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Have a look at the original post for places to buy casting products, I know there is an entry for the UK but not the netherlands.

If anyone could help Aekold it would be greatly appreciated and I will add the company and products to the original post.

Thanks for the advice. I found the following products on the site if The Modelshop.
I intend to use this for the mould:
http://www.modelshop.co.uk/product/Smooth-on_Mold_Max_20_CL10028
And this for the resin:
http://www.modelshop.co.uk/product/Smooth-on_Feather_Lite%C2%99_resin_1kg_kit_CR20028
If I am correct these are the same products you are using. Could you please confirm this.

Onze again thanks for this great thread. Owh and I found your space skaven thread, really awesome.

They may not be exactly the same products but they do look like they will do the job, If and when you order them and do some casting can you post whether or not they worked out and what the service was like from "the modelshop" it's always great to add another place to purchase casting gear to the original post.

Cheers

BLACKHAND

An amazing tutorial with a ton of helpful things. I was wondering how to make a full cast, such as the Nids attached to the bottom of your scratch built Tervigon. I was going to use this method to make some pilots and a few custom builds for different projects I have lined up (save me tons, instead of having to buy boxes of guys to cut up. ).

Check about halfway down this page it shows most of the process for the termagaunt, hope it helps!

http://www.dakkadakka.com/dakkaforum/posts/list/30/276630.page

I live in Vancouver, BC and after google-fu, have failed to locate any special effect, modeling or hobby stores that sell the silicon and urethane I need D : Does anyone from the Vancouver area know where to find it? Also using the above method can you cast marine heads, torsos, legs ect.?

recasting of Copyrighted works is not allowed for discussion here.

That being said, I don't know of anyone who buys silicone and resin at a physical store. I use The Engineer Guy who I think is based in Georgia. Decent prices and fast delivery.

aerethan wrote:
That being said, I don't know of anyone who buys silicone and resin at a physical store.

I did that very thing just a couple hours ago!

I think the difficulty of finding it in most areas probably has something to do with your observation though. I'm pretty sure the only reason the shop I bought it from even carries it is because the owner's a caster himself.

As for places to order it from in Canada, I'd refer you to the list on the first page, Marathon. SSC has all kinds of product available.

An interesting tutorial.

I'm wishing I had this 20 years ago - heh. I learned all that in my first 6 months back then.

Still, that was all metal casting (heat resistant RTV) so the miscasts went back into the pot. It set me up for resin casting though.

I've been using Ultrasil (I prefer it over pinkysil) and easycast myself - got put onto Barnes by a mate in the FX industry many years ago (we all used to use Dow Corning stuff through a local distributor back in the day).

Aesome work dude, really like it!

Good to hear you guys are still finding the tut helpful!

How would you go about casting a head?

When I do helmets I cut the neck a few neck rings below the helmet (I am talking a marine here) and glue it to the plasticard I am using as the bottom of the casting box. Once I have poured the silicone I just pop him out and pour the resin as normal, as long as you use a silicone with a decent amount of flex you will be able to pull the cast pretty easy. I find some of my older moulds have split a little at the edges but they still cast a decent helmet and are actually easier to pull the resin cast from

Hope this helps!

Hey BLACKHAND
Would casting tank treads be impossible? Also i heard from people that white resin isn't good for detailed pieces.

As long as you designed the back of the tank tread to be flat it would be simple to cast. And as for white resin not taking detail I have never had a problem, couple of tips though.

Pour the resin as soon as it is mixed, letting it sit for more than 10 seconds or so will lower the viscosity a lot and it will not reach the crevices of the mould or allow trapped bubbles to release. At least this is the case with the quick curing resin I use.

Always dust your moulds with talc powder, the granules force bubbles away from the surface of the cast so that they rise to the top (the flat edge which in a tank tread will be hidden). just shake a bit of talc in the mould then blow it out making sure the talc isn't trapped in corners.


Hope this helps, post some pics of the treads if you do them!

Recently made some very small castings to produce some infantry weapons.

