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Topic	Status	Originator	Last Posted by	# of replies

• glass brick		myglass	Donovan	1

• Electric Wire furnace		djglassmith	Donovan	1

• The basics of Electric Hot Glass Furnaces		Donovan	Donovan	0

• Combination Top load annealer / fuser		Donovan	Donovan	5

• Clam Shell (Color Pickup and Pastorelli) Kiln		Donovan	Donovan	7
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LATEST (8) POSTS within the "Equipment Building" Category!
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: Re: glass brick
	Hi Maria, I know more about pot furnaces than I do brick invested furnaces. I used some furnaces in school and at various shops that were made entirely out of brick/morter/castable etc.., and I think I could spout off about stuff I've read regarding high alumina bricks/AZS etc.., but I think I'd rather refer you directly to those books.. or maybe someone else will have some comments... So, two must have books for any shop: 1.) For everything you wanted to know about refractories but were afraid to ask... I'd suggest picking up a book called 'Glass Notes' by Henry Halem. Though this book lacks when it comes to wire furnaces... it is generally just a great book to have around the shop. ..lots of good info. 2.) Dudley Giberson's: 'A glass blowers companion' lastly, regarding iron in bricks.. yes, generally want to stay clear of bricks with high iron content.. for many reasons. HTH, Donovan
	DATE: GMT - 05/18/2009 \| 07:34 PM
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: Re: Electric Wire furnace
	Yea, I let the egg.bz domain expire out of laziness. :-) However, I think I can go into those build threads and repair any images there... Just give me a little time to get that done. ( busy the last couple weeks ). Regarding building a wire furnace.. I might suggest a slightly smaller crucible to start if you think you will be working on weekends only... perhaps a 75lb'er... just a thought. You could always build the size for a 100lber, but start with a 75lb crucible i guess... another thought. :-).. depends on your long term goals I think. There is a difference in build philosophies between a furnace that will be on 24/7 as apposed to a furnace that will be shut down on Sunday and then turned on again on Thursday. Good luck with the shop build, and If I can help in any way, just let me know. Donovan
	DATE: GMT - 05/18/2009 \| 06:49 PM
maria group: registered: GMT - 03/19/2009 You need to be logged in to reply	Go To: Subject: glass brick
	Hi Donovan what material the interior bricks of glass furnace (I mean bricks that contact with melted glass) made of ( I mean whether silica, alumina silica mixture ,etc...)..Did you know what are your bricks made of? I suppose the brick that does not contain iron does not change glass's white color , am I right? thanks for your interest.
	DATE: GMT - 05/14/2009 \| 09:04 AM
Dan Van Antwerp group: registered: GMT - 05/09/2009 You need to be logged in to reply	Go To: Subject: Electric Wire furnace
	Hi Donovan, I have read you posts about building a 100lb wire furnace. Unfortunately, the photos for the build posts have seemed to be lost. Also, I went to the euca.us site and was unable to navigate the site as the egg.bz domain seems to have a problem. Let me know if there is another way of viewing your build instructions for the 100lb furnace. I have a furnace building video from Mayne Island glass, but he only covers up to a 40lb furnace with wire (he has a 170lb model with Starbars...but I would rather start with something simple). I'm a weekend warrior, but I believe I will go through more than 40lbs over a long weekend. Thanks, Daniel
	DATE: GMT - 05/09/2009 \| 10:16 AM
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: The basics of Electric Hot Glass Furnaces
	In the current hot glass market, the three most common electric furnaces types are: Molybdenum Disilicide (MoSi2) (Short: Moly) Silicon carbide (SiC) (Short: Sic) Resistance Wire (Short: Wire) (ie. such as Kanthal A-1) Each of these choices has their merits and has their weeknesses, and I will go over some of the more apparent of these characteristics in this writing. I may focus more on "wire" furnaces for two reasons. The 1st reason is there is currently existing places on the internet to visit that express the virtues of the other two types of furnaces. (I'll point those out later) The second is that, after all my research, I chose a wire furnace over the other types of furnaces. In 2005 I set out to build an electric hot glass furnace. I gathered information from a variety of sources. Some information came locally, and some from the internet. Here is the basics of what I have learned: First, before I get into the virtues and negatives of the different types of elements, I want to briefly talk about two types of furnace designs. These are: "Side Access" (beehive) and "Top Access" It is important to note for this writing that, in having used both types of designs, I greatly favor "Top Access" furnaces (pic below) for mostly two reasons: 1.) The act of gathering glass is much much cooler. I don't care what you do with a "beehive" design, it will always be a hotter gather. 2.) Materials cost and operating cost: With less materials needed, both your up front (build) costs and your operating costs will be cheaper. You are not just heating the glass matter when running a furnace! You are heating furnace matter as well! So, "combustion space (chamber)" (term originating from gas furnaces used to describe the space inside the furnace), and furnace matter all play a part in the cost of operating a furnace. 