Quick Annealing Question

[richsantaclaus]

Is setting my kiln for BORO to ramp up to 1050 degrees, allowing 2 hours working time then letting the Boro glass soak for 1 hour before ramping down slowly until it hits 400 degrees the correct annealing program?

Please let me know as I usually only work for 2 hours or less when I torch.

Thanks for your help.

Rich

[Mr. Whale dick]

the soak depends on thickness, but a hour should be good (maybe excessive) for most things

i ramp down to 700

800-850 is the strain point i believe...

[Kool]

Hey Rich,
Like he said, it dpends on what you are making. I seem to recall you posting photos of marbles, so I'm guessing maybe you are making marbles out of boro, too? If so, an hour may not be long enough, depending on the thickness. There are a wide range of charts, etc., but according to the one I follow, the hour soak would be good for boro about 3/4" thick.
Other than that, sounds good. Cool slowly until you get to 900 or less (you want to get past 950--strain point), then it can go a bit faster. Of course, slow is subjective.

[richsantaclaus]

Thanks - I just made my 1st Boro marble - it was 1/2 great - clear and beautiful BUT the other 1/2, cracked and chipped. It went in the kiln round and smooth with nothing wrong but when it cooled, several places were totally cracked in spots with a big 1/4" chunck missing - still haven't found the glass in the kiln - very strange. this marble was about 1 1/4" in diameter.

Rich

[langglass]

bummer....between 1050 and 910 is very critical you have to cool it down real slow....slower than you think...i usually soak it at 1240 if i am using certain colors...then i take it down to around 1100 and then soak for around an hour and finish up any small things i want to add then i ramp down from there real slow...oh did i mention real slow...like 1 degree every 5 to 10 mins...i know there is a formula that you can use but just remember you can't over anneal...but some colors you can so just pay attention to the manufacturer when it comes to that

[Kool]

Thanks - I just made my 1st Boro marble - it was 1/2 great - clear and beautiful BUT the other 1/2, cracked and chipped. It went in the kiln round and smooth with nothing wrong but when it cooled, several places were totally cracked in spots with a big 1/4" chunck missing - still haven't found the glass in the kiln - very strange. this marble was about 1 1/4" in diameter.

Rich

That sucks. Worst part is if you're not 100% sure what caused it and have to figure it out...which means it could happen again.

If you're going to do stuff that thick, I would extend the soak to 2 hours. That way, you'll be good for pieces up to and a bit over 1 1/2 inches.

If you do that, my opinion would be that you would want to go no faster than about 30 minutes to get to 925 (from 1050). Then no faster than 40 more minutes to get you down to your 400. But like Lang said, you can surely go slower, and except in certain specific cases, it won't hurt. I just wouldn't cool any faster than that and would extend the soak if making pieces of that thickness.

I recently posted my schedule in another thread - it's good for pieces up 2 1/2", if you are interested.

Damn kiln varmints, always making off with the evidence.

[richsantaclaus]

I am interested - where is the thread?

Another thought, is it possible to save this marble - after all, it IS my 1st...lol Boro marble that is.

Rich

[steven p selchow]

A lot of this depends on color used and how its applied. I can put a piece in at 1050, leave it for an hour or for 10..shut off my kiln and cool to room temp, and never have a cracking problem...provided any glass added to the original piece is fused properly in the first place.

[Swampy]

There has to be a scientific method of calculating the rate of cooling from the annealing point to the strain point. If anyone can figure out the charts on the Northstar site, then you are bloody good.

I know with soft glass, if the temperature differential between the skin of the glass and the core varies by more than three degrees centigrade, then there is a good chance that thermal shock will occur. So I always calculated firing schedules using that value, when firing soft glass (Bullseye).

So applying that methodoligy to boro will give a very conservative schedule.

Just need to know the rate of thermal conductivity for boro to create the formula...

.

[richsantaclaus]

I have used soft glass for ALL my other marbles, several of which I have saved after a lack-luster performance in the kiln. I ramp them up SLOWLY to 970 degrees and punty them again back into the flame with NO problems.

Do you guys think it is possible to do that with my Boro marble but go back to 1050 degrees and re-punty and rework my marble OR am I asking for a BIG MESS of thermal shocked glass?????

Here are pictures of the marble for your consideration on what path I should go down, just forget the repair and make it an aquarium marble or really try to fix it. I think the only reason I am spending SO much effort on this marble is that it IS my first one and I really wanted it to turn out - I do like the 1st picture - the Boro is SO clear when compared to the soft glass I usually work with.

Rich

[steven p selchow]

several cracks are unfortunatly not able to be removed, its a waste of time trying. Another could be made with that time spent on trying to repair it.

