My Maxi seems to have suddenly developed an oxidising atmosphere so my silver glass is coming out without its shine - I've mainly been using/noticed the problem with Triton.
I have a Beadcube for teaching, and I turned that on specifically to anneal some Triton beads and it worked great, but I really don't want to be running two kilns at the same time if I can help it. The Beadcube just isn't big enough for one of my 'sessions' and I'm also not that organised to have a separate session for silver glass. I'm also too lazy/disorganised to have a separate silver-glass programme.
I use the same programme for both kilns, I garage and anneal at 520.
I'm not being completely lazy (makes a change!), I have read through some of the previous threads about this problem but I've got a few questions:
- most people seem to talk about using some Activated Charcoal but somebody said that's a fire risk and you should use Activated Carbon - is there a difference? where do I get the carbon from?
- as the Maxi does have an exposed element, can I actually use the Activated Whatever or will I damage my kiln?
- has anybody else's kiln (a Maxi in particular) suddenly developed this problem? Any idea why?
- is 520 too hot anyway?
Hi,
Activated carbon is the stuff you use for sintering bronze clay, you can get from people who supply PMC, like
www.pajed.co.uk
I haven't tried it for a reducing atmosphere though, so I can't tell you if it works.
Cathy
Activated carbon is used in fish tank filers and is cheaper from pet shops than PMC and craft shops. it usually comes in nets that you just cut open. I can send you some if you PM me your address.
Not sure about the exposed element though but I use it in my bead cube.
Nikki
Thanks for the replies! Nikki, I'll take you up on that!
Charcoal is carbon so I imagine the only difference is in the marketing and therefore the price.
I read that for my Bluebird, using charcoal with an exposed element will shorten the life of the element by making it brittle faster so therefore less able to expand and contract with changing teperatures (i.e heating & cooling) so it eventually breaks.
I can't believe I'm daring to try to help you Julie! but I'm wondering from my pottery firing days if your elements are getting old and are about to burn out therefore raising the temperature in your kiln. If so you could try annealing at 510 for an hour instead of half an hour (and put a transparent bead in to check it worked). Forgive me if I'm talking rubbish :-[...
Julie, the kiln should be okay as the element on the Maxi is an insulated ceramic element - it's not actually "exposed" as such - although you can see it. If that makes sense... Can't help as to why it's suddenly changed it's atmosphere though.
It's all that sea air that's been going into it- full of ozone!!!
Kazx
Thanks everybody.
Sal, that's good news.
Marg, that sounds scarily likely, and not such good news!
I'll drop Lee a line tomorrow, thanks all.
Julie, I always anneal my silverglass at a lower temperature, 510 degrees C.
And run every kind of beads together in one run, lower but longer, 1,5 hours instead of an hour.
Hi Julie.
Firstly your element, although appearing exposed as you can see it, is actually the most CONCELLED element of all types. So concelled it can actually be submersed in water.
It is totally 100% protected from anything you can do in the kiln and likewise the kiln is protected from the condition of the element.
The element is actually seasled inside the metal tube you can see that you think is the element. ;)
Oxidising atmosphere? That suggests that you have oxygen in the chamber which of course you do. I am presuming you mean a Reduction atmosphere which is an oxygen deprived atmosphere? Am I right there mate?
Getting a reduction atmosphere in a MAXI isn't something I would have thought that easy due to the fact that there is very little in the way of a door seal and a dirty great gap all across the bottom of the doors.
The is nothing within the construction of your MAXI that can possibly change it's state and alter the atmosphere in the kiln.
Only two things can do that 1) something has changed in the kilns structure....i.e. the door is hanging off etc or maybe that the brush seal is completely bare (though I'm not convinced that will do much more than make the kiln work a little harder)
2) there is a foreign body in the kiln that is causing it.
If something is removing the oxygen it has to be burning it out and no part of the kilns inner construction is at all flammable.
Odd one this is matey and I'm gonna keep a close eye on this thread.
And now I've read the title of this topic again "losing the reduction in a MAXI" I'll try again ::) ;D
My guess is that your door seal brushes have severely worn and you are getting in more Oxygen than your combustion method can cope with.
Or
Something has happened and your doors are a really bad fit and the extra Oxygen is getting in that way (unlikely though).
