Hotwalls I Have Seen

Rev. ... 2003-06-22, -07-03, -09-27, -11-29, 2005-02-06 cleanup
2006-03-15, -05-20, -08-15, -10-23, -11-11,
2007-04-02
[Search on date pattern to find latest changes, more than one may be found.]

This is a collection of pictures, many used elsewhere on the site, showing the hot walls (furnace, glory holes, etc.) of a number of different studios, with comments here on the topic of arranging equipment, etc.
[Please note that while these remain valid pictures of various layouts, the pictures were taken over a range of time and may not show the facility as it is now. Where changes are known to me, I try to mention them.]

As I have been working on this page, I note the frequency of high ceilings and metal walls around the furnaces. Insulation on the back of walls reduces noise and keeps the heat contained for controlled ventilation.

The Studio at the Corning Museum of Glass
is an elaborate modern setting. In spite of the walls and vent piping, it runs hot, perhaps because there is no insulation on the sheet metal. Space is provided for three benches (one center, one right, one out of picture to left), each with its own glory hole, (right edge, left center behind man in blue shorts, and out of picture to left) and roll around marvers are used to carry tools and provide flexibility. The glass wall (diagonal lower right) separates the public viewing bleachers from the blowing floor. Barely visible through the reflection is one of three substantial annealers, this with a lift up and roll back lids (that I didn't like). Behind the man in the red shirt is a smaller color furnace. A dedicated pipe heater is at the left edge and the clear furnace is just out of the picture to the left. [Image 1999-09, studio since expanded.] Floor plan

Hands On Glass, Corning NY
is a typical setup with a shield before the gloryhole and a hood over the furnaces and main gloryhole.
The series of disks in the center of the picture are the set of pneumatically driven doors for the glory hole.
Note how the furnace door near the front has a handle protected from the heat, but almost automatically lifts the door away from any glass on the furnace face and acts as a weight to push the door in from its top rollers. The pipe heater (handles in foreground) is, as I recall, dedicated rather than being a vent of the furnace. [Image 1999-09]

This is a very clean setup with no added ventilation. This is in Texas, so the high ceiling, windows above those shown and two large door openings take care of air flow. Like most Texas studios, she shuts down for the summer. The glory hole with the hot opening appears in both pictures. The exhaust pipe running out the window is for fuming and dusting pieces. A marver is just visible left. Notice the two identical rigs on the large and small glory holes for one handed opening of two doors and the huge encasement (with insulation) of the furnace. [Image 1998]

I am told.
A vent hood has been extended down to capture more of the hot air. Small and medium glory holes flank the furnace.

Almost nothing shows, very quiet. Moveable marver center front. Because of frequent power failures in this location in a freeway side arts village halfway from Tucson to the border, the site has a rapid start backup generator and UPS units.

Philabaums is a full fledged working studio that was the site of the demos for the 1997 Glass Art Society Conference
Here the furnace and glory hole are fully enclosed and the room was fairly cool assisted, I think, by the high ceiling. Note the huge number of pipes and punties waiting to be used, at about $100 each.

in a setup not being used by him any more [as of 2000, then being used in 2002] An open pavilion in Old English style, thus the clothes. Two furnaces, one for color, and a gloryhole. Modern pipes at right, wooden bench, annealer somewhat concealed, propane tank in the woods out back. The Faire also has several lampworkers. Andres was doing three renaissance fairs at one point, TX, AZ and NY. Scarborough runs weekends through May into June. Page with more photos

This furnace has a pneumatic door, too slow for my taste, and has a glory hole to the left and pipe heater to the right, shown below. Visible along the wall is a 4" white PVC pipe from a blower to the far right that is encased for silence. The pipe heater has its own small blower. For a long time this place had an exhaust fan in the window behind the furnace that was not framed out, so much of the air it circulated went around the blade tips and was not sucking from the room. The studio is located in the basement of a concrete beam and floor, brick filled wall, building used by an oil company for decades as a warehouse. Upper floors have various gallery spaces and living quarters unrelated to the glass.

