Tweaking my space (And other pipe dreams)

I’m always fiddling with my work space…all 32 square feet.  There’s more potential space in my basement but that’s currently occupied by a Model Railroad that I am loathe to tear out simply because I’ve put a ton of work into it (with a ton more to go) and at some point I’d like to return to that vice (well it’s a good one really).  Well in the meantime I’m always try to find new ways to create more storage.  I recently had a microwave on the floor in the corner and decided to move it out into the garage. I had originally thought that I would use it for making prototypes using my microwave kiln.  Well it went untouched for about 6 months and I figured I could make better use of the space and put a couple of shelves in there.   For those of you who are morbidly curious here is a visual tour of my space.

Here’s the entry to my lair.  I got some shelves for storing molds off to the right.

The kiln area.  The entire area is sheathed in 1/2 in inch durock with a double layer behind the kiln where it’s closest to the wall. The duct work for the kiln is for venting the space: one draws in cool air and circulates down around the bottom of the space to help cool the control box and the vent up top pulls the warm air out and vents it outside. the configuration works pretty well.  On the balance this is not the ideal situation; I wish I had more space on the back side of the Kiln but the double layer of durock does keep things nice and cool right on the other side of the wall.

The space underneath my workbench.

The topside of my workbench

The shelves above my work bench.  The duck work in the picture is for a kitchen floor vent.

Now do I have a dream glass shop?  Sure! Our garage is due for replacement and I’ve imagined taking it’s current 20 foot length and adding another 10 – 12 feet for a glass shop.  I addition, since we’ve never used the garage as an actual garage, I’ve proposed to my better half that once we rebuild the garage I could put a faux wall in about 10 feet from the actual garage door.  We’d use the from space for storage (lawn mower, gardening stuff, bikes, etc.) and use the remaining space as a hobby room for me and my wife: she could do her painting on one side and I could do my glass on the other.  We’ll see how things shake out.

One thing I needed to change was the chair I was using.  It’s a Swedish Balans chair and while it’s really comfortable I can think of at least half a dozen occasions where I’ve nearly killed myself (or something I was carrying) while trying to step over the chair or push it out of the way. I decided I needed something with wheels.

Here’s what I found at Goodwill.

OK.  I’ll admit it is a bit overkill for the space but I fell in love when I set my delicate posterior down in it. It’s truly an old leather captain’s char (captain as in Kirk…not Crunch) .

TTFN!

Messing around with Iridescent glass

I decided to make some decorative plates using iridescent glass.  I  built them directly in the casting ring on a broken piece of kiln shelf.  The shelf is just big enough to hold an 8 inch ring so it was easy for me to transport the entire rig to the kiln when I was done assembling the piece.  I don’t have a clamshell kiln so it’s a real pain (literally) to build something like this directly in the kiln.

I started off with a foundation of 3 mm transparent bull's-eye glass and then topped it off with a mixture of clear and transparent orange frit.  For this first piece I actually cut an 8 inch circle of glass and placed it on the bottom of the ring.  For subsequent pieces I used scrap glass for the bottom layer and used clear frit to make up the difference.  The first layer comes to about 9oz of glass. I then used about 3oz of colored frit and the remaining 6oz was the transparent red and iridescent glass. I carefully weighted all the components so I ended up with a little over 18 ounces of glass which will create a blank about 6mm thick.  So so first layer is the transparent glass, next the colored frit and finally the transparent red glass followed by the iridescent.

Here’s the shelf in place in the kiln.

All done!

I made another one using transparent blue and here’s one I did today using green.

Here’s the blue and red one with the edges ground and ready for a fire polish.

What’s up? This…

 

An Art Show Piece

Here’s the latest piece that will be on display at the Lincoln Artists Guild show at Out of the Box.

My main regret about this pieces is that one of the “points" is a bit cut off.  That’s how it kind of came out of the pot melt ring and it’s also due to a near disaster I had with this melt. I had a different border on it that didn’t turn out and I had to cut it off and replace it with the mosaic (and that was quite a nerve wracking piece of surgery).  Hopefully everybody will be razzle dazzled by the colors.  Smoke and mirrors ya know…

Now that was a fail Part 2: The Glass Strikes Back…

Uhhhhh there’s no redemption this time. Everything started off on a good note. I was able to re-fuse a piece that had broken off during ramp up. I had decided to incorporate a pot melt that I didn’t particularly care about just to try out this fancy shmancy mold. 



There was a little bit of overhang but I figured it would get drawn in as a glass slumped (and it did for the most part).

Here’s the results:
KA POW!

BANG!

ZOT!

OOF!

D’OH!

D’OH!, D’OH!

