Archive for the ‘Casting and Casting Materials’ Category
Model Railway Wagon
December 17th, 2009 | 
Author: Question:
Dear Sirs,
I have just finished viewing your web site. It is most informative and gave me a good idea of what is required to make models. So that you know that I am serious, I am in my seventies and coming back to railway modeling which I did many years ago. In those days I bought all my rolling stock complete or as metal kits. Now, I would prefer to build from kits. It not only keeps me occupied but ready-built rolling stock is more expensive that I can afford, at around $40-$50 a piece.
The attached image is a HO scale railway wagon in white metal. This is a very old kit and is no longer available. I would like to make a mould to cast it in polyurethane? Or what ever material you recommend.
After reading the notes on your website, I tend to lean towards silicone for the mould. What would you recommend as a casting agent? The heavier the better but I would not be disappointed if it wasn’t heavy. I also need release agents. Do I need it for the silicone? Do I need it for the release of the two-part mould? What else do I need? As you would have gathered I am new to this and will be guided by your advice. I would also appreciate it if you could tell me where I could find instructions (book/video) that would tell me how to construct the basic mould box so that the casting medium flows correctly and also allows air to escape.
Some of my old rolling stock still exists in reasonably good condition. With a little care I could disassemble these and maybe have 5 or six different models. So I have a requirement for say 10 different moulds with anything from 20 to 50 castings from each.
If it is possible, could you please construct a shopping list for me to cater for the above? I will then purchase these items from your firm. If the book/video is available I will also purchase that from you. I hope I am not wasting your time.
Thanking you in anticipation.
Valued Costumer
Answer:
Hi,
Thank you for getting in touch with us. I am also a model railway enthusiast and have played around with making moulds of my existing model kits. I would certainly recommend silicone for the manufacture of the moulds.
I have experimented with the use of metal powders in my casting resin to increase the weight and the results were quite good. I used CraftCast 75 for the casting resin and mixed in up to 50% iron powder to the mixture, making sure I mix the metal powder in before mixing the two parts A + B of the resin together. The reason you add the metal before is because once the resin is mixed, you will only have 2 – 3 minutes to get the resin mixture into the mould before it starts to set.
You don’t need a release agent when casting polyurethane resin into a silicone mould.
We are currently in the process of developing a mould box kit for sale but this is a few months off. Until then we recommend using small pieces of timber or lego to construct a wall around the original piece and to ensure it is water tight, apply non-drying clay such as our plastelina to the corners and edges of the wall.
A shopping list would be something like:
Aldax CraftSil 750 Silicone (to make the mould)
Aldax CraftCast 75 Resin (to cast into the mould)
Iron Powder
Aldax Plastelina (non-hardening clay)
Unfortunately we don’t have a video on this process yet, except for the online videos on our website which goes into some mould making with silicones.
I hope this helps. Please get back to me if you have any more questions.
Kind regards,
Joseph
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Question on Resin Mould
Question:
Hi. Do you have any picture frame moulds that would be suitable for resin?
Cheers
Valued Costumer
Answer:
Hi,
The only picture frame moulds that we have at the moment are plastics. These can only be cast with resin if you use a good release agent and one of our slow setting resins. The quick setting resins often generate too much heat for the plastic and cause damage to the mould. You could however cast a plaster into one of our plastic moulds and then make yourself a silicone mould.
If you do have problems in making a silicone mould though, you can click here for an article on our website on how to make one.
Kind regards
Aldax Moulds
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Posted in Casting and Casting Materials | 
Tags: plastic moulds, release agents, resin mould | 
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Question on Casting on Plastic
Question:
Hi. I was wondering if you can help. I would like to make a plaster reproduction of plastic lunchbox. I intended making a negative mould using latex or silicone. Can you advise me which products I should use to achieve the following?
- No damage at all to the plastic lunchbox. This item is nearly irreplaceable (plastic is black, glossy, scratched. circa; 1969)
My preference would be to use latex, but not sure if it will cure on plastic.
Thank you.
Valued Costumer
Answer:
Hi,
Yes, latex will cure on plastic. Have you had any experience in making latex moulds? You need to apply it on in layers and is quite time consuming.
Silicone will also leave the surface undamaged. Both silicone and latex do not require release agents on plastic so both will not do damage to the original item. The only risk you may have if using silicone is if something goes wrong with mixing, for example wrong mixing ratio, not mixed well enough etc. In this case you will have slimy, unset silicone covering your original which can prove difficult to clean. Latex is an air drying product so there is less of a risk of this happening.
Our latex is called Kwik Mold #70
We hope this helps.
Kind regards
Aldax Moulds
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Posted in Casting and Casting Materials |
Tags: latex moulds, plastic casting, silicone moulds |
1 Comment »
Question on Coloring
Question:
Hi. I am having no luck trying to color my slabs. I am trying to make them look like the bought ones – with whispy tendrils of color resembling marbling in stone. Instead they look like they’ve been thrown up on.
I wet the moulds and sprinkled oxide and dry sand in the bottom and placed the (white) cement a handful at a time, but it’s just splodged. How can I make the color more subtle and stone-like? Do I need to mix the oxide with something?
Hoping you can help.
