Advice sought for making 2 1/2"ish discs with a center hole

Brandywine · #1 2009-06-22, 2:07pm

Hey gang,

I would like to make some large discs that are consistant in width and diameter at around 2 1/2" across and maybe 1/4" thick. The finished disc should have a largish (3/8") hole in the absolute center of the disc.

Mostly I work off mandrel, but would consider a large mandrel if necessary.

What would be the best method for crafting these. A press followed by drilling out the center, or 2 1/2" plate BBQ mashers with a large slot half way through the center of the paddles for the mandrel?

At this time I am working with a 10LPM Oxycon and a GTT Lynx torch.

Thanks

pjmarchwinds · #2 2009-06-22, 6:35pm

flatten the disk, then punch a hole with a tungsten rod, then heat and open with the tungsten and tweezers.

drilling would be hard and dangerous(glass dust) but would work if you had a way to wet grind them.

rg9403 · #3 2009-06-23, 12:52am

I would say make your large disc and pick away at the center until the hole opens up.

Make your disc...
punty up like this -------O
with a pin flame only heat the center and pick away amounts of glass slow until its thin and you can tear a hole with a clear rod. just be careful as to where that flame hits and be careful of radiant heat. You might have to cool it down a bunch of times in between each tear.

just an idea....

menty666 · #4 2009-06-23, 6:23am

Can you color coat a point then spin it out like you were making a rondelle for a goblet foot?

I think one of things you're going to run into is the 1/4" thick part. The disc is going to have a lot of surface area allowing it to cool (relatively) quickly, so you risk cracking if you don't keep it fairly warm.

Cosmo · #5 2009-06-23, 6:44am

I would say coil up the color and blow it out into a ball. Open a hole and then flare it out to the right size.

Coffeebean · #6 2009-06-23, 2:26pm

are you wanting the shape to be very symmetrical and exact?

Brandywine · #7 2009-06-25, 2:03pm

Consistant thickness would be very nice. I wonder about a graphite/brass/stainless form and if pressing a sizeable gather would work, or cool too quick and be unmanageable.

The shape does not need to be exact but I would like it to end up nice and consistantly circular around the outer rim and centered on the hole.

Great ideas so far.

kebira · #8 2009-06-26, 6:40am

I'm thinking a graphite rod of whatever dia. you need the hole size, maybe a quick wrap and mash, possible.

Cosmo · #9 2009-06-26, 9:05am

Quote:

Originally Posted by Brandywine

Consistant thickness would be very nice. I wonder about a graphite/brass/stainless form and if pressing a sizeable gather would work, or cool too quick and be unmanageable.

The shape does not need to be exact but I would like it to end up nice and consistantly circular around the outer rim and centered on the hole.

Great ideas so far.

That's why I recommended blowing a sphere and then flaring it out flat. Thickness should be very consistent. And it should be pretty much round...

PaulaD · #10 2009-06-29, 9:24am

I would make it the old fashioned way! On a mandrel with the slotted mashers!
Paula