hot torch question

[Amethyst_briolette]

I have a mini cc, running on propane and a 10lpm oxycon (turned up to 5lpm usually) and I am finding that the knobs are becoming too hot to touch almost, and it only takes about half an hour or so for this to occur.

Is this normal? If so, how then do you use the knobs to vary your flame chemistry?

[Judi_B]

I don't use a mini cc, but I remember this being discussed some time ago. I think the key to keeping the knobs cool was more oxygen. People using two 5lpm oxycons weren't having the problem. So you may be able to solve the problem by turning your oxycon up a bit

[ziggys]

Hi,
I researched buying a Mini CC and 10lpm combo to death before I bit the bullet and bought it.
No-one could really say why the knobs get hot. Some said their's didn't get hot at all (!) and some said they did. It didn't seem to matter if they were on oxygen or a 5lpm oxycon or 10.
Mine get hot also. But not too hot for me to use without a problem. But I am not sensitive to heat either. You could always keep a pot holder by you if it's really a problem.
As far as setting the oxycon. Here's how I was told to set it by the manufacturer. Maybe it will help the hot knobs.
Don't light your torch. Open your oxygen torch valve all the way. Turn on the Oxycon and set it to 7, (below the arrow where it says 'Do not exceed maximum flow setting') if it's an M15. If it's another 10 lpm set it at 7 also which is the max., lPM needed for the Mini CC.
Then don't change it again. Always adjust the oxygen from then on at the torch.
I didn't know that and set the Oxycon according to when the torch was lit. I ended up going above the max., flow rate. Not good.
Plus I was told that is why I was getting a reduction flame. I'm not sure why, maybe because you loose purity, (so is less oxy in reality?) if you set it too high.
Anyway it works like a charm and it is everything I wished for hot knobs and all.
HTH?
Angela

[ziggys]

Re-hi,
After getting some much needed sleep I rememebered something. When you set your Oxycon you want to turn the knob for it just below the arrow that says "do not exceed maximum flow rate', not at 7lpm.
7lpm is the maximum flow rate for the Mini CC.
But you want the Oxycon set to the maximum it can achieve with the torch valve wide open.

If the knobs are still too hot to use, maybe you could call Calisle and ask about it. They are very nice and helpful. And they recommend only a 5lpm oxycon to run this torch so you should be fine there.
Good Luck and let me know what happens,
Angela

[swschoell]

I had the same problem in my teaching studio. I had 4 mini cc's. I think the final outcome was to turn up the flame (both oxy and propane). It seemed that a short flame was like holding the power back of the flame and the heat went to the knobs. When I had a larger flame I do not have the same problem. This is what carlisle came up with and it seemed to work.
Good Luck
Stacy

[ziggys]

Stacy, Thanks for posting this. I wondered if my flame was too small. I know Carlisle says a 3/8" candle and mine is smaller. But I read that you just want the very tips of the flame to be yellow so I that's what I was going by.
I'm going to turn mine up and see what happens.
Thanks again,
Angela

[Norskiglass]

It is in how you are adjusting your torch (if you do) running it with a little more O2 helps the torch run cooler. Alos if you are working into the the white candles this will push heat into the torch head.

I have no problems with knobs heating up however I have seen students working and as I adjust the flame to help em out the knobs are at times hot.

[ziggys]

Ok, Your posts confirm it. I am running my torch with the flame too small.
I have an M15 Oxycon and the max Lpm is 8 which I set it to, so I can't change that. But I can adjust the flame.

But I've been to ill to try it . Pneumonia sucks. I can't wait until I can light it again! I've only had it up and running a couple weeks and I waited over a year to get back on the torch. ARGGH!
(Sorry I need to whine a little).
Angela

[jaccarney]

i'll chime in too. my mini's knobs get hot when i run a small detail flame for a minute or so as well. when cranked up- the knobs are fine.

[kbinkster]

The longer you run your candles on a Mini CC, the better.

Here's what happens:

• with shorter candles, ignition of the fuel and oxygen happens near the face of the torch
• heat from ignition heats up torch face
• heat from torch face is conducted through brass body of Mini CC back towards the user
• the torch body overheats, causing hot knobs

So, the longer you run your candles, the further away from the face of the torch the ignition takes place. The further away ignition takes place, the less the face heats up. The less the face heats up, the less heat gets conducted back to the body and the knobs.

This torch can radiate a lot of heat from the body. Don't confuse this with radiant heat from the flame. A torch can have good radiant heat from the flame without radiating a lot of heat from the torch body.

The Mini CC takes about 11 LPM for its maximum flame. So, if you can turn your 10 LPM concentrator up to 10 LPM, then do it. What you do is open the oxygen valve on your torch all the way and turn on your concentrator. While the torch valve is all the way open, adjust the flow knob on your concentrator to 10 LPM. Then, you can adjust your torch however you like. But at least by doing this, you will ensure that you don't run your concentrator over the 10 LPM mark - which would shorten the life of your machine. For most soft glass work, the Mini CC needs about 7 LPM. You can try setting your machine to 7 LPM and see if you can get long enough candles with it.

The key is being able to run your candles out and still keep small tips on them. Longer tips indicate a reduction flame, and that isn't good for your torch, either. When you run shorter candles, try to get them with no tips. Carlisle actually recommends in the instructions that you turn down the propane (leave the oxygen where it is) to get a smaller flame. This is a cooler flame, but that's just how that torch is built. It really doesn't have a very good range of usable flame sizes.

The other thing to watch out for is the purity your concentrator puts out. If it is not putting out good purity, you could be running a reduction flame and not even know it because when the machine is pushing air, your candles won't necessarily be any longer. Air combusts fuel, too, so you will have a blue flame - the blue will just be a weaker color than the blue from a good purity flame. Anyway, running a constant reduction flame will overheat your torch, too. So, if you try running longer candles and still have big problems with excessively hot knobs, make sure your concentrator is putting out good purity (sometimes, all it takes is a change in filters to help that).

[Amethyst_briolette]

Good info thanks!! I think I am running too short candles.