Frit-Happens !

Lampwork => Common Problems => Topic started by: bellag13 on May 19, 2013, 08:41:13 AM

Title: reheating beads
Post by: bellag13 on May 19, 2013, 08:41:13 AM
I've done a search and to my surprise I can find a answer to this question but I expect its been asked, so sorry if this is a repeat

Can a bead be reheated and worked on if its been left to get cold (not annealled )
and if not why not ?
thanks guys :)
Bella
Title: Re: reheating beads
Post by: Dee Dee on May 19, 2013, 08:48:04 AM
Yes you can Bella - if you have a kiln - you need to bring it back up to temperature in the kiln very slowly and introduce it to the flame slowly too - there is a chance of it cracking though if you are not very careful!  If you haven't got a kiln, then no - you are asking for a glass explosion if you put a cold bead into the flame.
Title: Re: reheating beads
Post by: anditsinthefish on May 19, 2013, 08:49:31 AM
I guess in theory you could, however your chance of actually keeping the bead in one piece would be pretty low. You would probably have to ramp it up in the kiln slowly from cold and that might help... but I would assume the majority would thermal shock and break. However I do know people make donut beads and garage them and then make a pendant or whatnot and the pull the bead out of the kiln and attach them together (I think Kaz does this with her pendants) however, the beads never got cold they just were kept at 520'c. Wonder if any one has tried it from cold before?

xx
Title: Re: reheating beads
Post by: Dee Dee on May 19, 2013, 08:52:20 AM
Yes, I have, I accidentally got kiss marks when I put a bead in the kiln slightly too hot and didn't notice until it was out. I put it back in, slowly heated up etc and flame polished them out!
Title: Re: reheating beads
Post by: Margram on May 19, 2013, 09:01:23 AM
Yes, Pat is a great advocate of this and I've saved several beads by this method. If it is a large focal make sure to let it sit in the kiln at garaging temperature for an hour or so before taking it out. Be careful as the mandrel could be very hot. It's crucial to reintroduce it to the end of the flame very cautiously - I roll it fairly rapidly and dip in and out of the flame. You have to be fairly patient and only bring it down into the working part of the flame very gradually. It doesn't always work! But it's worth it if you've spent a long time on a focal. :)
Title: Re: reheating beads
Post by: Pat from Canvey on May 19, 2013, 09:56:11 AM
Yes it does work, as has already been said. I get tired very quickly when beading so I often put a half finished bead into the kiln and anneal as normal. Later, put it back into a cold kiln and reheat slowly to finish it off. The goddess bead I posted recently was in and out about three times because I wasn't happy with one of the boobs. It's only when  a bead is cold that I have time to really look at it and see a part I'm not happy with and make a mental note to work on that part. I've also put a long bead that I like, back into a cold kiln if I see that it's developed a thermal crack at one end because I wasn't careful enough when working on it. If it's already off the mandrel and cleaned of bead release, I take a fresh mandrel of a slightly smaller size, coat in bead release and carefully insert into the bead with a crack. Put into a cold kiln and bring the kiln slowly up to annealing temperature before working on the bead again. The release acts as a glue. To test this, I've also put a thermally cracked bead that's split in half onto a newly bead released mandrel and allowed the release to dry thus glueing the two bits together before reheating as I've said above. I wouldn't do this all the time but if it was an extra special bead, I'd give it a go. Nothing to lose if it doesn't work or simply put the two halves into a cold kiln and make cabochons with the kiln at 785 deg c. If you don't want do this, just put the cleaned, cracked bead back in the kiln and turn it into a cabochon. You can turn it into a pendant by inserting a loop of copper into the bead hole.
Title: Re: reheating beads
Post by: Josephine on May 19, 2013, 11:42:52 AM
You certainly can. Like Pat I have found bits on beads that aren't quite right, reheated and then carried on working on them. Its has generally been my large tree beads which are lentils and if they survive I reckon most things will. Just ramp up in the kiln and waft at the end of the flame to start with. Don't try and rush it in the flame or you might have bits of bead shooting off, not a good idea especially if they shoot in your direction, so keep your wits about you.