After doing some research I figured I’ve had just about everything bad happen that could happen (well not really…but I feel better thinking that way because I feel like I’ve gotten all the bad mojo out of my system in one fell swoop).
Here’s what went wrong.

1. The gaping holes in the glass: I don’t think they were air bubbles because the glass didn’t fully slump into the mold so there was plenty of places for air to escape.  I don’t think the holes were caused by thermal shock because they really look too organic.  It looks like the glass was torn as it was slumping.  Why? The border I added consisted of scrap blown glass and although it was fused together at a fairly high temperature (20 minutes at 1500 degrees) some of the bonds between the scraps may have been weaker to some of the colored glass coatings that were used.  Perhaps if I fired those kinds of borders at a higher temperature (1530 – 1550) that might create a stronger bond. Either that I should limit the size of those borders for 1/2 to 1 inch wide. I’ll need to experiment some more.
2. The stretch marks on the underside of the glass: I’m not sure about this.  The glass I was using was scrap system 96.  Here’s the slumping schedule:

RAMP	TARGET TEMP	HOLD
250	250	15
250	900	30
300	1100	10
75	1250	30
FULL	960	60
75	800	0
125	700	0
200	100	0

Here’s what I’ve come up with:

• The glass had been fired too many times.  Due to the thermal shock that occurred during ramp up I had to fire the piece two additional times.  So from beginning to end the pieces was fired a total of 7 times.  That might have caused the stability of the glass to degrade.
• My ramp up is too fast relative to the thickness of the glass and the kind of mold I was slumping into. The overall thickness of the pieces was about 7.5 mm and I thought I had a fairly safe ramp up but maybe not. In this situation slower is better; perhaps a 150 for the initial ramp to the annealing point and then 50 to the slump target temperature.
• The target temperature was too high.  Maybe I should do a longer hold at a lower temperature at, lets say 1150 to 1200 degrees.
• My blank was too big.  There was about a quarter inch overhang around the mold and It’s possible that the extra glass caused some resistance as it was being dragged into the mold creating the stretch marks (and contributing to the tears). Next time I’ll try making the blank a little smaller than the mold and see if that helps.

I was able to get a cross section picture of the piece after I broke it up and it looks like the stretch marks are a series of vertical cracks up extending about one half two thirds the thickness of the glass.

Interesting. 
    3. And finally…It didn’t slump into the mold completely.  I’m assuming it was partly due to problems #1 and 2.  Maybe for a mold like this it’ doesn’t need to slump to a “airtight” seal so to speak. When all was said and done it looks like it was probably slumped enough.
Well that’s enough wound licking for now.
Cya!

Like it never even happened…

Ha.

Here’s the piece after grinding and etching just before the fire polish.

This morning I just learned…

…my kiln doesn’t heat evenly.

The hard way.

The project was simple enough.  I had this pot melt that was a bit on the small side that I didn’t quite know what to do with.

And I had this funky mold I wanted to try out.

So I got out my 12 inch ring mold, put the melt in the center, surrounded it with scrap blown glass, did a full fuse, smoothed out the rough edges with the grinder and put it in the kiln again for a contour fuse to round the edges. Now I’ve had a piece thermal shock during cool down from an annealing that was too short and open the kiln briefly when it was a 350 degrees. This is the first time something has blown up on me during the heat up phase. Now when I head up the glass I’ve been using the “rule of thumb” rates that I saw (if I remember correctly) on the Glass Campus web site. The basic rules were this:

• 6mm glass –> ramp up at 400 degrees per hour.
• 9mm glass –> ramp up at 300 degrees per hour.
• 12mm glass –> ramp up at 200 degrees per hour.

Something like that.  The blank that was in there was only 7mm thick but I used the ramp up for 9mm glass just to be safe.  Here’s what happened:

 

Ouch!

The only thing I can think of is that the the borders I’ve been using for my plates are made up of pieces of scrap blown glass.  Now even though the pieces are “fused” together their bonds may not be as strong as they are in the pot melt itself.  I’ve used the same ramping schedule on other plates but in those situations the melt made up the bulk of the plate mass and so was inherently stronger and more stable. There could have been a coating on a couple of pieces that introduced a weakness in the piece that mad it more sensitive to a kiln that didn’t heat evenly.  That’s my best guess.  I decided to go ahead and try to fuse the darn thing back together again.  This time I’m ramping up at a much more conservative 200 degrees per hour.

I did a little grinding to try to get the pieces to fit closer together and I added a few scraps along the break just to make sure the pieces thoroughly fuse together. I also put kiln posts up against the pieces to make sure doesn’t “move” during heating.  OK it’s probably a bit overkill but color me paranoid.  I’m going to need to grind the darn thing anyway because it will end up being a bit oblong from trying to mend the break.

 

I’ll keep you posted in the results..