Small volume castings

[mistress of minis]

So, Ive been casting off & on for several years now, and when it comes to casting a few small parts like armor pieces for 25/28mm infantry, I still seem to hit an obstacle.

Usually when Im casting larger items I'll just drop the last few drops into one of my small bitz molds. But lately I just want to focus on my infantry, and mixing up small batches of resin for a few shoulder pads is very hard to get a 1-1 volume mix.

Does anyone have either an easy trick to get smaller volumes proportioned properly, or maybe a product similar to a urethane resin that might work for small parts in a silicone mold? (usually just a single piece top pour cavity mold)

[mangozac]

Hey Mistress great to have you on board!

A very worthy question you've brought up! As an example, my are about 7g of resin. Because it's just not possible to mix up 7g of resin (that would be 3.5g of each part), the only option is to mix for multiple moulds at the same time.

Initially I was throwing the prow mould in at the same time as doing parts for my Superheavy Assault Walker kit, but now that I've completed doing them, I'm now actually running multiple prow moulds.

I reckon you could get away with mixing as little as 10g (5g of each part) but less than that there's not much else you can do.

For small parts, so long as there's nothing too thin I wouldn't expect the mix ratio to be too critical. 10%-20% variation would probably be ok.

One other option if you only want to mix really small amounts would be to use droppers (one dedicated one for each part of the resin). A few drops of each into a small container and you're good to go....

[mistress of minis]

Ya, I was using some lab pipettes to draw the resin. You can get them with graduated volume markings so it makes getting the mix right. I jsut ran out since the resins tend to gum them up after while.

I may try some polyurethane glue on one of my old molds- it doesnt dry very fast though, so it may just be easier to find some pipettes online.

[mangozac]

Yeah glue would take too long to set. Tracking down some more pipettes would be the way to go.

Do you have any pictures to share of the stuff you're casting?

[mistress of minis]

I spent my disposable income on modeling stuff lol

Hence, my camera is 5 years old, and was a freebie salvaged from a former room mate after her great dane 'puppy' used it for a toy. It suddenly decided to stop focusing for macro shots

Right now its Imperial guard stuff, shoulder pads for the catachan bodies, little tracked units for my HW teams, back packs I sculpted. And, I might decide to sculpt some Tallarn heads and torsos to cast as a kit. I've been sculpting all of them individually, and havent decided if it would be easier to cast them or sculpt them lol

[mangozac]

Now you're just teasing! I vote that you get a new camera for sharing this modelling goodness of yours

[mistress of minis]

Lol, voting wont change the lack of camera or funds :p

[geomod]

I thought I'd chip in here.

I have been pouring casts of small parts using only 10ml of resin in my new pressure pot (thanks magozac, your guide was invaluable and I am VERY pleased with my initial results).

The cast only needs 5ml of resin. I use a 30ml measuring cup that I bought at Adelaide Moulding and Casting, but I am sure you could find them where you are.

This allows me to pour my small amount of resin, the remainder I use for spill coverage and as a guide for when the resin has gone off in the pressure pot.

I admit this does cause a certain amount of wastage but as I build up the number of moulds, the amount of waste will drop (I hope).

Cheers,

Geomod

[mangozac]

Geomod, that's awesome to hear that you've set up a pressure pot based on my posts!

You've certainly hit the nail on the head here: the best way to handle very small moulds is to have a whole heap of them for which you can mix and pour in one go. For example, my is composed of four moulds and while I always cast all of them in one go, I always try to throw in some other moulds as well.

[paulson games]

I pretty much try and do the same the smallest amount of resin I mix is about half an oz of each side (1oz total) the companies recommend always using at least 1oz. of each part to make sure that the mix is correct but I've found that I can just be very careful with the measuring and it works well. I use a bottle with a fairly small tipped end to help me control the pour rate better and graduated measuring cups like what you'd get with a cough syrup bottle.

I can usually get 4-6 molds from 2oz. worth of resin so I just pack in extra molds and if I have any left over I empty it into a cup I keep specifically for overage waste. I've found that under half is just too small to measure and mix properly.

I'll often have a quarter of an Oz. as waste but a few cents worth of resin waste isn't too big of a concern IMO.

[blind pig]

I never waste resin and even those last few drops go into what I call a waste mould, after a few dozen pours, I get a freebie of something useful out of what would otherwise be thrown away.