Pot Melt Problems

ianj · Post by **ianj** » Sun Mar 21, 2004 12:54 pm

Can anyone help me with a mud-mixing problem I'm having with potmelts.

I am using an 8" diameter flowerpot with a 7/8" aperture. After stacking equal quantites of Bullseye Emerald Green (transparent) and Canary Yellow (opaque) vertically in the pot (green then yellow then green and so on) I end up with a horrible brown mixed up mess.

Are there only certain colour combinations that work? Or should I be adding the colours to the pot in thicker layers (I only layered one thickness of green then one of yellow etc)?

I'm trying to achieve results similar to Steve Immerman on his website (clearwaterglass.com) but to no avail - so far.

For info the firing cycle I used is 932 degrees F to 934 held for 60 mins then full rate to 1700 held for 2 hours (the pot completely emptied), then full back down to 934 again for 60 mins then 176 to cool.

Any help offered would be gratefully received.

Thanks

Ian
http://www.glassfusion.co.uk/[img]potmelt.jpg[/img][/img]

Randy W · Post by **Randy W** » Sun Mar 21, 2004 1:55 pm

Three things determine how a pot melt turn out. How the glass is placed in the pot, the size of the hole and the height of the drop.

Try cutting the glass into 3/4" strips and place them vertically.

Open up the hole in the pot to and inch and a quarter. 1-1/4"

A drop from two inches high will give you a blotchy look, A drop from four inches will give you the tight rings you are looking for.

Try this link, it should help.

http://24.209.173.166:8080/magless/untitled1.html

Randy

ianj · Post by **ianj** » Sun Mar 21, 2004 2:53 pm

Thanks for the advice Randy - much appreciated.

I forgot to mention in my original post that the drop was about 4" - I'll try again using your technique. Your website is a great help, especially with laying the glass out in the pot and your firing schedules.

Thanks

Ian
http://www.glassfusion.co.uk[/url]

DanB · Post by **DanB** » Sun Mar 21, 2004 3:10 pm

I'm a glassblower not a fuser, but in my world yellow and green glass colors always chemically react together to make Turtle Poop Brown unless I separate them with a layer or two of clear. I expect that is what happend to your colors

ianj · Post by **ianj** » Sun Mar 21, 2004 4:40 pm

Dan

Thanks for the tip re green and yellow glass - I'll bear it in mind. I think my initial choice of colours for the experiment wasn't the best!

Ian

Rebecca M. · Post by **Rebecca M.** » Sun Mar 21, 2004 6:03 pm

I also had mud problems with my most recent potmelt. It had the yellow as well as red and some thin steel blue. They were all stacked in order with either clear in between and/or white-clear streaky and set up vertically around the inside. I have a small kiln and am not able to do a 4" drop. It was only about 1 1/4".
Looking at it I think the mud came from the yellow/blue reaction. Maybe. There are tiny lines of green and then blobs of yuck brown. Or maybe it was blue/red trying to make a purple. Who knows? Definately colors to not use together again. I'm using it to practice rims anyway. Not much to lose here.

http://pic7.picturetrail.com/VOL205/115 ... 648320.jpg

BTW, I couldn't get the link for your pic to work.

DanB · Post by **DanB** » Sun Mar 21, 2004 7:19 pm

I have found that Yellow and Blue hot glass color also make Turtle Poop Brown unless clear is imposed inbetween. Generally the reds and yellows react poorly with the greens and blues. If you had clear pieces mixed into the melt, then you may have had some of the mixture protected.

Rebecca M. · Post by **Rebecca M.** » Sun Mar 21, 2004 8:16 pm

DanB wrote:I have found that Yellow and Blue hot glass color also make Turtle Poop Brown unless clear is imposed inbetween. Generally the reds and yellows react poorly with the greens and blues. If you had clear pieces mixed into the melt, then you may have had some of the mixture protected.

I had clear or white/clear in between every piece of color, evidently not enough.

Turtle Poop Brown is a pretty good description. I wonder what the yuck gray color could be called? Pigeon Poop Gray?

Carla Fox · Post by **Carla Fox** » Sun Mar 21, 2004 8:18 pm

Randy:
Thanks for sharing. That was informative and grand to look at.

C.

Barbara Muth · Post by **Barbara Muth** » Sun Mar 21, 2004 8:21 pm

Ian, if you are using BE glass, they have posters with examples of color interactions. I routinely mix some of their greens and yellows for wonderful rich brown shades. I recommend testing colors together before firing them in a potmelt. If you see a line of another color where the two meet in your test, chances are that will be the color of your potmelt!

Have fun!

