Resin casting

Hi folks,
Just a little question of curiousity here. I went to make a mug of
coffee this morning and thought about fixing the lid to the hopper of
my coffee grinder. It's a really cool little machine. A perfect
miniature of the large Hobart coffee grinders from the 1920s and '30s.
Anyway it has this clear plastic hopper. The hopper has a round, domed
lid which is like a tall, narrow "C" shape in cross section. The lid is
cracked and has a chunk missing out of it, so I've taped it back
together for now. I was just wondering how hard it would be to cast a
new lid out of resin? I remember reading somewhere online about a guy
who cast replacement telephone cases in funky-coloured resin.
Anyone know how hard it is to cast parts out of resin, and how
expensive it is?
Best wishes,
Chris
Reply to
Christopher Tidy
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I do it extensively for scratch model making. It IS expensive, both the casting resin itself and RTV mold making material. If you design the pattern properly, with clearance angles, you can cast in plaster molds, but clearance angle is critical. The normal price for small bottles of casting resin (two part, so two bottles in set) is about twenty seven or twenty eight bucks. Don't know if one pair would do what you need, but my guess is, yes.
A company called Ace Resin offers a starter set of everything, with a good instruction brochure, but the bottles of resin and mold making material are smaller than normal non-kit pairs.
Reply to
stauffer
I do it extensively for scratch model making. It IS expensive, both the casting resin itself and RTV mold making material. If you design the pattern properly, with clearance angles, you can cast in plaster molds, but clearance angle is critical. The normal price for small bottles of casting resin (two part, so two bottles in set) is about twenty seven or twenty eight bucks. Don't know if one pair would do what you need, but my guess is, yes.
A company called Ace Resin offers a starter set of everything, with a good instruction brochure, but the bottles of resin and mold making material are smaller than normal non-kit pairs.
Reply to
stauffer
Go to:
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They have a lot of useful information on this type of molding and casting. And you can buy materials from them as well.
Christ> Hi folks,
Reply to
Billy Hiebert
Thanks for the thoughts. Sounds quite expensive. How much resin do you get in that pair of bottles for $28?
Best wishes,
Chris
Reply to
Christopher Tidy
A new coffee grinder would be considerably cheaper, but cost may not be the only matter of interest here.
Urethane or epoxy is the way to go. There are less polyester clear casting resins available at hobby shops. Beware of them. They shrink a lot upon curing and they are brittle in thin sections.
Here's another source of info and materials:
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Their Polyoptic 1410 would work well here.
You would probably need a source of fairly good vacuum (28mm Hg) both to degas (debubble) the mixed resin and to make it fill a thin shell mold.
There must be similar suppliers in the UK.
Reply to
Don Foreman
use polyester resin
Reply to
daniel peterman
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You can get their DVD "Making Patterns, Tools & Molds" on Ebay for about $10. Everything (and then some) you need to know. JR Dweller in the cellar
Christ> Hi folks,
Reply to
JR North
Be aware that making up polyester resin gets you into the "toxic stew" category.
I simply wouldn't use this for anything food related.
Be more inclined to try a food grade RTV silicone.
Maybe not so pretty, (I don't think they are available that turn clear when they cure.) but likely better for your health.
DOC
Reply to
doc
Sadly they no longer make coffee grinders which are anywhere near as cool as this one. If it's going to be expensive I'll probably just stick it back together for the moment and think about resin casting again when it breaks irreparably.
Thanks for the information.
Best wishes,
Chris
Reply to
Christopher Tidy
Roger that! Some things are worth restoring even if it costs more than a modern replacement of considerably less character. Assign the cost to the entertainment budget and grin.
Reply to
Don Foreman
This is definitely one of them. I'll have to post a picture of it. Remind me if I forget.
Chris
Reply to
Christopher Tidy
On Thu, 04 Jan 2007 15:02:15 -0800, with neither quill nor qualm, JR North quickly quoth:
I picked up one of those and the only gripe I had was that they referred only to their own brands throughout the videos. The CD contains lots of good info, though.
Reply to
Larry Jaques

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