View Full Version : what can I do to make melting fluorine glass safe?

Donna Milliron
01-05-2012, 04:12 PM
Happy New Year to You All!!

So, I have melted some fluorine glass in super small quanities - seriously small tests....and I have melted over and over phospate glass and although I seriously want to love the phosphate glass, it just don't compare to the fluorine glass. At all. No way.

So how can I opacify my glass without phosphate....or....what I really want to know is, how do I make it safe to melt up from batch these really beautiful fluorine glasses? What kind of ventilation equipment do I need and are there other things safety-wise I need to pay attention to?

Thanks so much for any information you can share on this!


Kenny Pieper
01-05-2012, 04:37 PM
The real thing in melting these glasses is to move the fumes away from you and out of the shop. Hopefully not into someone else s lunges!

Pete VanderLaan
01-05-2012, 06:17 PM
Kenny is right. The magic bullet is ventilation BUT you have an electric furnace if I recall and the fluorine will eat the elements alive.

Rollin Karg
01-06-2012, 04:22 AM
Real good ventilation in your shop or move your color pot outside. There are no shortcuts on this one.

Pete VanderLaan
01-06-2012, 06:27 AM
When Klaus Kugler finally got busted melting in his two car garage, what did it was an aerial photograph which showed dead trees all in a perfect cone coming out from the exhaust system and fanning out for quite some distance..

Rollin Karg
01-06-2012, 06:59 AM
I had a friend that melted some Fluorine Opal. In an effort to save two pennies he shut off his exhaust fan when he left that night. He came in the next morning and everything in his shop above about five feet was etched.

Pete VanderLaan
01-06-2012, 08:22 AM
That's the stuff. my fluorine melter in Santa Fe held 11 pots for the classes and three for rod production. The interior walls of the furnace looked like melting ice cream. That shop ventilated at 33,000 CFM by the way. Pencils left on the marver rolled towards the hood.

Donna Milliron
01-06-2012, 02:40 PM
Wow, lots to think about here. I'm melting in a 3 1/2 car garage, not a 2 car garage...but still :) And it is surrounded by trees, so that would be a dead give away, not to mention dead employees. Bummer.

So are there filters out there that you know of, assuming we can install and use an exhaust system with enough pull power to work, that would filter out the nasties instead of releasing into the airspace where my trees and bedroom windows are? I could vent it towards my pesky neighbor, but if the wind blew right it would still end up in my bedroom. The garage/hotshop is below the top floor of the house, so hot fumes are gonna meander that way as well. We have good ventilation installed now, but I can see to do this we need more or we need to move it to another location.

And yes, these are electric crucible kilns we are using. We manufacture them ourselves, so we can rebuild them whenever we need, but it still costs $$$

If these safety measures are not feasible, am I really just looking at phosphate to end up with my opaque colors?

Thanks for your advice, it is all sincerely appreciated.


Rollin Karg
01-06-2012, 03:29 PM
How big is the pot you want to use ? If it was 10 or 20 pounds and melting once twice a week I might feel pretty confident.

The second part is, how much air are you moving ? In Pete's old place, little kids would get snatched off the floor and you could find them stuck on the screen. Moving that kind of air over a small pot is not kill any trees or employees.

The last thing is it possible to shield the elements from the pot ?

Pete VanderLaan
01-06-2012, 06:32 PM
Scale is everything here. If it's small melts, you'll be fine but I recall you are selling color. In that case, involvement from your local EPA is going to be inevitable. They almost always get started from a disgruntled employee or sometimes a competitor.

Fluorine is a known carcinogen. You have to treat it with respect. Small scale, you will be OK but you may be able to consider building an electric monkeypot where the open hearth of the pot is separated from the elements by a cut piece of HD Board. That would work pretty well, but the fumes still have to go. Expect a very short pot life, don't ever let it get hotter than 2200F ever. Everything will disappear.

Virgil Jones
01-07-2012, 09:13 AM
I've noticed at a friends place when he fumes, depending on the breeze direction, the exhaust cloud travels from the backside of his studio around the side and then in the front door. He leaves the door open to get a ventilation draw with his fans. He's not been able to find a solution. He tried venting it out the back and then high up in the air, but on certain days it settles and drifts around front and back in. This might have to do with the trees and geography of his place. Something to consider.

