Thread: Casting & Stabilising Demo

Originally Posted by plantagenon

..I will throw a portable halogen work light in the car just in case. Won't hurt to have it.

I have a few if we need them, so i wouldn't bother. Forecast is for fine and sunny, so hopefully no need for the tarp .

You Northerners not only get the best weather but also great tuition!! Amos

If anyone has specific casting or stabilising questions, ask them here, then I might be able to answer on the video visually if we have time.

I have already been asked to cast some banksia and pine cones, so i will be covering them.

cheers

This the proposed schedule ,will be some things going on as well with mold making / casting , and possibly Tony doing his specials, so busy busy

Neils a bit worried about having enough time, so was thinking of posting the below as agenda. I know it is a bit back to front, but stabilising takes time, so we need to start up front.

1:00pm Welcome
1:15pm Stabilising Demo Part1 – Equipment/Resins/Example
2:00pm Casting Molds – Types & forms/making
3:00pm Afternoon Tea
3:30pm Stabilising Demo Part2 – Finalise example
4:00pm Resin Casting Demos – Equipment/With pressure/without
5:00pm Outstanding Questions/Chin Wag
6:30pm Dinner at local Chinese Restaurant

As you can see, very tight program.

so two cameras will be busy cheers ~ John

My questions,
I've already been told some answers but others may benefit if on film.

1) When do I use vertical and when do I use horizontal moulds.
2) At what stage of the resin going off do I actually pour. Mine always blends into one.
Do I go right away, wait for honey consistency, or wait for thickened cream.
3) Should I warm it to set quicker?
4) Proper mixing order for colour tint, pigment, hardener. I've been mixing colour in first, then vacuum out the bubbles a bit, then do final mix for hardener., but have no idea if this is correct.
5) How long under vacumm, how long under pressure.
6) What moisture content do I want to cast items like nuts and beans? Do I warm them in an oven before casting (how long and temp)? or use as I find them?
7) If the item has lots of holes to be filled and the resin level drops to far (which I can't see in pressure pot), do I get a bigger mould and overfill or do it in 2 parts and hope I can get the colour the same.

I'll think of more.....
Peter

Good questions Fly we'll see what answers come up hehe ,cheers ~ John

Great questions Fly ! I am particularly in the vacuum stableizing side of things I have purchased the pump but that is as far as I have gone because I am waiting on a clear cacuum chamber and am not setting it up with my pressure pot. I hope to be able to pick up as much info as I can from what is posted from the day and wish you great success and I am sure you will all have a great day.

Wish I could be there

Cheers Ian

Originally Posted by Dorno

Great questions Fly ! I am particularly in the vacuum stableizing side of things I have purchased the pump but that is as far as I have gone because I am waiting on a clear cacuum chamber and am not setting it up with my pressure pot. I hope to be able to pick up as much info as I can from what is posted from the day and wish you great success and I am sure you will all have a great day.

Wish I could be there

Cheers Ian

Hi Ian,
These are questions I want answered on the day. And I'll watch one of the video's being recorded as I am in Victoria.

Neil has said if anyone has any questions they want answered to post them here and he'll try to answer them for us.
I'm sure we can make a dvd and pass it around among us.
Peter

Hopefully we will cover on videos, but just in case, here are my comments. Please keep in mind, I rarely do multi colours as I don't do plain resin blanks (except left over blanks from resin chips)

Originally Posted by _fly_

1) When do I use vertical and when do I use horizontal moulds. Things that can have trapped air I do vertically, most other horizontally

2) At what stage of the resin going off do I actually pour. Mine always blends into one.
Do I go right away, wait for honey consistency, or wait for thickened cream.
For multi colours, you need them to be almost gelled, but for all others straight away when resin is as runny as possible

3) Should I warm it to set quicker? I always warm resin to make it as runny as possible, to around 25 degrees C

4) Proper mixing order for colour tint, pigment, hardener. I've been mixing colour in first, then vacuum out the bubbles a bit, then do final mix for hardener., but have no idea if this is correct.
That is the right way to do it, the only difference with me, is that I don't bother vacuuming the resin before adding catalyst

5) How long under vacumm, how long under pressure. For casting things, only vacuum to get bubbles out before pouring, then pressure. If pure resin blanks, vacuum Ok, no need for pressure

