Possibility of glass for URBA RTA, measurements in post.

[daveid777]

It has an outer diameter of 22mm, wall thickness of just under 1mm (.8mm by my digital calipers) , and is approximately 20mm in length (19.92mm by the calipers). The rta came with a PMMA section which I used for the measurements. Can this be done?
Thanks!

 

[OCD]

Hi Daveid, Thats a tough one as the glass would be so thin if we did make an ID match. The closest you would get is 22 x 1.0mm and that would have a slightly smaller ID. How tight is that tank on the device? If it is not terribly tight AND the metal part of the device that has to go inside of the tank section is no larger than 19.75mm it may work. This is a Quartz glass size and quite honestly I dont like Fused Quartz at all because it is much more fragile against impact than Borosilicate.

If there are no issues with using a larger diameter OD then our 25mm which is actually 25.4 x 2.4mm with an ID of 20.6mm may work. In the past we have done an outside bevel on the ends of tubes to taper them back to a device but it will certainly be considerably larger than the 22mm device. There is also a 24 x 1.8mm for an ID of 20.4mm which again would be larger OD but slightly less than the 25.4mm but we do not have that glass in stock as it is a size that has not come up for use.

Hope some of that gives you an idea of what can be done. If you have any other questions please feel free to ask.

 

[daveid777]

I'd be willing to try the 25 mm, as the quartz sounds like it would be too tight and the fragility scares me. I'll most likely use the steel tank primarily, but wanted glass for a little while so I can actually keep an eye on juice level/consumption (and the pmma doesn't appeal to me).

 

[OCD]

With the 25mm if you want the bevel then add that option and put in the notes 1.5mm so you will have about 1.0mm left of the flat on the end. This is just an aesthetics option so there is not a flat end sticking out so if that doesnt bother you it can be skipped. The bevel is about 45* but note these are done by hand so there is no rigid specifications and each one may well be slightly different.

This would obviously be under the custom cut to length category and there is a 3 piece minimum for custom tubes.

 

[daveid777]

So I got my glass, it's a bit loose, but I managed (with quite some work) to get one on using larger orings. The ones I ended up using were the inner orings from an IBTanked 22 mm tank. Could you recommend some orings that are slightly smaller? I think that would make it much easier. In hindsight, I think a slightly smaller ID would have been perfect.

 

[OCD]

Just a little confused here, you say the inner orings from our cartomizer caps (this would be the oring inside of the cap that seals to the cartomizer not the one on the outside of the cap that seals to the glass). Those would be 10.1 x 1.6mm orings and that is the same size of inner orings for all of our caps regardless of diameter (15, 19, 22, 25mm). That seems like a small diameter to me hence the confusion. Did they take a lot of stretch to get them on? What size oring was on the device originally? If they did need to be pulled quite a lot my instinct would go towards a 1.5mm thickness and a little larger diameter. Hard to imagine a smaller diameter but then I am not looking at the device, lastly... how was the fit? Could it have been slightly tighter or looser to make it just right?

For an oring that is very slightly smaller than the 10.1 x 1.6 that would be 10 x 1.5mm.

 

[daveid777]

I stretched the hell out of the orings. The stock ones were very loose. If the glass was slightly smaller ID, the stock orings would have done fine. To be honest, I don't know the best route to go here, a larger diameter but thicker oring would be easier to get installed. I will measure a stock oring today.

 

[daveid777]

Measured the stock oring, 18.25 x 1mm. Perhaps something in the 16-18 mm range with a 1.3mm or slightly larger thickness? Would this even be a size you stock?

 

[OCD]

Aha, that bites that they used a 1.0mm oring in the design. This is one of things makers do for some reason (I think maybe the sleek look, I dunno?) that really makes it tough to end up with a glass compatible device. There just isnt enough rubber there to cover the tolerance range of glass. Now if the device is designed for the express intention of not using glass then I can understand it and of course it would be up to the customer to figure out how to retrofit if they want a glass tank but honestly i think most folks feel when they buy a device it should work for whatever they want to use on it.

