Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

Afternoon Dakka,

Having seen some impressive results from other individuals, I'm looking to start some basic casting with resin.

I have a re-useable silicone mold, and would like some examples of basic, affordable casting resin. I'm aware you can use other materials, but I'm looking for reasonable detail, and the ability to stick pieces together with superglue (or equivalent).

I'm based in the UK, so UK based companies would be preferential, but not essential!

I look forward to hearing your tips.

My first resin casting was done in hirst arts molds with smoothcast 305

It has a decent learning curve to it. Mix really well, don't use wood spatulas, keep moisture out, MIX REALLY WELL.

Doesn't work with composimold though - which is a real bummer.

Big question;
How are you going to combat air bubbles?
The more detail on your master model the more air bubbles you will get.
While there are some resins and chemicals that will reduce bubbles they will not eradicate them. What you will need is something like a pressure chamber(it pushes air bubbles out) or a vacuum chamber(which sucks them out).Both of these cost a lot and you can spend upwards of £1000 or more. Also you'll need a good cleaning agent to take the shine off the castings so you can paint them.
There are various resins/plastics you can use and this site is one of the best and I'm sure he'll be able to suggest what you need.
http://www.tiranti.co.uk/EdgeImpactShop/category.php?Category=10

Slipstream wrote:
Big question;
How are you going to combat air bubbles?
The more detail on your master model the more air bubbles you will get.
While there are some resins and chemicals that will reduce bubbles they will not eradicate them. What you will need is something like a pressure chamber(it pushes air bubbles out) or a vacuum chamber(which sucks them out).Both of these cost a lot and you can spend upwards of £1000 or more. Also you'll need a good cleaning agent to take the shine off the castings so you can paint them.
There are various resins/plastics you can use and this site is one of the best and I'm sure he'll be able to suggest what you need.
http://www.tiranti.co.uk/EdgeImpactShop/category.php?Category=10

You need neither of those things for home casting. You also don't need specialist cleaning agents, any more than you do when cleaning FW models.

OP: Check out sites like tomps.com and, since you're new, look for resins with a longer pot-life and extremely low viscosity. They take longer to cure in the mould, but you will be glad of the extra time to mix without worrying you're going to end up trying to pour half-cured glop. Low viscosity is step one in combating air bubbles without ridiculously expensive professional equipment(ideally you also want very low viscosity mould rubber). Step two is learning how to structure your moulds and how to pour properly. Try something like this:



Pour into it very slowly from a few inches above the inlet - the goal is to maximise the surface area of the resin throughout the pour(increasing the chance any bubbles will burst), and also minimise the number of places bubbles would be likely to collect(hence angling the models slightly) & provide a way out for them if you can't(smaller channels from protrusions). Done right, the result should be good enough for anyone who's not going to be selling the final casts - you'll have a few bubbles to fill in at the end, but if you design the mould right they shouldn't be obliterating any detail.

Step three, if you want to go further, is to build a vibration plate. Two flat bits of board one bigger than the other, some long nails, hooks with a screw end, and some chunky rubber bands aren't expensive and allow you to suspend one bit of board, then add any kind of vibrating motor to the bottom of it. Put the mould on top, pour carefully as usual, then run the motor for a few minutes - the vibration helps to further prevent bubbles coming to rest on the exterior surfaces of the model.

As for cleaning off the mould release, warm water and Fairy liquid will do the job on every one I've ever tried.

Are you using composi mold?

I noticed that my molds will actually melt from the curing heat.

Yeah, composimold and smoothcast is a bad combination. I ended up making an instamold master, setting that in composimold for stability, then casting smoothcast inside that

Still melted the composimold through the instamold.

It's a shame too, I really want to see if the composimold resin works any better, as it is it is pretty useless

Many thanks to all for some great advice so far- in particular Yodhrin for the extra tips and tricks!