Hey Lee, you saved me an email!
Quote from: Lee - Kilncare on June 21, 2010, 09:41:57 AM
Only two things can do that 1) something has changed in the kilns structure....i.e. the door is hanging off etc or maybe that the brush seal is completely bare (though I'm not convinced that will do much more than make the kiln work a little harder)
Ooooh - this could be it. Remember the photo you saw of my doors - the brush seal has burned away! You were gonna get your chaps to call in ...
Or, it can just be that you anneal it too hot. Have a read on this one (sorry if you have seen it before): http://envisionsf.blogspot.com/2009/04/silver-glass-101-annealing-temperature.html
I know that you anneal at the same program temperature in both kilns, but have you measured the actual temperature? I lowered my garaging and annealing temp. to 500/510 for all glass after I read an article from Bullseye changing their recommended annealing temps. and times.
Quote from: Lee - Kilncare on June 21, 2010, 09:45:30 AM
And now I've read the title of this topic again "losing the reduction in a MAXI" I'll try again ::) ;D
Hehe!
Lee, sorry to hijack. But my new shiny new Bead M**** is now fitted and I can once again flout it around to the general public wtih pride!
Mine was very shabby so it must have been leaking like a dog but I wasn't losing any reduction. I would go along with the theories that either the kiln is a bit too hot (mine is so I run it at 490 for silvered glass) or you have a queer batch of triton or there's something foreign in your kiln.
Doh!!!!!!!!! So I was, O.K. I'll put it on the priority list.
Completely forgot about the photos mate. If just taken another look at them.
We'll get it sorted post haste!!
You should be careful about showing of yer m***** in public pal ;D
Quote from: Lee - Kilncare on June 21, 2010, 09:59:24 AM
You should be careful about showing of yer minge in public pal ;D
Ooh er!
Quote from: julieHB on June 21, 2010, 09:51:34 AM
but have you measured the actual temperature?
Nope! I don't have the technology - but I think I'll have a go at lowering the temp and see what happens.
Quote from: Lush! on June 21, 2010, 10:14:33 AM
Quote from: Lee - Kilncare on June 21, 2010, 09:59:24 AM
You should be careful about showing of yer m***** in public pal ;D
Ooh er!
erm....the door seal......good grief....some peoples minds ;D ;D
OH the fringe ;D
My curtains are looking a bit bare these days too Lee - can we buy replacements?
Kazx
Kaz is posh - she has a fringe! ;)
I'll show off my m**** with pride to all members of the public! ;D ;D ;D ;D
Update - I adjusted my temp down to 510 and made three little triton spacers, I put one on the left, one on the right and one in the middle of the kiln.
They've all come out with some shine (as opposed to none last time!) - the one on the right has fared best.
So once I've got my new er ... frilly bit ... I should be back to normal :D
Ahh great news mate. Keep us informed.
And Hi Kaz, click on the item you want off the MAXI page and you shall have ;D
http://www.kilncare.co.uk/kilns_glass_beadannealing_maxiprofessionalkiln.html
I think we worked out before that the coolest part of the Maxi is on the right, the middle is the hottest and the left is "middle" - so to speak. Sarah Downton has more detailed information on this as she has "mapped" the temp along the Maxi - and although each kiln will vary a little, overall they all have the "hotspots" and "cool spots" in the same approximate areas. She can confirm/refute this - I can't actually remember exactly.
So, it would imply that you need to go down in temp a little bit more - as you got more shiny at the cooler end (that's me - technical to a "T") I actually operate my Maxi at "490" as I believe it is actually a bit hotter in the kiln than where the temperature is measured at the pyro.
Yep Sal, spot on. The right is low, the left is middle and the centre is top, lol ;D
I garage at 465, I anneal at 483 and switch off at 320.
This gives a much higher temp at the centre.
I love the variation as I know I can keep stuff cooler at the right, eg Rubino, medium at the left, and if I want to kiln strike something more I shove it at the middle. Works every time ;D
Thanks Sal and Sarah.
I know you've mentioned this before but I can't ever get my head round stuff like this till I need to .. and now I need to and it all suddenly makes sense!
Yeah - I quite like having the variation too - makes the kiln much more versatile.