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This is awsome. Great job and thanks.

@Blackhand: Just bought a citadel basing kit (the 40k edition), and am strongly considering doing some casts of urban bases so I can get some mileage out of the etched brass and excess plasticard I have.

My question is, How do you ensure the bottom of the bases (at the top of the mould when you pour them) is clean enough and doesn't spill over the edges and leave you with messy edges?

Also, how do they sit on terrain? I find having a hollow base really helps in keeping my broadsides from prematurely nosediving off ruins before they get dark-lanced, so a flush base sounds problematic.

Thanks Blackhand!

Being careful to pour only just enough? the surface tension of the resin will usually keep it from spilling out of the edges of the mould. This may leave you with a rounded bottom so I then put a sheet of medium grit sandpaper on my desk and run the basae back and forth till the bottom is flat.

When I have flash on the bottom edges of the base I run a knife around it, following the angle of the sides and then sand it as above.

One the posts above suggests using pvc plastic laid flat on the mould to reduce flash but I haven't tried it yet.

TBH I have been casting most of my bases with the remnants of liquid resin left over from other castings so I have some bases that are normal size and some that are shallow, its not so bad as it adds some variety to the height of the rats without a ton of converting ( I hate a whole unit of models all exactly the same size!, they're not clone troopers!)

I have'nt tried em out on terrain yet...I guess it might help that they are heavier, but only slightly.

One tip when superglueing models to resin bases is to use a knife to slice a crosshatch pattern on the two surfaces that are going to have the glue on them before sticking them together. It increases the surface area that the superglue can grip on to and makes them really secure without pinning(thanks to The Painting Corps blog for this tip!)


hope some of these ideas help

Cheers

BLACKHAND

Thanks blackhand, the sandpaper is probably the way I'll go, I was just curious abouthow it goes with the easycast but sounds fine from what you said.

Will post up some pics of assembled resin casts later if I can.

Cheers, Klaw

Oh and don't breathe the dust, its nasty stuff

Hey guys I was just wondering if you would be able to take a look at these two products for me and offer some advice on whether they would be good for a casting noob. Thanks guys.

http://cgi.ebay.co.uk/Polyurethane-Fast-Cast-Resin-2KG-/230495368931?pt=UK_Toys_Wargames_RL#ht_1716wt_1064

http://cgi.ebay.co.uk/Terrain-Scenery-Wargames-RTV-3325-Silicone-Rubber-1KG-/250442696886?pt=UK_Toys_Wargames_RL#ht_1054wt_992

I would definitely go with the polyurethane, It looks like its liquid enough to reproduce detail and cures fast which is always nice.

I'm not so sure about the rtv rubber, I personally like a 1:1 mix which is simpler to use and means less chance of a mistake which could waste a whole mold. Might be worth looking for a simpler to use silicone rubber.

Hope this helps!

Ok well I'll keep looking into the silicone then. On another note does anyone know the weight comparison between plaster and resin. I only ask because I found the most amazing thread on warseer and it has rekindled my passion for some Hirst Arts molds. You guys should take a look, I'll post the link below when I get the chance.


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http://www.warseer.com/forums/showthread.php?t=260498

And just incase you want to expand beyond bases and shoulder pads, here's a little inspiration.

http://www.warseer.com/forums/showthread.php?t=177095

Yeah blackhands right. The 1:1 ratio for resin and mould compounds is something you should look for, very handy.

I've mucked up a batch or two just by adding a small amount too much of one component which prevented the pinkysil from hardening, and I can see this happening more easily with the small and frequent batch mixes you'd expect to use when starting out.

Yeah fair point. I really don't want to waste this stuff either at £35 + P+P its not cheap. I think I'll look into getting a few Hirst moulds first anyway, cheating I know, buying ready made moulds but I've wanted them for a long time anyway.

Hirst arts rock Lenny no shame in them at all

I am borrowing a set off my friend to cast up a bunch of castle ruins for my 40skaven and in reality its the only way I could achieve the look I'm going for.

Not sure about the weight differences of plaster and resin but it would be negligible I think.

For the project I am working on I bought a really hard plaster called Supercal 3 , In theory it is harder than dental plaster and should mean my casts will last the distance.

Yeah I heard of supercal, I think it may be the stuff Fireman Tim uses, it's supposed to be dead good.

Silicone Rubber will stand up to the abuses of Resin casting much better than polyurethane. Keep in mind that resin leeches certain properties out of the rubber each time you cast, so mold degradation is guaranteed, it just depends how quickly it happens.

The standard difference between Polyurethane and silicone is the ratio. Smooth On makes a 1:1 silicone that I use and am in love with. Other brands will require use of a scale to use silicone rubbers.

As for plasters, having done the whole Hirst Arts bit, dental plaster and supercal or anything like that is more or less the same at the high end. Hardness doesn't mean better. It may hold less detail, and after a certain PSI the hardness is negligible.

Plaster is a less hard set rule for mixing as it's difficult to mix up exact similar batches. The consistency you want for plaster is a lump free milkshake.