6) What moisture content do I want to cast items like nuts and beans? Do I warm them in an oven before casting (how long and temp)? or use as I find them? Anything cast in resin needs to be dry, resin does not mix well with moisture. Get them as dry as possible, but less than 12% is preferable. I do mine in a dehydrator, but oven at low temp should be OK

7) If the item has lots of holes to be filled and the resin level drops to far (which I can't see in pressure pot), do I get a bigger mould and overfill or do it in 2 parts and hope I can get the colour the same. Either way is Ok

I'll think of more.....
Peter

Tony should be able to help with pouring multi-coloured pour resin blanks, not my specialty

Sounds like i need to move my oven and dehydrator outside too

1) When do I use vertical and when do I use horizontal moulds. That is really a personal choice as either can be used at any time and for any form of casting really although I do think bubbles can release quicker and easier when laying horizontaly.
2) At what stage of the resin going off do I actually pour. Mine always blends into one.
Do I go right away, wait for honey consistency, or wait for thickened cream. That depends on what you are casting, if you are only casting straight forward blanks say mixed colours, then just before it starts to gel is best as the colours should not mix to much then. It does depend on the look of the blank you are trying to achieve though as sometimes you may want the colours to mix, in this case pour them a little earlier.
3) Should I warm it to set quicker? I sit my resin and pigment mixing cup in a cup of hot water during the mixing. This will also allow for small air bubbles to release easier from the resin once poured into your molds. Vibration of the molds once cast will also assist with release of air bubbles.
4) Proper mixing order for colour tint, pigment, hardener. I've been mixing colour in first, then vacuum out the bubbles a bit, then do final mix for hardener., but have no idea if this is correct. I pour my resin into mixing cup and place in a bowl of hot water, I then mix in my pigments thoroughly and then add hardener at the end.
5) How long under vacumm, how long under pressure. I have only used pressure casting a few times as I do not do a lot of casting of other materials. Neil may be able to advise more on vacuum casting. As far as time under pressure I have left mine anywhere from a few hours to over night. Longer does not matter as bubbles can not be pressurised out of the casting once the resin has started to cure.
6) What moisture content do I want to cast items like nuts and beans? Do I warm them in an oven before casting (how long and temp)? or use as I find them? I will leave this one for Neil to answer, all I know is that no moisture is good, resin and moisture do not like each other.
7) If the item has lots of holes to be filled and the resin level drops to far (which I can't see in pressure pot), do I get a bigger mould and overfill or do it in 2 parts and hope I can get the colour the same. Better to use a slightly larger mold that will allow you to slightly overfill however practice makes perfect and the more you do it the better you will become and your judgement in getting the right amount of resin in the mold will fall in to place.

I hope some of the above is of help
Cheers
Tony.

Thanks Tony,
With Neils and your expertise I should get there.

I have done solid blanks before and they all mixed into one blobby colour (had to paint inside to get something ok).

So I'm interested to see your demo for mixed colour blanks.

I now have 2 tube moulds and one horizontal solid mould. And about 60 pen kits to use up.

Will be a busy spring with casting one tube kit at a time.

Think I'm going to order mould silicone and try that as well...

Peter

OK, Just to make this complete I guess for anyone who finds it:
How about a list of places to get resin, pigments, tints and casting silicone from
I can start with supplies for melbourne near springvale road/ princess Hwy junction
Melbourne.
http://nuplex.com.au/

Originally Posted by _fly_

Think I'm going to order mould silicone and try that as well...

Should have a demo of that too

Peter,

I have been using pvc tubes for casting vertical blanks and they work very well and are cheap. I normally cast six tubes at the same time with all the tubes positioned in one of my ply made racks to hold the tubes. It works well.

Cheers
Tony.

I've also been using that method for vertical casting.
Chair stoppers filled with plasticine shoved in the bottom stop anything coming out.
Then 6 or 8 in a wooden rack like a test tube holder keeps them upright.

How do you get nicely coloured blanks when its vertical and you can't see how its mixed.
Do you just shove a skewer down and give several colours a mix, Or put a straw down the middle and pour one colour and then pour second down the middle of the straw as you pull it out, Can't see how that works if its almost gel stage. Or maybe outside is gelled and second colour is still liquid.

See we all have so much to learn.