assist but 200 # lid might still be too heavy for me
Con Paragon pearl 44:
-full shelf costs an additional obscene $845

Pro Olympic GF8:
-can get top loading as well as clamshell for an additional amount [great for slumping and manipulating)
-full ceramic fiberboard shelf is a reasonable 145
Con Olympic GF8:
-Additional cost to separate top and side elements.
-very heavy lid without enough real lid assist


Did I miss anything? Does anyone have either of these kilns and can give me some feedback? Have you had any problems? How effective are their lift assist mechanisms? Both companies admit that these lids are still very heavy and might be a problem for me. I added my own counter weight system to my present kiln but these kilns are too big to place where that might be possible.
They are close in price. The additional cost of the shelf for the paragon pays for the top loading option on the olympic so I am leaning towards the Olympic because I get more value from that than from the expensive shelf.

Any help would be greatly appreciated.
Cindy
Currently an inmate in the Torpedo Factory art Center, Alexandria, Virginia
Soon to be full time in The Villages, Florida

cindy brandt

cb designs
torpedo factory art center
studio #330
105 n union st
alexandria va 22314

http://www.cb-designs.com (still under construction)
cb@cb-designs.com
703-683-2060

http://www.torpedofactory.org/artists/brandt_c.htm
http://www.torpedofactory.org/commissio ... /index.htm

[Buttercup]

Cindy, what's special about that 845.00 shelf? If you like that kiln otherwise can you simply buy it without the shelf and buy a different shelf? I paid about 80.00 for a similar sized piece of 1" thick Ceramaguard HD fibreboard and trimmed it to fit. Works fine. Jen

[Morganica]

Agree with Jen. if the footprint is the same you should be able to use the same shelf in either. You might need to saw it down a bit, but $845 is a scary price for a kilnshelf--I'd rather spend that money on more kiln. If the shelf is mullite or even extruded ceramic, you won't be moving it much. A big fiber shelf at least doesn't need two people and an engine hoist to lift. If you work in a solo studio that might be a consideration.

I wouldn't worry too much about the lid weight; if it doesn't come with a lid lifter you can rig a system of counterweights that does much the same thing. I've even seen old garage door openers put into service for this. If you search this board for "counterweight" or "heavy lid" or "lid lifter" or something similar, you should be able to find examples.

I've heard good and bad things about both companies, enough to make me think that either would be an excellent choice. If you're primarily doing flatwork go for the larger footprint. If, like me, kiln depth is an issue, give up some width/length to get the deeper kiln.

One other style you might want to look at if you do a lot of kiln assembly: A modified clamshell or bell kiln with a roll-out table. If you've got the space, these are awfully convenient--the table is the floor of the kiln, and you can roll it out from under the bell, giving you room to work on all four sides. I've access problems with a clamshell--one side and about a third of the two adjacent sides are usually all but inaccessible and if you're, uhm, vertically challenged it can be a little difficult to work in a clamshell. You usually can get these raised to waist-height, too, which makes them very easy to use. Denver makes them, and probably other kiln mfgs have something similar.

[cbrandt]

Thanks for your suggestions.
It has been about 10 years since I used fiberboard shelves because I always found they dented easily. I remember buying the suggested type of fiberboard to give me a full seamless flat shelf to use over the half oval shelves that came in my first coffin kiln. I'll admit that I probably never used actual Ceramaguard HD shelves and what I did use was only ½” thick. I want my glass to have a smooth flat back and I found that after several firings the fiberboard shelves were so easily dented that the back of the glass soon had many bumps. Lately I’ve been using thick vermiculite shelves which give me a fairly smooth flat back but not for long. I looked into the corelite kiln shelves for my coffin kiln, but they have problems of their own and are hard to remove once they are in place in a coffin kiln.

With this new kiln, especially if it is a clamshell, I probably could try vermiculite shelves again. But the Olympic kiln shelf is only $145 for a ceramic fiberboard shelf which is supposed to be smooth and not as heavy as the old ceramic or mullite shelves. I don’t know anything about them but hope they don’t have the problems of cracking like the corelite shelves when used for casting. I just really want one large smooth shelf which could be used for my regular flat work as well as casting and doesn’t crack or warp when the kiln shelf is not completely filled.

Cynthia, I have been using a counter weight system to lift the lid on my coffin kiln for years, but it might not be possible to place this new kiln where a counter weight system can be setup. And you are right, I will have access problems, same as I had with the coffin kiln.