Barbara

Steve Immerman · Post by **Steve Immerman** » Sun Mar 21, 2004 10:05 pm

Becca wrote:I also had mud problems with my most recent potmelt. It had the yellow as well as red and some thin steel blue. They were all stacked in order with either clear in between and/or white-clear streaky and set up vertically around the inside. I have a small kiln and am not able to do a 4" drop. It was only about 1 1/4".
Looking at it I think the mud came from the yellow/blue reaction. Maybe.

http://pic7.picturetrail.com/VOL205/115 ... 648320.jpg
.

That's a really cool design. Did you have your pieces of glass radially oriented like the spokes of a wheel to get that pattern?

Steve

Rebecca M. · Post by **Rebecca M.** » Sun Mar 21, 2004 11:25 pm

Hi Steve, no they went around the inside perimeter of the pot like dominoes. I made little sandwiches of clear/color/clear-white/color etc., and stacked them vertically. They weren't exactly vertical either, but kind of leaning. That's the first time I did one and actually tried to calculate what would happen. I was trying to go for stripes swirling around. The radial spokes idea is intriguing, maybe that will get me where I want to go. But with different color combos.

I'm still limited on the height though, and don't know if it would make a difference or not in the final outcome. Probably, but I won't be able to find out for a little while.
I was wondering if one could cut the top off of a clay pot and not create some kind of stress to cause a problem in such high temps. It would leave the cut very close to the elements for me to get any kind of height. I like the wide shallow pots, but they aren't shallow enough. Anyone do this or foresee a problem?

ianj · Post by **ianj** » Mon Mar 22, 2004 2:41 pm

Becca

I've finally managed to post a picture of my potmelt at the following URL (the first time didn't work):

http://www.glassfusion.co.uk/Potmelt.jpg

Thanks for the advice re the colour combos - definately ones to avoid in future.

I like you potmelt as I hadn't seen a spoked one up until now - very nice.

Thanks to everyone for all your help so far

Ian

ianj · Post by **ianj** » Mon Mar 22, 2004 2:44 pm

Barbara

I've frequently seen the BE colour combo charts but it seems that this didn't sink in when I inadvisably chose green and yellow!

Ian

Rebecca M. · Post by **Rebecca M.** » Mon Mar 22, 2004 5:07 pm

Ian, that disappearing post was just a fluke I'm sure, and weird timing. Got your PM, but I wanted to show this and maybe get some feedback from more experienced sanders.
OK, this is the same one with the radial stripes and turtle poop issues;

http://pic7.picturetrail.com/VOL205/115 ... 648320.jpg

and this one is after I sanded the heck out of it to see if poop washes off.

http://pic7.picturetrail.com/VOL205/115 ... 005575.jpg

OK, so it broke, and I'll have to practice rims on something else, but I'm not discouraged at all. Most of it came off and it was looking much, much better. So what I want to know is;

A- Does this look like an annealing issue as far as breakage goes? I held at 960 for 1 hour, 100 DPH down to 750 and off. No peeking.
or
B- Would aggressive sanding and maybe too cold temp/water cause this? WBS, 60 grit and about 35-40 degrees outside in the garage.

Maybe both? It was 1/4 thick.

ps-Ian, you might want to try a cut or two on a tile saw to see if there is any really cool stuff inside. I did that with another one that broke (a pattern here?), made skinny strips and matched 2 mirror images, melted them together and made some pendants.

ianj · Post by **ianj** » Wed Mar 24, 2004 6:15 pm

Becca

I had a look at your potmelts and I like the spoked effect you seem to achieve. As I write this I have another potmelt on the go - this time with a less controversial colour combo (cobalt blue and clear)!

Some time back I had an annealing problem with my first potmelt. After three attempts it finally made it out of the kiln in one piece: I just re-fused the heck out of it each time it cracked, gradually reducing the speed of the anneal. In the end I think it cooled at the rate of 86 degrees per hour from 950. In hindsight that seems too slow now as I've been able to achieve "stable" results at about 176 p/h.

I will open the kiln door with great trepidation tomorrow morning!!!!!

Ian

charlie · Post by **charlie** » Mon Mar 29, 2004 7:47 pm

ijeffery wrote:Becca

I had a look at your potmelts and I like the spoked effect you seem to achieve. As I write this I have another potmelt on the go - this time with a less controversial colour combo (cobalt blue and clear)!

Some time back I had an annealing problem with my first potmelt. After three attempts it finally made it out of the kiln in one piece: I just re-fused the heck out of it each time it cracked, gradually reducing the speed of the anneal. In the end I think it cooled at the rate of 86 degrees per hour from 950. In hindsight that seems too slow now as I've been able to achieve "stable" results at about 176 p/h.

I will open the kiln door with great trepidation tomorrow morning!!!!!

Ian

i use

9999 970 30
75 850 0
150 700 0
off

for annealing pot melts. haven't had one crack yet.

WarmGlass.com