What's better for cooling?

[Bruna]

](*,) Right now I'm using 1" fiber blankets, but I've been meaning to try verimicuilte in a crock pot. Is this better than fiber blankets in any way? I need a way to keep the beads from cracking now that I'm upgrading my torch and still dont have a gas-kiln to do it properly. Another idea, what if I cut up the fiber blanket into little pieces and put THAT into the crock pot? :-s

Thank you very much for any imput. :)

[Dale M.]

Actually Vermiculite may be best thing for slow cooling glass, better than fiber blanket... Get the plain gardening variety used as a supplement to retain moisture in potted plants.

Placing vermiculite in a hot crock pot may be a "crock". I do not think anyone has ever definitively proven that heated vermiculite is better than non heated vermiculite. Only sure thing is crock pot will raise utility bill.

I noticed you mention a gas-kiln. And that you are in Mexico... I'm not aware of your situation there, but I have doubt that a gas fired kiln will be temperature stable enough for annealing glass. The most accepted kilns are usually electric. Would be curious to know why you specifically mentioned gas fired kiln.

Dale

[Bruna]

Thank you very much Dale.

The reason I'm going for a gas kiln is the cost of electricity. It's way too high to add an electric kiln. I still need to do more homework about it, maybe if I use vermiculite and batch anneal only once a week it wont be that bad! :)

The pot would've raised the utility bill too, but not as much.

Might a laboratory kiln do the job? *grin* oooo, talking sure does help get the blood flowing to the brain.

-Bruna

[Lyssa]

Dale, I'm studying up by reading old threads and found this one and wanted to comment.

In the short time I've been using my new minor (used to be on hot head, as you probably remember), I have come to believe that unheated vermiculite isn't going to "cut it" for slow-cooling the beads I'm making on the minor. In the last two weeks, easily 1/3rd of my tiny, itty-bitty, 6-8mm beads that I made with the minor and put in the cold vermiculite have cracked in half while cleaning. I'm not doing anything differently than I was doing with the hot head, and these are the same tiny, itty-bitty spacer beads that I have made tons of on the hot head with very few breakages. I'm rather disappointed as the crock pot does raise the electricity bill and I just can't fit an electric kiln in my life right now. I just wish there was another way!


Actually Vermiculite may be best thing for slow cooling glass, better than fiber blanket... Get the plain gardening variety used as a supplement to retain moisture in potted plants.

Placing vermiculite in a hot crock pot may be a "crock". I do not think anyone has ever definitively proven that heated vermiculite is better than non heated vermiculite. Only sure thing is crock pot will raise utility bill.

I noticed you mention a gas-kiln. And that you are in Mexico... I'm not aware of your situation there, but I have doubt that a gas fired kiln will be temperature stable enough for annealing glass. The most accepted kilns are usually electric. Would be curious to know why you specifically mentioned gas fired kiln.

Dale

[Lisi]

IMHO, the "annealing bubbles" sold by Artco are the best. They are very lightweight and it's so much easier to push the bead down into it. Less likely you are going to distort a bead that might have been just a little too hot when you put it in. When I was batch annealing about 2 years ago I didn't have to put them in a crock pot. But of course, I'm in deep south FL.

[Lorraine Chandler]

I agree with Lisi. I love the bubbles.

[theglassattic]

Ditto on the Artco bubbles!!!! I never really used the fiber blanket stuff, I had some but it was messy so I threw it out. When I went to Germany, my girlfriend had tubs of vermiculite, and I had never seen it used before. I loved the concept, but didn't like the stuff, so when I got home I did some research and found the bubbles. I adore them!!! I read that they hold the heat much better than vermiculite, too. I am always "playing" with concepts, designs, etc and I would run my kiln 5 nights a week and really only make a few sellable beads and my electric bill was kicking my a**. So now, I plan my time out- nights I'm going to experiment, I play away and use the bubbles, nights I'm serious, I turn the kiln on and get down to business. It has actually decreased my stress level, and I don't feel guilty about running the kiln when I turn it on. I keep the bubbles in the crock of a crockpot, but don't turn it on.

