Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

^
And do you use the pressurization techniques or just simple casting without pressure tank (to completely eliminate bubbles)??

=^.^=

Also, how fast does the resin you use set? The resin I'm currently casting with sets in about a minute or two, so I don't see how you could use a pressure vessel unless you did the pour inside while already pressurized.

I'm not sure if this has been asked, I still have yet to read through the article, but how would you make a two part mold out of instant mold? I've tried several times but it doesn't come out right. I'm going to have to find that moding material you use because I've been wanting to make my own bits for my Deathwing, but the molds dont come out right :/

Check my blog in my sig, I have a 2 part mold tutorial using instant Mold. msg me on the blog or here if you are still lost after reading it.

From how I have seen it used so far it is handy fro pressmoulding but not sure how good it would be for a two part mould that had to stand up to repeated castings, would be great to see how Theunicorn achieved it.

I wont post pics here, because I totally violated some IP with instant mold, but here is the link http://warfrog.blogspot.com/2011/05/saving-ebay-finds-by-casting-your-own.html

to my Blog tutorial. I also have a white metal mold making and casting tutorial as well as a Smooth cast / Smooth On resin tutorial.

BLACKHAND From how I have seen it used so far it is handy fro pressmoulding but not sure how good it would be for a two part mould that had to stand up to repeated castings, would be great to see how Theunicorn achieved it.

Best thing is that you just reheat and reuse, so how it holds up really is not an issue. I do intend to try using it instead of sulfur free clay for the first side of a Silicon mold, If it does not react to the Smooth On it can greatly decrease my 2 part mold making time. Because I hate cleaning clay off of my originals and mold boxes.

Here are some Necromunda Minis that I restored lost weapons using Instant mold and ProCreate.
http://1.bp.blogspot.com/-FSGDLrn2VD8/Tqyq065Wp0I/AAAAAAAAAq4/0s8ItCWAas4/s640/2011-10-29_21-37-57_643.jpg

And here is Instant mold and GreenStuff in a 2 part mold, copying tyranid vents I made on my Swarmlord
http://3.bp.blogspot.com/-MSdC30mbJX4/TpTgVRVQ4MI/AAAAAAAAAUo/4QxS-P0lSw0/s640/16782239631.jpg

The loss of detail on the casts is disheartening. Good idea on using it for setting up silicon molds though!

I'm not sure if anyone has come across this product but I picked up some a little while ago and just got round to trying it out. http://www.youtube.com/watch?v=06mSBb_rWMo

I did a 2-part cast of a Praetorian to check out the detail retention and I have say I was very impressed. The details are crisp and clean, the only problem I found was setting the model correctly as this stuff sets rock hard it can be a little tricky to remove anything with overlaps.

I can get Instant Mold to mold detail, I use a 2 piece mold and a very strong clamp to keep pressure on the halves while the GS or ProCreate is curing, the key is to use enough IM to have a around 1/4 inch or more of IM at the thinnest parts of the mold.

I don't like the Blu-Stuff product when compared to Instant Mold, Mainly because Instant mold is reusable

theunicorn wrote:I wont post pics here, because I totally violated some IP with instant mold, but here is the link http://warfrog.blogspot.com/2011/05/saving-ebay-finds-by-casting-your-own.html

That's actually what I had planned to try out. Thanks for the link

Glad it was helpful.

I have been away for far too long :(

@Gitsplitta & Blackhand: Hello again guys!

Turns out magic the gathering is also addictive

I have however gotten back in, to necromunda of all things, and am planning on doing some more casting on space marines and specifically weapons for necromunda.

I am currently in the process of back-tracking through the forums, but at the moment, is there anything on casting small weapons i.e. sniper rifles and shotguns?

would this work for creating a model?
if so would you cast it's parts or the hole thing?


Automatically Appended Next Post:

Captain Klaw wrote:I have been away for far too long :(

@Gitsplitta & Blackhand: Hello again guys!

Turns out magic the gathering is also addictive

I have however gotten back in, to necromunda of all things, and am planning on doing some more casting on space marines and specifically weapons for necromunda.

I am currently in the process of back-tracking through the forums, but at the moment, is there anything on casting small weapons i.e. sniper rifles and shotguns?

I belive WAR SMITH is.

http://www.dakkadakka.com/dakkaforum/posts/list/428357.page

But I dont think anything is availible yet.

kshaw2000 wrote:would this work for creating a model?
if so would you cast it's parts or the hole thing?


Automatically Appended Next Post:

Captain Klaw wrote:I have been away for far too long :(

@Gitsplitta & Blackhand: Hello again guys!

Turns out magic the gathering is also addictive

I have however gotten back in, to necromunda of all things, and am planning on doing some more casting on space marines and specifically weapons for necromunda.

I am currently in the process of back-tracking through the forums, but at the moment, is there anything on casting small weapons i.e. sniper rifles and shotguns?

I belive WAR SMITH is.

http://www.dakkadakka.com/dakkaforum/posts/list/428357.page

But I dont think anything is availible yet.

It greatly depends on the model and it's pose and parts. I'll give you some examples:



This model is posed as such that it could be cast as a single piece(as GW does). No parts are really posed in such a way that couldn't be cast in a 2 part mold.



This model has it's weapons pointed away from it's body. So the Body would be one mold, and the 2 weapons and hands could be done on a second mold(speaking in terms of resin work, metal spin casting allows for more stuff in a mold).

Please note that I'm not suggesting you cast these 2 models, I'm merely using their anatomy and positioning to answer the question. Some models are so complex that they will need several molds to make up all the parts(the Doombull in Finecast is about 5 separate molds and sprues).


As for casting weapons, the same principles apply to them as to other 2 part mold items. Make sure you have vents for air to escape, and a proper gate through which to pour(theunicorn's method of using a syringe as the pour gate is brilliant).

