Boro Questions

[Fruddy]

Sorry, sorry, sorry mods....

Please move this to whereever it needs to be, and I am also sorry that I haven't done a complete search of the Forum, but when I put in Borosilicate, it brings up so much.

I can't torch at the moment, so am doing a bit of research.

I bought two Momka rods last week.   Haven't tried to use them yet.   I have a Minor and one Oxy.

My questions are:-

Does Boro glass reduce and strike the same way that soft glass does?

What is the coe?  Take it you can't mix them with soft glass?

I gather that you can garage them whilst making soft glass beads and then anneal them later.  Is this okay?

Thanks for the advice.

[Redhotsal]

My questions are:-

Does Boro glass reduce and strike the same way that soft glass does?

What is the coe?  Take it you can't mix them with soft glass?

I gather that you can garage them whilst making soft glass beads and then anneal them later.  Is this okay?

Yes it does, pretty much. It's got a lot of heavy metal in it (there, you should throw one at your neighbours) so it does behave a little like Double Helix. It's a bit of a black art in getting some of the colours to come out though - and some of them strike in the kiln.

COE is approx 33. So it is LOW. You won't be able to mix it with your soft glass (COE = 104) - it's like oil and water.  Because the COE is very low this means the glass doesn't expand and contract much compared to soft (soda) glass. This means that it is STIFFFFFFF - so you may struggle with only one oxycon - you really have to throw the heat at it. BUT, because it is so stiff it is thermally very stable - so you don't have to worry about it cracking quite as quickly as soft glass does. In fact - many boro sculptures are not annealed at all. But a bead is pretty much a solid lump of glass so it will have to be annealed at some stage. I found that the boro stuff I've ever made has annealed fine on a 520C soft glass anneal. Not quite sure why as I gather you need to go up in temp for boro. You can check it with polarisers to see if it's stressy. There's probably a boro annealing schedule if you search the boro section though.

[awrylemming]

I've done a couple of things in boro on my Mega Minor in the last week or so, and can only say that getting the lovely misty colours that boro can give has so far eluded me, and it's like winding hard caramel onto a mandrel.  I completely gave up on making a nice round bead.  But it's brilliant for sculptural stuff - it stays where you put it, no oozing around and marvering, great fun 

[Chameleon]

I used to do boro bead sets on my minor with one oxy without any great problems, its slow but then so am I.

I actually got better "wispy" results then than i do now with 2 oxy's on using the minor part of my midrange+

If i do boro i do it into my normal kiln schedule and anneal after. As for striking / reducing, it depends on the colour. some do one or the other or both and there are some wysiwyg colours.

[Hamilton Taylor]

Borosilicate anneals at 565C.
There's a thread on annealing here.

[Billie]

OMG!!    You aren't going to start a boro stash as well are you Rachel 

[garishglobes]

If she is, I'm first to raid it! 

[awrylemming]

Fight you for first dibs 

[Steampunkglass]

There are lots of strange effects with boro, it will also depend a lot on the individual colour and brand. Most purples need to be struck to really get the colours out of them after a vigourous initial heat. Most makers (expect momka    I can't seem to find the same depth of information on their website ) produce really good data sheets on the colours which give lots of very helpful advice and tips to get te best out of the rods. I used to put the oxy up to about 4.5 on the minor and it was ok, but sometimes some colours when overheated reduced a bit too much. Putting clear over the top will help stop that happening so much.

[awrylemming]

I may have to ask you for some help Glenn ... 

[Steampunkglass]

I may have to ask you for some help Glenn ... 

Not a problem, but I warn you I am beyond help