tips for resin casting?

[silastic armor fiend]

i just became interested in casting resin and think it would be very helpful in the way of steampunk. i was wondering if anyone has some advice for me, specifically how to get rid of those little air bubbles and mix the dyes. all my attempts to color have resulted in a kind of muddled brown. if it makes any difference im using polyester resin. maybe somebody can suggest something better to use?
any replies will be much appreciated.

[Rev. Marx]

I've never used polyester resin, but I've done quite a bit of casting with urethane resin. Maybe you should give that a try.
Something like this...
http://www.micromark.com/CR-300-QUICK-CURE-CASTING-RESIN-32-FL-OZ,7776.html

I never have problems with bubbles, and I use dye in almost every batch (though I haven't tried to mix colors). I find this stuff pretty easy to work with. I could also recommend...
http://www.smooth-on.com/Urethane-Plastic-a/c5/index.html

[bizarre_chicken]

i just became interested in casting resin and think it would be very helpful in the way of steampunk. i was wondering if anyone has some advice for me, specifically how to get rid of those little air bubbles and mix the dyes. all my attempts to color have resulted in a kind of muddled brown. if it makes any difference im using polyester resin. maybe somebody can suggest something better to use?
any replies will be much appreciated.

When you've finished casting, carefully tap the edge of the container for about five minutes. This'll move the bubbles, cause them to surface more quickly. Also, it's better, when making models bigger than about 8cm in any direction, to do several small pours, rather than cast it all at once.
Ink works well for colouring the resin, but I've found more often than not it's the resin that reacts well to colour, not the other way around - if your attempts with colour are failing, use a different resin.

[Titus Wells]

If you can pour the resin slowly from a height into the mould this will help reduce bubbles. You need to make sure you use the correct type of casting resin. Something like Replicast, Por-A-Kast and Ultrakast is best for casting any objects larger than about the size of a key. If you use normal polyester or epoxy resins (gel-coat or layup) designed for fibreglassing you'll find the build up of heat when they cure will cause them to crack and burn... and it stinks! If you're creating hollow casings or making body armour out of fibreglass these resins are fine but I'd suggest no more than three layers of glass fibre at a time to prevent excessive heat.

[Gaspard de Coligny]

We need a sticky for resin use. And leatherwork...

REALLY.

[bizarre_chicken]

We need a sticky for resin use. And leatherwork...

REALLY.

You say that, but it doesn't tend to come up that often.
Not as often as air kraken....

EDIT:

Okay, maybe leatherworking.

[Gaspard de Coligny]

We need a sticky for resin use. And leatherwork...

REALLY.

You say that, but it doesn't tend to come up that often.
Not as often as air kraken....

EDIT:

Okay, maybe leatherworking.

What is important ? the value of the knowledge or the fact that the massive flood of newcomer are more interested in discussing the fact that there is too much wood brass and cogs in steampunk aesthetic ?

Sometimes, reading about a craft make you want to try it. For resin and casting, for the last 10 year i've regularly bought supplies... never done anything and let them expire because I was not sur how to do, which size was the limit between mild success and total failure and the fact that some sensibility to chemicals and chronical migrainas put me off from tinkering with too smelly stuff without real goal.

An howto about casting my first part of anything might put an end to this. I still have around 2 years before my current supllies are over their expiry date.

[silastic armor fiend]

thanks for the tips everyone!

What is important ? the value of the knowledge or the fact that the massive flood of newcomer are more interested in discussing the fact that there is too much wood brass and cogs in steampunk aesthetic ?

how could someone think theres too much wood brass and cogs? in fact, im pretty sure there arent enough   

[JingleJoe]

thanks for the tips everyone!

What is important ? the value of the knowledge or the fact that the massive flood of newcomer are more interested in discussing the fact that there is too much wood brass and cogs in steampunk aesthetic ?

how could someone think theres too much wood brass and cogs? in fact, im pretty sure there arent enough   

Yeah, I'm not entirely sure what you're getting at Gaspard.

As for sticky-ing certain tutorials, there is not yet one that encompasses enough of either of those two subjects to deserve a sticky, if you want information on these things dont forget there is a search function- when veiwing the How To section it should only search within this childboard, narrowing your search results to the how to's.

[Gaspard de Coligny]

thanks for the tips everyone!

What is important ? the value of the knowledge or the fact that the massive flood of newcomer are more interested in discussing the fact that there is too much wood brass and cogs in steampunk aesthetic ?

how could someone think theres too much wood brass and cogs? in fact, im pretty sure there arent enough   

Yeah, I'm not entirely sure what you're getting at Gaspard.

As for sticky-ing certain tutorials, there is not yet one that encompasses enough of either of those two subjects to deserve a sticky, if you want information on these things dont forget there is a search function- when veiwing the How To section it should only search within this childboard, narrowing your search results to the how to's.

The post I was answering to was stating that the question was not coming often enough.

I was claiming that it's not request statistic that make the value, but the knowledge itself. Also making a statement about the trend of the newcommer who's only interest in steampunk seems to be about the name.

Steampunk roots being DYI most basic craft techniques deserve a sticky. Electronic, sewing, leathercraft, casting resin, casting metal, and vacuforming being some of the first usually needed.

I know damn well that here is a search function... there's even a google search function for the whole intarweb. Is there a link with the organisation of the forum ? I hope no... Same for my workshop, I can either put the most important tools in designated place or dump everything in a drawer and use the "search with my hands and Mark 1 eyeballs" function. Is it practical or smart... not so much.

[Renquist Von Reik]

I love the smooth-on products Rev. Marx linked for you above.  Their ease of use and the quality is fine for my normal casting needs, not to mention the cost is more than reasonable.  Choose the right materials and they'll take almost any dings and knocks you dish out.