Anyhow what I did to make a couple two piece molds for really tiny bits:
1) build lego box and place it on a nice smooth surface (part of a CD case for me)
2) Fill the box about 1.5 standard lego bricks high with clay.
3) Press bits into the clay to about half depth. I tried to orient them so that there were as few "diving bell" type pockets for air to stick in as possible.
4) Pressed a bit of sprue into what was to the the top of the mold to serve as a resin reservoir.
5 - later cut) On my first try I also pressed bits of wire into the clay to form channels for the resin to enter and the air to escape, however a somewhat easier method occurred to me later.
6) Mix silicone rubber. I'm using smooth-on OOMO-30, from their starter kit. Nice thing is it is a 1:1 mix, so you can do it by eye in a cup. My only degassing was to wait a minute or so for some bubbles to rise. I have since read that the pouring in a thinnish stream also debubbles to some degree. Wear gloves. Have ventilation.
7) Pour over the mold. I just poured it on in one location allowing it to flow everywhere else. Made the mold half about 1 lego brick height thick.
8) Wait all day. The stuff stays sticky for some hours. So just leave it all day or overnight.
9) Disassemble lego box & remove rubber mold half. Peer at it, it's pretty cool. Get rid of the clay.
10) With a very sharp knife you can now remove any silicone you don't want to be in this mold half. I had a few places where the silicone had got under the bits into some gap between them and the clay. I'm about to make a mold for that half of the bit, so I can just cut that part off and the second mold half will get that part. Shouldn't be much if any of this.
11) Cut some registration holes into the mold. Just some nice wedges down into it around the edges and where you can fit them. Use a very sharp blade (eg new hobby knife blade).
12) Reassemble the lego box around the mold half.
13) Paint the mold half with a thin coating of petroleum jelly (Vaseline). You want it to cover the entire mold, but with a very thin coat. I used a cheap paint brush I had (now dedicated for this purpose).
14) Press the items you are making a mold of & the sprue for the reservoir back into their mold cavities. The petroleum jelly will help suction them in there so they stay put nicely.
15) Mix & pour more silicone. Wait 6 hours or so again.
16) Disassemble lego box.
17) Separate mold halves. Be careful. They might stick some. If you didn't get enough petroleum jelly they might be stuck. Maybe you could rescue that with some careful knife work? Depends how bad it is. There is a method to making molds where you cast one big block mold then cut it into a two part mold, but seems unlikely to work with these fiddly tiny bits.
18) Remove the bits & sprue and examine the mold. Cool!
19) Using a super sharp knife remove any little bits of silicone you don't want in there. Might be a bit of flashing type stuff in a few places. Remember you aren't making another mold half now though, unlike in step 10, so whatever you remove is going to be part of your casting. Should be very little of this though.
20) With a super sharp knife cut channels for resin to enter and air to escape or clean up any channels you molded in. Just little V shaped grooves. Try not to cut to much deeper than you want, but it doesn't have to be perfect. Lots of images of roughly how to do this. You can also take a look at a finecast model for tips. Basically you want to try to get a channel into any "diving bell" type geometry, and out of the end of any dead end. The channels for air escape can all connect together into a channel which runs out the top or side of our mold someplace (not inside the resin reservoir!). Just try to envision the resin pouring down the little tubes and air being pushed out and where a bubble might form. The resin channels I tried to make close to 1mm in diameter. The air ones can be really thin, but you want to make sure they are actually open channels. You can cut into just one mold half or both. I did a bit of both because some bits were easier to cut into one side or the other, but most of my air channels were all in one side. Would be a bit tough to make sure they were lining up perfectly.
21) Dust the mold halves with talc (baby powder). Knock off the excess. People say it helps the resin get into the details and tend to cause small bubbles to be internal rather than at the surface. I didn't try it the other way, but had no surface bubble problems so perhaps it did.
22) Put the mold halves together. Secure them somehow, but gently. My molds ended up being about 1 inch thick, 1.5 inches high, and 1.5 inches wide. Fit 2 guns in one mold and for close combat type weapons in the other. I secured them with a rubber band which was the right size to hold them together, but not squeeze them out of shape.
23) Assemble resin supplies. Resin parts, mixing vessel, stir stick, garbage bag, paper towels to clean up, chemical stopping gloves (not latex, latex is porous and is not good protection against chemicals), I used a cardboard box lid as a disposable surface to do the operation on, a small syringe is useful, could probably get by with a disposable spoon. I did this outside. The resin chemicals are fairly nasty.
24) The next steps you want to do quickly. The resin (at least the kind I have) starts increasing in viscosity in only a minute or two, and the more fluid it is the better.
25) Mix the resin (I was using smooth-on resin from their kit... kind of which I had a slower curing version). Go ahead and mix a bit more than you need, the amounts I was using were so small (probably less than 2ml) that it would be difficult to measure them out without real tools to do so (eg disposable syringes). I think I made about 10ml each time, but at the rate I'm going I expect the resin components to go bad before I use it up anyway and it isn't that expensive ($25 for a pound of resin). Pour part A, make a mark to double the height (my cup had pretty straight sides, so I could just assume it was a cylinder) pour in part b. Stir it up with your stick (eg a chopstick). Try not to put tons of bubbles in. Try to go quick. Try not to keep the resin part containers open long and close them tight. The stuff goes off by sucking water out of the air.
26) Get the resin into the reservoir on your mold. I used a little plastic syringe left over from a bottle of infant ibuprofen. That worked very well, if you can get one. Those things can be rather expensive to just buy one at a time though. It ought to be running down into the mold. Best case you will soon see it show up in the vent holes as it has gone all through the mold. However most likely there are still bubbles in there. You might even see some trying to get out of the resin channels or air vents.
27) Gently squeeze the mold to coax those bubbles up and out. Add resin as necessary if more is going into the mold. With this size of mold the whole thing is still rather flexible, but the bits are so tiny that the resin and bubbles get trapped very easily. I did this out of desperation on seeing those bubbles, but it worked fantastically. You will see the resin get gooier and gooier.
28) Wait a good hour or two for the resin to harden. You can demold much quicker (15 min for the resin I'm using), but the castings are fairly bendy. If you wait they will get much harder and won't bend.
29) Carefully peel off a mold half and extract your castings. Look for bubble problems, see if maybe some of your vents/channels aren't working well enough.
30) Do more castings! It is likely that the next few will work a bit better as you can go quicker having just done it.
31) Put everything with unpolymerized resin parts in the garbage bag for disposal. If there are a few items you want to reuse (I'm reusing the syringe) you can often pop the resin off once it is hard... or just leave it. But any such item should be considered contaminated. I'm keeping all this stuff in a box in my garage.
32) Let it sit even longer to really really finish hardening. Mine seemed still slightly bendy until I left them all day/overnight. Hard enough to demold and to hold their shape, but maybe not quite good for cleaning them up.
33) cut off flash/channels/vents
34) sand seams underwater (to catch the dust)