Lawrence Ruskin
01-07-2012, 10:04 AM
Many Fluorinated and Chlorinated hydrocarbons cause cancer, mutations, birth defects, that sort of fun stuff.

I use a book called Artist Beware by Michael McCann when I am using a new product, but nowadays it's easier just to check on the internet.

I remember at Pilchuck asking about hydrofluoric acid and the reply was, go ahead and use it under supervision, but be aware there are serious health risks.

Maybe, you could find something else to be fascinated by...

Pete VanderLaan
01-07-2012, 12:03 PM
It's a lot like asking "How can I smoke tobacco safely"...

Eben Horton
01-09-2012, 08:03 PM
It's a lot like asking "How can I smoke tobacco safely"...

with a bong silly. :)

Dave Bross
01-10-2012, 05:34 AM
I'm going to come at this from another angle...


I know I have opinions on how good, or how popular things I make are going to be....and I'm wrong most of the time. This is discovered by running it past other people. A lot of other people to get a better statistical accuracy.

Have you shown phosphate colors to those who might buy the glass?

The phosphate will never do an enamel white (repeated strikes can get close) but it's been more than well recieved to my experience. Particularly the "fire" aspect where it reflects blueish and transmits reddish.

Have you tried making fairly dense colors?

Want some really good recipes for those?
Email me.

Pete VanderLaan
01-10-2012, 05:39 AM
Donna makes color for lampworkers.

Dave Bross
01-10-2012, 08:59 AM
I know.

The recipes I had in mind were from Dudley's old hand out sheet. The opaques were all phosphates so I extracted the colorant percentages and melted them in my formula and got colors that are nicely in between what's needed in density to blow out a ways, but not too much for lampworking.

It's kind of like being a teenager...the older you get the smarter your parents become.
That's how I look at what Dudley does from my perspective...with the necessary caveat that he can get away with things that no one else will.

One other thought...a lot of the old phosphate recipes had enough arsenic or antimony added to "enamel" them. Still very toxic but not so hard to contain as fluorine.

Pete VanderLaan
01-10-2012, 10:27 AM
I view arsenates with great respect and avoid them. They linger.

When you are making color commercially, if you mess with stuff on the bad boys list, Chrome, Fluorine, Cadmium, you are eventually going to be found. Usually an employee who is unhappy is the source of the complaint. Doing it in your garage can be problematic.

Pete VanderLaan
01-10-2012, 10:28 AM
I view arsenates with great respect and avoid them. They linger.

When you are making color commercially, if you mess with stuff on the bad boys list, Chrome, Fluorine, Cadmium, you are eventually going to be found. Usually an employee who is unhappy is the source of the complaint. Doing it in your garage can be problematic. I don't think I can say this more diplomatically than I am saying it.

Dave Bross
01-10-2012, 10:55 AM
Yeah, good point. Better to just plan for the (toxin free) future then try to scramble when busted.

Particularly in a commercial setting.

Pete VanderLaan
01-10-2012, 11:53 AM
Check your message box.

Donna Milliron
01-11-2012, 06:11 PM
Hi Peter,

I think I get that you are trying to tell me as diplomatically as you can that doing all of this in the garage is a bad idea. We know that, for a lot of reasons. We will eventually move this over to our warehouse but for now this is the space I have to work in. I am trying to stay away from pretty much anything that will harm the people working on this - our whole "crew" is one employee/friend, my husband and me. This is all very small scale so far as commercial glass goes but I would love for it to grow. What I am aiming for is to move into the warehouse and move Arrow Springs into a smaller space.

I use very little Potassium Bichromate, 60 grams in 15k of glass, no arsenic, no fluorine and no cadmium. My query was just because I want to make some opaque glasses and the phosphate just seems to produce dead colors instead of vibrant ones, not to mention the texture is never smooth. I did some tests with some fluorines - when I do tests they are done in another space with a very small crucible kiln kept right by a door with fans behind it blowing it all out into the wide open spaces of the 5 acres we are on - and the tests are only 300 grams each. I never said that because it must look pretty ridiculous to most of the hot glass artists here working with 400 lb. melts - me with my little 300 gram tests - but the fluorines I did were so beautiful! I just wanted to know how do the "big boys" do it - how do you or anyone else who knows melt that kind of glass and make it safe? There must be some filters - some kind of system we could build that would work. There aren't exactly references written for things like this that I can find.

