Minor Upgrade Question

jesnbec73 · #1 2024-01-09, 11:24am

I've used the Nortel Minor for nearly 30 years now, and I love it but I'm wanting some more heat. Trouble is my studio is small and I can't get a big boy torch, so I need to upgrade to something comparable in flame size to the nortel minor but with more umph. I can get my hands on about 10lpm of O2, maybe 15, but I'm not going back to tanks if I can help it. Was thinking about the Bethlehem Stacks, or the Mid-range with the surface mix top fire, orone of the GTT's, but it needs to be comparable in flame size to the minor, or at least not much larger than that. Budget is less than 1000, lest I incur the wrath of the spouse.

kevingreenbmx · #2 2024-01-09, 11:58am

I have a GTT bobcat I got a few years ago that is very similar in size to the minor, but with a LOT more heat capability. I liked it quite well till my work outgrew it.

jesnbec73 · #3 2024-01-09, 12:10pm

I was looking at the Lynx and saw this in the manual...
"Never run a soft low or short flame. This will cause the burner to overheat."
That sounds kind of scary, I use short flames all the time for detail work, is the bobcat the same as well?

jesnbec73 · #4 2024-01-09, 12:28pm

Anybody here suing the Bethlehem Star Torch?
https://www.bethlehemburners.com/torches/star
I really lked the Bravo as well, but I don't think I have enough O2, I've got three 5lpm concentrators and one of them is probably dead.
*Using, not suing lol

kevingreenbmx · #5 2024-01-09, 12:29pm

Quote:

Originally Posted by jesnbec73

I was looking at the Lynx and saw this in the manual...
"Never run a soft low or short flame. This will cause the burner to overheat."
That sounds kind of scary, I use short flames all the time for detail work, is the bobcat the same as well?

GTTs use the gas flow to keep the torch face cool, and unlike most other brands, the torch face is sheet metal instead of being solid or the ends of a tube bundle, so it's a little more sensitive to small, lazy flame settings. That said, people use very small flames on the Lynx all the time without issue. With the two oxygen knobs, for inner and outer oxygen, you have remarkable control over the flame shape and characteristics, and can achieve a very fine, narrow flame or a very wide bushy flame. I do not think you would be disappointed in it or have problem with it.

Keep in mind though that GTT flames are fairly hot and aggressive, made for boro. They can be a bit harsh on soft glass. if you have the ability to run compressed air, the compressed air version really helps with that by bringing the flame temp down.

echeveria · #6 2024-01-09, 12:56pm

I used a Bobcat for years, until the knobs needed adjustment, and I never sent it in for that. I would say just don't run it all the time on a low flame. It should be fine for stringer work, etc.

jesnbec73 · #7 2024-01-09, 3:31pm

Quote:

Originally Posted by kevingreenbmx

GTTs use the gas flow to keep the torch face cool, and unlike most other brands, the torch face is sheet metal instead of being solid or the ends of a tube bundle, so it's a little more sensitive to small, lazy flame settings. That said, people use very small flames on the Lynx all the time without issue. With the two oxygen knobs, for inner and outer oxygen, you have remarkable control over the flame shape and characteristics, and can achieve a very fine, narrow flame or a very wide bushy flame. I do not think you would be disappointed in it or have problem with it.

Keep in mind though that GTT flames are fairly hot and aggressive, made for boro. They can be a bit harsh on soft glass. if you have the ability to run compressed air, the compressed air version really helps with that by bringing the flame temp down.

Awesome, thanks for the info! The main thing I'm looking for really is speed for 104 marbles, it takes me over a half an hour, sometimes an hour, to get a decent implosion marble made and I'm only working one inch diameters or less. I have some serious lower back issues and can't sit at the torch for hours on end like I used to so anything with more umph would be great. The Lynx is looking pretty good for the price, also looking at this Bethlehem Star, I think it's new though so there isn't a lot of feedback on it yet...
https://www.bethlehemburners.com/torches/star

kevingreenbmx · #8 2024-01-10, 6:23am

I've heard good things about the Star, and generally Bethlehem burners are easier on soft glass and run better on concentrators than GTT. I haven't used one myself though.

rcktscientist · #9 2024-01-10, 10:52am

The Bobcat is a great choice. I run mine on 10lpm and can work up to 1" solid boro all day long. A bit slow on 1" but not terrible. The Lynx is ok on 10lpm but you run the risk of overheating since the oxy is limited.
The low flame issue is mostly related to triple mix torches. The Bobcat can actually handle those flames quite well but the torch barrel does get pretty hot. You can still get a nice pin point flame with plenty of oxy running. I actually leave my oxycon at max and turn down propane only, unless I need a tiny reducing flame, then I run that briefly and back to max oxy. Almost 4 yrs old and the torch still looks new, all ports are perfect, and the body and face have not become discolored.

