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Resin Casting - Urethane Casting

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Title says it all.

I am interested in getting into casting some resin items. I am not thinking of complex shapes like cars, more scenic items I have struggled to get or want more of. I may get brave enough to do some figures.....who knows.

 

I was told one of the best was aluminite products from USA. Haven't been able to find in NZ.

Eventually, found one manufacturing company Nuplex Resins, who now have a retail division; and have both the silicon moulding compounds and casting resins. The guy I spoke to said that as an example, they sell them to wargamers for casting figures.

 

Waiting on the product catalogue etc to arrive by snail mail.

They even have a "how to" DVD. so that sounds hopeful.....

 

So what brands of product do/can you get and use in Oz.

Are there any common 101s I should know....like what you cast the silicons moulds into to start with, I presme something which is as near to shape as possible to minimise wasting extra silicon - SHOOT it's dear....$90 a litre...guess it gets cheaper in bigger sizes.

 

I STILL haven't found a source of urethane for casting tyres..........anyone able to recommend common brands in Australia, I'll do a brands/agencies search in the NZ companies register, to see if I can match up.

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Hi,

 

The products I use in Australia are as follows:

 

  • Moulding compound: PinkySil by Barnes. Its more expensive than most of the other silicon moulding products (AUS$66 for 1 litre), but is a simple 1:1 mix, and is thinner and runnier than most of the others, so is excellent for fine detail, but is very fast setting, so you have to pour it fairly quickly and smoothly.
     
  • Solid casting: Easycast by Barnes. Very fast setting, easy to use, 1:1 compound, sets white, although the colour turns yellowy as the raw products age, so depends on how quickly you use it up. I only buy in 500ml lots (AUS$22), so it doesn't go off before I use it, as I only cast very small parts, and only a few at a time. You can tint this any colour using their pigments. Very good for small parts, as you can demould and cast again within an hour if you need multiple copies.
  • Clear Casting: EasyCast Clear by Barnes. Expensive (AUS$20 for 200ml), but gives a very clear glass like finish that is not affected by most liquids (ie won't cloud if you spill or clean with Mineral Turps or even acetone), and reasonably flexible (wont shatter or split easily like plastic). I have cast small and large windscreens, headlights, etc, and can be tinted. It is very prone to bubbling though, as are all similar products, so should be used with a vacuum degassing chamber, but I don't have one, and with careful use and patience, you can get excellent results without one.
  • Flexible casting (Tyres): EasyFlex 40 by Dalchem. Barnes do not package their polyurethane in small enough quantities for me, so I use Dalchem for this. The EasyFlex range comes in a variety of shore hardness ratings. I use the 40 for Scalextric cars. 30 would probably give you more grip, but would wear quicker, and might tend to flex too much on the wheel, but I haven't tried it myself yet. Can be tinted with the same black (or other) pigment I use for the solid & clear resin. This stuff takes at least 12 hours to cure enough to demould, so I suggest you make up at least 2 moulds for each tyre, otherwise you'll get frustarted by only being able to cast one tyre per day.
  • What do I mould in?: just find yourself a cheap clear multiple compartment box, with compartment sizes to match the small to medium sized pieces you are casting. You need at least a 1 cm buffer around the entire piece, so its not distorted when you bind the 2 halves of the mould together with rubber bands or similar. For bigger pieces, you just expand some of the compartments by cutting away the dividers. I pciked up a $2 box at the Reject shop, which had 18 compartments, each about 40mm x 60mm. I created a long skinny compartment and a wider compartment by removing different walls. I'll see if I can find any pics of it for you. For tyre casting, you can either use the same compartments and include several tyres in the mould, or you can use small mixing cups or similar, with diameters a fair bit bigger than the tyres if you want to make individual moulds for each tyre. I have probably poured close to a 100 moulds using this one box, so it was good value for money.

 

I am sure there must be similar products available in NZ, but if not you can probably order it from the Aussie suppliers anyway.

 

Learning to mould and cast is best acheived through trial and error, as not all products are the same. Just be prepared to throw away a lot of your early work as you find out the vagaries of each product.

 

Although, once you have worked out what you want or can actually get in NZ, and respond back here with the actual product details, I am sure there are plenty of people on the forum who have used those products at some stage and can give you some useful start up advice.

 