We have already discussed getting the EPA in on things when we move to the warehouse and are producing more than 10 or 20 lbs of glass in a melt - we are small and we melt infrequently right now as we get started. We are already registered with them anyway for our sandblasting, so they will find out at that point. Right now though I don't think we hardly qualify as more than hobbyists.

So, there you go. That's the whole deal - I just want to make pretty colors, I just want to melt glass and make colors for the lampworkers that aren't already out there. I love doing this and so does my entire crew of 2 people, although Bret, our employee/friend might just be doing it because he found when he says he is a glassblower/hot glass maker it's a chick magnet :-)


Pete VanderLaan
01-11-2012, 07:43 PM
Chrome is also a carcinogen. It tops the list. You could google the stuff. It was publicized in the movie Erin Brokovich. I have one friend who was permanently disabled with Cadmium over thirty years ago. I know one person on this board who had lead arsenate poisoning and it may shorten his life. He's still had a good one. I have had antimony poisoning. I say all of this because in every instance it could have been prevented with good ventilation.

I applaud people making color, genuinely but you really have to do it safely. I do not honestly think that having a furnace by the door with some fans is a ventilation system. Even if you are trying to grow and move in to the big facility you still have the reality of today and you need contained ventilation. I have had my old shop vents described as weapons grade or as Rollin put it that you had to scrape people off of the air intakes and it is not that great an exaggeration. The room, 24x24 with a 16 ft ceiling changed the total air every 20 seconds. I felt comfortable standing in front of a furnace melting cadmium glasses.

Running this board is very enjoyable for me. I try to disseminate information to my very best ability. Part of doing that is throwing up red flags. At least once every six months someone comes on here asking about using hydrofluoric acid and every time they get the message from a variety of people that your first mistake is your last mistake. It does not forgive. It burrows on contact until it hits bone marrow and that you get a disease that looks just like Leukemia. It takes subcutaneous injections of calcium glutamate below the injury site to neutralize it.

When the fluorine in your glass combines with the moisture in the air which is part hydrogen, you are in effect making hot hydrofluoric acid. I would suggest that that is not adequately ventilated with fans by the door. I will not suggest that I think it's safe to do that. As Rollin said, at least put the thing outside.

To do it legally, you would need a scrubber ventilation system. The systems vary from State to State. I can't give advice about scrubbers. It's not in my area of expertise.

When I was running my color rod company and we were moving tonnage through the shop each week, I recognized that the business could actually succeed but I also knew that I would spend the rest of my life with White Chevy Malibus with government plates in my driveway just based on STEL limits alone. . I didn't want to go through that, so I stopped. Now I make small amounts of colors that the other guys just can't or won't make. Small is beautiful.

As a sidenote. 300 gram tests are too small to give reproduceable results. I consider a 7 lb test to be as small as I will work. Also, if you are getting texture in your phosphates, you aren't melting them right. They are a very hot fast melt with everything screened through tiny screens.

Donna Milliron
01-11-2012, 11:41 PM
Hi Peter,

Thanks for the info. Just to be straight, the only crucible kiln by the door with fans is the little test crucible kiln that I melt 300 grams with. The rest are in the
"garage" which has two walls of windows and no front door in addition to overhead ventilation. And of course 300 grams doesn't do anything but give me an idea of what might be nice enough to pursue. If that looks good we melt it next in a Colorado Melter that holds a little less than a kilo and if that looks good we move it up to the crucibles we buy from you.

I am just after making this safe - fun and profitable would be nice too. That's why I come here to the forum, to learn. I sincerely appreciate the information I get here. We had talked about a consultation a while back, but I don't have that kind of cash right now. I realize how valuable your time is and any help you put out there isn't never going to adequately appreciated, you have to be doing this because you really do love what you do. So, again, thanks so much for what you do here, for all I have learned from you and others here, I sincerely appreciate the help.


Pete VanderLaan
01-12-2012, 06:41 AM
I understand your position. I do consult. It's continually interesting to me to watch people fade away when they have to pay for information. Glassblowers simply don't think that intellectual property is worth anything. They think blowpipes are worth something. They think molds are worth something but they usually think that they are being overcharged. They sell their work for a lot of money in my mind.

