resin mold problems

By sakura_petals. 15/06/11, 09:35 am

So I'm having trouble with this heart brooch I want to make. I was going to make it out of resin but the mold isn't smooth enough, I tried smoothing it out with varnish but it just peels away from the plaster. Is there an easier way? Plus if I do make it out of resin what can I use to colour it? I need it a pink colour. I have the heart shape that I made the mold from but I don't know what I have to do to it to make it look like a resin/transpartentish brooch.

I'm trying to make Usagi's heart brooch from my sig, if it helps.

By Highlander. 15/06/11, 12:48 pm

What are you using to mould with?

I haven't used resin before, so I'm taking a stab in the dark. But there was a recent thread with the main theater suppliers in NZ, and they may have products or advice they can offer.

https://cosplaynewzealand.forumotion.com/t11003-silicone-and-resin-suppliers-brand-help

Also I think neimhaille has a thread on resin if you search her stats.

Local firms: Spotlight, Hands, or these from the drawing room:

Norski Kleer-Kast Resin, clear but takes dyes?

http://www.thedrawingroom.co.nz/craft/crackle_mediums

Can you sand or scrape it smooth? Or would a clay/filler/bog be useful to smooth it? Or Gedeo Restoration Plaster which is designed as a filler.

http://www.thedrawingroom.co.nz/craft/modelling_clay

By sakura_petals. 15/06/11, 02:05 pm

I talked to Hands and they suggested the plaster of paris I was using. I've tried sandpapering it but it's not smooth enough. I've read through the resin thread by neimhaille but not recently but I don't recall mention of dyes and when I got the resin form Bunnings they didn't know anything about dyes. I used modelling compound to smooth it out before but when I put varnish over the top of it the varnish flaked.

I think now I'm open to alternatives to the resin as it's too soon to geddon and I have my main cosplay to finish/worry about.

By Highlander. 15/06/11, 02:16 pm

A silicone mould? Drawing room have a two pot stuff. If the drawing room sell resin you can dye they must know what dyes? That place in the other thread certainly could advise you.

I'm sure the hands staff are good at some stuff, but can't be experts at everything unfortunately.

Maybe you can sand the resin?

By Cookie Monster. 17/06/11, 04:22 am

You can just use a few drops of paint into your resin to colour it. And plaster isn't really that great for small sacle casting, but it can be done.

Also what type of resin are you using? E.G. Urethane, Polyester, epoxy....
This can be why you you resin it's moulding so well.
I don't really reccomend sanding unless you use several girts of fine (up to 6000) sand paper and a 1:1 resin kit, because if you get your hardener for the resin wrong, and you start to sand, it can gouge instead and lead to "clouding".

By sakura_petals. 17/06/11, 04:44 am

Klear Kast is the name of the resin. The problem I have is with getting the mold smooth enough to not have to worry about sanding the resin once it's set.

By Cookie Monster. 17/06/11, 06:23 am

Stupid question; are you casting the mould, or scuplting it?
Pressing objects into window putty or Selley's Kneed-it which have been dipped into water after being freshly kneaded is great for making a cast of fine detailed, small objects. - The water will help keep the putty smooth with minimal distortion from pressing in the object

By sakura_petals. 17/06/11, 07:11 am

Casting, I think. I have a mould already of plaster but the options I thought would work (like varnish) to smooth it out didn't work. It's not a detailed item I want to make - just a plain heart. What could you suggest I use to smooth out the plaster? Or should I make another mould and start again?

By Cookie Monster. 17/06/11, 07:25 am

You can only smooth by sanding really. I suppose you could paint the mould with acrylic enamal paint but i have strong doubts it'll help.

By Mischa. 21/06/11, 02:15 am

Adding a varnish/substance to the inside will work if there is holes, but if bumps are the problem it will only make them bigger.

I would cast the object then sand it smooth- or try a new mould :'( - towards the end of my big gem casting I scraped the inside of my mould with my fingernail and ended up with scratched casts- resin picks up everything!

I found transparent glass paint to be really good for colouring my gems- I didn't add it to the mixture because I'm a wuss and wasn't sure of the proportions! , but painted it on afterwards.

Good luck!

By sakura_petals. 21/06/11, 03:26 am

Thanks, I'll have a go with the glass paint.

By flash. 28/06/11, 09:38 am

I'll add in some tips;

If you are forced to sand the plastic to smooth, one thing to remember is to stop every minute or so when you're on the finner grade of sand paper, as the heat caused by the friction can cause it to melt (had that happen to me once D| ).

To make it shine or to find places that aren't as smooth use clear car polish.

Also, you don't necessarily have you use transparent glass paint, nail polish works wonders.

By Mischa. 28/06/11, 11:46 am

^ I hadn't though of using nail polish, but now you mention it they are very similar! Very Happy

By sakura_petals. 28/06/11, 01:19 pm

I had thought of nail polish as a tutorial of making small gems out of hot glue suggested the use of it.

Thanks for all your ideas. I've completely run out of time to so anything with the resin at the moment but when things calm down again I'll be having another go at this project.

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