Good luck! :o


Graeme

~~~~~~

 

(Life is like a sewer....................What you get out of it depends on what you put into it!)

 

My Website

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As Graeme mentioned look at Barnes,I use either Ultrasil silicon OR Tufsil25 for moulds all from Barnes.

New Zealand agents are:

Top Mark

Unit 4/136 Marua Road

Ellerslie Auckland NZ

Telephone: 64 9 580 2488

Facsimile: 64 9 580 2466

A good video is at: Freemans Supply

 

You can down load the videos for free.


Phil

 

Hobart Miniature Car Club

 

Tassie Resins

 

Email

 

 

 

 

 

 

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nz

 

you can also go see aldax mouldings (aldax.com.au) here in sydney. they have a forum and how to videos on line.

they also have an ebay shop with links to it. they have a video on casting a military figure using something like pinkysil and a 'hard' urethane. although me thinks they don't do soft rubbers all that much for tyres.

 

oz

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Thanks for the great help guys.

 

Rang TopMark, they have most of the Barnes products, - including small volumes of the urethane Graeme.

So have sent off an email with a list of stuff I need, waiting for prices on the vairous pot sizes. Seems like they have stuff in 250ml, 500ml, 1 litre, 5 litre etc.

 

Tey also had another silicone compound called Trade 26

 

Trade 26

TRADE 26 is a high strength, two component, tin catalysed RTV silicone rubber. It is designed as a 26 Shore A, low viscosity rubber providing excellent physical properties, long library life and accurate detail reproduction. TRADE 26 displays good dimensional stability, low linear shrinkage and features a lower viscosity than comparable systems. TRADE 26 is widely used in such trades as the cement casting and Film/TV industries.

 

Ideal for -

 

Multi-purpose Mold making

Figurine & Giftware Moulds

Polyester, Urethane and Plaster Casting

Moulds Requiring Fast Turnover

Sizes: 515gm, 1.03kg, 5.15kg 20.6kg

 

Anyone used that variant?

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I had some correspondence with Paul Gage from Canada re tyre making (and Graeme - who was a great help - thanks again Graeme)

 

I notice on his website (search for his name and tires) he now uses a Shore 30 Compound for tyres -

 

- be careful when mixing - I made 10 tyres the other day not sure what I did wrong but they came out feeling like jelly babies - (thankfully only 10) not sure if I made a mistake on the mix ratio or added too much colour... any suggestions Graeme or Phil as to which one would cause the jelly babies :o otherwise I have been really happy with the outcome of my tyre making might need branch into making some replacement mirrors now :o

 

 

cheers

DM

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Also watch the percentage of pigment you add to the mix as this also can change things.


Regards

Rob

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DM,

 

The pigment should not affect the polyurethane, as you only need a small drop in it anyway. I think it more likely a ratio issue, although it would have to be way out to produce a result that soft. From what I remember when I bought the Dalchem EasyFlex, reducing the amount of the B component will produce a softer result (I use easyflex 40, and I think he said dropping the B component by 10 or 20% would reduce it to shore 30), but you would have to have got the ratio way wrong to get a result that soft. Still, it does show the importance of getting the ratios accurate.


Graeme

~~~~~~

 

(Life is like a sewer....................What you get out of it depends on what you put into it!)

 

My Website

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Similar to Graham I use the Barnes products, however for a box I use a bunch of Lego blocks, which allow for different size "boxes" to be created:

 

http://routedtrack.hobby-site.com/?file=cars.html

 

Sorry if the site is slow; it's being hammered by spammers (for the last 45 days!)

 

Cheers

 

Richard

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Hey, nice site Richard.

 

The graphics of casting the HO shells were useful to me in vertical take off mode learning..... not that I plan to attempt cars anytime soon, but I would like to do some other complex shapes like figurines.

 

Well Graeme and Phil, with your combined wisdom and advice, I have now paid the NZ Barnes agents for Ultrasil, easy cast, flexicast 45A and pigment, and they should be here Friday, giving me the weekend to start messing around with mould making.

 

If the flexi 45 is too hard for tyres to USE on cars, I can always use it for statics like tyre walls, until I find a cheaper product to use for bulkier items like that.

 

thanks again.

 

mark

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I can see it now. Slots shouting to his wife from the basement. Honey can you call 911. You know that little adult toy you wanted me to cast. Well the original isnt coming out of the mould. HELP and for gods sake dont let the kids come down here. :angry2: :arggg: :D:D

 

 

hat coat Im outa here.


cheers

rick1776

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Hey, nice site Richard.

 

The graphics of casting the HO shells were useful to me in vertical take off mode learning..... not that I plan to attempt cars anytime soon, but I would like to do some other complex shapes like figurines.

 

Cheers, there have been a few other casts, such as a 1/32nd chassis, GT40 and a few figures, but I haven't updated the site in ages :lol:

 

Richard

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I went to buy a body today and the website says I can pay an extra $1 for a fibreglass body instead of a resin body. Whats the difference?


ok....you try racing with one eye closed.

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Fibreglass tend to be a little stronger,BUT can have air gaps between the gel coat and the mesh. If that is a Can Am body from the UK ask what scale it is! There are some sites selling bodies as 1/32 BUT they are about 1/28 scale.


Phil

 

Hobart Miniature Car Club

 

Tassie Resins

 

Email

 

 

 

 

 

 

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Could be the same place . They do a lot of Can Am cars. I am after a Maserati 300s and these seem to be the only ones that make them.

Edited by rumrunner

ok....you try racing with one eye closed.

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I do a fair amount of Casting and mold making for my figure work (for models rather than slots). I can offer a couple of tips that haven't been mentioned.

 

  • Mold preparation. Once your mold is finished Give it a good wash in detergent to clean it and reduce the amount of Static in it. When its dried sprinkle some neutral talc onto and into it (I use Baby powder). Tap it around inside and then bang the mold to get rid of excess. This will help to protect the mold from the resin and keep static to a minimum (so it doesn't pick up dust and hairs).
  • Mold Release. Don't buy it... Its evil stuff and very expensive. Get a spray bottle (the type you use on plants). Get some petroleum jelly (Vaseline) and dissolve it in Lighter fluid (Naphthalene), put it in the spray bottle and use that. Spray on a thin film, the lighter fluid will evaporate off leaving a very thin smear of the Vaseline. This is especially useful for making 2 part molds as RTV loves sticking to itself.

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