Thursday, October 14, 2010

Count Down Fun! 5! Part 1

Here's a quick sneak peak at one of our new Fern Pendants!
Sterling Silver and Bronze.
The stream pebble is set in a Sterling step bezel, and then coated* so it is "wet".
The Christmas Fern is cast in Everdur, my favorite of all metals, a Silicon Bronze alloy used for sculptural work and jewelry.  It's a lovely metal!

Keep an eye on this Hummingbird Vine! 
Ipomoea guamoclit
Also known as Cyprus Vine or Star Glory.

I'm going to try an experiment with today's Count Down!  If I have a chance I'll post updates as the day progresses, instead of trying to catch up tomorrow.  Lets see how it goes . . .

*We get the "wet" look on the pebble by using the nastiest cheapest clear fingernail polish from Wally's World!  We also use it to coat the Silicon Bronze so that it won't oxidize over the years.  We have some Silicon Bronze Earrings that we made 20-some years ago that where treated this way after being heat coloured.  They still look as good as they did when we made them.  So we know this coating is good for at least 20 years!

Oh, the Hummingbird Vine bloom?  You'll just have to wait and see!

The Fern flask is going into the preheated kiln now.  If all goes well I should be casting around 8 or 9 tonight.  A little later that I would normally prefer, but not too late.

Count Down Fun! 7! 6!! Catching Up, I Hope . . .

This is the morning of Count Down Fun Day 5, as I try catch you up on what we did on Days 7 & 6.  (Lets see if the video works!)

Last time I talked about investing the new Seasonal Botanicals.  On Day 7 they went into the preheated kiln at 300 F at 10 AM.  I spent the day waxing new Fern Seasonal Botanicals.  And waxing, and waxing, and minding the kiln.

It was a pretty well behaved burnout cycle.  There's always a lag between the kiln temperature and the actual temperature of the flask being burned out.  Especially at the lower temperatures, but once the water content has been forced out by the heat and you reach the 1000 degree point the flasks tend to be pretty responsive to temperature changes.  (Though just because of their size and weight there is still a bit of a lag in temperature changes.)  Anyway . . .

Because of the time/temperature lag I start counting down each stage of the burnout cycle once the kiln actually reaches the new temperature range.  For example, the main high temperature for a 3" by 3" flask is 1350 degrees F for three hours.  So when I go from the 2nd stage at 700 F I don't begin timing until the kiln is actually at 1350 F.  And that's the fiddly stage for my old electric kiln.  (An American Ceramics kiln that I dearly love and owe an awful lot to.)  An hour and a half into the 1350 F stage I'll pull the flask, rotate it approximately 90 degrees and turn it over so the sprue former pour cup is now facing up.  Then back in, make sure it's at 1350 F and time for another hour and a half.

The actual pour was at 6:30 PM.  Wait about 15 minutes to let the flask cool then quench.  Then you finally get an idea if all of the wax work and then the burnout and pour worked.

I don't have a way to edit video yet, so this 3 minute clip is a bit rough.  I tried setting the camera up facing my casting area.  From the camera what you see is:  my Vic 9 vacuum caster, my Kerr Maxi Electro-Melt  (100 oz capacity!), and behind that the side of the kiln.  The very loud noise you hear is the exhaust fan.  The even louder noise later is the vacuum caster when it's turned on.  It's dark, but wait till you see the molten metal flowing!!!

Here's a quick timeline:

.10 Charging the Maxi-Melt with 90 grams of Sterling Silver (3 oz) when it is at 1850 F
.30-.40 Rocking the Maxi-Melt to help mix the alloy and sometimes, if it's a lot of metal I can feel if it has begun to melt
.50 checking the melt. Nope, not ready.
1.40+ rocking the Maxi-Melt, feels good, lets check it!
1.50 quick stir with my quartz stirring rod to make sure the melt is complete & to mix it
2.04+ turn off the kiln, pull the flask and set it on the casting table, turn on the vacuum pump and check the vacuum gauge to make sure the flask is drawing a vacuum
2.19 the beginning of the pour & my very favorite part of casting. All the hours and days of work lead up to the next few seconds.

After the actual pour I dump any residual slag out onto my fire resistant base and make sure the graphite crucible is clean. Turn off the Maxi-Melt and unplug it.


The last bit is jumpy because I wanted to show what the flask looks like from my view as it is glowing at me.  Sorry 'bout that, but after the Fair I'll have time to work on editing some more videos.

After cooling a bit I quenched then put it into a glass jar to devest in the ultrasound.  Made dinner and we both decided that we were pretty much done for the evening.  Around midnight I transferred these castings to a pickle jar and left them in the ultrasound for the night.  I turned the ultrasound off when I went to bed around 2.

Just as a reminder, there's a reason I look like this when I'm casting!!!
  • Full respirator ~ don't want to breath in any metal fumes!
  • Casting glasses ~ I'm looking directly at and into 1850+ degrees F!
  • Welding glove on my right hand ~ I use tongs to pull the flask out of a 1000 degree F kiln, and then I use my quartz rod to stabilize the 1850 degree F graphite crucible as I pour.
Yesterday, Day 6 I spent working on new Fern Botanicals.  And working on them, and working on them.  I have to admit I was in a groove and loving it.  They came along really well, but took a lot longer than I had meant them to.  (I thought I'd get them burned out and cast yesterday.  HA!  I just kept working on them.)  I left the earlier Botanicals in the ultrasound all day.  Just got distracted and left them running in fresh water.

Pat got a lot done on the production earrings for the spinner rack over the last few days.  Yesterday she finished the larger pendants that had been on the bench.

We stopped and I made us dinner around 7:30.  Then I went back to working on the Ferns.  I pulled the castings and dried them off . . .

And that was when I finally saw that some of them had shrinkage porosity and aren't usable.  Blankity-blank-blank-blank!!!  It was my own fault.  So there's nothing to do at this point except make a note in my casting log and remember to have a heavier sprue the next time . . .

So, of course, I stayed in the office working on the Ferns and boy did I overcompensate!  I began to actually spruesprue them up ~ after I completely over did their sprueing!  There is no way they will have any shrinkage porosity.

But what a pain they're going to be when it's time to de-sprue them . . .

So now it's the morning of Count Down Day 5!  In four days I'll be loading the display in the car.  In five days we'll be setting up at Booth #109 in the arena level of the Asheville Civic Center.  In six days the Fair will open at 10 AM and we'll be there, all set up and ready to go!

Counting the days  .  .  .