Making a mold of a bowl

[S.TImmerman]

Hello,
Is it possible to make a mold of the inside of a bowl and utilize it? I was approached and asked if I could make 12 salad bowls just like this bowl which is made if some type of hard plastic. I do have a quart of silicon mold as well as ceramic mold and clay.

Thank you

Shereen

My new year resolution is to be grateful - on the morning of dec 24th my husband was brought by ambulance from a doctors appt and was quickly diagnosed with a brain tumor. After missing christmas , our 20th anniversary we found out it's not Cancer and can be removed without blinding him as it's on the optic nerve. Yes, I am grateful !

[Kevin Midgley]

yes, but why bother when these are available?

http://www.ebay.com/itm/Arcoroc-France- ... 1529797377

You might if you checked their catalog find the same pattern.

[Rick Wilton]

yes, but why bother when these are available?

http://www.ebay.com/itm/Arcoroc-France- ... 1529797377

You might if you checked their catalog find the same pattern.

REALLY???

[Kevin Midgley]

Rick, yes I know really? but I'm pretty sure I've seen the 'same' sunflower pattern done commercially in glass before.

[Morganica]

Arcoroc has a lot of this kind of stuff, at least in clear glass. The question would be if they're wanted in some kind of color or pattern, I suppose. The other question would be whether the design itself is copyrighted.

But yes, you can definitely make a mold of this. Several ways to go about it: The easiest would be to just make a silicone negative mold and then use that to pull a lot of refractory plaster molds from it. Then you can cast, do pate de verre, slump, whatever, into each.

The other way would be to make a permanent refractory--this mold looks as though it's not got any undercut/locking issues to prevent it--from it, and then coat it with release and simply use it multiple times. It would take longer to make the permanent mold, but simpler to just keep reusing it. OTOH, you'd have only one mold, so if you need 12 of the things, you'd be firing it 12 times. (unless you made multiples) If you simply pulled plaster/silicas from your silicone negative, you could make them all at once, fire all together (assuming your kiln is big enough), and have done.

There'd be another advantage to doing it that way, too: You'd have the same firing characteristics for all the pieces. If you're using a striking color, or a pate de verre technique, there can be variances between firings that might change appearance slightly. don't know if that matters.

[S.TImmerman]

Morginia ,
That's a great idea, I am going to change it a bit and they don't want clear. The colors are yellow/brown to go with green plates. Not my choice tho' however it's not as bad as the customer who wanted a full size ferret SG window a few years back for her bedroom window. Thank you very much for your reply!

Shereen

[Bert Weiss]

I would figure out a way to flatten the image, then mold and cast flat pieces, and slump them in a separate firing.

[rosanna gusler]

I would figure out a way to flatten the image, then mold and cast flat pieces, and slump them in a separate firing.

yep. me too. r.

[Jenna]

That begs the question of how exactly to flatten a design such as this...would love to hear your approach! How do you do this without distorting the design?
(Something I have thought about myself for other projects and have not found a tequnique for, yet)

[rosanna gusler]

That begs the question of how exactly to flatten a design such as this...would love to hear your approach! How do you do this without distorting the design?
(Something I have thought about myself for other projects and have not found a tequnique for, yet)

i would make a casting mold out of paper clay. i would not try to copy the other bowl exactly. the flower design is opretty simple. r.

[Bert Weiss]

I never tried this, but I wonder what would happen if you worked with plasticene to make sections and flatten them. It this fails, I would look for a flat pattern to copy, and then slump it. You can purchase all sorts of plaster or cast metal patterns that might be appropriate.

[The Hobbyist]

I would make a plaster cast of the center medallion. Then roll out a flat circle of clay. Press the medallion into the center and hand carve the petals and scallop the edges. Check for any under cuts that need easing and then bisque the clay when it's dry.

This will yield a mold that can be used to kilncarve the design into the top or bottom of the glass blank you have cut (and fused) to size. Since the mold will impart the design and well as a texture from the Kiln wash that surface can't be made smooth and shiny. If kilncarved on the bottom of transparent glass the finished bowl will have the design but be smooth on the inside for use and cleaning. That won't work with opaque glass.

The kilncarved piece can be slumped in any bowl mold to get the desired salad bowl shape.

That's a lot of work but you would have the option of composing the blank with different colors and well as frit or stringer appliques.

Jim "The Hobbyist"

[charlie]

[quote="The Hobbyist"]I would make a plaster cast of the center medallion. Then roll out a flat circle of clay. Press the medallion into the center and hand carve the petals and scallop the edges. Check for any under cuts that need easing and then bisque the clay when it's dry.

This will yield a mold that can be used to kilncarve the design into the top or bottom of the glass blank you have cut (and fused) to size. Since the mold will impart the design and well as a texture from the Kiln wash that surface can't be made smooth and shiny. If kilncarved on the bottom of transparent glass the finished bowl will have the design but be smooth on the inside for use and cleaning. That won't work with opaque glass.

The kilncarved piece can be slumped in any bowl mold to get the desired salad bowl shape.

That's a lot of work but you would have the option of composing the blank with different colors and well as frit or stringer appliques.

Jim "The Hobbyist"[/quote]

...taking into account that bisquing a clay blank will chase shrinkage of up to 20%, depending upon the clay.

another way to do this is to take a very flexible sheet of clay, drape into the inside, press down to make an impression, peel out the sheet, and flatten it. it would be easy to make the sheet with a slab roller, if you know a ceramist in the area.

[The Hobbyist]

I think as you flatten the sheet it will stretch and distort the design also thinning out the clay, around the perimeter, significantly if the bowl is deep. This clay will also shrink as you mentioned.

Jim "The Hobbyist"

[Bert Weiss]

I would rather kiln cast over plaster investment than clay. The shrinkage issues are large, and if not configured right, can break glass. I think the right shape can be done. I know the wrong shape can't.

[S.TImmerman]

Thank you all so much, what I've decided to do is carve the shape on a leather hard 14" round peice of clay. Fire it with vent holes. Pre fire a 1/4 in piece of glass and then use the mold with enamels/frit. Then slump it.

Would screening enamels over the prepared mold be better than using frit to pick up the lines in the carved piece?

Shereen

[JestersBaubles]

Shereen, I came across this on Bluefire:

http://www.bluefiremolds.com/files/mold ... WL%20MOLDS

7027160.jpg (24.14 KiB) Viewed 33554 times

It looks very similar to what you show above, though I don't know about size.

Dana W.

[S.TImmerman]

Thank you Dana,

The customer is still in Europe so as soon as they sail back I'll share this mold . I'll check bluefure contact info and call them about the size. I doubt my customer cares but it would be much cheaper to use a ready made mold.

I'm still going to do the clay process as I love to learn new techniques - I just ordered 50 lbs of hydroperm but as far as I know you can't reuse it if you make a mold.

Thanks
Shereen

[Vonon]

Shereen, Would you please post your results with the clay mold? I presume you will bisque fire it first and kiln wash it but am curious about the results you may get using enamel powder to pick up details. I made a clay tile with decorative incisions to use as a pattern mold. The markings were not deep enough to transfer a satisfactory pattern but your inquiry inspires me to try adding frit and/or enamel powder to see if that might be a fun road to go down. Alas, my roads are getting shorter these days but what the hey!