The performance difference between a Minor and Bobcat on 10lpm is noticeable.

The Beth Star and Lynx are very similar. For soft marbles, maybe the Star is better since you get a wider flame. If budget isn't super important, this may be your best choice.
I'd also look at a Scorpion/Lynx which is Lynx center with 8 outer ports, basically a "bigger Star torch with more flexibility"

Best of luck!

jesnbec73 · #10 2024-01-10, 5:20pm

I just dropped my three concentrators off at the local repair guy here and he's going to be able to get two of them running, one is one of those m10's from Unlimited everybody got took over and he said it was a lost cause, and he's going to cut me a deal on a 10lpm, so if all goes well I'm looking at 20lpm total. That should allow me to run a decent torch when it's all said and done, was also considering that Bethlehem Stacks set up, it's pricey but looks pretty tough.

KJohn · #11 2024-01-10, 5:23pm

Yeah! I'm so glad I saw this thread. My alpha zonked last night and I bought the Star! I'm so excited

I don't think that's how LPMs work, but I could be wrong. You would be yoking them? And that would be excellent. I wish I had a local place to repair them

rcktscientist · #12 2024-01-11, 8:47am

Check your oxycon outlet pressures while running to ensure balance when tied together. Otherwise one will "push" the other one and reduce its lpm flow.

*On oxycons, outlet pressure changes with flow adjustments.

kevingreenbmx · #13 2024-01-11, 9:52am

Check valves help with that, Oxycons operate on a pulses, as the sieve beds switch between filling and exhausting, so the check valves prevent backflow when the multiple cons are running out of phase with each other.

jesnbec73 · #14 2024-01-11, 11:01am

Awesome guys, thanks for the advice on the check valves, hadn't even thought of that.
Speaking of Oxy Cons, this M10 that the repair guy said was a lost cause...
It cuts on, runs just fine for a couple of minutes, purity seems good, according to the flame anyway, and then it just shuts itself down, lights are on but noone is home.

The repair guy won't work on it because apparently the Unlimited Oxygen guy that put out all those M10's jerry rigged them. Is there somebody here that is familiar enough with those particular machines to maybe help me troubleshoot that one and get it back up and running? I have a friend of mine who wants to get into glass but they are poor as a church mouse and I'd love to get that one running and donate it to their cause, surely if it runs fine for a few minutes and puts out good O2, it can't be too big of an issue?

Found this on an old thread here,
http://www.lampworketc.com/forums/up...?viewid=268847
Is that ok for a 10lpm and a 5lpm?

echeveria · #15 2024-01-11, 11:29am

I think UO took 5lpm machines and did something to them to make them deliver 15 or 20 lpm. He sent me one to "test" and I told him it was crap, and he got pissed and tried to charge me for it. I told him to have his shipper pick it up. It has been years, and it is still sitting here. Maybe he did that for the 10's too.

rcktscientist · #16 2024-01-11, 1:10pm

The cranked up machines were never reliable, I think everyone knows that by now.

As far as check valves, they don't help with merged oxycons. The checks are wide open when they are running. If one oxycon drops pressure, the check valve(s) won't close but the pressure balance is affected. They only help if the pressure drops to zero but even then they don't prevent vacuum, just prevent backflow. Balanced outlet pressure is key to max performance.

kevingreenbmx · #17 2024-01-11, 1:17pm

https://bradshawoxygen.com/

that guy is really good at working with lampworkers to get Oxycons back up and running. he is very active in many of the Facebook "concentrated lampworking" groups.

jesnbec73 · #18 2024-01-11, 2:00pm

Quote:

Originally Posted by kevingreenbmx

https://bradshawoxygen.com/

that guy is really good at working with lampworkers to get Oxycons back up and running. he is very active in many of the Facebook "concentrated lampworking" groups.

Yup, he's less than a mile from my house. He's the one working on my other two machines. He seemed like a super nice guy, really knew his stuff and I highly recommend him at this point. He's also into home hyperbaric chambers, which really interested me, apparently they can do some amazing things for inflammation which pretty much rules my life lately. But he's the one that said he couldn't do anything with the M10 I had, which I completely understand. Wonder if I could maybe get a hold of that dude that originally put them out, or if his bad reputation has him all paranoid and surly now lol.

jesnbec73 · #19 2024-01-11, 2:02pm

Quote:

Originally Posted by rcktscientist

The cranked up machines were never reliable, I think everyone knows that by now.

As far as check valves, they don't help with merged oxycons. The checks are wide open when they are running. If one oxycon drops pressure, the check valve(s) won't close but the pressure balance is affected. They only help if the pressure drops to zero but even then they don't prevent vacuum, just prevent backflow. Balanced outlet pressure is key to max performance.

