In my search for quartz tubes I've come across quite a few sellers online selling "quartz" glass tubes for the commonly sold pyramid style propane
patio heaters. They are 4" in diameter, and nearly 50" long for only about $80 USD. Assuming these are genuine quartz tubes, it could be one hell a
deal. I am looking to build a tube furnace, and despite this being way bigger than I initially wanted to build, it may make alot more economic sense.
Can anyone verify that these tubes are actually quartz and not just borosilicate? I already messaged a seller, and they said it is quartz, but I'm not
sure I trust how well amazon sellers actually know the technical details of their products.
Also, are there any simple non-destructive tests to test for quartz vs borosilicate glass? I may just order a few of these tubes, and test them to see
if they are quartz or not, and would rather not break them so I could return them.
[Edited on 18-3-2021 by BobD1001]Twospoons - 17-3-2021 at 16:20
See if it will pass short UV light. If it does then its quartz.
[Edited on 18-3-2021 by Twospoons]Morgan - 17-3-2021 at 16:28
If you tune in starting a little after the 14:30 mark there's this Applied Science cautionary tale. https://youtu.be/Xr1AiExSAnU
And this. I guess they make both but replacement tubes might be boro depending on the source and most likely the cost. https://youtu.be/xyUtriix_N0
There are these and other shapes made for UV bulbs that are not too expensive. https://youtu.be/ddqYSZd29a4RustyShackleford - 17-3-2021 at 17:06
I wasnt aware there was decent size quartz glass for such good prices. Fortunately even though the video is old, the tubes seem to still be available
on ebay.macckone - 17-3-2021 at 19:22
The quartz used in patio heaters is usually of a 96% silica.
It is somewhere between common 3.3 borosilicate and fused quartz.
The shock resistance is similar and the softening point only differs by about 80C from fused quartz.
The expansion also very similar 0.750um/m degree C compared to 0.700um/m degree C.
They are similar enough that standard taper joints don't need special handling.