I was really surprised at how well this worked. Good castings of the guns first try, the swords & soforth took two tries (more bubble problems).

Makes no financial sense, probably cost me $80. But it was fun and I have only used about 10% of the rubber and resin so far.

Dahl Corp. wrote:Hey BLACKHAND
Would casting tank treads be impossible? Also i heard from people that white resin isn't good for detailed pieces.

I think you misunderstood the white resin bit. The problem with white resin is that the details don't show up in pictures or much to the naked eye even though they are there. A simple wash with a black ink or wash will show all of the detail so that pics will be clear and it makes it easier to see if there are any bubbles or defects. The resin itself(in my case Smooth Cast 305 from Smooth On) picks up detail 1:1 with the original.

BLACKHAND wrote:As long as you designed the back of the tank tread to be flat it would be simple to cast. And as for white resin not taking detail I have never had a problem, couple of tips though.

Pour the resin as soon as it is mixed, letting it sit for more than 10 seconds or so will lower the viscosity a lot and it will not reach the crevices of the mould or allow trapped bubbles to release. At least this is the case with the quick curing resin I use.

Always dust your moulds with talc powder, the granules force bubbles away from the surface of the cast so that they rise to the top (the flat edge which in a tank tread will be hidden). just shake a bit of talc in the mould then blow it out making sure the talc isn't trapped in corners.


Hope this helps, post some pics of the treads if you do them!

Thanks for the tip Blackhand!

Wow, nice breakdown Cosmid thanks for posting!

@Aerethan - Hey your still watching! And yeah I always need to wash my bitz before I post pics on Dakka.

@Dahl - No worries!

aerethan wrote:

Dahl Corp. wrote:Hey BLACKHAND
Would casting tank treads be impossible? Also i heard from people that white resin isn't good for detailed pieces.

I think you misunderstood the white resin bit. The problem with white resin is that the details don't show up in pictures or much to the naked eye even though they are there. A simple wash with a black ink or wash will show all of the detail so that pics will be clear and it makes it easier to see if there are any bubbles or defects. The resin itself(in my case Smooth Cast 305 from Smooth On) picks up detail 1:1 with the original.

Oh I see now

BLACKHAND wrote:

Always dust your moulds with talc powder, the granules force bubbles away from the surface of the cast so that they rise to the top (the flat edge which in a tank tread will be hidden). just shake a bit of talc in the mould then blow it out making sure the talc isn't trapped in corners.

