Rebuilding Kiln Lid

[Kayak]

Is it possible to rebuild a kiln lid? My Duncan EA-1029 Pro-Plus runs great but the ceramic fiber lid and floor are in tough shape. I'm considering building (vs. replacing) the lid using firebrick and kiln cement. Is this an option? Thanks for your feedback. I've been searching for answers for weeks and was led to this forum.

[hitchmss]

Your lid and floor are fiber? There are some electric kilns which have a 1" layer of fiber outside of 2.5-3" of IFB (insulating fire brick aka softbrick), however Ive never seen an electric kiln lid/floor made entirely from fiber. Can you post pictures so we can see the construction?

 It is possible to build a floor/lid for an electric kiln, but the work that goes into making a good one, may be much more than its worth to buy a new one, that is, if you can buy replacement parts for this kiln. Using a refractory mortar/cement is not like using a mortar on a floor tile in your bathroom; you have a very limited amount of working time before the mortar dries out, and wont bond to the brick next to it. IFB's are quite porous, and unless you dip/soak the edge of the brick in water you are going to mortar, you will find that by the time you get your sides coated with mortar, that it will have skinned over, and it wont stick to the brick you want to attach. Too much water on the brick and your mortar will be thinned out, too little water and it skins over rapidly....there is an art to it.

There was a video I came across at one time which detailed a popular kiln manufacturer making their kilns; it was amazing to watch their workers assemble all the bricks needed for a floor/lid in a matter of a couple of minutes. I cant find the video, so hopefully someone else will post it, and it will give you a good idea of what kind of technique is required if you want to mortar the lid together.

Aside from the working time of the mortar, having too much, or too little mortar between bricks can lead to a sloppy, and less than desirable job quite quickly. I would say that unless you have some very good confidence in your abilities to do this, to just buy new parts....may not be as cheap, but you will be happier in the long run.

Now, it would be much easier to make a new lid/floor that isnt mortared together......However, while a lid, which doesnt have any weight being forced down onto it, would be fine IMO to be rebuilt without mortaring together, I might give some pause to doing this with a floor. The mortar locks all the bricks together, but it also has a downside too; because it is one homogeneous mass, it does not expand/contract easily; this is why you see cracks in the lids/floors quite often. A "dry set" brick will expand/contract along each joint, but it REQUIRES the band to hold it all together; if your band is too tight, or too slack, it could lead to issues, as well if the band ever fails, you will have a pile of bricks. Only relying on the kiln's legs/support frame and the metal band to hold your floor bricks tight and flat, with a lot of weight from your pots and kiln furniture, might be a recipe for disaster.

Ive taken lids/floors from kilns and replaced 1-2 bricks and the bands when needed repairing, and was comfortable dry setting these bricks. Repairs lasted many more years without any issues.

If you do make your own lid from bricks, you will also have to cut it into its proper shape; factories use a automated router which operates at high speeds, and imparts little to no torque on the bricks/mortar. If you've never cut IFB's before, you will be amazed at how quickly the HIGHLY abrasive refractory will turn a sharp saw blade into a butter knife. If you wanted to use a high speed power tool so that you didnt impart torque to your freshly made lid/floor, and possibly knock the whole thing apart, be aware that you're going to need LOTS of blades for whatever your using, it will likely destroy the tool (the dust will eat bearings for breakfast), and is going to make a lot of not healthy for you, dust. If you want to keep dust down, and not destroy tools, and use a handsaw, you're going to need to take your time cutting out all those edge bricks....be careful to not break your new lid apart. If you do go this route, keep the old lid so you can use it as a template to cut out your new one.

My suggestion would be to just buy new parts, and save your time for something else. Keep the old lid or floor, and slip it under your new floor....kiln will be a couple inches taller, which I think most folks appreciate a little more height (except for those that are vertically challenged), but it will also be a little more insulated, which might lower the cost of your firings by a smidge. It will help support the new floor too. Dont place your old lid on top of your new lid with the same premise in mind; the lid of your kiln creates a parabola/arc during the firing from the expansion of the hot face of the brick, against the cold face of the brick. Not allowing this curve to occur naturally, or as easily, will put excess stress on your lid, and lid banding. The floor of the kiln is less of a concern in regards to this, because you already have all the weight of the pots/kiln bearing down on it, so its having trouble moving already.

[Mark C.]

Are these parts still available from Paragon (they bought out Duncan years ago)????

You could build a lid if you are experienced in this. If not than just buy a new one or if other parts of kiln are about toast consider new kiln???

There is a lot to it-you can see a lid being made at the Paragon site-your SS band needs to be in great shape for reusing.

[neilestrick]

Don't build your own unless you've done it before. It's not as simple as it seems. Mortaring bricks is a skill, and it much more difficult than working with regular tile or brick mortar. I would never use a brick lid that wasn't mortared. You'll never get a regular body band tight enough to hold it all together, and bricks will slide out, especially with opening and closing it all the time.

Chances are you will not be able to find a fiber lid like the one you've got, unless Paragon has one laying around, as they carried parts for those kilns until recently. I don't know if they carried refractory parts for those kilns, though, or just electrical parts. Give them a call and ask.

You can use a brick lid or floor from any manufacturer that's the same size. Round kilns are pretty standard sizes. The only problem you're going to have is whether or not your existing hinge system can hold a brick lid, since it will weigh a lot more than the fiber lid. You may have to upgrade your hinge system to hold the weight. A new lid and floor for a 10 sided kiln will cost at least $250 each depending on the size and manufacturer, and it will probably have to ship them via freight since UPS tends to break them. That'll cost another $150. So now you're up to $650 or more to fix an old manual kiln. You'll have to decide whether or not it's really worth it.

Another option is to buy an old used kiln locally off Craigslist that has a useable floor and lid, and use those.