I have been having lots of bovva making beads in the last week or so - everything I make seems to go wrong at the moment. If you remember, I asked the question about the oxycon and maintenance as I had just replaced my propane (got a very big tank!) and the torch did not seem to be behaving very well. Anyway, following that I have cleaned the filters and gave my torch a really good clean too but I am still having problems. Two of my competition beads cracked today a couple of days after annealing and cleaning (eeek I hope none of the beads I have sent to customers develop any problems!). Thank goodness I had not written the submission or sent the photos yet.
I have three ideas in my head - either the torch & oxycon combo is not getting hot enough (that's what it feels like as I am find it's really taking ages to get a gather for a stringer or murrini), the shop is too cold and it is affecting the oxycon operation or I have just lost the knack of making beads. My gut instint says it's still the oxycon as although I can get a blue flame OK I am having to keep the propane quite low (and I have whapped up the Oxy to 5). There does not seem to be much radiant heat around the flame and I think this is why some of my beads are cracking - I had some crack today as I was decorating them - admittedly working 2 to a mandrel but that is how I would normally do it anyway.
Sorry for rambling, but any suggestions anyone?
Kaz
Have you still got your old hothead and connections (did you have one in the first place)?
If you connect that up and have a go, and it behaves then you know it's the oxycon or propane. If it misbehaves then it's the cold.
This may be grasping at straws but could it be that you have inadvertently bought an empty tank of propane. Daft as it may sound this happened to me once - from a BOC depot. I thought I was going round the bend but they had sold me a duff budgie ::). - I also have a very big tank.
Diane x
I don't think it's that Diane as this had started to happen on Friday before I got the new tank and when Mark took it to swap he said the old one was not empty.
I'll get him to give it shake to see though (I can't move it!)
Kazx
It sounds very much like when I was having a problem with my oxycon a year ago :(
Did it die Julie or did it recover? I have just enough money in my Paypal to buy a new torch but now I am wavering in case I have to buy a new Oxycon!
Kaz
winter is when we always get to hear oxycon woes! they really are designed for warm dry rooms and the cold and the damp affect them something wicked..
if you can, feed your oxy warm dry air - about 20-22deg centigrade for choice.. the problem with cold moist air is that it allows the zeolith beds (the oxy's lungs) to clog up - especially if there is small amounts of fine dust in the mix..
secondly, turn the oxy DOWN to 4 or even 3,5 for a bit... this sounds totally counterintuitive but the logic is simple.. the oxycon will give you purer oxygen the more time it has to produce each lungful of air... turning it up to 5 actually reduces the percentage of oxygen it produces in the outlet air.. we find 4 or 4,5 the absolute max for the units in perfect warm dry conditions..
also, if the shop is much colder than normal it may well simply be that there is a bit of thermal shock going on.. if the beads are being annealed straight away and still cracking then try increasing the "soak" time from 30 minutes to an hour, and make sure the ramp is low enough back down to room temp..
one last final thing.. they are prone to add additives to propane over the winter season - to stop it freezing in the tanks if you leave them outside - its an outside chance but a quick check with your gas boys can help confirm this.. it may be a combination of all of these that is affecting the flame quality..
the winter period is ALWAYS the toughest on oxycons... try everything you can to keep them warm but more importantly dry!!! they are quite sensitive beasties!.. 8)
Thanks Q - You're a star! I very much think it is connected to this cold snap we are having. I have a fan heater so I will set that going when I go to the shop and see if that helps the Oxy along a bit and I will reduce the setting too. I appreciate your help - thank you!
Kaz
Thank You again Q! Your advice was spot on! When I went to the shop this evening I gave the Oxy its own little fan heater (while I froze!) and reduced the setting to 4 and within a short time we were cooking on gas again! I managed to make 2 big whoppers, 2 focals, 2 crunch sets and a whole load of spacers plus a couple of trial beads in the 2 hours I was there - so productivity has been resumed!
Thank You :-*
Kaz
Quote from: Kaz on November 25, 2008, 10:29:26 PMwithin a short time we were cooking on gas again! I managed to make 2 big whoppers, 2 focals, 2 crunch sets and a whole load of spacers plus a couple of trial beads in the 2 hours I was there - so productivity has been resumed!
Kaz
2 hours!! it'd take me 2 days to achieve that on my HH. Must get grown up torch.
just relieved it is such a simple fix... we all have to suffer for our art, but please don't let your legs fall off from the cold!!!!
;D ;)
Can I ask a weird question.
Would it be possable to run a really long tube from the house where you could keep the oxy con, to the shed about 25 metres away?
Justa thought, because soon I will be using one.
Denise
Quote from: Hotglass28 on November 26, 2008, 03:12:48 PM
Can I ask a weird question.
Would it be possable to run a really long tube from the house where you could keep the oxy con, to the shed about 25 metres away?
Justa thought, because soon I will be using one.
Denise
As my shop is next door to the owner's house that I rent from I don't think I could do that. Not sure in principle whether you could though?
Kaz
Doesn't someone do exactly that? Is it Emma Ralph?
Yup - to a point.
I have my oxycons up in my bedroom and run a hose out of the window to the shed below. It isn't quite 25 metres though, more like 6 to 10 or thereabouts. It works very well indeed.
The oxycons love being inside. No more yellow-light hissy fits from them!
If you can find a way to do it, I highly recommended getting those oxycons inside. I have no idea if putting the air through a longer hose has any detrimental effect. I can only say that I haven't noticed it. BUT... I never tried it any other way, the moment the second oxycon arrived, I switched to this set up. So I don't really have experience of running two oxycons in the shed to compare it to.
I have no idea if one oxycon alone could cope with a 25 metre stretch. When I was researching all this idea, I found there were a lot of people saying online "it can't be done" but no-one backing that up with any fact. It was all people who had never tried it saying it couldn't be done, or boring me with endless formulae about why it should not be possible. Well formula say bees can't fly, thinks me so I thought sod it, lets just see.
You can usually see with the oxycons if they are struggling as the little ball will start to drop. I would imagine that so long as that ball is remaining constant, you should be ok.
Emma
When it's very cold you may need to keep your Propane cylinder slightly warm as well.
Propane is in a liquid form in the cylinder and needs to absorb a certain amount of heat from the environment to " gas off" . If you feel your cylinder it will often feel quite cool even on a warm day if you have ben working for a prolonged period as the liquid is absorbing heat from the steel cylinder. Propane gasses off at temperatures down to -6c ( possibly lower) but the rate at which it gasses off drops as the outside temperature falls particularly once the temperature where your cylinder is kept approches freezing.
What may be happening is that your propane pressure may be falling as you work as the "gassing off" process in the bottle is not quite keeping pace with the rate at which you are using gas.
Standing your Propane cylinder somewhere slightly warmer may help, even moving it into the sun on a very cold clear day can help ( Do Not do this in the summer).
Marion