[LarryC]

Artco....bubbles....nuff said :)

[ewdb]

i've been using the same $2 bag of vermiculite in a crockpot (heated and unheated) for about six years - although now that i have a kiln i use it mostly for test beads. when i'm just using vermiculite (e.g. when it's too hot to run the kiln) and i'm making big and/or sculptural beads i've found heated is the way to go - i preheat for an hour before hand and then leave it on with the cover for an hour after when i'm done before turning the crockpot off.

my theory is the preheating has less to do with slowing the cooling of the bead as much as evaporating any moisture/humidity that might be lingering in the vermiculite and cause the hot bead to crack - in my area of the world that's an issue - drier locales i would guess not.

I haven't bothered to try the bubbles cuz the vermiculite has always worked for me (plus i'm cheap, lol - i prefer to spend any extra cash on glass) ;-)

[Anne Londez]

Back when I started... I won't say how many years ago... I used to have a lot more breakage with the crockpot than without. Not that it actually was worse than no crockpot but the main factor at that point is usually your temperature control in the flame and it was too erratic anyway. Plus from a technical point of view, the temp of the crockpot is so much under the tension point of the glass that it has no effect whatsoever.

Re: gas kiln, be careful of one thing: the atmosphere in a gas kiln can be reducing, which is not a good thing for glass. Unless you want all your glass reduced of course !

[essiemessy]

Interesting..
I use a crockpot with vermiculite. The few times I've got to the torch, having forgotten to preheat the crockie, I've lost beads.
I have very, very few losses with the preheated vermiculite and, although the temperatures reached in a crockpot is negligible compared to a ramped-up kiln, I have found, particularly in winter (believe it or not, it does get cold here, too), that it must have something to do with minimising possible shock - at least somewhat adequately.

However I Hadn't thought of high humidity, prevalent around these parts, apart from it playing havoc with how the gas (HH) hits my clear glass. So, maybe that could very likely account for losses in 'cold' vermiculite.
Thanks for the food for thought :-)

[Jazarra]

So I had my DH look for vermiculite in the Walmart garden section they only had perlite ??? Where can I get vermiculite and does perlite work the same ??? "sigh" Prob won't be able to check back till tomorrow for an answer cause I am so sick right now and just got up to ask this question because it is the last thing I need now to start practicing with my HH at home :) And want my DH to pick me up some for the weekend :) Thanks

[Lorraine Chandler]

Be careful with vermiculite, you shouldn't breathe the dust and pour it outside with a respirator or mask on, same goes for the fiber blankets, you shouldn't move them too much and breathe the fibers that are released from movement.

Lots of things used in lampworking can be dangerous to your health. Research and proper safety equipment should be utilized at all times.:wink:

Best thing if you can't use a kiln right away is to use the bubbles. They are teensy tiny glass beads and they work great. Call Malcom at Artco Inc.

You can get vermi at any large garden center.

[Lisi]

Malcolm told me that the bubbles are a type of perlite, but they are smooth instead of rough-pebbly which makes them the perfect medium for cooling beads. If you haven't tried them, you don't know what you are missing! Not too expensive and worth more than you pay for them ;)

[Anne Londez]

I didn't mean that the atmosphere would have any influence on how the gas hits your flame but rather how you work, whether you are able to even out the heat correctly when making your bead and things like that.

Maybe if the room temp is really low, like around 10°C-15°C, then warming the vermiculite would make sense just because the coldness of the atmosphere (and of the cooling medium) would give too big a thermal shock to your hot glass. At normal room temp though I believe it does nothing much.

I don't know if you are in the habit of letting your bead "flame anneal" for a minute before putting it in the vermiculite but that does make a difference. The term is misleading because it is NOT real annealing but it is a first step: once the bead is ready, let it harden all over and rotate it at the very back of the flame quickly so as to even out the temp overall but without it going back to glowing. Do that for a full minute and your rate of broken bead will lower dramatically.

I'm sure you are aware that beads with differences in thickness (thin and thick parts) and/or beads where many different colors are mixed (all of a slightly different COE) are more difficult to keep from breaking in such conditions.



Interesting..
I use a crockpot with vermiculite. The few times I've got to the torch, having forgotten to preheat the crockie, I've lost beads.
I have very, very few losses with the preheated vermiculite and, although the temperatures reached in a crockpot is negligible compared to a ramped-up kiln, I have found, particularly in winter (believe it or not, it does get cold here, too), that it must have something to do with minimising possible shock - at least somewhat adequately.