I also like the idea of a bell kiln and since I am vertically challenged I thought it might be perfect. But then when I saw the clamshell/ top loading option of the Olympic I liked that too especially for deep molds. I guess my problem is that I am trying to make this kiln work for flat work, deep slumping and casting.

I did previously consider the Denver bell kilns but had some concerns about their kilns having insufficient insulation. This kiln is going to be located in a garage in north central Florida with an overhead exhaust fan but no air-conditioning so I felt it might not be a good choice. Do you think I should be concerned about this?

[Buttercup]

My brick kiln has a home-made lid-lifting device, super simple, some 2x4's, rope and a pulley. It's not pretty but it's functional and requires minimal effort. Hooking a loop in the rope over a nail in the framework holds the lid open. It is operated by standing in front of the kiln. This kiln is now in a corner so access is only possible from the front and one side.

It started out with a counter-weight but that went down behind the kiln and collided with the thermocouple. The lid is not so heavy as to need a counterweight so that was abandoned.

The kiln is on a wood stand on castors with a sheet of cement board under the kiln. The 2x4 framework for the lifting device is attached to the wood stand.

If you'd like a pic I'll take one and post it. Jen

[JestersBaubles]

I have a Skutt GM1414 which is similar in size -- I really like it. The Glassmaster controller is the easiest to program while also being the most feature-rich of the three other kilns I have.

Lid assist that came with it works great.

Dana

[jim simmons]

Hi Jen.
Would you please do this?
Thanks.
jim

My brick kiln has a home-made lid-lifting device

The kiln is on a wood stand on castors with a sheet of cement board under the kiln. The 2x4 framework for the lifting device is attached to the wood stand.

If you'd like a pic I'll take one and post it. Jen

[Morganica]

I've got a GM1414, too, and it's not the best choice for long, flat pieces--it limits out at 10x36 inches and that's really pushing it. Much wider than 10 inches, and your pieces get shorter and shorter. You also need to compensate for the difference in element proximity by baffling and/or using a slower schedule.

BTW, if you're trying to do deep slumps and casting, 12 inches isn't much. By the time you get through adding top and bottom clearance, mold thickness and glass reservoirs, you've only got 5-6 inches of casting height to play with. In my Skutt, that often means I'm only doing open-faced casting, where I can put the glass directly into mold or suspend it on an open grid above the mold.

When I'm reservoir-casting in my Skutt I do a lot of mold engineering so that I cast pieces on the side with multiple reservoirs. Sometimes I simply can't get the mold AND enough glass reservoir in a 13-inch depth for one firing, so I'll break the piece up into smaller components, cast those. Then I do whatever coldworking is necessary to the components, and combine them in a new mold. Since most of the glass is already in the mold, I only need enough reservoir space for filler glass.

(for an example, see http://www.morganica.com/bloggery/2009/ ... g-part-ii/)

IOW, it's a pain in the neck.

[Buttercup]

Jim, as requested, here are the pics of the very low-tech kiln lid lift-assist. Hope that helps, Jen

[Buttercup]

Tried to add to the message after I'd added the pics but couldn't. (Told you I was strictly low-tech.) Anyway, just wanted to say that the cover for the electrical box on the lid is temporarily off. Don't operate like this at home. It just had the fibreboard in the lid replaced and the elements reinstalled.

The framework was hastily erected from material we had around, 2x4's from concrete forming. The short vertical board is there to stop the lid going right back and smacking into the sending unit which is mounted on the wall behind the kiln. If I want to quickly peek in then I just raise it enough to see in without fully opening it. Hope that helps.Jen

[cbrandt]

Cynthia, what a wonderful piece and a terrific explanation of what was involved.

I did take your suggestion and looked again at the Denver “modified” clamshell, in particular the KL-CS50RT. The size of the kiln will actually work better for me since it is shorter in width and wider in depth, perfect for my long narrow pieces. And the shorter width makes it easier to place in my garage. Of course the best part is that instead of spending hours leaning over the side of an oval kiln I will now have a flat table, fully accessible from all directions to build my pieces. So I just ordered it and can’t wait to have it up and running.

