Saturday, February 22, 2014

Turtle or Turdlo?

Back when one of my daughters was a toddler she had a tendency to add “lo” to certain words.  Squirrel became Squirrlo, turtle became turdlo, squid became squidlo and so on.  I would gently correct her but soon she started doing it deliberately and get the biggest kick out of my feigned indignation: “It’s squirrel not squirrlo”. It was a fun little game.  Good memories.

So what does a turdlo have to do with the next piece I put together.  I guess I’m trying to suggest something about the mixed feelings I have over how it turned out. 

I had a pot melt that I accidentally broke into a couple of pieces and I decided to go ahead and break it up some more and re-fuse the pieces into pendants.  The problem was the pieces that I had fused seemed to be a bit oversized for pendants.  I started arranging them on a 10 X 10 glass plate and at first I though I could make them look like a very abstract school of fish swimming in the sea.  Well that wasn’t really coming together to well but as I arranged the pieces I began to see another pattern beginning to form.

Here is the “turtle” tack fused to the glass.

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I decided to fill in the turtle’s body with medium opaque green frit and use transparent blue for the ocean.  I dug through my scrap glass bin and found some pieces that looked fairly organic and sea shell like.

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Here’s how things came together in the kiln.

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Here’s the result after a contour fuse (1400 Deg @ 10 minutes).

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Wow.  Yeah I suppose it came out “OK” but I’m seeing two problems with this.

1. I had envision the turtle’s body having sharper boundaries and I’m not really sure why I thought using medium frit would provide that.  It looks kind of sloppy to me.  But then again this is an abstract piece so then…well…whatever.

2.  I should have used a lower fusing temperate. it should have been more ink the tack fuse range like 1350.  the “sea shell” pieces I added pretty much lost their surface texture and slumped too much.

So is it a Turtle or a Turdlo?

I see said the blind man…

I my last post I spent a fair amount of time licking my wounds do to a massive air bubble that formed under a piece I was firing.   I was fairly confident I could fix things by doing another tack fuse.

Well it worked…sort of.

The bubble fused flat and there’s a hole where a check of glass broke off.  Not a big deal since that will be filled in with frit.

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The point where I got hammered was the cool down after the anneal soak. After the piece had been out of the kiln for about a day a crack formed along the boundary of the pot melt.

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I spent a couple of days scratching my head of over this one before I realized what the problem was.  I used a cool down schedule which I though was appropriate for a piece that had an overall thickness of ~9 millimeters.  the problem was my piece was not uniformly 9 millimeters.  Here’s the cool down portion of my schedule.

Ramp Target Hold (in minutes)
FULL 960 80
75 800 0
150 700 0
200 100 0

I think this would have been OK if the piece was uniformly 9 mm thick but this was too aggressive relative to what I was trying to do. 3mm glass is going to cool much faster than 9 mm and that’s what introduced stress along the boundary of the pot melt.  If anything I need treat as though I were cooling down something that was 12 – 15 mm thick due to the varying glass thicknesses.  Here is the schedule I plan on using next time.

Ramp Target Hold (in minutes)
FULL 960 100
50 800 30
75 700 30
100 100 0

I’m thinking (knock on wood) this should do the trick.

I’ll keep ya posted.

Monday, February 17, 2014

You probably don’t want to forget this step…

Normally after I put kiln wash on a shelf I put it in the oven and let it bake 200 degrees for an hour and then bump it up to 500 for 15 minutes or so to get all the moisture out.  On this occasion I forgot to put a timer on and it ended up baking at 200 degrees for a couple of hours.  I figured this was enough, let the shelf cool down again and then used it a few hours later to tack fuse this project.
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The failure to bake it at 500 degrees turned out to be a mega fail.
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OUCH!
I figured I could fix it by drilling a hole in the bubble and then taking the piece to slumping temperature.  I flipped it upside down and filled the depression with water.  I cut the hole using a 1/8 inch carbide tipped glass bit and a Dremel moto tool.
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Of course one hole wasn’t enough for me.  I was being a bit paranoid and tried drilling a second one because I was worried that the hole would seal up as the glass settled and I’d still be left with a bubble.  The first hold drilled clean. The second one not so much.
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But this doesn’t necessarily bother me either since I had planned on putting a layer of colored frit on top and then doing a contour fuse.  I’ll just fill the hole in with frit. Unfortunately the small cracks pictured here weren’t content on staying “small” and grew to split the piece in half.  I’m still pretty confident that I can salvage it and fuse it back together.  The lesson here is you want to make darn sure you’ve got all the moisture removed from your shelf before firing something like this.
Dang! This smarts though…

Thursday, February 13, 2014

More Trouble…

…hopefully a good kind.

I decided to keep using the mini melt rings for doing pot melts for now until I can get the right furniture for melting directly into casting rings.  My last attempt didn’t work out so well.  In order to keep using terra cotta saucers I really need something like this.

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I found this at Delphi Glass. The problem here is that it’s designed for their pot melt system so it’s only 7 inches wide and from what I can tell the hole itself is no more than 5 inches in diameter.  In order to take advantage of the 8 inch saucers I really need something that’s 10 inches wide with a 6 to 6.5 inch hole.  I’m fairly sure I wont be able to buy something that ready made so I’ll have to make one myself out of a kiln shelf.  In theory that shouldn’t be to hard if you have the right equipment to cut a hole.  There’s one catch; I don’t have the right equipment. 

So in the meantime I’ll stick with using the mini melt casting rings.  The main disadvantage to that is I’m introducing and extra step in the process.  I have to take the blank and do and extended full fuse at 1500 for about 45 minutes to flatten it out.  But this isn’t really what this post is about.

I was looking at my 8 inch ring and thinking “I can probably squeeze 2 of them in my kiln and maybe even a 6 inch melt as well”.  I had been doing my melts on a kiln washed shelf set directly on the bottom of the kiln.  I decided lose the shelf and line the bottom of My 16 X 16 inch kiln with a 17 X 17 inch piece of 3 millimeter fiber paper. 

Here’s two 8 inch melts in situ (I’ve been dying to use that somewhere…Crappy Diem!)

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Here are the results:

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For the next batch I did 3.  If it weren’t for the thermocouple I could squeeze in another 6 incher.

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While being able to crank out a bunch of melts out a small kiln is pretty cool there’s a downside to this.  I have further processing to do on these blanks and I can really only do one at a time especially if I’m flattening them out.  Hmmm…maybe I just need a bigger kiln…Muah Ha Ha ha ha.

Yup.  This is trouble.