Hope this helps, post some pics of the treads if you do them!

Hey BlackHand, do you use a release agent? or does the talc powder do that for you? or both?

I normally use Ease Release 205

The Pinkysil I use is really flexible and I can twist and flex the mould to pop out the resin.Part of it may be because the Easycast resin is made by the same company to specifically work with it.

That said the Talc powder does seem to create a surface to the resin which separates well.

I used to worry when I used release agent that it was going to obscure details by pooling if I sprayed on too much, has anyone ever experienced this?

See thats why I was asking I find i get alot bubbles and lose some tiny detail when the release agent pools.

I just worried about the mould, if I dont use the release agent.

if what you say is true about talc powder that that should reduce my bubbles

I found my casting changed drastically once I started using Talc, I went from spending hours GSing voids and bubbles to getting about a 90% success rate on my casts, the 10% failures where pretty much pouring the resin too late and losing viscosity or not suqeezing the mould to dislodge bubbles from tricky overhangs.

When it comes down to it, reducing the lifespan of your moulds by a few pulls is worth doing if your casting success rate goes up.. if that makes sense

I've used both talc or release agent or talc and release agent together.

I didn't like the results with just talc. It made the surfaces a tad grainy. Mould release works best, just a thin film works wonders. I use it primarily to exend the life of a mould by preventing the resin from leeching oils from the silicone. It's a little expensive, but it goes a long way.

@ Blackhand -- how do you deal with the resin fumes after mixing in the catalyst, while pouring. It feels like 1-2 minutes of noxious death. I'm ordering a 3m respirator for my airbrushing, I think it may be something to use for casting too.

@AesSedai - I havn't had a problem with resin fumes at all, what products are you using?

Again, because the products I use are designed to work together (I don't get paid to plug them by the way, honest!) I havn't noticed a degredation of the silicone due to the leeching by the resin, but it may also be the limited number of casts I am doing.

The eayscast I use is a 1:1 mixture not base:catalyst so that might be why yours produces fumes where mine doesn't, not sure?

But hey I am so desensitised that I don't even where a mask when I sand resin, will probably come back to haunt me though....

If you are using SILICONE rubber molds, then no release agent is needed. If you are using URETHANE molds, then you need a mold release. Keep in mind this is strictly for resin. If you are casting dental plaster or the like, then no mold release is ever needed as it's a water based cure.

Smooth Cast does not give off any fumes at all. I cannot comment on other products as I stick to what works for me.

If you are using Oomoo(a Smooth On product that is a 1:1 mix RTV silicone rubber) and Smooth Cast products such as Smooth Cast 300 or 305 then all will work well right out of the box.

If your resin involves fumes, I'd look for a new resin. But that's just me.

I'd also add that I haven't once covered my face when working with resin or rubber. I'm smart enough to hold my breath if I'm sanding or sawing resin.

Whoa, your resin doesn't produce any smells? Are you serious?

I too have only used 1:1 compounds. Resin and hardener. I called the hardener a catalyst but that might not be the correct term. I'd like to link some products but, I can't pull up good websites do to searching in English for Japanese products. I have been using basic polyurethane systems.

I have used multiple kinds of resin. Each compound has smelled like toxic death post mixing. In the case of a very rare soft cure, the smell lasts more than a year.

Blackhand wrote
But hey I am so desensitised that I don't even where a mask when I sand resin, will probably come back to haunt me though

Dude, please don't take gambles with your health. You and aerethan are my resin casting heroes, so don't develop respiratory problems, okay? Masks are cheap.

aerethan wrote
I'm smart enough to hold my breath if I'm sanding or sawing resin.

Those dust particles are light and stay suspended in the air for a a minute or two. Then they settle on surfaces and get kicked up into the air again. Eventually, they are sucked up one way or another. Vacuum or nostrils. You can sand in a tub of water or you can wear a mask. aerethan you beast, you airbrush too! You must have a mask already, don't you? It's a 20 dollar investment for peace of mind/convenience (you can take a breath now) at the least and a sensible health precaution at best.

I don't use a mask for airbrushing either.

I didn't notice any smell but I did the casting and one hour cure outside to avoid any fumes... and I was using very small amounts.

If I didn't get a hard cure I would throw the castings away. Don't want unpolymerized plastic seeping out.

Sanding in water was very easy.