What I really wanted to add is that their site has a lot of really really helpful video guides to casting and mold making and I'd highly recommend looking into them.  They were a tremendous help to me when I was just getting started!

http://www.smooth-on.com/media.php

[silastic armor fiend]

thanks for the links everyone! it really came in handy. right now im making an arm guard. the mold is drying right now but ill post pictures in the appropriate place as soon as possible

[Gaspard de Coligny]

I love the smooth-on products Rev. Marx linked for you above.  Their ease of use and the quality is fine for my normal casting needs, not to mention the cost is more than reasonable.  Choose the right materials and they'll take almost any dings and knocks you dish out.

What I really wanted to add is that their site has a lot of really really helpful video guides to casting and mold making and I'd highly recommend looking into them.  They were a tremendous help to me when I was just getting started!

http://www.smooth-on.com/media.php

Can you say goldmine ? many thanks for this discovery...

[Otto Von Pifka]

smooth-on is great to start with, they even have little sample kits to get your feet wet.
the oomoo molding RTV is about as easy to use as you can get.

definitely read all the paperwork and watch the videos! they have all kinds of novel methods and tips that come in very handy.

get on the mailing list and you should get invited to assorted seminars in your area, if they are available.

If you think the project you have in mind might be too complex to do, then find something simple to practice with. assemble some tools to make your work easier and get disposable cups and spoons to keep cleanup simple. I use clear plastic cups for mixing so I can tell at a glance if I'm mixing well without folding in too much air. dusting molds to help pull in the resin helps as does chasing out tiny bubbles with a toothpick. a pressure pot is a good extra item to have if you have a air source, and better yet, a vacuum source.

and as far as expiration dates on materials, once you open any of the containers, the clock is ticking MUCH faster. trying to cast with old materials is just a waste of time and effort in most cases.

[groomporter]

Another source here in the US is http://www.iasco-tesco.com/ Unfortunately they don't have an online catalog, but you can order one or download a PDF catalog

[SteamPunk Glass]

One tip a resin caster gave me a while back was to make sure the resin is warm when pouring it, I always wondered why I got great big bubbles in my cold 'dirty' shed (where I do anything smelly or dusty). If the resin is warm it's easier for the bubbled to escapes, I've even seen hot air guns used to warm the surface to help drive off the bubbles - although made me nervous doing that because some are flamable - I used a heat lamp for a fe minutes and it really did seem to help

[groomporter]

Temperature can help, but it also can work against you. The warmer it is, the faster the resin will cure, so if it is too warm it has the possibility to become viscous before all the bubbles reach the surface.

Of course, what kind of resin are we talking here, something clear? I'm more used to using opaque urethane resins.

One the of the best tips I had for making the silicone molds I use is mixing petroleum jelly with naphtha as a mold release to paint on your master part when making a mold. Mix it thin enough that you can paint it on the part, but thick enough to leave a film on the surface.

I have also used Ivory soap dissolved in water, but I find that the petroleum jelly/naphtha solution has worked better for me.

For casting the actual parts I use an aerosol  "Stoner Urethane Mold Release E236" and I find that my molds last for more runs than with the stuff I was buying from the local Smooth-on distributor

[Titus Wells]

Macwax! 

[groomporter]

Macwax??
For polishing Scotsmen?

-Sorry couldn't resist

[silastic armor fiend]

i got a can of fiberglass resin and i like that a lot more than the polyester that i first got. ive had a lot more luck with it and it dries so much faster. i checked out smooth on's website and they have a lot of really helpful stuff. i spent ALL night browsing their site last night. the other websites you guys offered were helpful as well.
the first arm guard i cast with the fiberglass, of course its supposed to look beat up and weathered. its not quite finished but worthy of being posted:

[Titus Wells]

Macwax is a spray-on wax mould release. It's extremely useful!

[vt13013]

One tip a resin caster gave me a while back was to make sure the resin is warm when pouring it, I always wondered why I got great big bubbles in my cold 'dirty' shed (where I do anything smelly or dusty). If the resin is warm it's easier for the bubbled to escapes, I've even seen hot air guns used to warm the surface to help drive off the bubbles - although made me nervous doing that because some are flamable - I used a heat lamp for a fe minutes and it really did seem to help

Being only rudimentary familar with resin casting, do you use some sort of jiggler/vibration to coax the bubbles out as well?

Cheers.

[Gryphon]

Smooth-On's biggest competitor in the US is Polytek (www.polytek.com)  They are across the street from each other in Easton, PA.  I have used quantities of both, I prefer Polytek's pourables and Smooth-On's thixotropics.  My favorite latex supplier is Cementex in NYC.

One of the cool thiings you can do with resins is mix powdered metals into them so that they can be buffed to a shine after the batch sets up - this is called "cold cast metal."  If you mix in enough metal(70%+,) your castings can even take a patina.  My favorite supplier of metal powders is The Compleat Sculptor (www.sculpt.com)

A vacuum pot is the most reliable way of degassing; sometimes with the more viscous pourables, it's better to degas the pour batch BEFORE pouring it into the mold.

[Professor Z]

I did a lot of casting for a living some years back for the movies. We dusted the surfaces of our silicon molds with baby powder.

Take the foot of a nylon stocking or pantyhose and pour a half cup in. Tie it off. Tamp it against the surface gently. Then give it a gentle blow. Don't worry, the resin will soak up the powder. The powder actually draws the resin into details. That's why it works. It also breaks up the surface tension.

[silastic armor fiend]

ive been casting pieces for a super hero costume im working on. i made a rigid fiberglass resin mold (my molding rubber is dreadful) and ive had very good luck dusting the mold with talcum powder before casting it. i couldnt be happier with it.