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Re gas a Co2 tube

wby300

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I am planning to make an airtight box big enough for a long Co2 tube to fit into. I have the gloves for the box and am looking at some 1" thick plexiglass and 1/2" aluminum sheeting. I have a bottle of Co2 mix gas that came with another machine and I just got a nice medical vacuum pump.

I am not 100% sure how I want to do this, I could put some vacuum in the box and then remove the rear end cap. Add some gas to the box to bring it back up to atmospheric pressure, then vacuum again, then put the cap back on? Anyone done this before? While trying to find out about regassing a tube all I could find out is it costs about 1700.00

So if anyone has managed to do this before let me know if this will or wont work. I dont have everything to get started yet, so I am up for suggestions on other things I might need to do this also.
 





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That is an unusual way to regas a tube but it might work.
You will need to be sure you get that "cap" secured and you
will likely need to reallign the mirrors if I understand you correctly.
Look for cracks or obvious leaks first.
HMike
 
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You do realize that the vacuum on a box large enough to contain a CO2 tube will put thousands of pounds on the box sides, right? :undecided: Why not pump the tube directly?
 
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got a picture of the tube?

going to convert it to a flowing gas type? You will need to re-align the mirrors as the change in pressure can cause them to move. With a proper vacuum you should have a pink glow... if it is purple it means you have a leak in the system that will need to be addressed. This is of course for a flowing gas type system.

Or are you trying to re-gas it and seal it? For this, I might suggest you talk to your local neon sign guy. They regularly deal with evacuating the air out of a tube, filling it with the gas of choice, and sealing it.

No matter which one you choose to do, you will need to be sure there are NO leaks in the system.

I can tell you, this is what it looks like when you get a leak in the system, note the purple glow. My DIY flowing gas CO2:
9d187d32-1.jpg
 
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wby300

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It is a sealed tube, it was made in 1990. I would think a leak that small would be very hard to detect, it does lase but the machine it is hooked to says it is low power and needs calibrated. I want to get it fired up without the computer first, to see how it works on straight power.

It comes on as a pinkish purple, but it wont go over 4 watts according to the machine its in. At about 4 watts the machine locks down and says it is low on power and needs calibrated. I have contacted the company the machine originally sold through but I keep getting the run around just to get the manual.

I do understand vacuum, as stated the box will be pretty solid. I also didnt mention that I have a piece of high presure water line, 8 or 10 inch that the tube will go down in and the box will be on the end. So the box will only be a foot square or so, just big enough for the gloves and hands to work.

I do have a flowing system also but havent messed with it, dont want to use the gas before trying to regas this tube. I might get a hold of a neon sign place though, I had not thaught of that.


I figured the mirrors would need aligned, but I would think the rear one would be the easiest so thats why I was going to remove it.
 

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Measure the tube current first. If it's anything like the Chinese tubes I'm familiar with, it should be somewhere in the range of 15-25mA. What power should it be outputting?
 

wby300

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It is a US made tube, supposed to 50W but I have not tried to run it straight off the ps yet. I will run it straight pretty soon and see.
 

LSRFAQ

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It is a US made tube, supposed to 50W but I have not tried to run it straight off the ps yet. I will run it straight pretty soon and see.

Your going overkill. Co2 contains nitrogen and oxygen radicals when it lases.
Thus the electrode structure can see air, unlike a Argon laser.

Thus you do not need the glove box at all.

However, sealed tubes have other gasses in them besides the He:Co2:Nitrogen mix, to recombine the small amounts of Co2 that breaks down into carbon and oxygen when the tube is running. Without those gasses, lifetime is greatly shortened.

Steve
 

wby300

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well that would make it a lot easier to do. If I do not use the vacuum chamber, then I will have to make a fitting to put on the tube to draw it down. I have considered cutting the glass nipple used to fill it originally, off. I could mount some kind of one way valve there so it could be drawn down then the hose removed and a cap put on it. I might still be overthinking this, but I dont know how else to draw down the vacuum on the tube.
 
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well that would make it a lot easier to do. If I do not use the vacuum chamber, then I will have to make a fitting to put on the tube to draw it down. I have considered cutting the glass nipple used to fill it originally, off. I could mount some kind of one way valve there so it could be drawn down then the hose removed and a cap put on it. I might still be overthinking this, but I dont know how else to draw down the vacuum on the tube.

Did you sucseeded ??
 
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This thread is over 6 years old and the OP hasn't posted here in a very long time. Don't use your first post to necropost to old threads as it is a sure way to get negative rep against you. No one posts to these old threads without adding some new information. Just thought you ought to know.
 
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This thread is over 6 years old and the OP hasn't posted here in a very long time. Don't use your first post to necropost to old threads as it is a sure way to get negative rep against you. No one posts to these old threads without adding some new information. Just thought you ought to know.
Well, at least im not the only one reading this old posts, here is the new info, i have sucseded at re gasing a worn out chinese laser, i have drilled the glass envelope, epoxied an air conditioning 3 way service valve done vacumm to 0.01microns using a difussion pump, and after that filling to atm pressuere with laser mix srtarted to vacumm with HV on till max power is obtainned, power decreases some 15 to 25 percent on first hour of operqation, but after letting the tube rest for 24hors it returns to a stable level, i have managed after more than 3 years of experimentation to sucsessfully regas both RF and DC laser with DC laser in operation for more than 6 months and still 95% of initial power.
 

LSRFAQ

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JB weld is a bad joke when it comes to long term outgassing. . Hysol C1 White or Torrseal is the minimum material used. Even those need a considerable amount of baking, plasma cleaning, and outgassing under vacuum. Most tube manufacturers pay for a custom high grade epoxy mix to their own specifications. When i inquired it was well into the 2000$ region for a few ounces. Just out of curiosity, how do you intend to get the trace gasses needed for sealed service and how do you intend to do a seal with a leak rate of 1x10^6 per year or less?
Usually it is not just He, N2, Co2 in most sealed systems.

Steve
 
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