Vacant

My space is vacated and I'll soon be setting up shop. I purchased 500 lbs of fireclay and some mullite grog to make thick tiles for the hot face of the floor of my kiln. I'm actually going to hand mix and then pound these tiles. I'll cut them out using a template once I measure shrinkage by firing some off in my small electric kiln. I'll only be able to guess at shrinkage since I'll only be firing to cone 6 in my electric, but it should be close enough. My final kiln dimensions will be dependent on these tiles anyway. I'm going to attempt to make them 12" square and 1.25" thick. I've also decided to make back up tiles of fireclay and vermiculite which I plan to pound out and cut with a similar template. I'll follow that up with a layer of red brick for the base layer on top of the cart. Yes it's going to be a car kiln. I can't imagine making a kiln this large and loading in it nearly 4 feet deep.

Stuck here again

Waiting is the worst...

Especially when you have about three grand laid out in products and material and you're simply waiting for someone to vacate your space.

Mobilization

My terrific aunt April sold me her trailer. It's a small steel flat bet with two wooden panels in the floor. I'm putting two cattle panel pieces in place of the wood and building the kiln in the back of the trailer. I have yet to decide how the floor/door is going to be built and I'm running out of time. I need to get it built and start making pots.

The decisions still to be made:

Floor brick:

• High duty firebrick
• Silicon Carbide

I have both of these available to me at the moment for a good price. I would like SiC to try them out more than anything. 

Car Kiln Cart/Standard floor:

I could build this either way. I have the materials available to me to build the cart, I'm just not sure I want to mess with it on my first ever real kiln build of my own. If I'd done it in previous kiln building workshops I'd feel more comfortable. Either way I'm going to essentially have the same materials, just arranged differently.

Burners:

I've been toying with the idea of actually throwing, or molding some fire clay burners. I've got loads of high refractory fire clay and grog that I'm going to mix for the saggars anyway. I have enough clay to build a small kiln out of it, and at the price of it I probably should do just that for my next project which will be a soda kiln.

I could easy enough go get some black metal pipe, cut it to length, rig up the oil line and air and spend my time tuning them instead of going through the effort of making them from scratch materials. It would be smart to do both I guess then I get burners for sure either way. Never heard a potter crying because he had too many burners laying around.

I have however decided to go with a compressed air system after all. The blowers are fairly cheap, but the compressor does double duty and I'm running lower and lower on funds for the project. Purchasing a compressor seems like the smart thing to do considering how much I'll use it for glaze application anyway.

To sum up:

This downdraft kiln will be a cattle panel frame, fiber blanket kiln on the back of a flat bed trailer with compressed air, vegetable oil powered burners, and it will either be a car kiln or a standard floor with a swing open door that bolts shut. Either way it will most likely have SiC brick floor to test it out prior to building a full SiC wood kiln/soda in the future. This future project will most likely be a pellet/oil kiln and not actually wood. I've been toying around with recycled fuel pellets and I aim to come up with a working kiln based on them in the coming year.

Hiccup

The company who sold me the basket was out of Kansas City MO. This company sells these baskets on ebay. I chose to buy one from here because my purposes don't require that it be fresh and clean just that it be strong and straight.

Well long story short the guy tried to bait and switch me with a low shipping quote for "commercial address" then jacked up the shipping quote to almost double for a "residential fee." I told the guy to go stick it in his ear I wasn't paying double, I'd already told him I wanted lift gate service to my house before the quote. 

So I've looked around and can buy some other baskets for about the same as he was offering. I also realized I don't really need a basket, it just makes it easier to move later when I buy a house. So I did a bit of research into fencing and found a 4 gauge wire cattle panel. These come 16ft X 50" and would be plenty strong enough for my purposes. I've decided to make the first one out of these cattle panels because the cost is so cheap. 60 bucks will get me the entire outer shell including hardware to bolt it together with U-bolts.

After giving up on the trailer thing my generous aunt April is going to sell me their all metal trailer for a good deal. This does a couple of things for me. It gives me the ability to set the kiln up as originally intended, completely mobile, and it takes care of the issue of me having to prepare a ground site which was proving to be more work than I'd wanted it to be already.

