Vacuum stick stack

[BlueLilyStudio]

Just tried my first 70mm vac stack on a friends lathe. It went okay , but about halfway through it got the worst devit I've ever seen, (While I was doing the vac/meltdown ) it looked like it was literally covering the rods inside, and I'm pretty sure there is no way to get rid of it..... Not sure where I went wrong, What kinda torch/flame are you using on 70mm lathe stacks? any advice would be hella appreciated, peace.

the problem you are having is due to skuzz inside the tube, you really have to clean the tube and rods so that you don't have that problem.

[B-Rye-oNeR]

Word, it really started to fill with condensation as i stared to melt/vac, could that have anything to do with it ? ?, I did try to clean everything , but coulda done a better job of it . Thanks alot !

[BlueLilyStudio]

Word, it really started to fill with condensation as i stared to melt/vac, could that have anything to do with it ? ?, I did try to clean everything , but coulda done a better job of it . Thanks alot !

yes this is exactly the problem, the condensation is creating the scuzz. You also have to clean the tube while it is relatively cool because otherwise it won't get clean enough. I use window cleaner and paper towels to clean my tubes. The cleaner causes the residue to leave the microscopic crevices in the glass and is replaced with the cleaning product which evaporates. Even clean looking glass can make a very dirty paper towel after a few wipe downs. Then its loaded and straight into the kiln so it doesn't get moisture or more dust and contamination in the tube.

[STROKER]

^^^listen to this man when it comes to vacstacs.
i have watched matt make a 75mm vacstac that weighed 3 lbs look very easy and the end product is as perfect as i have seen.

clean glass is for sure essential.

[B-Rye-oNeR]

thanks, I used some 38mm as a handle for the 70 mm to keep the core and the rods in place, when I was doing the seal between these two tubes is when the condensation happened. And I also cleaned with water when the tube was still fairly warm. So I guess that pretty much explains it.

I know using the 38mm as a handle was probably not necessary, but I couldn't figure out another way to keep the rods/core from moving inside the tube.

thanks for the response. It was sooo nice doing the SS on the lathe, and not hugging and turning a huge pc of glass for half an hr.

[ITIS]

Just tried my first 70mm vac stack on a friends lathe. It went okay , but about halfway through it got the worst devit I've ever seen, (While I was doing the vac/meltdown ) it looked like it was literally covering the rods inside, and I'm pretty sure there is no way to get rid of it. Got some usable tube and was a good learning experience, luckily I used half clear, and it was a fairly sm section.
This was my first experience with a cradle burner, I usually just use a big hand torch that kinda looks like a red max major ( I think dude bought it off someone here) Not sure if I just had the wrong flame chemistry or what but it really fucked up about half the pull.
Any tips for lathe vac stacks> ? .... Not sure where I went wrong, What kinda torch/flame are you using on 70mm lathe stacks? any advice would be hella appreciated, peace.

the problem you are having is due to skuzz inside the tube, you really have to clean the tube and rods so that you don't have that problem.

This is not devit, you are trapping the water in there and that is the scuzz you are seeing. Best way to get rid of it, is to pre-heat the whole thing before you begin. I use a modified toaster oven to bring it all up to 350-400 deg F. before it even goes on the lathe. This ensures that the air inside is dry. since water evaporates (becomes vapor) at, or just slightly above it's boiling point.

(The water vapor is from atmospheric humidity. When you cork the tube, seal it and apply vacuum, the gas inside the tube is no longer exchanged (what is inside, stays inside, mostly). All this water vapor from the air is still inside there and has no where to go. It is a closed system (no air exchange). It gets hot, the water evaporates but it is still in there. This vapor then gets trapped and leaves little tiny ity bity water bubbles and produces what I coined "The Disco Fog")


One other thing that might help, if you don't want to pre-heat. When you notice the condensation building up release the pressure and un-cork the tube to let some of the steam out.

Cleaning it really well is a good idea too, but ...... well it is not as crucial as one might expect.

Cheers & good luck.
-Austin

[B-Rye-oNeR]

makes sense, I've never seen it on a pull I've done by hand, which I always preheat. Thanks to both of you for the great advice. My next lathe pull will yield much better. peace.

[chayes]

It's not water vapor causing the problem, it aint dirty tube, and it sure aint mcdonalds grease. Think about how glass actually works is all I'm gonna say.

[B-Rye-oNeR]

[Lmwfy]

It's not water vapor causing the problem, it aint dirty tube, and it sure aint mcdonalds grease. Think about how glass actually works is all I'm gonna say.

even though there's no real answer here, I'm inclined to agree..

