[greybeard]

I've just aquired a sharplan 720 co2 laser (not yet delivered), and the seller is generously giving me the gas installed, but needs the cylinder back as it's on a lease contract.
I've started to try to find gas suppliers for a suitable mix.
Can anyone recommend a UK supplier among those available ?

I'd also be glad to hear of anyone on the forum with a simillar model - no manual with this one.

John

[KTP]

Check Sam's laser faq...I think we talked about a 733 or something awhile back..might be some info in there. Your 720 will probably lase on just about any CO2 laser mix...the expensive thing is renting the cylinder...I would try and buy one if I were you. I rented He, N2, and CO2 cylinders to make my own mix (for experimenting with my sharplan 1060, lasersonics 250Z and refilling some coherent rf excited lasers). I pay way too much per month for cylinder rental...I would be ahead if I had just bought them 2 years ago instead of starting the rental.

[greybeard]

Hi KTP.
Yes, I've started devouring Sam's pages, and from the photo somewhere, I guess the 720 is similar.
The previous owner of the laser has already mentioned that he thought he was being ripped of by the supply house, but I've yet to get all the details from him (the unit is due to arrive next week).
My first idea last night was to acquire a co2 cylinder. I assume I could fill that if I had to return his bottle before I used all the gas.
I know that oxygen cylinders have a different thread on the fittings, for safety reasons, but would, say, a 20 oz 'paint-ball' co2 cylinder have the same fittings as a commercially supplied laser mix bottle ?

John

[KTP]

Be carefull as I think paintball type cylinders are rated at 800psi and the cylinder you have to return is probably around 2500-3000psi. That much pressure is like a stick of dynamite or more...

Also, think about the volume. Even in a slow flow laser, the volume in a paintball cylinder is not going to last very long...

[greybeard]

A good point KTP - I have enough problems, without dodging shrapnel as well.

I will almost certainly end up with a commercially supplied mix. I have just thought that I might have luck with a neon sign making company only 30 miles from me.
Reading Sam's pages is quite encouraging re other sources, but I can see that any other route to getting the mix is likely to mean some outlay in hardware.
I've already got quite a lot of ex pub CO2 meters/valves/etc so I will keep that option open.
John

[KTP]

don't be afraid of making your own mix, but be carefull. The CO2 laser has such a high gain that it can lase with a wide range of mixes. Of course some will have much more power than others, but I have even heard of people getting a laser to lase off of helium, air (for N2) and CO2 made by bubbling baking soda in vinegar. Of course this is only a rumor..but I bet it could work...

Best just to get the right mix though, unless you want bragging rights to something crazy...

[KTP]

oh, one other source you may not have thought about.

Medical supply companies that deal in used medical stuff. I have one local to me where I purchased a ton of gas valves, a cylinder of N2 and CO2, and even my sharplan 1060 CO2 laser. They gave me the laser for free actually, and I think I paid about $100 total for the valves and cylinders. Most of them do not really know what a CO2 laser is/does. They got paid to take it from a hospital and dispose of it. Go figure.

[greybeard]

I'm not sure what the set up is on this side of the pond re disposal. I think a discrete enquiry via a surgeon I know might be a good start.

[Com]

Have you tried Boc gases?

[greybeard]

Hi Com.
Much water has passed under the bridge since I started this thread, but little gas
Yes, I have tried BOC, and like all the industrial suppliers, they want more for a gas cylinder rental plus the cost of the gas plus delivery plus vat than the cost of my laser.
In fact it's cheaper for me to buy a thirty watt sealed tube laser than buy gas at that rate, if you take into account the lifetime of the sealed tube.
However, if you have a personal interest in this problem, there are postings on another forum(diy laser cutting on yahoo) where we're looking at ways round it.
John

[ImanCarrot]

dunno if they're any good, but have you looked at these?

http://www.linde-gas.co.uk

Cheers.

Iain