I had a guy call me up two days ago and all his work is blowing up. It had all started to weeks earlier. I asked him what he used for a clear and he told me. I asked him how long he had been in that pallet of it and he said since August. I asked him if he was using any new color. He said yes, he had just gotten it in the last few weeks.

He insisted that the problem was the clear because the color supplier said so. I asked why he was calling me and he said that I understood this stuff. I indicated that I indeed do understand this stuff and I charge for doing Hagy seals, dilatometry, and annealing tests. I charge $400.00 per day which in my mind is pretty cheap for solving your problems. He didn't seem to think so, so he's back to having every single thing he makes break.

I know a color supplier in the boro group who is making his Hagy seals by welding them from top to bottom. That isn't how they are made and the seals are worthless. They indicate absolutely nothing. Is it my responsibility to tell someone charging $40.00 per lb how to do their job?

I'm telling you that fluorine is dangerous unless you do things right and even then its dangerous. It gasses off on the blowpipe or punty rod. It will make you feel like you have the flu. You seem to want to skirt that very basic statement and make fluorines. You don't want consultation. That's your choice. I don't have any extra time right now any ways. I'm building a moly panel for someone who hired me to do it because they didn't know how. They are paying me about $500 a day to put it together and it takes three days. I will do an excellent job. The client will have no problems. He gets his p[arts from me and I profit on the parts. They will work the first time.

I have another guy who keeps calling me and he is going to build his own moly. He is going to order the elements himself since I'm such a rip off. He tells me so. He keeps calling about design and yesterday was asking about getting elements that extend down below the pots. I said you can do it but they're impossible to ship and have survive.They are a bitch just to install. He wanted to know if he ordered special elements, would I stock replacements for it. I said "No". I then told him he would have to recalculate his secondary voltage output. He wasn't sure what I meant. He will have trouble. I am not giving out information without being compensated and at this point he is Jeff Thompson's "Red Flag". I chose to not engage.

I have another client who I consider a friend. He was eating up his elements and I suggested that he needed to remove one component of his batch and replace it with another. That will stop his problem. Since he has paid $1500 for taking my chemistry course and gets his pots from me and he gets a lot of big pots, I am quite willing to offer up advice forever. He's already acknowledged intellectual property.

I have yet another guy who has this really big contract to melt a wispy milk glass. He wants to make this opal and wants again free advice on how to make it. I have done what I'm willing to do but now he's melting Fenton cullet and it isn't dense enough for him. I suggested that Fenton didn't sell the cullet because they were in love with it. I think he is going to quit the job before he says he would pay for a glass body.

I am hoping that one can see a pattern emerging here.
Is any of this making sense? These are my normal days.

Rosanna Gusler
01-12-2012, 08:28 AM
wow! you are a lot less cranky than you claim to be. rosanna

Pete VanderLaan
01-12-2012, 09:37 AM
I'm a righty tighty kind of guy.

Tom Fuhrman
01-12-2012, 10:37 AM
Has anyone on this board ever attempted to use any of the air filtration systems produced for the welding industry for their glass exhausting. About 20 years ago, I represented a company that was building these and you could set them up near your welding operation and they would filter over 99% of any gases and particulates from the air. We sold them to several big companies that had large welding operations and they made great improvements in the air quality in their factories and also met with OSHA requirements. Some were made as portable units that could be rolled around to different work locations. They were ultra HEPA filters in them and caught particulates down to a couple millionths of an inch. One might be able to put this next to the exhaust on a furnace and improve their air quality. Just curious if anyone has tried this.

Patrick Casanova
01-12-2012, 10:38 AM

I think you are completely correct in wanting to be compensated for your time and expertise. It is valuable knowledge that it took you years to come buy and I'm sure there were numerous expenses in time and money along the way. Part of the disconnect for some not grasping that is that they come from a school background where everything is given freely, or so it seems. They forget that they paid thousands of $ in tuition to be there... so even that wasn't free.

Dave Bross
01-12-2012, 12:10 PM
My, my, but aren't we all mellowing nicely in our old age....

Those jokers Pete mentions would have been torn a nice new orifice a few years ago.

Probably = wisdom to let 'em twist in the wind anyway....fun to watch.