[ITIS]

If you say so............. I don't know a lot about how glass works, but I still vote water vapor............... I have seen it so many times in my own stacks it is not even funny. It took a while to convince myself too. however once I started pre-heating no more bad funk only the good funk. Of course it might be a coincidence and not a true causality, or maybe I really am as ignorant as I fear.............. To each his own I have seen the funk and I beat that funk (with a $10 toaster oven from the thrift store and some DIY improv). I pass on what I know about the funk and that is all I know...... good luck curing the funk. (maybe put some gold bond in there, or fast actin tinactin. That shit always kills the funk).

[BlueLilyStudio]

It's not water vapor causing the problem, it aint dirty tube, and it sure aint mcdonalds grease. Think about how glass actually works is all I'm gonna say.

sounds like you know something but are unwilling or unable to explain it... it is vapor from the condensation that forms after several times cutting the tube...I wipe it out and its clean every time, don't wipe it out and its there...

[B-Rye-oNeR]

There was literally oz s of water I poured out of the 70 mm tube after sealed it to a pc of 38 mm and cut it, It was kinda gross, so I believe this was the cause. I love that so many experienced cats are putting in comments on this tho.

[chayes]

If it's water vapor why will it do it on one rod in one pull and certain colors in another pull? How can it happen even with a preheated tube? If it's water how can the same exact thing happen in ribbon cane made with a press? It just doesn't do it to the same degree with ribbon cane as the tubing though, but it happens.

[B-Rye-oNeR]

I think I see what you are saying now, but this crap I got was covering all rods in a section in the middle of the pull like they were completely coated with it. I cleaned rods and tube well, but the tube was still warm when I cleaned it. (with water) I'll try to get some pics, the pull is still at dudes shop.

What you are talking about sounds like what you get when pcs of glass that are two different temps come together, it can leave that haze. Which I wouldn't rule out completely.

Do you ever use carriage burners when doing lathe stacks? I know you used a GTT in a vid you posted, that inspired me to try it on the lathe. THe heat of the carriage burner seemed much different than what I am used to, not sure if this could have played a part.

thanks

[BlueLilyStudio]

If it's water vapor why will it do it on one rod in one pull and certain colors in another pull?

that one rod, and the certain colors in another pull, are the dirty ones, or they have a textured surface that traps the skuzz, like periwinkle or moss.

How can it happen even with a preheated tube?

even though the water has evaporated small amounts of impurities are left behind in the glass surface...think about paint drying, if you get contaminants in the fluid that may not be visible when they are dissolved, once the water evaporates the contaminants are left behind and begin to build up on one another.

If it's water how can the same exact thing happen in ribbon cane made with a press? It just doesn't do it to the same degree with ribbon cane as the tubing though, but it happens.

dirty glass, clean it first.

[chayes]

I thought it was water for the longest time, I've thought it was dirty glass. If you eliminate these factors and it still happens well then what is it? Seriously don't just say water and dirt because they are an easy answer. Mcdonalds grease was an easy answer too, but it was wrong. I just had to stop eating greasy fries to figure that one out.

[ITIS]

I thought it was water for the longest time, I've thought it was dirty glass. If you eliminate these factors and it still happens well then what is it? Seriously don't just say water and dirt because they are an easy answer. Mcdonalds grease was an easy answer too, but it was wrong. I just had to stop eating greasy fries to figure that one out.

I agree 100%, It is always possible for multiple problems to exist. If you eliminate one (the water in this instance) and it still happens then there is obviously another issue. But the water is definitely an issue, maybe it is not the only one. It was a big one for me for a while. I may have spoken too brashly before. My apologies if I offended.

[mark206nj]

Well, I am back on the torch again after a year and a half break. Ok, it was a mandatory break. Had major nerve damage in my right hand. Lost 90% of sensory and 75% of motor. Yada, yada, yada........5 surgeries later and lots of physical therapy, I am able to spin glass again.

Made several spoons the first week and then made 4 medium sized bubblers in the 2nd and 3rd week. All of this with my old stand-by 25mm swiped with color and then swiped again with clear. Then I read THIS thread. Holy shit! I've always had tons of trouble with trapping air in my stickstacks. This sounds like a god send. I've got my old shop-vac set up with a couple reduction hoses to get me down to blowhose size. Drilled a few holes in the vac line to get air from the atmosphere. Got all my prep work done and am gonna try this tech today. I will most definately post pics of the set-up and final tube, as soon as possible. If this is as easy as everyone is sayin, I'll be a tube makin' fool from now on.

Peace,
Mark

[Julian]

That's nuts Mark, glad you're back in action!