Split Mould Casting Technique

[geomod]

At this stage Mangozac, I have no idea.

I have only just started using the degassed pinkysil for anything other than open face moulds.

I like the denser pinkysil because it helps to make the split mould self supporting, meaning that I can tape the mould together rather than using supporting boards as described in your original post.

I will keep an eye on the mould performance over time and let everyone know what I find out.

Cheers,

geomod

[geomod]

Also, I forgot to mention.

I am one of the 'crazy' high CFM vacuum pump users. My pump is a 10 CFM unit that pumps down to -27mm Hg in about 20 - 30 seconds on my paint pot. If I do one batch of about 200ml at a time, I can get away with degassing the pinkysil.

I have had one unfortunate occurance when the pinkysil wouldnt collapse during degassing. I found out that this was because it had set.

Cheers,

geomod

[blind pig]

I think Barnes suggest degassing most of their resins.

I will degas my Pinkysil for larger moulds, ones that have to be "perfect" or more usually if i can be bothered.

Degassed Pinkysil would be closer to what Barnes publish as the Product Properties.

Has anyone given Barnes "Banana Skin" a go? another platinum cure silicone that is even softer than Pinky and is just a wonder to use!

[mangozac]

[blind pig]

No, I've used it for a really delicate cast and it will hold itself together without support. Much more fluid and detail holding than pinky.

Dunno that I'd use it for everyday use.

[mangozac]

Just had a look at the TDS and it sounds interesting. Same price as the Pinky so I'm not sure what the advantage would be for the stuff I'm going. I'd be worried about it warping larger mechanical parts - might be fine for figures and the like though?

[Kennui]

Was I one of the instigators of this thread?

One day it will be useful.. My good friend helped his brother move to the city, conveniently near a barnes store. Almost got talked into buying a starter kit

[mangozac]

Quite possibly. It was prompted by someone on WAU asking questions...

I'm actually quite surprised how much product Barnes apparently sell to people who walk in off the street and decide to have a go at making something as a weekend project. I would have thought the silicone and resin costs too high for someone who just wanted to dabble with casting something random like jewellery!

I think I need to stop recommending that everyone use 4PU though: they still didn't have any in stock when I dropped in on Saturday. It's apparently a month overdue! I've got my name down and will have to get them to post me some when it comes in

[blind pig]

Resin jewlery making is a growing hobby amongst the Tupperware Society.

The Saturday Courier Mail (or was it Sunday C M?) a couple of weeks ago had a two page story on a Mum who started producing her own bangles (using Barnes pre-made moulds) and has grown it to a nice little business. She was imbedding all sorts of stuff as well as colours into clear resins and selling them......

You should grow-up and buy some bigger containers of 4PU, Zac, that way you won't run out

[mateo442]

I saw a neat trick for those of you doing split molds. freemansupply has a video advertising their clear silicone rubber for moldmaking. What they did was attach some clear tape to one edge of the part they wanted to mold and then use a marker to color the outside edge of the tape. After the clear silicone had cured, you could see the black marks on the edge of the tape. It made it easy for them to cut down to the tape when the demolded the parts.

[mangozac]

I probably would have just drawn directly onto the part without the clear tape!

[lastspartacus]

This looks terrifying. How do you deal with complex minis? Do you add a fill space to the side that provides a nice flat plane to cut down along?

[mangozac]

It's really not very hard to do. You align the model so that you will be cutting the split along the most appropriate edges. When cutting you just follow the contour of the model.

I took some pics when I made a mould yesterday that I want to upload into a new tutorial. The thing is that I just don't have time to edit them and write it up at the moment

[Commissar-Krad]

I will find such a tutorial very useful when I start casting up the ship!

[factor40]

I'm finally starting to experiment with split molds as well. Any pics you can post here would be greatly appreciated Zac!