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Can A Candle Produce Enough Heat To Fuse Lid To Body?


dhPotter

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Well, perhaps I have misread, or misunderstood the information presented, could be...

 

The question becomes, what is the more plausible explanation for glaze bonding of a gallery and lid in a ceramic candle lantern such that the glaze from one piece breaks off and remains bonded to the other, to the degree that grinding would be required in order to remove it?  Wax?  That would seem far less plausible than heat work generated by the candle flame over the hour timeframe.  Wax, cannot bond ceramic to the point where grinding is required in order to remove the ceramic from the opposing part of the vessel.  I don't see how that is even theoretically possible.  

 

Perhaps part of the circumference of the lid, was indeed red hot.  I see no reason why the entire lid would have to be red hot, or why heat would transfer through the base of the lantern and burn through the table, given the convection currents likely present.  In a vacuum, heat radiates outward in all directions but when convection currents are present that is no longer the case. 

 

I accept that the situation occurred as described, and though I do not discount the incredulity of the event, there seems no other explanation apart from, heat work of the candle bonding the two pieces.  Wax, is not relevant in terms of bonding ceramic, it is the other way around of course.  So, what is the more plausible explanation? If there isn't one, then the candle flame bonded the two pieces until a better explanation surfaces :)

 

A candle flame's blue section reaches 2,600F.  If you can accept that a small bead could be fired to vitrification within the blue flame of a candle, or that glaze would melt in the blue flame of a candle over an hour's time, it then stands to reason that it is actually possible that the heat work of the candle fused the two pieces.  At this point it seems the only possible explanation.

 

I am happy to be corrected or proven wrong in my presumption!  

 

If not, then, why not?  There seems to be certainty that the candle flame did not fuse the pieces, yet no information or logic is presented to explain "why not", why the certainty.

 

I hope we figure it out!  

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Here's a thought.

After a quick search, a candle can reach 1,400F

I think it's possible that the temperature could have even been lower with a flux.

What if a flux such as borax that is in a candle wick happened into the mix?

Stearic Acid certain waxes, from what I found, were also listed as fluxes.

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Thanks, Mark C. 

 

So many aspects to think about with pottery.  The more I work in this medium and the more I read and research, the more I realize how DEEP the subject of pottery is. There is a ton more consideration of how the piece will/ can be used by the user, than I ever thought.

 

Pottery really does parallel programming.  We try to idiot proof programs.  It appears we need to apply the same thought to functional pottery.  Try to think of all the different ways a user may use/ abuse the product. 

 

Thank You to all on this forum for your sharing of insights and practicality which, it appears, only comes from experience. 

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I'm a bit surprized a large candle would burn well in that  light with no holes towards the top of the design. you did write that it was meant for a T light and that you had placed a large candle in it? May have to alter the design so that a large candle does not get used :D

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I was in the scented oil candle burner business in the 90's-we slip cast about a zillion of them-they where cone 10 porcelain.5 inches tall with a large cut out in front for the candle.

Cupped on top for theessential oil and had a candle (tealite) on bottom-we had a small 1/2 inch hole to vent heat near top.

Never melted any glaze -we tested them with all sorts of candles large small etc.

If you can melt a cone 10 glaze with a candle I would like to see that. 

maybe David Copperfield could do it with mirrors I know he can make pigs fly.

we wholesaled them to a large herb company still in business today-the liability for candle stuff in house is huge.

The place was Aura Cacia -you can find them in natural food stores

They also tested them-they found that low fired pots came apart with candle heat over time.

I boxed up many a pallet of lamps back then-I still have a few kicking around.

I cannot melt glaze with my acetylene torch

I'm open to new ideas as i like pushing the limits

I just need to see the rubber meet the road.

Mark

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Well I found that there is an inconsistency.  I get 2,165 watt-hours energy potential in that 206 cc candle volume but also know that a paraffin candle with an ordinary wick outputs about 33.5 watts of power so, if the candle burned away in only an hour, something else must've happened as well. Even if that candle output 75 watts, it should have burned for 29 hours to consume all of that fuel.  Was a lot of the candle still there?  Perhaps there was a backdraft and the thing got much much hotter for a brief period, or something like that. Scary some more!

 

It is cone 6 materials not 10, cone 6 stuff could fuse at much lower temps than 2205F, I do it all the time, though it does take 8+ hours.... 

 

I am surprised to learn that an acetylene torch does not melt cone 6 glaze! Can't get my mind around that either though I am not doubting Mark's experience, never tried it. Gonna though... I know enamels are routinely torch melted at around 1500F.

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If the pot got hot enough in that area to melt the glaze, it would have been glowing, at least in that area. You can't get the inside wall of a pot that hot and not have the outside nearly as hot, too. The wall is not that thick. Even tack fusing glass needs 1300F degrees.

 

If the top of that pot was hot enough to melt glaze, the bottom would have been hot enough to burn whatever surface it was sitting on. In a 7 inch tall piece you could not get the top up to 2000F without the bottom getting up to at least many hundreds of degrees. Stick a 7 inch long tube of clay in the peep hole of your kiln till it glows and try to grab the cooler end. Plus the pot probably would have cracked if one spot was heating up that much.