I wonder if I should let the Bradshaw guy know that I plan to merge them then so he can callibrate the pressures, or is that some lickety split thing I can do with a pair of channel locks?

rcktscientist · #20 2024-01-11, 5:52pm

Quote:

Originally Posted by jesnbec73

I wonder if I should let the Bradshaw guy know that I plan to merge them then so he can callibrate the pressures, or is that some lickety split thing I can do with a pair of channel locks?

Excellent idea! Talk to Bradshaw about it, probably the most knowledgeable.

jesnbec73 · #21 2024-01-12, 12:12pm

Anybody here ever heard of Prometheus, I think they are a company based in Turkey.
They have some terrifyingly cheap torches but they don't look too far off from similar Nortel models...
https://www.prometheushobby.com/Flam...769c69c87.html
Just asking, so don't flame me too hard lol

jesnbec73 · #22 2024-01-12, 6:25pm

Does this seem valid?
https://www.youtube.com/watch?v=HkePQgP30ew

rcktscientist · #23 2024-01-15, 10:28am

I looked into those torches and decided to stay away. First, they were always sold out when I checked. Second, I worried about getting support from overseas. They were 100 euro plus vat/shipping/etc. Also, it seemed like it would cost more than a Minor or even a Bobcat so I picked up a Bobcat.
Things may have changed and it might be worth buying one but my guess is that it's like a Minor but slightly weaker and will cost more to own.

jesnbec73 · #24 2024-02-21, 12:25pm

I pulled the trigger on the Bethlehem Stacks, we are planning on getting a building setup for a studio in the next year or so and I figured that would be more bang for the bucks in terms of getting two for one. I don't think I have enough O2 for the bottom stage yet, but we're going to get a couple more 10lpm's when we expand. Right now I've got one 10lpm and three 5lpms so I should be alright on the top one for the time being. Thanks for all the advice guys, if any of you have tips or experience on the stacks I'd love to hear 'em.

jesnbec73 · #25 2024-05-15, 12:12pm

Alrighty then, I have finally got two 10lpm machines and I will be trying to get everything set up this week for the Bethlehem Stacks. I wanted to run this by my distinguished colleagues here just to say I asked somebody, which will in theory, at least sound reassuring to a concerned spouse. LOL

Two machines, T-Grade O2 hoses connected to each one which will run to a O2 Y connector into a single hose which will then connect to the 2nd O2 Y connector which hooks up to the two fittings on the torch. I will 'balance' the output of the two machines by adjusting the flow rates, then theoretically, will be able to push somewhere close to 20lpm for the torch. Any safety objections to this I might have overlooked??

I'd love to put an oxygen by-pass in here somewhere so I can do reductions and the like without having to adjust the flow on the actual machines, as it is, I imagine I would have to use the other torch as a sort of O2 pressure release... this seems screwy to me and I feel like I'm missing something basic here but I really don't want to go back to tanks if I can help it. How can I safely adjust the O2 flow rate without fooling with the concentrators, or impeding their output to the detriment of the machines, would a bypass be something I could set up to be adjustable in-situ without an engineering degree? I will be stopping by Mountain Glass tomorrow to get the second Y connector and some hose, am I going to have to budget a pedal setup? Wife is already freaking about the money I spent on the extra 10lpm (I got it for $650 delivered though woot!!)

Thanks in advance for any advice guys, I know this post is complex, but I'd rather avoid any mushroom clouds or wife-ack if I can help it.

rcktscientist · #26 2024-05-16, 7:21am

Glad to hear things are moving along!

Be mindful that a 10lpm machine should be run at about 8lpm to ensure good purity. There are a few machines out there that can run up to 10lpm with good purity but you need an O2 meter to verify it, I actually have one but still run it at 8.5lpm. So, you'll more likely end up with 16lpm with both machines together.

The outlet pressure can be measured with a 0-30psi gauge (or even 0-15psi) with barbed fitting, just add some O2 hose. Connect the gauge to the outlet for 1 second and read the pressure. This stops the flow so make it quick. The on-board flow meter is not the same as a pressure gauge.

For a bypass, you can Tee-in a pressure relief valve. I tried with a compact, 7.5psi one from McMaster but it didn't work as expected. It did relieve the pressure when I lowered my oxy at the torch so the machines ran full constantly. But, that particular relief valve 'leaked' a bit even with my torch oxy valve wide open so I was always losing a bit of punch. I chose to just run full most of the time and turn them down only when I need a small, reducing flame. Otherwise, I only adjust my torch propane valve and make it work for everything I do. Seemed simpler for me but your results may vary.

Good luck!