3.) Top furnaces give the owner the option to access the entire crucible at a wide variety of angles. Basic Overview of Electrical Element Types: MOLY: Moly furnaces are the buzz right now. They have a strong following on talk.craftweb.com (an active Hot Glass forum) where Pete (the owner) is not shy to express his bias which is Moly elements. Moly elements can last a long time, much longer than the other types of elements that are standard in the market place right now. This type of element operates comfortabley in ranges well above that of the cooking temperature of glass (2200F to 2400F) which makes them a good fit for someone who is looking for minimal maintenance over a long period of time. Moly elements are fragile, mostly before they are installed and when cold. There are many stories floating around of breakage during shipping, so be cautious of this. It is also a good practice to order spares when ordering these elements. For the small business hot shop, moly elements most commonly come in a U shape (to drape down from the top of the furnace). They also come in an upside-down "L" shape. However, because moly elements become somewhat elastic at glass cooking temps., the L shape is not used as much and requires a more sophisticated engineering design (that really has yet to make it's appearance to the public). This point boils down to limitations in furnace design. You will be hard pressed to find a "top access" furnace design that employs Moly elements. Moly furnaces usually require an extra cost of a transformer. This transformer is not unlike what you might see hanging off of a power line on the corner of your street. This transformer, not unlike the one on the power line, impedes RF signals. So, if you like listening to the radio in your Hot Shop, or if you use other RF devices in your shop, you may want ot consider one of the other options. Because of the transformer and the preferred electrical control system, and because of the limitations in furnace design from the limitations in element mounting, Moly's are usually quite a bit more expensive than the other types of furnaces. SiC: The Sic furnace design is a very tempting design for me. I will probably end up building a SiC furnace in the near future. SiC elements have a longer life span than Wire elements (usually up to 3 years depending upon design) and a shorter life span than Moly elements. A Sic furnace does not require a transformer. I see the Sic furnace as being a low maintenance and low cost option (furnace design and longevity). Though the elements are expensive, you usually do not see as many of them, compared to the other two types of furnaces, installed. One downfall of SiC elements is that they will degrade slowly over their life span (unlike the other two options). Their resistance and voltage specs will change because of this degradation. However, I don't hear that many complaints from SiC furnace owners on this issue. The selling point to me for the SiC furnace, besides low maintenance, is furnace design. The SiC furnace is a great candidate for a "top access" furnace. Using starbars or "globars": http://tinyurl.com/2qjzz2 these elements can run along the full side of your furnace, leaving the top for the door. WIRE: Are you a do-it-yourselfer? Wire furnaces can be a dirt cheap way of both getting into, and operating, a glass shop. However, you, or someone you know ;-), has to be a good "handy man" with furnace maintenance. This design is by far the most maintenance intensive choice of all these furnace types. However, a "handy man", may just smile to him/herself, 3 years down the road, when he/she (trying to be politically correct) has invested monetarilly only a fraction of what others have invested in his/her furnace. For the handy man, or for a person on a budget, or for the person who likes to listen to the radio ;-), the wire furnace is a good option. To give you an idea of this, I built the 100lb (up to 150lb) furnace pictured below at a total cost of around $2500.00! Compare this to a stadleman Moly of the same size, or even more contrastingly, an electroglass SiC furnace, and you may just gasp at the difference. :-) You will want to add to this setup a spool of Kanthal wire, and a custom built coiler. A spool of Kanthal wire may run you about $800, but it will provide elements for you for around 3 years! (running 24/7). The coiler can be custom built. The wire furnace, like the SiC furnace is not limited in furnace design. One can build either a "top access" or "side access" design. DETAILS OF THE WIRE FURNACE: With the high maintenance of this design, comes a required knowledge of details that will help you get the best life out of your furnace. Since this writing is not about the wire furnace alone, I will leave much of those details to a future writing. However, I will point out a few of the most common maintenance areas: 1. Change of elements: The change of elements can vary, but ideally, will be yearly. A more realistic expectation may be 9 months... shorter when you are first learning. (24/7 operation) 2. Coils should have a 3 to 1 stretch if possible, and should have breathing room within the grooves. 3. Try to create your brick grooves in a way that does not require pinning! 4. Kanthal 11ga. 5ohm elements are a good starting place. I use 9 elements wired in 3 sets in a 3Phase Delta configuration. 5. Melt Cullet instead of Batch to avoid the high Batching temperatures. (you don't want to go higher than 2200F with a wire melter IMO. If you are wanting to melt batch, GafferBatch is a batch that works very well with a wire furnace because it cooks nicely at 2200F) 6. Do not get any glass or batch on your elements! 7. See: http://egg.bz/default.tpl?PageID=18&PageName=Photos&sec_id=18&sec_status=main for more pictures in a "How To" for the wire furnace pictured below... (Select Album "EDC Furnace Build") Whatever electric furnace type you choose, I hope this helps in consideration for an electric glass furnace! Donovan
	DATE: GMT - 12/06/2007 \| 10:51 AM
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: Re: Clam Shell (Color Pickup and Pastorelli) Kiln
	The heat is on!
	DATE: GMT - 06/14/2007 \| 07:39 PM
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: Re: Clam Shell (Color Pickup and Pastorelli) Kiln
	The back side....
	DATE: GMT - 06/14/2007 \| 07:38 PM
Donovan Brooke group: registered: GMT - 05/09/2007 You need to be logged in to reply	Go To: Subject: Re: Clam Shell (Color Pickup and Pastorelli) Kiln
	This project is done... time to play!
	DATE: GMT - 06/14/2007 \| 07:37 PM

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