The Hickory Street glory hole which uses a rectangular burner. It is quieter and produces an even heat without the torch effect that many workers use. This burner is mounted on the centerline so it does not swirl the gases as some are arranged to do. The multiple bends in the gas/air pipe relieve stress with temperature changes and allow routing the pipe from the welded housing of the burner to the mixer in back.
The door is a double pivot door-within-a-door, the smaller door cast into expanded metal. The doors are opened with a loop on a rod over a post above the center edges of the door, which I find awkward, and difficult for a person working alone, as I do.

Hickory Street Pipe Warmer, the temperature varies across the hole, hotter at the left, but other warmers have different patterns of heat, some trapping heat furthest from the burner. A pipe and five punties are a common layout for the multiple color pieces done here. Leaving a pipe or punty at red heat for long periods is not good for it. The temperature that various people choose for their pipes varies from a very dull red to a bright red. [Facility now closed, equipment moved 2005]

The modern art glass movement is considered to have started in the early 60's with a meeting that became the Glass Art Society. That first session involved people building equipment from scratch in what was then the garage of the museum. This is a much more modern setup being used at the 30th anniversary meeting. Another furnace to the left of the picture is supplying the glass being used. Note the cutoff valves in the pipe above the units. [And this setup has been totally replaced with a pair of modern glass studios in the new structure. http://www.toledomuseum.org/Visit_GlassPavilion.htm 2008-04-28]

A small operation using a lot of millefiori cane (see below). Two small glory holes and a very large annealer (off to right) used also to slump glass panels for cabinet fronts and other curved glass applications. Not quite visible to the left of the white box center left are two color furnaces, shown below. Note the slope of the marver, shown below.

The two kilns are used for melting color in three crucibles each. The color is color bar melted directly. The white box to the right is a small annealer, being used a color pickup marver at the time of the picture.

Although not instantly noticeable in the picture, this marver has a sloping panel attached so that the glass is worked horizontally but takes on a cone shape, where tilting the pipe up or down would tend to move the glass in the shape. This pre-shapes the glass for the optics.

Bowling Green State University, Bowling Green Ohio, opened a brand new glassblowing facility in a brand new arts building just before the 1993 Glass Art Society Conference in Toledo Ohio. This is a long narrow, industrial strength facility. The hot wall is shown at right with serious ventilation and housing. The red disks at the top of the face are part of premix control units, the gas is mixed into the air at the intake of the blower. Because of this location, to produce a reducing flame in a glory hole requires an additional valve to inject gas. The industrial controls for these burners are on the wall around the corner at the rear of the photo. The glass window showing at the edge is a viewing window from the hallway - unlike many studios, there are no bleachers.

The front view below shows two of the glory holes and a small furnace, with three different kinds of doors. The door to the right, for a large arched gloryhole is a pair of equal weight balanced panels with a V edge on each, forming a diamond shaped hole as they open. A motor drives the chain that connects the doors and the controls sit on the floor. The builder sent me an e-mail to correct my impression that the hole was square and mentioned the motor was very slow.
The center furnace door runs on a pair of tracks above and below the door, most of the weight on the lower ones, the uppers easing movement. The slope of the door brings the lip closer to the glass for easier access.
The left gloryhole door is a rather common hinged door within a door in this case executed as cast panels, the 4 handles flanking the yoke, where they can be reached by the glassworker, but where they are exposed to the heat - wood handles help.

Some of the ten annealers in the facility, many of which are capable of handling casting and kiln casting. Each group of five are controlled by a Digitry Controller, shown in the background. The flames on the door of A5 remind people that the thinly insulated doors get hot.
Two more large (about the size of B3) top loaders, a large front loader and other small front loaders (garages) make up the complement.

This is an historic hot wall, being that of Harvey Littleton, one of the founders of the modern studio art glass movement. It is from his book, Glassblowing, a Search for Form. Note that all the furnaces are small tank furnaces, built up of unmortared firebrick held together with steel frames. Note also the lack of insulation; a tank furnace must leak heat so the glass is chilled before it gets through all the cracks, freezing and sealing the tank. To the right a frax lined gloryhole and an annealer.

GAS (Glass Art Society) 95 Conference was held in the area of Asheville NC, including a visit to Penland School. A large number of studios in the Penland/Asheville area were open for visits and I was in place early (before they opened) and took a big chunk of the day hitting them (and driving back country roads.) The purpose of these photos is to sample a few hot walls and there is a separate page with more on the conferences. Narrative

This is the new hot wall at Penland, just barely opened on time for most of the 1500 participants to show up. The two pictures show the wall with two furnaces, gloryhole and garage and across the room giving some idea of the space in front of the wall - large. Note the bench with a large amount of adjustment for height and angle. I have some pictures of this space filled with several hundred people, plus workers, full to the gills.