Kenny Pieper
01-12-2012, 03:11 PM
Penland has a color pot furnace that has both a recuperator and a HEPA filter in the exhaust. Eddy Banard / Wet Dog Glass built it. I know they have had some problems with it but its a great idea. I think much of the problem with a filter is that you have to cool the exhaust gasses enough before reaching the filter so that it dosent burn it up and still have a draw in the flue. Eddy tried to solve this with a blower forcing air in after the recuperator and before the filter that came in at a T. So this extra air from the blower created a venturi to move more air through the system and also added cool air to the mix. This blowers speed was regulated with the control system so that when the furnace was on high fire so to this blower would speed up.

Donna Milliron
01-12-2012, 07:37 PM
First let me say thanks to Tom, I will look into this idea. Bret has been researching filters and this gives me more information - thanks!

Peter - when I asked you about consulting your quote, and I quote was " I have a minimum of $500.00 for the first two hours and $100.00 per hour thereafter. VISA/MC works fine. When you pay that, I don't hold anything back. You get what I know." in your post above you were talking $400-$500 a day, for that kind of money I would have jumped at the chance to pick your brain. I knew at the price you quoted me originally even though it would be worth every penny, I just didn't have that many pennies. At $500 a day, that would be a frickin' steal! At $250 an hour + I was afraid to get started.

We are not producing enough glass - yet - to hardly cover our expenses. What it does for us at Arrow Springs is drive other sales. When I put out a new color the lampworkers jump at it because it is NEW and then they buy whatever else they need at the same time. Competition is fierce out there right now and we have 13 employees that have been with us forever -they are family - and we don't get sales here unless we have something NEW. And on top of that I get to do what I have been studying and playing at for 20 years on a small scale on a little bit larger scale. And some of the glass we have sent out there is doing some pretty nice stuff, people like it.

Peter, I have nothing but respect for your knowledge, for your incredible generosity in hosting this forum and for the help and instruction you give here for zip, zero, nada. Like I said, you seriously have to love what you are doing because you aren't getting much if anything for it. So if you can help us at $500 a day we have something to talk about.

Thanks, sincerely - thanks! Donna

Pete VanderLaan
01-13-2012, 05:33 AM
I'm getting paid $500 per day to be a factory line guy assembling an electrical panel with parts I understand and have researched to a degree. . If I'm writing formulas and testing them, it's a very different game. My friend Frank Wooley charges $1,000.00 a day. Right now you have free consultation telling you you have to ventilate your studio and it appears to me that you want to do that in a way I consider dangerous.

Fluorine from a furnace is a somewhat hydrated gas, not a particulate. I have my doubts about the things Kenny and Tom refer to, bur if it worked it would be a good thing.

Kurt Johnson
01-13-2012, 03:12 PM
Following this thread I have become curious as to the possibility of gas off when glass is overheated in the torch.
Are all those nasty elements bound up in the glass body?
Many lamp workers use way too much heat and don't have very good ventilation. We use all sorts of glass with a lot of metals in them and furnace color bar as well.

Pete VanderLaan
01-13-2012, 04:45 PM
Answer : Yes.

Fluorines gas off. Sometimes they actually smoke. If you get your nose close it will hit you like smelling salts. Some are more stable than others. The worst are the enamel whites which have a sweet smell. That smell is arsenic which will give you a reasonably blinding headache if the exposure is too great. I think lampworkers have a lower risk than offhand workers but it is still present.

This is where general studio venting is important. Air needs to really move. I rarely find a studio that I consider adequately ventilated.

Edward Skeels
01-23-2012, 01:26 PM
just an fyi.

your small test melts won't scale to a working melt. compatibility in fluorine opals depend on batch density (wet or dry, pelletized or dust charge) charge weights, bagged or shoveled, temp of charge, time between charges, time and temp of refine (minimal) and residence time in the pot before ladling out the remnants.

if your goal is to melt 40 pounds at a time, then at some point you'll have to melt 40 pounds repeatedly and check the compatibility with a repeatable test.

color density varies with degree of crystallization and so follows compatibility. more dense fluorine opal is less expansive.

you can't b.s. this process. it's an expensive education.

Pete VanderLaan
01-23-2012, 01:45 PM
ed is as usual, correct. I considered the minimum size melt I would ever do for anything to be seven lbs. Fluorine opals are like herding cats. Laminating them to clear glass bodies is not something one can generalize about.