 

Personally, I would not sell a candle holder with a lid. The odds of someone grabbing that lid while it's still hot are too great. Not only could they burn their fingers, but they could knock the thing over when they pull back their hand, spilling hot wax all over the place.

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Yeh Nell I believe you are right.  Yet still something happened to fuse... Was the lantern in the kiln at the time the candle was burning? :)  Most importantly is the danger of someone losing fingerprints/burning house down while trying to pick off that lid, could happen to anybody who didn't think through what was going on, someone who came into the room etc.  I've seen people put plates on top of pans to cook then absent-mindedly grab the plate with their hands 15 minutes later, ouch!  At the least it should say   "hot surface" or some such on the lid, otherwise it is sort of a trap...

 

I think the experienced potters saying it is unlikely, are correct.  I just trip on that if it happened, how else could it have!  With the math not working out, I have to say though I still entertain the slim possibility, it is some wafer thin slim possibility!

 

But what did happen!!! Still wonder.

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As a test, I put a small puddle of glaze on a brick and hit it with my propane torch. After about 3 minutes with the torch as high as it would go, the glaze began to soften slightly. It was not melted to the point that it could flow, more like thick caramel. It wouldn't even stick to the metal rod I was poking it with. Around the edges, where it was glowing the brightest- light orange- it did stick to the brick a little bit.

 

I'm thinking the mechanical bond from the wax residue to the glaze must have been the culprit. I know wax residue doesn't seem like it's strong, but we're not dealing with a layer of wax smeared on the surface. We're dealing with very tiny bits of heated residue that can fill in the microscopic irregularities in the surface of the glaze, creating a strong mechanical bond. Think of how you have to rough up an inner tube with sand paper before cementing on a patch. The idea is that the cement can go into all the depressions and have a greater surface to grab onto. In the case of our candle, the vapor was small enough to fill in the depressions of the glaze, giving a bond that was greater than the bond between the glaze and the clay. The heat of the candle in that spot also could have weakened the bond between the clay and glaze, making it easier for the pluck to happen.

 

So that's my hack scientific theory!

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Patsu - The Lantern was on a dining table under a ceiling fan.  About 1/2 of the candle burned.

 

Neil - I did grab the lid - burned like nine yards of _____.  Also, my mom picked it up and hot wax went everywhere.  Need to rethink the lantern thing...

 

Got to get another candle the same size to test again in the lantern.  Will let y'all know...

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So you're saying, it could happen, there it is then!  Right? Propane isn't even hot!

 

I'm saying a glaze in the direct blast of a propane torch could make the glaze soften enough to stick. I'm in no way saying a candle can melt the glaze. I am saying the pluck happened do to combustion residue.

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Neil, Oh :)  heh

 

Dhpotter not sure you're up for bragging rights yet but you may be in the running for a Darwin award, be careful!  You might put some crumpled layers of aluminum foil under that lantern if you're gonna use it again...

 

I've made a small cone 6 stoneware bead and hit it with a dab of blue rutile glaze.  When it dries I'll attempt to fire it in a candle flame, and share the results.

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Well the bead blew apart in the first few seconds, should have predicted that... Now trying a bit of overfired cone 6 witness cone, it seems stabile over the first few minutes.  So I've got a time lapse movie camera on it taking a pic a minute over 5 hours.  Should be able to tell if the shard changes state at all.  Not the best test but I've got no bisque beads to try yet.  The bottom of the witness cone shard appears red hot already though it wasn't in this pic.

 

post-18942-0-92025600-1410640039_thumb.jpg

 

It's now mushrooming or something I think, tried to get a pic of it red hot. Pic below is before the mushrooming.   Pretty obvious that this would occur... Doesn't prove anything but, does prove that a candle flame gets at least to cone 6 + and hat the heat work of it can be effectively transferred to ceramic and affect it..

 

post-18942-0-19250300-1410640883_thumb.jpg

 

Now I don't know what's going on.  Maybe that is soot, really no idea, ha ha.  Smells a little funky, Neil can I get a quote on a downdraft vent for this kiln :)  I don't generally leave kilns unattended, but invited out for a few drinks... Hope it all goes to plan! :)  You might be first to the Darwin award dhpotter but I'm right behind ya!

 

post-18942-0-58176600-1410641554_thumb.jpg

 

Looking this over, this doesn't actually prove that a candle flame gets to 6+.  Doesn't prove heat work of a candle can affect ceramic, either.  Can't make these calls until the cone is analyzed.

post-18942-0-92025600-1410640039_thumb.jpg

post-18942-0-19250300-1410640883_thumb.jpg

post-18942-0-58176600-1410641554_thumb.jpg

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Well, that is understandable.  It is a small section of the end of a previously fired cone, I used side cutters to snip off some cone.  then that wire is copper milled to points.  Some interesting things are happening in this process right, there is an electrical current being generated by the flame's impact on this copper wire.  

 

So it is always about the nature of the matter, and never about one's " pet perspective. "  And so, I am not convinced at this point that the state of the cone shard, has changed at all.  If anything, our experiment thus far reveals that significant buildup can occur; this buildup, obviously could accumulate in significant structure as to snap off a bit of ceramic.  