Hit me up if you want some pointers on casting plaster.

Thanks for the tips Aerethan! I will definitely be contacting you when I get to casting some of the Hirst arts stuff I am borrowing.

I have used Smooth On in the past and I agree that it's ease of use is a big drawcard.

Hey just got some shots up of some of my converted bases, moulds, casts etc.









Something to do while I wait for the Pinkysil to dry.

Those turned out great CK! Love the look too!

Lennysmash wrote:Yeah I heard of supercal, I think it may be the stuff Fireman Tim uses, it's supposed to be dead good.

Since you are in the UK, try talking to the guys at Tomps (online store). From what I have heard, they are pretty good at helping people out if they are not quite sure what they want/need. Their prices also seem pretty reasonable.

Ok so I've just checked out the website and it has helped a ton. As suggested by some I think I'll be going for a Silicone rubber. However I first need some more advice on the differences between condensation cure and addition cure RTV's.

Atm I am leaning towards an addition RTV due to the simpler mix ratios and its lower viscosity but anyone with first hand knowledge of one or both of these products would be heartily welcomed.

@aerethan, thanks for the tips and the offer. You seem to have experience with both plaster and resin would you be able to tell me which is the lighter. I'm looking to get some Hirsts in the near future and was wondering if casting them in resin might be lighter than plaster.

Sorry would someone be able to assess this product for me also. It wouldn't be my final choice just something to play around with until I can get a better grade of silicone. Sorry I know I'm asking loads of things here but I promise I'm doing my homework on this stuff too.

http://www.tomps.com/shop/value-rtv-silicone-05kg-p-247.html

@Captain Klaw -Very nice bases, I may have to make some similar ones for my necromunda gang.

@lennysmash - Sorry bud I am not sure what the difference is between condensation and addition cure RTVs maybe wiki it?
Having a look at the link I can only think the product has the same problem as the others you found which is the 20:1 mix ratio, but as a cheap trial product it looks fine.

And don't worry about asking questions that's the whole reason I started the tutorial!

Resin is by far lighter. Just keep in mind that it degrades molds where plaster does not.

What I did with my hirst arts molds is cast in resin once, then use that pull as masters for a second mold that I used for resin casting, keeping my Hirst mold as a master.

Lenny, I really recommend finding the Smooth On 1:1 silicone if you can as it's the single best product for resin casting as it doesn't require a scale and resists resin damage alot better than polyurethane.


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As requested from a PM, here is the resin that I use. For Hirst Molds I'd use the fast demold time, for 2 part molds I'd suggest a higher demold time as they have a higher pot time, which lets you pour more steadily.

I also use 10cc syringes. As soon as I start a non illegal project I'll post pics of how I do them.


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http://www.smooth-on.com/Urethane-Plastic-a/c5_1120_1209/index.html

I'm about to cast (almost finished sculpting/creating) some heads (10 of them) and was wondering what the best way of arranging them in the mould would be?

They each have a rimmed helmet and fixation for a gas mask, so they are slightly overhung in places (basically I'm sculpting heads with helmets and masks similar to this image.

I was thinking of casting them in a line, all facing in the same direction (so like a line of people standing one behind the other in a cue), with the neck towards the top of the mould (each head is currently on a wire rod for sculpting, so I would suspend them all in my mould area, then pour the mould agent) to make a single piece mould, then when it was set I would carefully cut between the heads along the line to create a 2 piece mould (although still try to keep the mould joined at the base to provide stability and ensure it is shut at the bottom - don't want all my resin to run out the bottom ).

Any thoughts on this? It will be the first small scale casting I will do (I've made one mould previous to this and the first which is not just an "open topped" flat mould- the parts to build a small one person drop pod that I built), so I am just wanting to know how people more experienced would choose to do it.

|...|....|
0...|...0
|__|__|

this is the best way I can describe your mold layout, ignoring the dots.

The middle is a straight channel that then turns out in one or 2 directions. then you turn back up, add in your piece, then add more channel to allow air to escape.

When you pour, you use the middle and slowly pour until resin comes out each side hole.

The other option is:

___________
|....|....|
0....0...0

With this setup you need to be very careful about air bubbles as there is no vent on each piece to let air out.

More than anything, trial and error. See what works for you, and never expect your first mold to work quite as intended.

EDIT: just saw that you intend to use a single piece mold, in which case the second diagram is the one you want.

SilverMK2 wrote:I was thinking of casting them in a line, all facing in the same direction (so like a line of people standing one behind the other in a cue), with the neck towards the top of the mould (each head is currently on a wire rod for sculpting, so I would suspend them all in my mould area, then pour the mould agent) to make a single piece mould, then when it was set I would carefully cut between the heads along the line to create a 2 piece mould (although still try to keep the mould joined at the base to provide stability and ensure it is shut at the bottom - don't want all my resin to run out the bottom ).

