Melting large gathers?

[jeepinwelch]

When I make murrini the final blob of glass ends up being more than my torch can handle. I usually spend at least an hour gettin it hot enough to pull. I have a piranha with 2 5lpm oxycons. I also have a bobcat sitting in the drawer that I haven't gotten around to selling. What I am wondering is if both torches hooked to 1 concentrator each would be hotter than the 1 torch hooked to 2 concentrators? Any one have any experience with something like this?

[Lisi]

I don't know about that, but may I make a suggestion to you??

If you are going to be making a lot of murrini in the future, you should invest in a Mini CC. That torch would be sweet with 2 concentrators! The flame is bushier and lots of radiant heat to keep a large gather of glass evenly hot for a good pull.

When I pulled long canes of 4 swirled colors, I pulled a gather that was almost walnut size using my Mini CC before that jerk friend of mine broke it. I could never handle them that large using the Bobcat. Flame is too sharp and focused.

How large a gather are we talking here?

[lunamoonshadow]

Where's JoJo? :lol: That girl had a HUGE batch of boro heated up at the glass jam!! Ed--got a photo for us??

[jeepinwelch]

How large a gather are we talking here?
It's about the size of a lemon when I'm done. I can get a fairly bushy flame on the piranha but it doesn't get quite hot enough. That is why I was thinking that the additional torch aimed at it might help. I just don't wan't loose more heat than I am gaining by splitting the oxygen.

[Lisi]

It's about the size of a lemon when I'm done. I can get a fairly bushy flame on the pirahna but it doesn't get quite hot enough. That is why I was thinking that the additional torch aimed at it might help. I just don't wan't loose more heat than I am gaining by splitting the oxygen.

OH chit!! :shock: A lemon!! I think you need to step up to a hotter torch, I don't know...... Hopefully you will get some better answers soon!

[ArtcoInc]

Assuming a neutral flame, and complete combustion, the amount of oxygen you have available (2x 5 lpm) will be the limiting factor in how much heat you can get. Mark Wilson (aka Laserglass) posted a thread in here discussing this very thing:

http://www.lampworketc.com/forums/showthread.php?t=49835

So, you can either have all of the heat coming out of one torch, or half of the heat coming out of two torches. The total BTUs will be the same.

Now, will it be more effective to have two smaller heat sources vs one large heat source? I suspect not.

Malcolm

[Cosmo]

I would unhook that Piranha and hook up that Bobcat. That will make things a lot quicker.

Also, a slightly reducing flame will penetrate glass quicker than a neutral flame.

[jeepinwelch]

Thanks for the info Malcolm. That is what I suspected but it wasn't the answer I was hoping for. I really don't have room for a 3rd concentrator but I may be able to borrow one from a friend to hook up to the bobcat to get the additional heat. It could be interesting! I'll have 2 inches to move.
Someday, in my next house, I will have room for a big girl torch and oxygen tanks! My husband's requirements for our next house is more garage so I'm going to hold out for a bigger workshop.

[jeepinwelch]

I would unhook that Piranha and hook up that Bobcat. That will make things a lot quicker.

Really? It seems to me the piranha put out more heat. I can melt faster with it than I can with the bobcat. Does the bobcat have more penetrating heat for something larger?

[Lisi]

It's a hot torch, and I run my Bobcat with an Airsep that puts out 15lpm at 18psi.... I have trouble with something as large as a walnut. It's hard to keep it evenly hot for a smooth pull.

Hey, you guys.....I really don't think she can get something as big as a lemon fully hot with such a a sharp focused flame, unless she spins it quite rapidy??

Or could I be wrong?

[Cosmo]

Really? It seems to me the piranha put out more heat. I can melt faster with it than I can with the bobcat. Does the bobcat have more penetrating heat for something larger?

The Bobcat is a much hotter torch. At least, that has been my experience.

[jeepinwelch]

It's a hot torch, and I run my Bobcat with an Airsep that puts out 15lpm at 18psi.... I have trouble with something as large as a walnut. It's hard to keep it evenly hot for a smooth pull.

Hey, you guys.....I really don't think she can get something as big as a lemon fully hot with such a a sharp focused flame, unless she spins it quite rapidy??

Or could I be wrong?

I really couldn't work quite as large on the bobcat. There didn't seem to be enough radiant heat.

[Lisi]

I really couldn't work quite as large on the bobcat. There didn't seem to be enough radiant heat.

