Batch annealing schedule - moretti glass beads in an SC2.

[Sarah]

Hi Andy

Shirley's right but I wouldn't use this program for a garaging schedule either. Mine is set to about 25c below the annealing point while I'm working. When I'm done for the day I take them up to annealing point for 90 minutes then down to strain point at 60c/hour.

I don't hold them at the annealing point while I'm working as this can affect some colours. And I make some large (2") beads which need a little longer.

The link you sent also doesn't say what CoE glass it is. I wouldn't use a program without knowing what it's designed for.

Sarah
xxx

[Andy Davies]

Thanks Sarah, this is the problem all along, the information is too sketchy, Pat kindly gave me the link but unfortunately it doesn't really help.

I'm specifically looking for the manufactures guidance on Effetre CoE100 annealing.
But I'd also like to know the fusing temperature, the satin point the annealing temperature etc    I'd like everything helpful that Bullseye publish.

Wheatear or not I'll push the limits is another thing but at least I'd like to know what the notional limits should be.

It's probably from having too many years in 'Process engineering' but if you make the artwork  it'd be a shame to wreck it because you don't know how to control the process.

I guess there's a lot of just playing safe and hoping for the best. (Victor Meldrew moment)

   All the best . . . Andy

[garishglobes]

You may need to contact Effetre http://www.effetremurano.com direct and ask them?

[Kaz]

Good luck with that!
But it's 104 COE not 100 if you want to be precise!
It's not a matter of us playing safe and hoping for the best; it's years of practical experience and a vast collective knowledge that is shared through this forum.
Kazx

[Kalorlo]

You could have a look at http://www.isgb.org/forum/showthread.php?2904-Moretti-glass-strain-point-temperature, though it appears that even when Effetre *has* provided tech specs, it hasn't always been correct...

[Andy Davies]

Thanks Kaz you're right it's the Coe104 I want, the CoE100 is the old glass I've being playing with, and hey, I'm not knocking it at all.

I always reckon if you want to know how to do something you need to find someone who 'knows how' but I'm getting conflicting answers and I'm frustrated that the Effetre information seems to be a secrete.

If I can get definitive information from the manufactures I'll share it here.

All the very best and please accept that no offence is intended and I hope none was taken.

                        Kind regards  ... Andy   

[Andy Davies]

You may need to contact Effetre http://www.effetremurano.com direct and ask them?

Thanks garishglobes   Thanks for the link I'll contact them now and see what happens.
   
    ... Andy 

[Hamilton Taylor]

Page 2 of the effetre catalogue gives the annealing temp as 470C, coe as 104 +/- 1.5

I use 480 - 510C, depending on what other glass I have with it

I use 420C as the strain point, which works just fine in the work that I do.

HTH,

Sean

[Andy Davies]

 Thanks all
I've been to the website http://www.effetremurano.com/ that garishglobes gave me but I can't post an enquiry as I get an error message.

I've found another address for them . . .  F3ind2@effetre.com but this turns out to be no longer in use.

This is the latest email address I have for them. . .
                                                                       comm.murano@effetremurano.com

I've requested some technical information from them regarding annealing schedules etc. as I want to get there suggested ramp rates.

By the way the top website is interesting to look at; well it was for me, to see the range of millefiori they have. (I don't have their catalogue)

                 . . .  Andy

[Pat from Canvey]

I expect you realise that their ramp rates might not suit your kiln and will need to be adjusted. Before I bought my bead kiln, I used my old ceramic Fulham Pottery kiln. With that I can only dial a top temperature, a soak and a rate from 1-4 and full. After an hour soaking at 520deg C (or what the digital display was telling me was 520 deg C), I turned off the kiln and let it cool naturally, (about 12 hours)  Beads were fine and still whole after about 8 years. I do realise the need for precision in some areas of life, (daughter is an aeronautical engineer and always demands precise measurements for any sculptural pieces I make) but glass is not precise.