It's an easy wager to say that your first mold or three may not be perfect. But mistakes will teach you what you need to know that we can't type here for one reason or another.

EDIT: stolen from the link above my post:


That is what a proper setup for making a weapons sprue looks like. Use small wire like paper clips for vents and leftover sprue or plastic rod for the frame. I imagine his casts will turn out well, especially if he's pressure casting.

Captain Klaw wrote:I have been away for far too long :(

@Gitsplitta & Blackhand: Hello again guys!

Turns out magic the gathering is also addictive

Hey Klaw, good to see you back.. and yep magic took several years of my life before wargaming took over

As for casting guns, Aerethan has it right and the pic he posted is a perfect example of how to do it.... course getting a decent two part mold is an art itself but a decently constructed master sprue like the ones in the pic is a must.

Of course I'm right! have you met me?

/narcissism

I agree that while a proper master sprue is mandatory, it doesn't guarantee that the mold will come out perfect. Bubbles can wreck the most well thought out plans.

For my rinky dink home operation I use the "bombs away" method of pouring silicone rubber as I don't have access to a degassing rig. Sadly it isn't a precise science but more of an art that one has to do to learn.

Is there any silicon that can be used for hot plastic, instead of resin?

define "hot"

Aerethan wrote:define "hot"

Just above melting point I.E liquid

If you are using anything that hot, I'd recommend any of the metal casting rubbers that are made for high temperatures. Micro Mark sells a kit for that I believe.

Our two-part liquid RTV (Room Temperature Vulcanizing...cures without heat) silicone mold rubber is ideal for making duplicate parts with our casting resins. To make a mold, mix parts A and B together and pour into a mold box containing your pattern. After curing, the mold is soft and pliable and reproduces every detail of your pattern. And, because it is genuine silicone rubber (withstands up to 600 degrees F), you can use these molds to cast small metal parts with our low-temperature alloys. Instructions for making molds are included.

It might be worth finding out what the max working temp is for Oomoo silicone from SmoothOn.com

I picked up the syringe injection technique in the past few years from someone online, funny enough I would have credited it to Aerethan off of the top of my head but I am truly unaware of where I "stole" the technique from.

These Necromunda dudes were acquired as bitz or in ebay lots as incomplete miniatures. I made replacement guns from originals that I owned using Instant Mold and ProCreate. In this case I chose this method over the usual silicon and resin because I did not need more than 3 of the bitz to complete the missing pieces. The quality is a little less than what I can achieve with Smooth on products but the cost is incredibly lower because the mold material is nearly infinitely reusable.

Check my blog for a complete walkthru

Afaik I was the first one on dakka to use the syringe idea, which I stole from a youtube video I saw years ago, but I didn't think to use the syringe itself as the gate.

@Aerethan:

How succesful is the syringe method? I can see how complicated moulds like the weapons sprue might be difficult (especially without the vacuum chamber)

Is the idea to inject the resin down one side through one or both side tubes of the master sprue, and have it fill upwards through vents at the base, through the guns (or what have you), pushing the bubbles with it as you go?

@Blackhand: how does pinkysil deal with pressure and or talc? in a fiddly two-part mould like this, I imagine bubbles and leaks can be problematic.

Nice to be back.

Pinkysil loves Talc, I use it everytime now. The only effect is a slight texturising of the resin but it helps the paint grip so its a win/win.

as for injecting I haven't had the chance to try yet but if you build a decent mould box that encompasses the mould on every side but the one you are injecting into then it should be fine. If you decide to use rubber bands to hold the two sides together than make sure to use pieces of card on the sides of the mould to distribute the pressure of the rubber bands or the interior of the mould will be warped.

Captain Klaw wrote:@Aerethan:

How succesful is the syringe method? I can see how complicated moulds like the weapons sprue might be difficult (especially without the vacuum chamber)

Is the idea to inject the resin down one side through one or both side tubes of the master sprue, and have it fill upwards through vents at the base, through the guns (or what have you), pushing the bubbles with it as you go?

@Blackhand: how does pinkysil deal with pressure and or talc? in a fiddly two-part mould like this, I imagine bubbles and leaks can be problematic.

Nice to be back.

WIth a syringe I push resin into the main pour gate as well as pull it out from the vent channels It helps to remove large air bubbles.



You can on this photo where the syringe pour gate was once it began to back up with resin i would put the tip into the vent gate and draw up resin and air bubbles from the pour gate. I used rubber bands and mdf boards around these molds when pouring resin

Hot Damn! I never thought of drawing out of the vent gates, thats genius!

Where do you get your syringes, are they reusable, and if so how do you clean them? Also what resins do you prefer for this technique?

Smooth on products, I have tried others and smooth on seems to be the best I can find
http://www.smooth-on.com
I order mine from Atlanta from these guys http://www.theengineerguy.com/cgi/commerce.cgi?display=home

Resin casting tutorial
http://warfrog.blogspot.com/2011/11/resin-casting-tutorial.html

Mold making tutorial
http://warfrog.blogspot.com/2011/11/two-part-mold-making-tutorial-resin.html

Syringes on eBay 100 count $18.98 delivered to your house
http://www.ebay.com/itm/10mL-Vet-Syringe-10CC-Luer-Slip-100-bx-10CCVLS-/280715778535?pt=LH_DefaultDomain_0&hash=item415bf6d9e7#ht_1371wt_952

I get alot of uses out of them. I keep 2 labeled for A & B measuring for tiny pours and a couple for mold injection, once the resin sets I use a 2mm brass rod to knock the plug or cured resin out of the syringe, do remember to remove the plunger before the resin cures.



Automatically Appended Next Post:
Anyone following this thread should also check out the resin addict forums as well. Its great for all skill levels of sculptors and casters.