I'm sending in my Mini CC for repair very soon, so when it comes back, I'll mail it to you to try out for a while. I owe you one, and don't say no. ;) :D

[Lea Zinke]

JMTC, but Stump's class taught me to heat your gather rather slowly moving from left to right and back, horizontally, while rotating slowly to allow the heat to penetrate evenly thoughout the entire mass. Meanwhile as the ends begin to glow, you can start pulling ever slowly to get them to thin out slightly to avoid losing alot of your pull at each end. But slow and steady she goes...it works for me. Here's a new murrini from this week. Also did a 12-flower cane bundled "bouquet" -- haven't used it yet!
191247

PM me if you need more info, HTH!

[monarae]

In my masters of glass book the guy who makes the blown birds uses a circle of torches. When I saw it I wondered why and decided that it was increasing the radiant heat.

[jeepinwelch]

I'm sending in my Mini CC for repair very soon, so when it comes back, I'll mail it to you to try out for a while. I owe you one, and don't say no. ;) :D
Thanks for the offer but I really don't know if I need to try it. I love my Piranha and it is rare that I need more heat. It's just every now and then I get the bright idea to torture myself with butterfly murrini then I'm over it for another 6 months. If I can add the fire power of the Bobcat I think I'm set.

JMTC, but Stump's class taught me to heat your gather rather slowly moving from left to right and back, horizontally, while rotating slowly to allow the heat to penetrate evenly thoughout the entire mass. Meanwhile as the ends begin to glow, you can start pulling ever slowly to get them to thin out slightly to avoid losing alot of your pull at each end. But slow and steady she goes...it works for me. Here's a new murrini from this week. Also did a 12-flower cane bundled "bouquet" -- haven't used it yet!
Your swans are gorgeous! I've never thought about thinning out the ends but I can see how that would help. I've always been afraid to get distortion so I've kept it in a huge glob. Awesome tip! Thank you! I do use the slow side to side heating method and it still takes me forever!
In my masters of glass book the guy who makes the blown birds uses a circle of torches. When I saw it I wondered why and decided that it was increasing the radiant heat.
I talked to my friend and she will be out of town for a few weeks and said I am welcome to borrow her concentrator. Hopefully I can get the same results as the guy blowing the birds! It will be interesting.

[kbinkster]

If you find the Bobcat flame to be too focused or without enough radiant heat, turn down your oxygen (or turn up your fuel) a tad.

The Bobcat flame is about an inch or so in width at the shoulder of the flame when run on 10 LPM. The Piranha flame is narrower - its width can appear different depending on what angle you look at it, too, since the flame is not a round flame, but more of an oval.


But, back to your original question about using one 5 LPM machine to power the Piranha and the other to power the Bobcat and using the two together: why not try it and see what happens? You won't be getting more heat, but you will be getting more coverage if you line them up so that they are not hitting the same spot on the glass. I have not tried this, but I don't see how it would hurt anything. Maybe you can practice on making a big gather out of some scraps that you can then pull down into stringers or something.

I think that if it doesn't work and you are finding yourself in this kind of pinch more and more often, you ought to look into getting a larger torch and more oxygen.

[theglasszone]

Jeepie...first off, I LOVE the murrini you've been making! Just received my blue tang and they are lovely and wonderfully detailed.

Now I gotta wonder what I'm doing differently than you? As you know, I'm on a Hot Head, and I have made some pretty large gathers, am also working in 104, and as long as I have gas to burn (use 2 tanks and usually switch from one to the other about 3/4 the way thru creating the gather) I can get the glass hot enough for a good, smooth pull.

I'm wondering if some of the differences may be:

- Hot Head has a bushy flame and lots of "radiant" heat. Because the flame is so "wide", maybe your Piranha's flame is a bit too narrow and concentrated. Any way to adjust that (making it more of a redux flame)? Maybe that will help.

- Once I have my gather created, encased and puntied up, I center it in the flame, and turn it very slowly. Fast turning makes it take forever to heat! Also, I make sure (since I'm using Noodlesaurus' wonderful steel punties: http://www.noodlesaurus.com/catalog.php?item=189&catid=17&ret=catalog.php%3Fcategory%3D17) that I keep the punties pretty hot so they don't "rob" all the heat from the gather.

- I also do the gentle pull once the gather starts really heating up; this allows the gather to thin down a bit, making it easier to heat the entire (smaller) glob faster.

- Here's another trick! I heat the gather for about 5 minutes straight - direct flame heat and slow turning. I then very gently start to push the gather together, sort of like smooshing a marshmallow, and just slightly and carefully. I SWEAR this helps to drive the heat into the center of the gather! I then slowly pull the gather gently apart, which starts the gather "thinning". I do this a couple times during the super heating process.

- It seems that you can eventually "feel" when the gather is really starting to heat properly through and through. Gentle, very slight bending and pushing together and pulling apart seems to help get it to just the "right" heat stage. Do you know what I mean when I say, when it's "ready", it feels like a soft marshmallow when you gently bend/pull apart/push together the gather? I've learned no matter what, to be patient and WAIT until the gather is to this marshmallow-hot stage before pulling.