[Shirley]

I don't know about information being conflicting. I think it's rather that there are so many variables involved that things change a lot and people's experiences vary too.

As for Effetre keeping things secret, maybe, but more likely they are just being Italian!

[Hamilton Taylor]

Effetre catalogue link (rod)

Sean

[Andy Davies]

 Thanks Pat 

    I'm not moaning but oh boy I feel like I need to justify myself. . .

What I'm setting out to do is design a table top annealing kiln that will in fact perform in the similar fashion as your old ceramics kiln.  Switch it off and walk away.

In order to design the kiln for a satisfactory 'uncontrolled ramp down' I need to know what the target ramp rate, from the stress-relief point down to the strain point, is for the glass in question and the type/size of beads I want to make. That's why I'm looking for the guidelines from the manufacture as a starting point.

It's only when I know the specifics that I can start the design and of course I can build in whatever safety margin I wish. The aim is to keep the physical size and cost to a minimum but importantly to remove the need for a programmed temperature controller.

As you know a single point temperature controller is cheap when compared with a munity point programmable controller and very simple to set.

Another bonus would be that the kiln could be unplugged and left to cool down with total confidence and in the same way, in the event of a power cut, the kiln simply assumes a safe ramp down. We get power cuts were I live.

I can understand some folk's resistance to me wanting to put a technical slant on the topic as it is after all Art not a science but there is a place I believe where a bit of science can help the artist. (having said that the topic title is batch annealing)  I've designed several industrial glass heating systems including one for fusing two  10" diameter borosilicate thick-walled tubes together for the scientific glassware industry and several 100 KW units for producing industrial ceramics fired at over 3,000°C where the problems are horrendous. I've also made glass moulding equipment for making industrial valves (they're like the old radio valves but much bigger.)  I haven't done much with annealing glass thought.

So I kind of have a bit of background with glass which I'll write about some day. What I don't have any experience with is hand lamp work.  The major part of my work has been in heating and melting metals but where I have been involved with glass it's been in high volume production with precise production rates where you hardly ever get to see the glass it moves so fast.     

If I do design such a kiln then my plan would be to freely publish the plans for anyone who wanted to build one. I'd design it with easily obtainable materials and for construction without special tools.   

Anyway I just thought that might clear up why I want to have a specific answer to what should be a straightforward question. 

By the way I wonder where your daughter works, I've made equipment for Boeing, British Aerospace, Rolls Royce Aviation etc so you never know, it's a small world.

Kind Regards . . . Andy

[Hamilton Taylor]

Andy,

I don't think there is a resistance to a technical slant - glass is a very technical material.

If you only want to anneal beads, design for a hold temp of 500C. That will be fine for garaging soft glass, be it effetre, vetrofond, lauscha, bullseye, or whatever. It will also work fine as an annealing temp for batch annealing if that is your wont. If so, make sure it heats at about 250C/hr or slower to avoid thermal shock, and cools with no power at 50C/hr or slower to avoid reintroducing stress, and hold it at 500C for as long as you like - I fancy an hour, for beads, and up to small marbles (3/4"). This will leave you with perfectly adequately annealed beads - but will become increasingly inappropriate as you get into sculpture, larger marbles, or other glasses, and may cause livering in striking glasses, or overstrike in silver glasses. This is probably why very few glass artists work without a multi-step digital controller on their kiln.

Interesting project - I look forward to seeing your results!

ETA: You may already know, but the Rakow library at the Corning Museum of Glass hold pretty much everything there is to know on the subject of glass. Its free to access their resources, even to borrow books via the inter-library loan service. I was stunned.

Sean

[Sarah]

Hi Andy

My advice would be.....

If you're looking to design a kiln then follow Sean's advice. 

If you want to bang your head off a brick wall trying to more get info out of a company that doesn't want  to provide then carry on with your search   


Sometimes you have to work out what's important to you but you don't need to justify that to anyone.

Sarah
Xxx