I would just add that the beads I have worked on have been annealed. If they haven't they might be a bit more shocky so be careful when you put them in the flame.
Title: Re: reheating beads
Post by: bellag13 on May 19, 2013, 11:51:06 AM
Ha, and there was me thinking I was asking a silly question :)
thanks very much for the detailed answers
I don't think this bead is worth the effort but now I know what to do I will look at them a bit differently
thanks again
Bella
Title: Re: reheating beads
Post by: GaysieMay on May 20, 2013, 08:35:49 AM
Just to add to what has been said already, I usually leave them in the kiln for a bit once its come up to temperature and work on them halfway through a session.  I always introduce them to the back of the flame and bring them forward - haven't had one crack yet.  Good luck  :)
Title: Re: reheating beads
Post by: Hamilton Taylor on May 20, 2013, 09:18:42 AM
FWIW, you can bypass the wafting-induced stress, by resetting your kiln a bit hotter - 530, or even higher - making sure that the bead/piece is fully heated through, and moving from kiln to flame quickly, getting the glass heated in the flame fast. As long as the glass is above the annealing temp, you won't shock it, however hard you try. Of course, the hotter kiln may act to overstrike silver glasses, or soften particularly soft glass (although I've not had this happen, personally). I have reheated and worked quite large pieces this way.

Sean
Title: Re: reheating beads
Post by: Moira HFG on November 15, 2017, 08:40:53 PM
Here's a topic I'd like to revive, if I may.
I would like to reheat some beads to rework them. They are smallish ovals, about 10mm by 8mm., still on the mandrels.
So - can someone who has done this please tell me how long the ramp from room temp to 530 degrees should be? I'd rather not heat them at 90 dph for 6 hours, if an hour and a half at 350 dph would be ok!

Thanks,
Moira
Title: Re: reheating beads
Post by: Redhotsal on November 16, 2017, 08:31:57 PM
Hi Moira - I reckon you will be okay ramping up quite quickly. Works for me, at least. (Actually I believe my ramp up is even quicker)!
Title: Re: reheating beads
Post by: Moira HFG on November 17, 2017, 08:20:42 PM
Thanks, Sally! I was nervous as I hadn't done it before and I'm so used to creeping the temp up slowly for my pate de verre...
As I had a mould to pack with frit anyway, I gave them 2 hours to get up to 530 degrees - and they were fine.

I love Reich Mystic Orange. The beads go into the kiln looking like burnt toffee, and mostly come out a beautiful golden caramel. This lot however looked like a satsuma caught in a searchlight  :o
All nicely caramelised now. :)

x
Title: Re: reheating beads
Post by: flame n fuse on November 18, 2017, 09:51:29 AM
Good to know you sorted it. I don't do this often, but my notes say that I take the beads up to temperature at the same rate as I would to batch anneal - ie going up at about 260 per hour - which is pretty much as you did. What did you use to hold the roasting hot mandrel?
Mystic orange - not used it much - I've made a couple of small sample beads and one is a slightly translucent bright orange and the other is a sort of creamy opaque pale orange, with bright orange around the mandrel (probably overcooked? but actually quite a useful colour). What does reichenbach mean by 'mystic'?
Title: Re: reheating beads
Post by: Enchanted Cobwebs on November 18, 2017, 09:17:24 PM
for me mystic green and mystic blue are part of my basic flower colours, all the others I cant get anything consistent out of but interested to know what others get
Helen x
Title: Re: reheating beads
Post by: Moira HFG on November 19, 2017, 12:27:15 PM
I suspect it means 'striking'. The violet is quite variable, and the orange gives anything between completely clear (some spacers recently, that was a surprise!), milky off-white to quite a dark toffee brown if worked hot and long. If this was made by Double Helix it'd cost a fortune!

Here's the beads I reheated:

(https://farm5.staticflickr.com/4557/38518845431_6e37037585_m.jpg) (https://flic.kr/p/21FM9LF)Bonfire beads (https://flic.kr/p/21FM9LF)
Title: Re: reheating beads
Post by: flame n fuse on November 19, 2017, 10:07:17 PM
I've got mystic green but never really used it. Will have to dig it out and give it a try. Mystic blue looks pretty, will make a note to order it next time. I like effetre green cave. My sample set shows mystic green and green cave are similar. Effetre lime green is my favourite spring green.
Title: Re: reheating beads
Post by: Enchanted Cobwebs on November 20, 2017, 08:07:03 AM
Quote from: flame n fuse on November 19, 2017, 10:07:17 PM
I've got mystic green but never really used it. Will have to dig it out and give it a try. Mystic blue looks pretty, will make a note to order it next time. I like effetre green cave. My sample set shows mystic green and green cave are similar. Effetre lime green is my favourite spring green.

Most of my leaves are mystic green like on my cherries and I also use mystic green on the base of my thistles. I use mystic blue for my bluebells, closest colour match to the real thing. It behaves very well and is delicate enough for petals. Cant get images on here as photobucket is being off with me but there are some in my Etsy shop. I have tried the other mystics but orange coral and red I got whiteish with a core of slight colour. Mystic violet was a murky colour and so I never tried again. I have a weekend off from shows this coming week so I might get some play time in. If anyone has suggestions on what to do to make them bloom. I only make tiny things though these days so sometimes maybe its not been worked long enough