Rollup Techniques

[Will McGowan]

I've been a creeper on this forum for awhile but have never gotten the nerve to actually post. There are people here who know a hundred times more than I do so please forgive me if I am asking an obvious and stupid question.
Eventually, I would like to attempt rollups when I have the necessary equipment so I have been looking at a few examples and techniques. My question is, why would you want to do a rollup with just the collar and not a bubble to support the rollup underneath? It seems to be unecessarily difficult and not very beneficial. I realize that you would not have to run a furnace for the collar technique but besides that, is there any great advantage?
I know that it all depends on the look that you are wanting and could also affect things like sandblasting, reducing, thickness and size but I just wanted to hear what everyone here thought about the pro's and con's. I am absolutely not knocking anyone's technique but just wanted more input before I pursue further on my own.

[Jeff Hoover]

I'm not qualified to answer, but you got me curious so I did some searching. While these pages:

http://www.amsmith.com/rollupsclass/rollupsclass2004.html

http://www.glassblower.info/Cutting-Edge/Jeff-Lindsay-Reticello.html

don't address the *why* of collar instead of gather, they are great photo spreads showing the steps of the collar method.

[Rick Sherbert]

If you are rolling up something with a texture or an uneven surface, such as a big sheet of murinni, you don't want to use a bubble for risk of trapping air between it and the roll-up. I'm sure there are other reasons, but that's the excuse I use....

[Wes Hunting]

using the roll up greatly mantains the integrity of the decoration when blowing thin work.

[Brian Mazrim]

Its also a little easier to adjust the rollup on a collar thats alittle too big or too small than on a bubble thats too big or small.

[Pete VanderLaan]

Originally posted by Wes Hunting
using the roll up greatly mantains the integrity of the decoration when blowing thin work.
*******************
Bingo.

It's just the same as not getting a first gather and then rolling cane into it and expecting a tight pattern. There will be space between the canes and it doesn't look good.

[Marty Kremer]

There's also the compatibility issue- if you use a collar, you can cut it off after transfer to a punty.
And you can cast the collar of the same glass as the rollup if you don't have a furnace.

[Greg Frankhouser]

Is there a problem with gathering over a collar rollup?

Do MOST gather OVER a rollup?

Greg

PS
I seem to remember some of Wes' early rollups/ murhini robots. I'd listen to him on the bubble thing.

[Rick Sherbert]

Originally posted by Wes Hunting
using the roll up greatly mantains the integrity of the decoration when blowing thin work.

So are you saying do it on a collar or a bubble?

[Wes Hunting]

collar

[David Patchen]

Ahh, this is a great question with no really straightforward answer as it depends on what kind of glass you're working with and what you're trying to do with it.

The word "rollup" is vague as some people use it strictly to refer to bullseye or other sheet glass that's pre-fused in a kiln, then later warmed back up and rolled-up on a collar. This is the strict definition IMHO. Other people use 'rollup' to refer to picking up cane and/or murrine. If you're 'rolling up' bullseye, you can't gather over it or pick it up on a bubble because furnace glass isn't compatible. So you're limited in a large degree on what you can make out of it, but really massive rollups can make reasonably large stuff.

Picking up cane and murrine where the furnace glass is compatible with the pattern gives you much more flexibility but it's tricky to do perfectly. I pick up cane on a bubble when the pattern is too thin to pick up on a collar. It also helps speed up making a larger piece as you're starting with more glass and more heat. The pickup has to be really uniform in the size of the cane and the shape, size and heat of your bubble has to be exact or you're going to have trouble. Your pickup also has to be perfectly tack fused and the right heat. Coordination is key b/w you and your assistant and you really have to nail it to make it work nicely. You have to close it correctly and marver it correctly or you'll trap bubbles. I actually have a series of photos of making a piece picking up cane and murrine on a bubble on my website. Check it out under 'in the studio' if you're curious.

