Goblet Forming

Cornbread · #1 2012-05-23, 11:02am

What's up folks? JB here.

So I'm trying to broaden my skill set when it comes to glass. I want to make goblets. I keep having failure after failure trying to figure out how to work hollow form. It's my first time to really play with tubing outside of tube implosions. I've read and watched youtube trying to figure out the tricks. I've noticed most goblet makers use jacks. Is this something that makes it easier or is it a standard practice or what do you think I should do to get that "making the bulb" go off in my head. I know part of it is because the glass I'm using is too small. Im using med wall 28mm (because that's all I have). I plan on ordering some heavywall so I can use some of the more commonly used sizes.

But the main question is about jacks. yes or no? and what size(s) should i get? any recommendations for goblet videos (paid or free)?

thanks,
Cornbread

wickedglass · #2 2012-05-23, 5:32pm

jacks can help ... although I use them sometimes, there is really no need for them. Boro has a relatively short work span, so you're better off using a graphite rod, if anything. Jacks chill the glass really quickly and if you're not careful, can leave scratches as well, which graphite won't.
Sorry about the freaky perspective on the photo, my camera seems to pull the image at the edges on zoom and it makes the feet look weird ... they're not. These are all goblets for my mum's collection, she requested a bunch of different goblets for celebrations. The only tooling i used on these is the paddle on the foot to make sure it's straight and a marver for a couple of the stems (and of course grabbers to hold all the bits

). The sandblasted one is about 15 years old.
You have to remember that using tools leaves tool marks ... it's a personal preference, but I don't like tool marks on my goblet cups and feet.
The trick is to set up the shape first, blow the top really thin, remove the point to a reasonably small hole and open it in the flame by turning carefully. It pays to know your flame and the heat in your glass really well.
But yeh, a long graphite rod, preferably set into a handle, will do the trick just as well as a pair of jacks and not suck the heat out of the glass at a fast rate of knots. If you want to get really fancy, you could make yourself a pair of graphite bladed pachioffis, those are basically jacks with round dowel shaped blades, usually cherry wood soaked in water, but for lampworking graphite is more practicable. They're also cheaper than jacks.
I'm lucky I did some years at the furnace, so I have all these things to play with, although I generally opt to work without them. Part of my glass working philosophy is to use as few tools as possible in my work, if any at all.

patienthand · #3 2012-05-23, 6:25pm

I use graphite mostly, and I use standard wall tubing, I like thin delicate goblets and I find I get more on center bubbles with standard wall, buts its also how I learned and what I know best. My trick for goblet top openings is to try not to use tools at all, and leave no tool marks. I flame cut the tops and then open it up by heating the thin flim of glass left after the flame cut and pulling the glass out and it will pop itself open. I use a rod of cold boro to grab that film in the center and pull it away. I cut exactly where I want the lip to be. the trick is to use a very fine hot flame and heat where you want the lip to be and then pull to make it thin there, keep heating and pull it off,,, never ever stop rotating the glass.

its hard to explain without visuals.... if you ever see it and have someone talk you through it, its not that hard, just takes practice practice practice

wickedglass · #4 2012-05-23, 6:28pm

^ that explains opening the top a lot better .... although that poodle disturbs the hell out of me

Baywinger · #5 2012-05-24, 12:41am

I added a pair of jacks to my bench last christmas I found they have helped my hollow work.

Cornbread · #6 2012-05-24, 10:35am

Thank yall. This helps a lot. I may get a pair for kicks if I can find an affordable pair, but like you Wicked, I enjoy using as few tools as possible. Something about the feeling of using only glass to create glass art is satisfying.

Patient, I will keep at it with the tubing I have. Thanks for the tip. I can learn with what I have.

one other question though. Do you guys make your points with a handle on both sides or just a handle/blowtube on one side? The tutorials I got from The Flow all show using two handled points.

juba · #7 2012-05-24, 11:07am

You should check out the Mickelson Egg. I have never used one but they look pretty cool! http://www.mickelsenstudios.com/Egg.html check out the video at bottom of page. Good luck.

wickedglass · #8 2012-05-24, 4:31pm

I pull double sided points but then make a constriction in one side, take that side off, add colour for either an avoglio or a knop, shape it and punty, then blow the goblet or foot ... I've gotten to really like my blow hose over the years. Silicone rubber, 4mm diameter OD and no swivel. It allows the work to be made in front of the eyes.

Cosmo · #9 2012-05-25, 8:53am

Some good advice here already. I'll add this (the best piece of advice I was given for doing this kind of work) - when you open the hole that will be the top of the goblet, make the smallest hole you can. The smaller the hole, the more even it will flare out.

I used one of those eggs a while back, and it worked so well I took some sandpaper to half of my large reamer and smoothed out one side. It's one of those things you don't realize how much you need it until you use it.

menty666 · #10 2012-05-25, 7:59pm

How do you use a hose with no swivel? Just keep going back and forth instead of full rotations?

Oh, and be careful about not getting molten wax all over your bench (and glass...damn it) if you use the jacks. I'm not a huge fan of mine. I didn't realize the difference when I bought them and got flat blades instead of round ones. For lampworked goblets the round ones might have been a better choice.

Though if I had to do it again, I'd just get the graphite pachioffis.

gmarv · #11 2012-05-26, 5:43am

hey chris do you have any trouble when spinning the point without a swivel or is it loose enough that it slips around, seems like it should wad up. i would probable have the hose wrapped around my neck in a knot hang man style.

wickedglass · #12 2012-05-26, 12:27pm

The hose is silicone rubber and very flexible (it's almost not there) and because the diameter is so small, it allows for a fair few full rotations before twisting up and having to be turned the other way. I also rock (back and forth) my glass a lot. Rocking, however, takes a little practice to get the heat base even. The way I learned was to always turn the glass away from me in the European style, but why confine myself to turning the glass one way when I can turn it both ways?