Here's an example of how big I get my gathers - definitely bigger than a walnut!

http://i185.photobucket.com/albums/x280/theglasszone/Bead%20Photos/Rubber%20Duckie%20Murrini/DuckGather5.jpg

Here's a pretty good representation of how "bushy" the flame is that I'm working with:

http://i185.photobucket.com/albums/x280/theglasszone/Bead%20Photos/Rubber%20Duckie%20Murrini/DuckGather7.jpg

The steal punties definitely make the job WAY easier!

http://i185.photobucket.com/albums/x280/theglasszone/Bead%20Photos/Rubber%20Duckie%20Murrini/DuckGather9.jpg

Remember that end-capping the gather will help it stick to the punties. I use my plain old Moretti stringer to make my end caps. I think this actually HELPS the rod thin out during the pull (I think this clear melts/pulls faster than the opaques used in the gather itself) so that even if the gather is larger than the punties, if it's hot enough and heated evenly enough, it thins and pulls nicely at the final stage:

http://i185.photobucket.com/albums/x280/theglasszone/Bead%20Photos/Rubber%20Duckie%20Murrini/DuckGather10.jpg

Hope some of this helps; keep up the wonderful work and I SO wish I had the means to make those darling butterflies like you do! They are fantastic! :)

De

[jeepinwelch]

Hi Kimberlie. I have a loaner concentrator so I can try 2 on the Piranha an 1 on the Bobcat. I think the trick it going to be getting the torches positioned right. For some reason it seems like the Bobcat had a narrower flame but I have never run them side by side before and it has been a few years since I fired the Bobcat. I have dreams of a bigger torch and more oxygen but I will have to make due with what I have for a while longer.

Thanks for the tips De! The flame on your hothead does appear to be bushier than mine. I hope by adding the second torch I will get more radiant heat. Looking at your gather I would estimate mine is about 3 times that size so that could be one of our main differences. I've tried but I can't go any smaller and keep the level of detail. If I center it in the flame the sides never heat up so I have to move it slowly side to side as I rotate it. I guess size really does matter! (Just don't tell the guys.) I have been looking at those punties but I'm just not sure if they are something I would use. One of these days when I have a few extra dollars I might have to break down and buy some.

[Lea Zinke]

Jeep: Hey again, great, glad info was helpful -- yeah, the real secret is just the "slow & easy does it..." . We all at this point of the process are getting a little unnerved, lots of glass/work/sweat invested, and we're anxious to get it done and in the kiln, but patience really really pays off at this point. And all of De's info is spot-on and I took her advice about the punties. For years, I've been building up the cone and using huge diameter clear as my punties, these make it eversomuch easier! Thanks, Noodle!

De: As always, great information & photos!!!! Awesome job!!!

[jeepinwelch]

Hey Lea, after using the slow & easy technique for so long I'm hoping to find a way to speed it up. It wears me out to sit for over an hour getting a gather hot enough to pull. Cross your fingers for me that my experiment works!

[Frit Diva]

Anybdoy know who sells those big steel punties like De is using in the photos? Thanks!


Jo

[Lea Zinke]

Yes, De has the site for them in her post -- click on it, take you right there! They're wonderful.

[KayG7]

She cited the source in her description:

"- Once I have my gather created, encased and puntied up, I center it in the flame, and turn it very slowly. Fast turning makes it take forever to heat! Also, I make sure (since I'm using Noodlesaurus' wonderful steel punties: http://www.noodlesaurus.com/catalog....Fcategory%3D17) that I keep the punties pretty hot so they don't "rob" all the heat from the gather."



Anybdoy know who sells those big steel punties like De is using in the photos? Thanks!


Jo

[pam]

Try aiming the torches at each other (each one angled slightly up so that their flames cross in the center). Looks sort of like this - /\ This will be similar to a crossfire and will probably give you more heat. You work in the center.

[FourTailsLampwork]

A LEMON! Wow.

I gave up a Bobcat for the Piranha, and I have to say that I am with you in *lurving* my Piranha. However, most of the time my beloved sits on the shelf in favor of my Cricket, which generates a lovely flame AND a lot of heat.

OTOH, I like the idea of hooking up two torches to one oxycon each, and setting them up as Pam describes. That might work for boro. After all, hooking up 2 oxycons to one torch means you really only get 7-8 cfm out of them, whereas with two you could conceivably go to five.

If you get a Cricket, though, do not give up that Piranha. It does better on a Regalia or a Hurricane, or a tank. Until she went to a Cheetah, my sister found that the Piranha really rocked when she hooked it up to her Hurricane (I am *so* jealous!), and was phenomenal on tanked oxy as well.