Thanks,
Valued Costumer
Answer:
Hi,
You probably know by now that mixing oxides and getting decent results can be an art form in itself. We used to can a resin kitchen benchtop manufacture in the neighboring factory. The method they used to create realistic marble benchtops can be applied to concrete casting. What you need to do is to create your base color concrete by mixing some pigment thoroughly into the concrete mix. This will give a solid and consistent color. Pour the concrete into the mould. To create marble effects, you can drop a small amount of pigment (diluted with some water if needed) into the mould and use a stick to swirl the mix creating patterns. Don’t swirl too much or the effect will diminish.
If you are trying to get stone like effects as opposed to marble effects you can use the method you have already been practicing but not with straight oxides. A pure, solid oxide straight out of the container is hardly realistic. The secret lies in the mixing of the oxides as it does with artists’ paints. An artist would hardly ever apply a pigment straight out of the tube onto the canvas. They would usually have to mix it with other colors. Just to give you an idea, try to mix some of the stronger colors with white sand to dull down the saturation of the color. Mixing a sandstone color may require mixing some yellow (or sandstone) oxide color with some red and a fair amount of white sand.
The color of the concrete poured into the mould will also play a part in the final appearance. The concrete color will always show through so it is important to mix an oxide into the concrete which will complement the colors you have sprinkled into the mould.
Keep trying. I’m confident you’ll get there.
Kind regards
Aldax Moulds
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Posted in Casting and Casting Materials |
Tags: coloring, concrete casting, concrete mix, Concrete Moulds, marble effects, stone-like effects |
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19th May Customer Questions
Question:
…..and I really appreciate the time you put into your customers…..
I have searched the site for help but specifically would like the following information..(no rush as I appreciate you have a business to run as your first priority.)
1. I have been trying to embed a picture in resin (the jewellery resin slow curing one) and I would like the background of the picture to look transparent and the actual picture to look as though it is floating. I did a two step process (two layers allowing the first layer to cure and then attaching the picture – however even using water slide decals – there ends up being a cloudy haze in the background – Has anyone done this before and am I using the right medium?
2. MORE IMPORTANTLY – I have a charm about 2.5 x 2 cm that does not have a base like your toy soldiers or knight – but I would like to cast another one- It is a small toy motorbike with fixed wheels. I am about to order some craft Sil and wonder how to complete the project – again is there any further videos on the subject or help that anyone can forward on please?
My projects are moving forward and I am having a LOT of fun – Lets hope it grows to something bigger and better! 
Answer:
To have your picture transparent you will need to scan it and then print it on clear film. Enclose your charm with a box or something to prevent the silicone from flowing all over the place, pour the silicone and then cut the silicone mould down one side side to release the charm using a new scalpel blade.Then cut an opening in the base through which to pour the casting resin. All the best with your projects. Stan
Have a great and prosperous week!
Related Posts:
Materials for Making Toy Soldiers
Question:
Hi, just wondering if you sell moulds for casting lead alloy soldiers or more specifically the kits, ingredients to make these moulds. Any help would be much appreciated.
Answer:
Hi.We stock the silicone suitable for casting low temperature metals suitable for toy soldiers and have plans for making a kit in the new year.
All the best,
Stan Alderson
Related Posts:
Colouring Plaster and Concrete
Question:
Hi there, I’ve got a question. A guy up at bellingen uses some sort of color to color plaster like a sandy color. He says he dips it in. I can get you a pic of an item if you want to see one just curious if u have any ideas and other colors as they look pretty good and i got a lot of wall plaques i wouldnt mind doing.
Answer:
Hi, You get the colours in concrete and plaster by adding metallic oxides. We just put the colours up on our web store where you can see them. Click here to see the range.
All the best for Christmas.
Joseph
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My Crystal Cast Epoxy Resin Doesn’t Set
Question:
Hi,I purchased some Crystal Cast Epoxy Resin last year, Tuesday 10th April 2007 and it has worked great on two occasions.I have just opened the bottles and used the formula as always but the resin has not set?I used 50/50 mix and stirred for 2 minutes but it has stayed tacky after 2 days?Can you advise, is the product out of date?Can you supply
something I can spray on the surface to harden the liquid on the surface?
Kindest regards, waiting in anticipation.
Answer:
Although the shelf life after opening is 6 months sometimes we get good results for much longer periods it all depends on how it is stored. Cool dark places are best. There is nothing you can spray on to assist hardening but you might try gentle heat. We use an oil heater and place items on top that we are having difficulty with., No guarantees but you might save it.
All the best.
Aldax Moulds
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Fabric Covered Lamps
Question:
Hi. I have a question regarding a craft project I am working on. I am making lamps out of chicken wire and covering the frame in fabric and then coating the fabric in varnish. At the moment I am leaving the chicken wire inside as extra support. What I am after is a product that I can paint/apply over the fabric that will be hard enough for me to remove the chicken wire frame so that it is a hard, free standing structure. Can you suggest any product that I could use?
Answer:
There is a product called Aristocrat that leaves a coat equivalent to 50 coats of varnish and is colourless that should do the job. You will find it in our shopping cart on our mould website www.aldax.com.au Do not hesitate to contact me if you have any further enquires.