I would go with this plan but how thick is the wire the heads are sculpted on? you may want to thicken it up with Gs or modelling clay so that you have a larger channel to pour the resin into,
Oh and try and add a few bits of sprue to your helmets to trap bubbles of air away from the resin!

other than that just have a go!

The wire is pretty thick, about 2-3 times as thick as a regular paperclip. Will that be thick enough?

And when you say add in some sprue, what do you mean?

I could always chop the wire down, drill some holes in a bit of sprue, then mount the heads on the sprue so the base of the neck is touching the sprue? It would be easier to thicken the join as well...

Then I could use the same technique as you used in your tutorial of then sticking the sprue to some backing and pouring in the mould material normally, rather than suspending the whole thing as I was planning.

resin channels should be as thick as sprue as much as possible. Heads can always have their necks filed down after being pulled.


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I should also mention that if anyone decides to go with 10:1 silicone, you can get a digital scale on ebay for about $9 shipped from hong kong. just make sure it measures down to 1/10th of a gram.

Found out this morning that my part A of oomoo 25 set itself after sitting for about a year so I ended up using some 10:1 silicone I had sitting around that apperently has infinite shelf life.

Being that this project is legal I'll post pics of the mold tomorrow after it is fully cured.

I would mount them on sprue and then on backing board, it means you don't have to be so accurate with the amount of silicone you make up, as long as you have enough to cover the heads with a fair amount as a "base" for later when you flip it you will be fine. Suspending the model and having to pour up to cover the sprue can mean you end up with silicone left over or not enough and you have to scramble to mix more and get it in the mould before it sets...hope that makes sense

By glueing on bits of sprue I mean looking at the heads and thinking about what will be the lowest parts of the mould, this is where the bubbles will form. Get some thin sprue or plastic rod, cut small section of it then glue them to the place where you think bubbles will form. When you pour in the resin instead of bubbles forming in the head they will be forced down the channel the sprue formed in the mould. It may mean a bit of cleaning up once you pull the cast but that is preferable to cleaning up bubble voids with GS.

@Aerethen - Will be very cool to see pics of your mould , I have the distinct feeling you have done this more than I have and will be cool to see how a more expereinced caster sets up their moulds.

For my molds, the first thing is setup of the masters. I use glass from a picture frame to make one piece molds on as it is perfectly flat and easy to remove silicone from.
For this mold today I used regular PVA glue to secure the masters onto the glass.
Once the masters are in place I then use lego bricks to form a rectangle around the pieces with at least 1/4" clearance on each side, the same clearance that the masters have from each other.
For a single piece mold of 20mm bases I only went 2 bricks high which was plenty.
I then secured my lego form to the glass with PVA glue. Once the glue had dried, I mixed up my silicone. Today I had to use 10:1 stuff as my 1:1 apperently expired it's shelf life and set itself inside the bottle.
I used 124.5 grams of silicone which then required 12.4 grams of setting agent.
I poured the rubber in from a corner, letting it ribbon over itself. I hold the cup high enough that only a thin stream of rubber falls in, which causes most major bubbles to pop on the way down.
We pour from corners where there are no parts of the masters present. You want the rubber to envelope the masters as if a wave was washing over it from the shore.
Provided you are doing this on a level surface, the rubber will even itself out on it's own, giving you a near perfect flat bottom.
The demold time for this rubber was 4 hours, I let it sit for about 6. Interesting sidge note, non dried PVA glue will cause rubber to not set, so my corners are now drying properly after the mold was taken out.
To remove the mold, disassemble your legos until the mold is sitting on the glass alone. Then, flip the glass over and carefully pull one corner of the mold off until you can see it start to let go thru the glass. Do this
in small sections and slowly so that you don't tear the mold.
Once the mold is off the glass, it's time to remove the masters. Carefully flex the mold in each direction for each master so that the sides come loose. Then for my bases I used surgical pliers to pull out the masters.

Now that your eyes have gone crossed from reading all that, here's some pictures of todays last minute decision project:







These are ruined temple bases that I will be using for my upcoming High Elves project. I will also be offering them for sale after I build up a small inventory of them. Casting takes time to build numbers.

Wow, never thought of using glass as a base, do you glue down your legos? it doesn't seem like you do by the pictures, do you ever have silicone leak out from underneath them?

I've got to say I am a lot more impatient than you, I use superglue to hold down my masters a then sand them to tidy them up afterwards, but I think thats a result of having a silicone and resin that both have a demold time of 20 mins. the attraction of going from master to mould to casting in one night is too much and I tend to rush it Result? bubbles!

I will definitely copy your method of pouring silicone to reduce the bubbles though, it makes a lot more sense then my method of using an old brush to paint on a a layer of silicone then pouring the rest in, I have found that it just ends up making slightly submerged bubbles that pop after the master is taken out of the mold and ends up filling every time I cast.

http://www.youtube.com/watch?v=ART2V2ICxZI

I use PVA glue to glue down the legos yes. My resin is 5 minute demold, although for 2 part molds I'll be switching to 30 minute demold resin for the increased pot life.