How do I measure my mold? -

How do I measure my mold?

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Posts: 26
Joined: Tue Feb 10, 2004 10:20 am
Location: Columbus, Ohio

How do I measure my mold?

Postby Bellknap » Thu Feb 19, 2004 10:02 am

Glass pals, I have ordered the mold you are seeing and question how to measure. I know on my round bowl molds you draw around and go in say 1/4".
However if you want the fuse glass and have a specific design as a square insert in your fused do you measure so that the square will slump correctly and proportionally into the square of the mold? Thanks so much, Lydia

Tom White
Posts: 174
Joined: Tue Mar 11, 2003 9:14 am
Location: Houston, Texas

Postby Tom White » Thu Feb 19, 2004 10:28 am

I do not know of a way to predict what size blank you will need to get a specific sized square slumped element out of any mold before you try one piece. If you have a blank fused you can measure the length across the middle of the blank then take a flexible measuring tape and place the center point of the measured dimension at the center of the mold and conform the tape to the shape of the mold to get a fairly good idea where the edge of the glass will end up when that blank is slumped in that mold. The best I have to offer is to mark on the mold the size square you need then measure along the contour of the mold from side to side to get a strarting estimate of the size blank needed. I would try an experimental firing with inexpensive glass first before wasting expensive glass if I'm off on size.

Best wishes,
Tom in Texas

Posts: 26
Joined: Tue Feb 10, 2004 10:20 am
Location: Columbus, Ohio

Thanks Tom

Postby Bellknap » Thu Feb 19, 2004 4:31 pm

Thanks Tom for your input. You Texans are always great folks. Of course I am partial as our home office is in Houston, Stewart Title....Lydia of Ohio


Postby Cynthia » Thu Feb 19, 2004 5:12 pm

Here's a (long winded) thought. Measure the size of the foot, measure the size of the slope or rims. For the sake of illustration, lets say the foot is 6" sq. and bordered by a 2" wide rim. That would mean you have a square mold that measures 10" straight across...but if you measure the rim from the outside edge and follow the contour down the slope to where the foot, or flat square base begins..It should be slightly longer when taking into account the arc and distance of the slope than it would be if you measured the distance "as the crow flies" straight across. So I am thinking you might have a rim that actually measures 2.2", making the overall size of fused glass when flat 10.4" square. Make sense?

My thinking is that the foot or center square won't distort in the bend, and as the glass drops into the mold the rim won't either, but if you take into account that you will need to make your piece somewhat larger, and design that extra distance into the area of the rim to the leading edge of the foot, you should get a bend that the design (assuming that you intend to design the piece to visually match the angles) will match the angles of your mold without issue.

I am guessing on this since I have not tried it...but from what I have observed happens to the glass as it bends, I believe that if you bend the glass slowly, say at 100 dph from 1000 to 1200, it should settle into the mold without stretching and actually bend and slide into the mold accomodating the slope of the rim and matching the angles.

Just a thought :wink:

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Joined: Tue Apr 08, 2003 7:50 am
Location: Bristol, UK

Postby Peg » Fri Feb 20, 2004 8:37 am

I have that mould - and dishes made with it are my biggest sellers. I think people like the depth of the finished item, as most slumped dishes are very shallow. (my mould of this shape is 8cm deep)
Anyway - I start with a blank about 1cm larger than the mould width (which is about 33cm), and I slump veeeeerrry slowly and quite cool (730 deg celsius). Too fast and/or hot and the sides start to buckle in.
(the blanks are made up of 3 pre-fired layers - base 3mm coloured, middle coarse frit, top 1.5mm clear - this makes a very heavy and substantial dish).

The middle square will stay in the middle (and nearly the same size) if you go slow, and the faster you slump the more the sides will curve in - which can look quite deliberate and attractive!

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