However I Hadn't thought of high humidity, prevalent around these parts, apart from it playing havoc with how the gas (HH) hits my clear glass. So, maybe that could very likely account for losses in 'cold' vermiculite.
Thanks for the food for thought :-)

[Jazarra]

Malcolm told me that the bubbles are a type of perlite, but they are smooth instead of rough-pebbly which makes them the perfect medium for cooling beads. If you haven't tried them, you don't know what you are missing! Not too expensive and worth more than you pay for them ;)

That's Great but next payday isn't until the 24 th :( uuugh

[Lorraine Chandler]

Malcolm told me that the bubbles are a type of perlite, but they are smooth instead of rough-pebbly which makes them the perfect medium for cooling beads. If you haven't tried them, you don't know what you are missing! Not too expensive and worth more than you pay for them ;)

The bubbles are teensy tiny glass beads and they work great.
Perlite is a hydrated volcanic ore from the Pennsylvanian era of geology, with the approximate chemical composition of glass.

[CSimi115]

So I'm about to order the "bubbles" because I'm tired of usuing the fiber blanket and the mess it makes when it starts to fall apart. Is the concensus to use them with or without a heated crock pot?

Thanks
Chris S.
Newbie

[Lisi]

So I'm about to order the "bubbles" because I'm tired of usuing the fiber blanket and the mess it makes when it starts to fall apart. Is the concensus to use them with or without a heated crock pot?

Thanks
Chris S.
Newbie

You can as long as your weather is warm enough. When it got down to the 40's and 50's in my studio that year I was batch annealing, I didn't heat the bubbles. I stuck my fingers down in them and they weren't cold to touch, so it was okay. I didn't lose any of those beads and my customers haven't reported any broken ones either. I made only the small rounds, like 8-12mm so I didn't have problems. I still make just the rounds because it's my personal preference.

You are taking a risk if you batch anneal beads that are pressed in molds, shaped on a marver, or rolled in bead rollers. Unless you make them pretty small (like under 14mm) and flash in the flame to heat evenly all over before putting them in the bubbles/vermiculite, blanket. I would garage those tool shaped beads larger than 14mm just to be on the safe side.

[shawnette]

I purchased an empty 1 gallon paint bucket & lid, lined it with fiber blanket and filled the middle with annealing bubbles and it works great. I save my crockpots for cooking...

[LarryC]

So I'm about to order the "bubbles" because I'm tired of usuing the fiber blanket and the mess it makes when it starts to fall apart. Is the concensus to use them with or without a heated crock pot?

Thanks
Chris S.
Newbie

I use them without. I think the big advantage of these is that they dont throw off fiber that is hazardous to your health like fiber blanket does. No one should really be handling fiber without wearing a respirator.

[essiemessy]

I didn't mean that the atmosphere would have any influence on how the gas hits your flame but rather how you work, whether you are able to even out the heat correctly when making your bead and things like that.

Maybe if the room temp is really low, like around 10°C-15°C, then warming the vermiculite would make sense just because the coldness of the atmosphere (and of the cooling medium) would give too big a thermal shock to your hot glass. At normal room temp though I believe it does nothing much.

I don't know if you are in the habit of letting your bead "flame anneal" for a minute before putting it in the vermiculite but that does make a difference. The term is misleading because it is NOT real annealing but it is a first step: once the bead is ready, let it harden all over and rotate it at the very back of the flame quickly so as to even out the temp overall but without it going back to glowing. Do that for a full minute and your rate of broken bead will lower dramatically.

I'm sure you are aware that beads with differences in thickness (thin and thick parts) and/or beads where many different colors are mixed (all of a slightly different COE) are more difficult to keep from breaking in such conditions.

Thanks, Anne for clarifying :-)
I know that the flame part wasn't what you were getting at - I'm just saying that extreme humidity does play a part in how my clear finishes up on the bead - far more prone to sooting - and made that distinction in relation to the role humidity could possibly play with regards to the 'environment' inside the crockpot if not preheated.
Because of my choice to batch anneal rather than garage, I do have to pay more attention to 'walking' (I think Mustang Dawn used that description)the bead out of the flame, and this has also contributed to the extremely low numbers of losses with marvered, and sculpted beads to date.

Regarding bubbles, I'd love to try this out, but am happy with the vermiculite's performance, even though it's a bit dusty. Then again, with the salt, silica particles (located on the beachfront), rubber (8 lanes of highway, two international airport runways), jet fuel, dust, and exhaust fumes (see note on rubber :lol: ), vermiculite is not a big factor right here ;-) so I'm happy to stick with what is working.