Honestly, I don't recall which studio this was at. I will try and figure it out from the order of the images on the negatives and my narrative. A tank furnace built in a surplus stainless pot of some kind, small work space.

This studio, visited late in the day, is on the second floor of a building that was a store. Note wood posts.

This is a place I have not visited, but it is an example of a small home setup, rather well photographed. Click on the link above to visit, back arrow to come back here

Wimberley Hot Glass is continually improving their hot wall and viewing area (on this side of wall to the left) Notable in this shot from 1998 are the independent pipe heater to the right of center (click for a bigger view.) Wimberley used an interesting furnace door mount - a long arched pipe installed in the left rear corner of the furnace frame, up and over to the door, so pulling on the door swings it out and away and it slowly swings back into place. The pipe is visible in the center of the door here. My page

Jim Bowman's new shop has enormous working space of which this is just the overhead view from the gallery/coldshop/stained glass area into the hot shop. The hot wall is to the right and the outside access doors to the left. The rails on the left edge of the picture are around a viewing platform that overhangs the space and there is more viewing along a rail to the right of the photograph. At the time this picture was taken, it was newly set up having only an elaborate hood with a rail inside to shuttle a blocking metal shield across the space. Viewed in April 2002.Floor plan

This is the studio of Dick Moiel and his wife Kathy Poeppel and many more shots are shown here. Behind the camera is a large garage type door and to the right is a walled in gallery and kitchen area. Not much detail of a fairly standard set of equipment is shown. The sliding panels provide heat shade. Large exhaust fans on the back wall (right and just peeking past the panel) The air conditioning ducts are aimed down at the usual locations for the benches (3, one off right) The dust catcher box right is attached to a shop vac. The red box to the left is an annealler. Although the building is a typical small industry fame building, it is surrounded by condo complexes and apartments, Houston's contribution to non-zoning where neighborhoods are controlled by deed restrictions rather than zoning. The seating space holds about 50-60 people. Floor plan

Visiting a variety of studios in the Seattle area during the Glass Art Society results in a lot of repetition of details. Almost everyone is using 2-3-4 unit door hinged on door units for glory holes. Almost everyone uses adjustable rails on the floor for the yoke, sometime welded across with a strap, sometimes loose. Also, most of the work benches do not have an extension of the seat for holding tool, but have a low table or hassock the same height as the seat but relocatable forward and back. Besides these pictures, see more here firthm\seastu1.htm

Tacoma Glass Museum hot shop, huge glory hole, shield cut away at bottom to clear yoke. Large paddle to shield opening. Window to observe. Shelf on shield. More pictures of interior firthm/seatac4.htm
Huge glory hold with most door sets I have seen. Each door is hinged off the larger door behind it and each door has a pin pointing up near the inner edge on which to place the hook or loop of a rod used to open and close the doors.
	The hot wall at Pratt. Annealers are on the wall to left rear of the camera. Additional studio shots of Pratt and of Martin Blank's studio can be seen in the Glass techniques page and among visit pages Seattle Studios
	.
The Corning Museum of Glass (CMOG) drove its trailer rig across the country from its summer home setup in a parking lot at the museum and opened up on a neat location with a grassy amphitheater before it. It is powered by local power and natural gas. It carries its own lighting and sound system and has glass panels across the front.
Charles Freidman has a very nice backyard shop with very good construction techniques - note the sheet metal stud and girder layout with the cement board corrugated panels. 2003-11-29	He also was giving away grilled salmon and provided a nice sit-around space for talking and noshing.

The Chihuly hot shop, used during GAS for a demo of photosensitive glass. The people are standing in a viewing/walkway that is lined with hundreds of bottles of colored powder and frit (right) and illuminated by a clear ceiling with curtains that can moderate the southern light (left and right) The end of the walkway is a storage area for colored twisted pieces (left) The hot shop itself is nothing unusual and can probably be better seen in videos of the place than here.