Now all I have to do is figure out how I'm going to frame in the door supports. I'll probably have to get my friend Cyris to weld a simple tube frame. If I have the money I might have him weld the frame for the whole kiln which is only 8 tubes altogether.

This pen is made of a similar cattle panel to what I'm going to use to build the support structure of my kiln.

A tisket a tasket

Look at that huge basket! 0,0



So this is a picture of what my kiln will be made inside. It's a 4000 lb rated industrial wire basket. I will be making a basket lid for the top and cutting a few holes for the stack and burner ports. I could easily make an updraft kiln out of this, but at this time I've decided to make the first fiber version a down draft with a short fiber stack. It will be lined in the bottom with a few layers of ceramic fiber paper 1/8 inch thick, and a layer of insulating fire brick. The walls will be constructed of 3 inches of fiber and hand made refractory ceramic buttons, held in pace with Kanthal A-1 wire.

The hotface of this kiln will be 1" layer of 2600 degree blanket made by Thermal Ceramics called Cerachem. The backer is 2" layer of 2300 degree blanket made by Harbison Walker. Both of the US companies produce superior and reliable products. I chose blanket for my kiln because of it's ease of construction.

The links below are to the two companies I purchase refractory products from. The top link is a pdf of the Thermal Ceramics blanket, and the other is the history of Harbison Walker (ANH), because their data sheets are not available to the public. None the less ANH is a great company, the sales staff at the Clackamas distribution center will bend over backwards to help meet your refractory needs.

http://www.barteltinsulation.com/pdfs/CERAMICBLANKET.pdf

http://www.hwr.com/EEC/Incineration/HWRHistory.asp


The buttons will be fireclay mixed with Mulcoa 40 grog (3X8 and 35 mesh) and some ball clay. Somewhere around 50% fireclay, 40% Grog, 10% Ball clay will be the mixture. I'm making a small mold to pound them into so I can pop out the buttons and fire them off easily and uniformly with good density and strength.

I did a lot of research on wire to hold these in place. This kiln will primarily be for cone 6 however I will end up doing cone 10 now and again for specific things such as the ceramic buttons. Maybe some other refractory items for my studio such as saggars, tiles etc. I may also make some parts for an outdoor oven which my mom is building this summer. So the wire must be able to withstand 2400 or so just to make sure. Most Nichrome wire will not withstand above cone 6 for very long. The Kanthal A-1 is a proven material for electric kiln elements for high fire even up to cone 11, 12 and will easily withstand my kiln temps.

Originally I had planned on buying a cheap wire feed welder from Harbor Freight and welding together some round steel rod making myself a box. When I found the one similar to the picture above the price was hands down better than all the long hours in the welding booth. I picked mine up used, but couldn't find any good ones locally and had to pay for shipping from back east. All in all it was still worth it getting me two huge baskets 44X55X44 for 65 each, plus shipping of 200. Altogether 330 bucks and all I have to do is fashion a lid and I'm done. Not to mention there is no worry about the strength of the material because it's an industrial quality basket rated at 4000 lbs. Another reason I chose this route is because I am still a renter and will be moving. Even though this is a heavy basket it can be moved even once the kiln is completed. One better plan is to build the kiln on the back of a trailer, which still might happen if I have the cash. I want to make sure I don't short myself before getting my burners completed first.

This brings me to the burners. I've decided to experiment with a large ventilation blower. It's a fully adjustable inline centrifugal blower made for industrial ventilation. It blows 450 cfm maximum which is more than enough. I'm going to try and rig up two burners to the same blower because this thing should have the power. I will have to build a small sheet metal splitter box that merge the 6" duct with two smaller burner pipes. I've decided to go with a small heated metal pail of about 1 gallon or so in size for the oil. I going to install a small heater either under it or inside it with which to heat the oil. The oil lines will not have far to travel this way and there will not be too much oil close to the fire. The entire apparatus will be strapped to a cart or hand truck for easy storage in my garage when not in use. I'm going to install a small port in the splitter box and a butterfly valve in which I can block off the blower and send some LPG down the burners to preheat before igniting the oil. This is all an unproven, untested system that I've never seen used before so we'll find out if it even works.