Author Topic: Molds and resin casting  (Read 1517 times)

Doctor Quest

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on: July 01, 2020, 01:23:56 PM
I don't know if this is the right spot for this but...............

Does anyone have any experience with molds and resin casting? I am working on a non-gaming project but I expect some folks out there might do their own castings of miniatures, etc.

I did the requisite googling and found some good information but like most googling and youtubing the amount of information can be overwhelming.

I am looking at duplicating some simple shapes so I think a single mold would be sufficient for this project. Here are some materials recommended by a youtuber I found.

Molds:

https://shop.smooth-on.com/mold-star-15-slow

Casting resin:

https://shop.smooth-on.com/smooth-cast-65d

Thanks in advance for any help. If this works I'll be taking orders for replica STTNG phaser 1s............ :biggrin:

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GROGnadsUSA

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Reply #1 on: June 29, 2021, 03:56:36 PM
Hoi, as 'moi' were informed about "Alumilite" 'Site'/'Cite' casting materials, well over a decade ago. I had even obtained a 'Sample' of a USD "Half Dollar" coin(front) of this material, and it proved being quite durable/breakage resistant/lightweight as well, overall. It is 'moi' recollection that any 'Mould' would consist of being flexible, pliable-(for 'Item' removal once 'cured'), and somewhat cheap to produce whatever, in 'miniatures' "Fashioning" purposes. That's what I expected of thus, but, still, not quite inexpensive enough to the point where I could afford the entirety for this 'process', or, FREE then. 



Hethwill

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Reply #2 on: July 15, 2021, 07:21:35 PM
The fellow behind Korhyl Miniatures works a lot with that process in a "home" environment so to say so might be worth to have a chat with. He posted his entire process to make the moulds and resin casts, even the failures.

Here's his twitter

https://twitter.com/korhyl/status/1415408008616685569



Hethwill

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Reply #3 on: July 23, 2021, 08:04:39 AM



besilarius

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Reply #4 on: July 23, 2021, 12:29:56 PM
If you want to cast items with metal, like lead or tin, you may find RTV (Room Temperature Vulcanized) silicone rubber easy to work.  There are different grades, my recollection is we used 37.
Iit was easy to work.  We'd place the master half way into a base of modeling clay.  Check that the seams won't cause air bubbles.  Make a cardboard box to fit. The base.
Pour out a reasonable amount of the rtv into a cup and add the curing agent.  Mix well and pour into the mold box.
In an hour it should be hard, remove the cardboard and the clay, being careful to not pop the figure out.
Thinly paint the rtv with a soapy wash, reattach the cardboard, and pour the other half of the mold.
You may need to create air channels for the air in the cavity to escape
  We used pins that touched the figure when pouring the second half.
When the mold has hardened separate the two halves carefully.  (This is why you have the soapy wash.  Otherwise, the new rtv will bond with the first pour.)
Cut a funnel into the base of the figure for the molten material to be poured into the mold.
The biggest problem we had was air pockets.  If the metal didn't fill the mold, we'd use a dusting of talcum powder to lubricate the mold.
Since this is a gravity pour, to get enough pressure for the molten material to fill all the cavity, sometimes it is necessary to make the mold longer.  That is to make the pouring spout you cut into the rtv longer.  This puts more pressure down the spout.
And after maybe five minutes, the metal has cooled and set.  You can trim the air channels, the sprues, with nail clippers and use a file on the seam lines.
Hope this helps.
« Last Edit: July 23, 2021, 04:44:53 PM by besilarius »

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Doctor Quest

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Reply #5 on: July 23, 2021, 04:58:21 PM
Thanks for all the posts!

I need to get back to this project at some point. You know how real life is.

"Everything you read on the internet is true." - Benjamin Franklin

"Something so addictive about the whole kill and loot dynamic, though." - Gusington