 

At this point I wonder if dhpotter would like to comment as to whether the accumulation on the gallery or lid, was possibly present before the first use of the candle lantern or likely not, because that would be the crux of my presumption - if the flaw were not present as an effect of the glaze firing, then there is still no plausible explanation as to how the surfaces could have bonded so permanently. If the material transfer was as solid as I have presumed, then we still have no explanation as to how this remaining bond occurred.  Again I am not talking about some sort of crust that breaks off ceramic, it is the bonding that resists the separation attempt with the rubber mallet hit, and the remaining solidity of that inadvertent bond, that suggests that the candle flame bonded the two pieces.  That is the presumed condition that has no other explanation.

 

As to time lapse video, I got a lot despite battery swap delays.  The firing continues as I type.  Unfortunately, several long segments of my video capture have more people than me in the background, which is of my son's room, which is a wreck.  I hadn't put much thought into what was in the background of the shot...  Recording of the firing continues as I write. 

 

Anyhow I'll get it up on vimeo.  In the meantime here's a current shot of the firing, Nothing much seems to have changed

 

post-18942-0-35756800-1410660606_thumb.jpg

 

So here's the link to the video. Got about 85MB of capture, this is 22MB of that.  Nothing much changes since the first few minutes.  Firing continues as of 10:57 my time.

 

https://vimeo.com/106079104

 

 

 

 

 

post-18942-0-35756800-1410660606_thumb.jpg

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 In a vacuum, heat radiates outward in all directions...

 

 

How does heat exist in a vacuum?

 

Also, take note that in order to melt cones, there is a base required temperature and your value of 2600 F is a best case scenario. If you do further research, you will find values more in the order of 2000 F and lower, much lower. 

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When it's light out, look up.  That's how. The nature of radiation passing through the vacuum of space necessitates that it exists in it. Though a vacuum in itself does not store heat.  

 

Hmmm.  That is to say, though some vacuums can exist where heat may not be transferred through them at some given time, the vacuum of space in eyeshot of the sun,  always has radiation passing through it which upon reaching a physical surface, can accumulate as heat.

 

It could be argued that, in a vacuum, heat does not exist even though it can emanate from one source in a vacuum and accumulate at another distant point. 

 

What do you think?

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Heat needs something else to be relative to, in the simplest idea that a vacuum is empty then how can something be hot or cold if there is nothing else.

I think heat only really exists when there is something to be hotter or colder than. Are electromagnetic waves hot? I don't know, they have energy but is it heat energy until it is transferred to some other atom?

 

 

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The problem with my experiment was, that the cone shard was not in the blue section of the flame, which is the hottest part. It was above it, in a much cooler location - I didn't want to adjust it as it was fairly miraculous to get those copper wire tips to hold the cone shard in the first place.  I have plenty of candles :)  I am aware that there are many varied estimates of the temperature of a candle flame however I believe 2,600F is accurate for the blue flame section of a paraffin candle.  I haven't checked it out yet but based on my placement not being perfect,, the cone shard probably has not change state.  Still there was a lot revealed.  It definitely got red hot, part of it did. Also not that it's a big deal, but I am not trying to develop a perfect physics lesson, just trying to fire a bead in a candle flame which I suspect can be done in the right circumstances.  I just need to bisque fire some beads to prep them, then get a bead suspended in the blue part of the flame. I'll try again.  

 

Saying that in a vacuum heat radiates out in all directions, was something of a jumbled statement on my part wasn't it.  I should have used the term "energy" instead of "heat".

 

I'll post the last timelapse when I get it up on Vimeo; it doesn't reveal much more, just what appears to be more sooty mushrooming.  

 

The only sensible explanation that I have read here, for the fusing of dhpotter's candle lantern lid, is that the fused, broken piece existed before the candle was first used, and simply went unnoticed.  Obviously the lid had to be removed prior to the candle's having been placed in it.  If the ceramic was clearly a fresh break with no soot on it, and still bonded, that would tend to rule out the possibility that it was already there.  Fun stuff!

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Well I looked at the shard at 400X and compared it to the rest of the cone that I did not 'fire.' I see no difference.  In this test the candle flame did not affect the piece of witness cone.  The mushroomy buildup was fine soot that had no density to it, couldn't even feel it  About 8 hours in direct yellow candle flame does not appear to affect a sliver of cone 6 witness cone.

 

Based on this I have to say, I have learned more and now further doubt the possibility of cone 6 glaze melting glaze in a candle lantern. Next test will be of a shard of 06 unfired cone, in the blue flame.  If I can't get that to change state then a bead probably isn't going to vitrify in the candle flame either.

 

Here is the 400X video if anyone is interested, rather underwhelming... The test shard is on the left, control shard on the right.  hard to hold the pieces still at 400X.

 

https://vimeo.com/106104656

 

Seems I was wrong in thinking that the lid could have fused to the gallery via a candle flame, but I'm okay with that.  Important aspect of the learning process is, admitting when one is not correct!!! :)

 

Edit - maybe not so wrong after all, gotta love when that happens.

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