There are a number of pictures here in my NJ trip page. In the montage below. The setup is inside the original glass factory with a replica of an old gas furnace holding modern pot furnace and glory hole. Besides viewing benches on the raised ledge on left, the white benches at their feet are on a walkway with a rail that allows close approach to the back of the glass workers. A huge cold working space is visible through the doorway center rear. Separate benches are provided for the demos and for the fellows working in sight of visitors, but not required to demo. 2006-08-15

This is perhaps the smallest space I have seen holding a studio. Feasible because of electric melt. The site is uses frames, so link is to first page, click on Glassblowing and make choices. http://huntrods.com/~huntrods/index.html 2003-11-29

Notes on traveling and visiting
I tend to try to organize as much as I can when traveling, learning as much as I can in advance and attempting to deal with the possible sources of error. Some people are much more casual. I consider it reasonable to find out names and phone numbers in advance and try to pin down who is available.
One source of information is the Craftweb Glass Forum http://talk.craftweb.com/ where a question describing the area and dates will usually get a response. My classes page classes.htm lists a number of studios. A Google search for glassblowers or glassblowing with city or state will produce some results. Always ask, when contacting studios by e-mail or phone, about other studios in the area so you can look for them by name even if the contact does not have an exact location.
I make up a tentative schedule since on my trips I am sometimes driving a couple of hundred miles in a day, trying to visit 2, 3, or more studios while getting someplace (I rarely have plans that involve staying in a place and wandering off in various directions.) I then call or e-mail the studios that are within range and indicate my travel plans are still rough, but would like be nearby on a certain date and could I visit and would they be doing something or is that a date when they are normally batching or traveling for sales, etc. (or even be gone to a show.) I also ask if they can identify any other studios in the area or on my route. I let them define the area, but I get pretty specific about my route - "coming up from Minneapolis on I-94 and going on to Carrington, North Dakota, by evening." I use the info to refine my planning.
Driving 60 or 100 miles to visit a couple of studios only to find one closed and the other batching isn't the best. I normally do a follow up call the night before to confirm that everything is okay and that I expect to be there in some time block, like morning, early afternoon, etc.
The greeting one gets at a studio will depend on the owner and chance. Some owners defend their need to work, "but you're welcome to watch", while others are willing to chat. Some will be doing sales to other people and fitting you in and won't talk shop at all. And some will change course in mid-visit becoming more friendly or less (some are very sensitive about technique questions, for example.) Courtesy and caution seem to get good results and keeping questions in line with what the host wants to offer. It really helps if your questions are not too naive, but two hosts may take the same question in different ways. Simple technical questions within your knowledge - what batch, what color, how often do you batch, how many pieces per day - will prove moderate expertise to most workers and open up the conversation (as opposed to "How do you blow glass?" "Is it hard?")
I would consider the ideal context of visiting studios to be able to plop down in the middle of several studios and have several days to go in different directions to visit and stay for more or less time at each one and to return if something was coming up in the evening or over a weekend. I rarely get the chance to do this. The places I visit have few studios and when I am away from home, I am usually moving on the way some place or having to travel to get to the nearest place. (Like New Orleans from the middle of Louisiana.) 2006-10-22

Vetro, Grapevine Texas 2004 Vetro Glassblowing Studio & Gallery, 701 S. Main St., #103, Historic District of Grapevine TX (just behind the Grapevine Visitor Information Center in the same parking lot as the Tarantula Train depot) You can always visit www.VetroArtGlass.com for more information or just call or email.
The space is nicely laid out with aluminum bleachers and lots of display space, both in the walls of the shop space and in the gallery. I met the owners and got some nice compliments on this operation on the web. I learned that they used Spiral Arts software to plan the ventilation. The ducting over the hot floor is make up air for the hot wall exhaust so incoming air comes right down behind the benches - lean back and enjoy. The door to the left is into the gallery and at the front of the seating. The corner beyond the door is cut at a 45° angle with a large multi-pane window for viewing the hot floor from the gallery. The walls behind and to the right have niches with lighted glass in them. The audience and gallery air conditioning is on the ceiling of the gallery to left.
Swamp coolers will be rigged for summer use and a separate air conditioning system is aimed at the viewing space. Windows in the gallery also allow viewing.
The space has been in the planning for two years and was installed in what was an open shed in about four weeks of intense work. 2004-05-08

Hot Walls of glass studios

Hot Walls
of glass studios