On the oring sizes, I see now why such a small diameter 10.6 x 1.6mm worked out for you because it was really stretched to get on there where a 18mm originally sat. That would be 18 or 18.5mm btw, I know they can be tough to measure (orings are ID x CS - Cross Section) since they move around easily but you get close then go by the standard sizes to figure out the rest.

Not a chance on the 1.3mm CS, I think there might be some Japanese Standard like 1.25mm but for the most part it goes 1.0, 1.5, 1.6, 2.0mm for widely available sizes and these are the only sizes we have. Another reason why its nice when 1.5 is used because 1.6 being just a touch thicker can often be used as an adjuster.

Google 1.25 orings and you can find them around. I would guess you are right in looking for something like the 16-18mm though I dont really know how the fit is and how the different oring CS will settle in the groove. Thats something you just have to play with but the 1.25mm will certainly give you just a little more material and sit into a groove designed for a 1.0mm much better than the larger CS ones will.

 

[daveid777]

Thanks for all the help, just fyi the tank came with a steel and an alternative pmma section with no intention of glass being used. The steel looks awesome, but I want to see my juice level (and that my wicks are all the way to the bottom of the tank). I will look for some orings tomorrow and let you know what I find. I must say the 1.6 was an awful tight and almost impossible fit, but I am more stubborn than most people!

May have found the perfect ones, here's hoping! 16mm ID, 18.5mm OD, 1.25mm thick. Going to order these, and see how it goes. Was thinking of going to ace hardware also to see what they might have.

 

[OCD]

No problem at all and yes that is the qualifier on these atomizers. If they sell with Metal tube or plastic sections then there is no expectation of them being designed properly for glass so that is something folks should look for when purchasing them if they want to be able to use glass on their device as most do. Even vaping non reactive eLiquids such as my own I feel much more comfortable using glass plus it just looks nice.

Now if a device is sold with a glass section then it should be designed to properly fit glass within the range of top tier glass makers specifications. Sadly this isnt always the case, I have purchased devices that came with glass in the box that would not fit and I have measured one that due to poor QC or whatever reason was so close to nominal leaving no room for tolerance that the majority of glass would not fit on it. I can only assume that when sold new they simply kept trying until they found one that fit. Unfortunately we cant keep sending out free replacements until one fits.

It really is simple for the makers of these devices, make any metal part going into the tube section 0.25mm (minimum) under the nominal standard glass tube size and use a 1.5mm CS (or thicker) oring.

Those two things would make for a much better product serving the wider range of their customers. For customers who dont want glass buy anything you like but dont expect glass to fit it as there are limited sizes and a greater manufacturing tolerance over PMMA or Steel. For those who do want to use glass use your voting dollars to push for those two things to be a standard by using atomizers that meet this design criteria.

I would remiss if I did not mention end sealing atomizers (liquid seal is on the end of the tube rather than the ID) and devices with a metal sleeve. Most end sealing atomizers have a lip the OD of the tube must go into and of course sleeves must allow the tube to go inside of it. These cases are the same only they deal with the OD of the tube so they need to be 0.25mm over nominal size.

Also, I use 0.25mm as kind of a catch all but each tube size has its own manufacturing tolerance and most are greater than 0.25mm but the vast majority of glass in the range of sizes we typically use should be within a quarter mm +\- most of the time. The 22 x 1.8mm glass tube has about the best tolerance, I suppose it has to do with how well the machines that draw the molten glass are able to keep it within that tight range. Thicker or thinner wall or larger diameter and the tolerance begins to get larger.

Lastly (and sorry this has gone long) fused quartz should never be used. This is just a come on buzzword thing with no benefits for vapers in terms of the glass itself and quite expensive to deal with. Fused quartz sizes do not for the most part cross over to BoroSilicate (PYREX) sizes so if you purchase an atomizer sized for this glass you are pretty much stuck with it.

 

[daveid777]

Alright! The new orings seem to be perfect! Thank you again for all your help.