I still have to figure out what kiln shelf I want. I’d like to get by with the fiberboard shelves since they make more sense in a fiber kiln than a ceramic or corelite shelf would. But I really want a very smooth back to my glass, and I just don’t know if I can get that from a fiber shelf. Holly from Denver kilns sent me detailed instructions on how to use rigidizer and shelf coat to get a flat surface. But I’m still thinking of ordering the corelite as well since it would be shipped with the kiln and I wouldn’t have the high shipping cost if I decide I want it later. Or I might return to the vermiculite shelves which I have used in my coffin kilns.

I hope some fiber kiln people will give me feedback about what shelves they use, their longevity what they like and don't like about them. I’m particularly interested in whether they place their fiber shelves right on the floor of the kiln or up on kiln posts.
***
Jen, here is a photo of the counterweight system i made for my oval kiln. The weights were old gym weights with some sand to get the perfect balance. Very simple and very effective.

[Buttercup]

Very tidy! I'd have preferred not to have the wood frame but it was necessary because my workshop is corrugated metal so putting a hole through the wall is not a good idea. Also, the kiln will eventually be repositioned when the workshop is extended so the frame can go with it. The walls will still be metal. There currently isn't room to pull the kiln forward enough to make room for a counterweight that won't interfere with the thermocouple. In the last workshop the rope went up to a low beam. Jen

[cbrandt]

Well I may have to resort to a wood frame if the new clamshell is too heavy for me to lift without a counterweight. I won't know until I return home if I have a wall or ceiling to mount my pulley on. I guess I should have waited to order the kiln but I know what kiln I want, I just don't know how to make it fit in a space already designed for a smaller kiln. Worse comes to worse I will have to do what I swore I wouldn't do - move a very heavy 48" x 24" x 72" storage unit filled with glass. I dread taking all that glass off the shelves piece by piece setting it somewhere safe then replacing it piece by piece after taking apart, moving and reassembling the 110# gorilla storage unit.

[Buttercup]

My arms are not long enough to lift the lid without the pulley and rope system. Since I'm not blessed with the ability to tie my shoelaces without bending down I guess I'm stuck with the pulley system. Jen

[Marty]

Several thoughts-
The counterweight does not need to be anywhere specific, you could add another pulley (or 2) and direct the weight someplace else and it would still work.

I don't like the idea of anything flammable or meltable near that oval kiln lid. The outside temps on that oval kiln lid get at least hot enough to char paper and melt plastic (how do I know?!). Use garage door cable instead.

Jen- "The kiln is on a wood stand on castors with a sheet of cement board under the kiln." What's the outside temp at the bottom of the kiln? I found that 2 layers of cement board (supporting a brick kiln bottom) is barely enough. The stuff is not refractory and when I rebuild the kiln I'll change it out for something better, or add another layer of brick.

[Bert Weiss]

When I put a kiln on a wooden bench, I use hollow cement blocks between the wood and kiln (holes aligned horizontally). This has worked fine for me. You can store stuff in the cement block holes.

[Rick Wilton]

I tried a counter weight system once but found it too finicky. So I bought a hoist

Much easier to get the lid an inch or a foot up.

[Buttercup]

Thanks for the heads up, Rick. I know the lid and sides don't get hot ( unlike the 'full metal jacket' small kiln). I can always put my hand on them. The underside may be a different matter. There is a sheet of steel under the brick bottom, inside the angle iron frame. The kiln is lined with 1/2" fibre board on the sides and bottom, but I've never felt under it so can't say how hot it gets. The air around it doesn't get warm. It only has top elements. Looks like a stand rebuild will be necessary as it would be too high and maybe too heavy for the stand if bricks or cement block is added. That said, it's been operating like that for years, even experiencing one serious overfiring when an 'industrial electrician' installed the mercury switches sideways so they didn't shut off. I really don't want to take any risks so will look into changing it. Thanks, Jen

[gottev]

It sounds like you've figured out what you want regarding the kiln. For what it's worth I recently purchased the Pearl 44 and love it. I also got the shelf with it, although at a lower price because I was able to get it wholesale through D&L. I had used the kiln about 4 times, and although I had kiln washed the shelf with BE kiln wash, I also used Papyros paper for each firing. Then I fired a few pieces at 1460 directly on the shelf and when I took them out, several large chunks of the shelf came off as well. I emailed the pics to Paragon and they immediately (yes, immediately as within 4 hours) refunded my money for the shelf. I still love the kiln but am looking for a good replacement shelf.