Problem annealing silver glass

[Shirl]

I am having a bit of a problem with DH silver glass when I use it on top of the bead.

I usually batch anneal and the beads look lovely when they come out of the bubbles, but after they have been batch annealed they loose some of their shine.

Do I need a special annealing programe for silver glass?

[Redhotsal]

Silver glasses tend to anneal at a slightly lower temperature - I usually drop mine by 20-30 Degrees. But the reason you are losing the shine is probably due to having a slightly oxidising atmosphere in your kiln. Put a pot of activated charcoal in with the beads and this should solve the problem.

[Shirl]

Thanks Sal, I will try dropping the temp, will the other glass (effetre) be properly annealed if I do this though?


I will also put in a little pot of charcoal

[Redhotsal]

This is not easy to answer. A lot depends on your kiln - and what the ACTUAL temperature is inside the chamber as opposed to what the controller says it is. For example - my kiln, a Maxi, is actually hotter inside than the recorded temperature on the controller. So I anneal at 500 degrees. If the kiln is too hot a lot of Double Helix strikers will go tan coloured.

But - as you say, are you annealing your Effetre? Or even Lauscha? From my own tests it seems to me that Lauscha needs a hotter kiln than Effetre. The only way to check this is to see the stresses that are in the glass after annealing. I do this with polarising filters - but then you could argue that this is only good for transparent glass, not opaque.

From experience - I can say that, for my kiln at least, annealing at 500C does anneal Effetre, does NOT anneal Lauscha, and is still a little too hot for Double Helix. From a "retaining the shininess" point of view the temperature is not the key factor, the presence of too much oxygen is what is going to take off the lustre, so the charcoal will help keep the glass shiny (reduced).

HTH

[Nikki]

I have to use charcoal if I batch anneal silver glass, its okay if they go straight in, not sure why its different. I have lots of charcoal if you need some just PM me your address.
Nikki

[Shirl]

Thanks Sal, I think I will just try the charcoal then at first, and then if I dont have any sucess I might try lowering the temp. I need to have the kiln hot enough to anneal the Effetre as I use the DH to decorate on top, and its mainly opaque so the filter wont work in this instance.

Nikki, thank you for the offer, but I do already have some activated charcoal that I use in my fish tank filter, I think thats what I am supposed to use? How much do you put in and how many firings can it be used for before its no good?

[Nikki]

Hi
Just put in a tiny amount, only about 8-10 tiny pieces and only use them once they usual turn a little grey after use. Put them at the side of the kiln that the silver glass beads are in and try to keep away from non silver glass especially turquoise.
Hope that helps
Nikki

[Shirl]

Yes it does help, thank you Nikki

[Blue Box Studio]

Where do you get the activated charcoal from?  I hadn't realised it was different from ordinary charcoal. I've been using the charcoal blocks hubby uses for burning insence but they are hard to come by and he's noticing the stock is going down.

[Shirl]

Well I dont know if mine is the right stuff but its actuated charcoal for use in filters for fish tanks and I got it from the pet store. It looks like small chunks not much bigger than rice grains, but black of course

[Blue Box Studio]

Thanks.  Will get some from Pets at Home when I go for cat food this week.

[Margram]

I'm sure I read that if you lower the temperature you can lengthen the hold at top temp and that will help to anneal...

[Shirl]

Well....I put in a batch of beads to anneal overnight, and put in some charcoal and used my usual batch annealing programme that holds the top temp at 520 for 1 hour.

This is what I found this morning. These all have DH helios on top and they all went in the batch(after previously cooling in bubbles) with a lovely silvery blue high shine.

They are on different colour bases and the ones in the centre on the coral and orange all have gone a dull olive green!

What am I doing wrong?

[Veebee]

Were they in different parts of the kiln Shirl? My SC2 is way hotter at the back than (not unsurprisingly) near the door. I have a raised kiln shelf in too, so I put shiney silver glass near the door and under the shelf, never near the back ( I also batch anneal) and always use (yup, the fish tank stuff) carbon with silver glass. I have dropped my temp to 479 and hold for an hour ( I think my kiln runs hot and I have checked that they are annealed properly afterwards  )
I have found helios to be a bit fickle and have always lost some shine, but most other silver glasses seem to respond to this schedule

[Shirl]

They were on skewers on a rack in various positions. I did an overnight batch anneal which meant that the bead door was tightly shut all the time.

i did wonder if it had something to do with the base colour as all the orange ones went green.

if I drop my temp. how can I check that they are properly annealed as they are not transparent?