Posts Tagged ‘latex moulds’

Question on Making Aquarium Ornaments

Question from a customer:


I have found your website very helpful & it’s given me hope my ideas may come to life, though I have a few questions.

I am looking at making aquarium ornaments. I have already made some rough caves from a mix of concrete & sand, in a sand mould, that are holding up well, but wish to expand my designs & materials. Some ideas will need me to use cement, though many new ideas I’d like to use recycled plastics with more intricate designs.

If I understand your articles correct, latex would be the best to make moulds for both mediums. Is this correct? Could a latex mould be used for both plastic & cement? I understand that any mould I use cement in cant be too detailed, unless of course you have a suggested recipe that will pour easy but not crumble in the water.

Any ideas, hints, suggestions you have will be greatly appreciated.



You can make the mould latex as it is the cheapest to use and cast in lightweight concrete or resin filled with cheap fillers such as marble dust. Both are used widely in the industry.

All the best Stan Alderson

Question on Casting on Plastic


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



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