[Kool]

I am interested - where is the thread?
Rich


Here you go:

http://www.thegldg.com/forum/showpost.php?p=76254&postcount=7

I have my kiln at about 1000 all day, and just start the program when I'm done working. The post in the link above should give you the rest of the info.

Almost forgot. Swampy, what you are looking for is in Contemporary Lampworking. I figure my scehdules based on what he printed in the original version.

[richsantaclaus]

Thank you for the link - I'll make this marble an aquarium ornament I guess and try again.

Rich

[Skye Perry]

I think its funny that i always read this glass has been properly annealed for strength and duranbility .This is a myth anneal does not make the glass stronger instead it relieves unwanted stress not all the stress but enough to not break or crack .You want 25% or less stress .It is impossible to remove all the stress .Your first program should be set at between 950 and 975 this is the strain point of boro depending on the brand I am at 975 because i use kimax and its strain point is 960 to 970 this also will not strike or overkiln colors that do not like to be overstuck or over kilned .Ramp 2 is for anneling and striking after i am done for the day the proper annealing temp is 1075 this will also strtike most colors some may need to strike at 1125 so i anneal 1075 for 1 hour to relieve unwanted stress and strike most colors .If you strike at 1125 for one hour ramp backto 1075 for 1 hour . Ramp 3 Know you glass is annealed and you want cto bring the kiln down slowly 1 degree per minute back to the strain point 950 from 950 drop 4 degrees per minute to 300 then just let it cool ambient . If your kiln does'nt cool to fast you can let it cool ambient after dropeng to 950 that is what i do with no problems .

[Satori]

I think its funny that i always read this glass has been properly annealed for strength and duranbility .This is a myth anneal does not make the glass stronger instead it relieves unwanted stress not all the stress but enough to not break or crack .
It's all how you look at it. Glass that is stressed is more likely to break...correct? And glass that is properly annealed is less likely to break...correct? So glass that isn't properly annealed is weaker...and glass that is properly annealed is stronger, respectively.

Though annealing itself is not what GIVES the glass it's strength and durability, it does prevent the weakness associated with stress and therefore allows the glass to be naturally strong and durable compared to unannealed glass.

So the statement "this glass has been properly annealed for strength and durability" is not false because annealed glass IS stronger than unannealed glass due to the lack of stress. There is no "myth" to that statement.

[David]

It's all how you look at it. Glass that is stressed is more likely to break...correct? And glass that is properly annealed is less likely to break...correct? So glass that isn't properly annealed is weaker...and glass that is properly annealed is stronger, respectively.

Though annealing itself is not what GIVES the glass it's strength and durability, it does prevent the weakness associated with stress and therefore allows the glass to be naturally strong and durable compared to unannealed glass.

So the statement "this glass has been properly annealed for strength and durability" is not false because annealed glass IS stronger than unannealed glass due to the lack of stress. There is no "myth" to that statement.

What Skye is really saying is " You can`t anneal out bad glass blowing" and that`s really what Rich`s problem is. He has no idea what he`s doing and he needs to learn to make the piece and not try to save it with some sort ot of kiln majic. I think Steve is saying the same thing. Which is basically "try it again until you get it right"

David

[richsantaclaus]

David - I plan on putting it in my aquarium and making another one. It's just that it was my first - old sentimental me...lol

Rich

[David]

Rich,

I understand. I still have a few first "whatever the hell these are" displayed in a shadow box.lol And not for sale!

David

[hookedonsilicate]

Hey Rich check this out. Its got alot of good info. Also bundhu's contempary
lampworking has got some real good info and ramp tables

http://www.glassalchemyarts.com/support/articles/frame.html

[steven p selchow]

Skye is somewhat correct on cycles. For striking, a cycle is necessary, to acheive a certian look..crystal growth is one instance.

I have pieces that I made 19 years ago, crack free, no ramp or cycle used, the only thing wrong with them is their dusty.

To each is own, my end objective is that the piece lasts forever, crack free, and if these old pieces I speak of, have no cracks or checks in them after this long..I doubt they ever will.

My first pieces were sentimental as most, but you'll learn from that.

[richsantaclaus]

I love the site - thanks - it is FULL of great info for a learner like me. I wish I had someone near me to actually show me the ropes. I don't think I am that bad at soft glass, done alot in 8 months I think - developed a "bubble and copper" style that few have tried before.

One of the main reasons that i wanted to try Boro is that it seems to make marbles that are prettier than soft glass, by that I mean, the clear is very easy to work with with little or no having to pick out the imperfections before you make the marble. I "peel" soft glass by the tons!!!!! Didn't have to do that with Boro - nice stuff!!!!

Rich

[Jamn!]

K Maybe its the Margaritas but I think he's not helping very FM..... ( ShT)
What's UP??? Santa is asking fora little help.