I pick up cane and murrine on a collar when the pattern has texture that would catch bubbles if you slapped a blowpipe with a bubble on it. It's also ideal for making really large work while preserving the details. It's a much more forgiving technique so even if you are working just in cane and starting out trying to 'rollup', I'd use this technique. Still has its own inherent trickiness, but much easier to fix mistakes in collar size or with the pickup behaving badly on you. Dante has a great series of photos of him making a large Gambo using murrine picked up on a collar on his website. I do it the same way for my murrine pieces.

You can pick up unfused murrine or circular murrine on a bubble without trapping bubbles (usually). Trial and error, analysis of problems, more trial, etc. are the path to enlightenment. I think Ed Schmid's Advanced book has some info on pickups.

[Will McGowan]

The collar option makes a lot more sense after ya'll pointed out the sizing, detail, and bubble issues. I started out fusing system 96 because I figured it was the best option to combine the cullet and fused glass. Is that the standard when it comes to mixing the furnace and sheet glass or is there other, better options? Also, are there any problems with using a pickup kiln instead of the pastorelli and glory hole? Just seems easier to have it sitting and ready instead of timing everything perfect.

I was hoping David would chime in because I have looked at your step by step and Marioni's series. I really do appreciate you guys that share your knowledge so freely. Everyone in this forum has so much information and are eager to help. Just great people.

One last question. I had read on the Johnathon Schmuck's page that you bevel the ends that will meet. Does everyone do this, and is there a standard angle or some way to figure it? Just checking if this was standard practice because that page was the only place I had seen mention of it.

[Garner Britt]

Will,

Here is a decent write up on the process

http://www.bullseyeglass.com/education/#tipsheets

download tip sheet 6

-The roll up on a collar is the only way I currently work. Contrary to some, my process is this...

-fused panels 1/2" thick (all s96, some sp and color, cane etc)
-coldworked, beveled to about 60 degrees (this depends on the size of the panel)
-bring the panels and a soup bowl of cullet up to 1350 in the kiln.
-Transfer soup bowl to recently lit glory hole.
-Make collar from really seedy cullet
-Roll up panels directly out of the kiln (many use the pastorelli, I work solo and just find the kiln is much more accurate and controllable)
-close up seem, I work from the moile out and sometimes can get it together perfectly with heat and gravity
-jack down bottom, cut of frigger

-proceed as normal

The only drawback I find with the collar method is the inability to maintain a nice thick bottom. Starting with a 1/2" panel and blowing it out obviously puts a limit on the thickness one can retain.

This is not a cheap way to blow glass. I haven't done the full evaluation (energy, etc) but I do know a small piece maybe 6"dia x 1' tall has about $15 worth of glass in it, sucks when that hits the floor...

Start out with scrap glass or just clear to get the process worked out. Those early experiments may very well be your cullet latter.

[Paul Bernstein]

Thanks all for a great question, and lots of helpful links and information. I have been learning to do collar rollups from Leana Quade at Pratt. She teaches fusing a strip of clear pieces to the edge you want to roll up on the moile..that way you can roll up the clear, and not impact the color/design part of your rollup..and then neck off at the clear line when puntying off. Also, sometimes, after our cylinder is formed, we drop a cookie of clear, or even frit colored, compatible with the piece, and pick that up...after, you can then marver it in, and then jack and cut off most of the patty, or make that the bottom of the piece..either way, that adds some thickness to the bottom. (ps, this is my first post on CraftWEB..woo hoo)..

[David Patchen]

You should be able to get decently thick bottoms. What if before you closed your rollup, you paper it in, heat, paper it in, heat, then either pick/neck/snip or drop the cookie and neck. All the heating and papering in should thicken the glass at the end of the cylindar.

BTW, I wish losing a piece cost me $15! I wish it only cost me $50!!

[Garner Britt]

Originally posted by David Patchen


BTW, I wish losing a piece cost me $15! I wish it only cost me $50!!

losing a piece always sucks. My point is that rolling up fused sheet glass is expensive in terms of material. I've figured it's about $10 per pound, alot more in material than furnace glass with an overlay or some frit....

On the other hand, I don't have a furnace running 24/7, no assistant(s) to pay (although maybe that would have saved some of those suicidal pieces...) and I own my shop. I'm not really experiencing the true costs.

garner