Bottles for DIY lamps - will they break?

[Adrian]

I am considering some different glass cylinders as bottles for DIY lamps. Question is if they will break due to heat differences in the glass. First of all a 9*40 cm vase like on the picture. I suspect that the bigger the vase, the more likely it is to break. In general, the flower vases and cylinders you can get are pretty thin. Anyone with experience? The 9*40 cm is only a couple of liters, maybe someone had succes with that size or (a lot) bigger? A 35 liter vase costs nothing in IKEA.

[Steffen Pfauhaus]

Yes they break unless you use for example glitter powered by a LED Bulb. 

[Marco Pulone]

if you want a recommendation for glass cylinders I believe Voss bottled water is a good source. comes with a cap too.

[andy ross]

As Steffen says, unless you're using an LED bulb you're looking for trouble with shop-bought decorative glass, I'm afraid...

The glass used in "heat" lamps is borosilicate - Pyrex to you and me - which will cope

[Adrian]

I found several borosilicate cylindrical glass containers! :) I bought a 2,5 liter storage bottle from Bodum and will try to fill it with water and put a lamp under it. Plan is to fill it with mathmos lava and fluid and have a custom base (a black wood stove exhaust pipe).

[andy ross]

Bodum make those glass coffee jugs that sit on hot plates all day, yes?

Can't see why not, but I certainly wouldn't leave them unattended (insurance companies are not adventurous...)

At that size you shouldn't need much heat, either - 40w? 60w? - spread as widely as possible - not halogen?

The original Lunars held about five litres I think and used 75w, 100w now...

Good luck!

[tim]

i think you will have good luck with pretty much anything so long as you are heating it relatively slowly and the glass is of a decent quality and doesn't have any defects. i have only had a bottle break on me once and it was because there was a hairline crack in the glass before i began.

i still would advise against using a vase as a bottle though because you can't really put a cap on it. you probably don't want to be sniffing perc all day long as you run the lamp, and if you ever knocked it over that would be very bad.

[Arne]

Voss bottles do work, I made several of em and nothing broke, exploded or cracked so far. 

Of course pyrex glass is the safer way but Lunar bottles arent so special either, it's just a huge whiskey bottle...same for the smaller version which comes with the petite jardinieres. Also I made a candle powered lava lamp a while ago and tried several different small bottles without any issues. Heat is not such a big problem for glass, especially if theres liquid inside to distribute the heat throughout the bottle. Whats critical is differences in temperature like pouring a lot of very cold water over a hot bottle or pouring a litte very cold water over a extremely hot bottle. The only way I ever cracked a bottle was when I tried to make a glitter bottle which didnt work. all the glitter just sat at the bottom and reflected the heat back to the bulb which caused the bottom of the bottle to become very very very hot which resultet in too much tension within the glass and formed a crack...didnt leak or anything, just a crack...crack is not to be trusted so I binned it.