Usage Guidance

Mixing Ratio
Rapids is a 2:1 mixing ratio by weight, which means for every 100g of Part A, you need 50g of Part B. For example:

200g Part A : 100g Part B

When measuring in a measuring cup by ml the ratio to follow is slightly different. For every 100ml of Part A, you need 60ml of Part B. For example

200ml Part A: 120ml Part B

Go over to our Vista Resin Calculator which will do all the working out for you.

Mixing Technique
After measuring out the Resin and Hardener it’s now time to mix the two together. At least 3 minutes is required for mixing and it is good practice to transfer into a second cup for some further mixing. This way you can ensure there is no residual hardener unmixed which might be poured into your piece and cause a defect.

When all lines and imperfections have been removed you can be assured the epoxy is completely mixed. You can over mix and also mix too quickly causing excessive amounts of air to be introduced during this process. This can cause unwanted bubbles to form so be cautious of this.

The second the two components are mixed together a chemical reaction will begin. Often users decide that they will leave the mixed Resin into the cup for some time afterwards which creates a thicker Resin. When making a piece with several colours this can help to stabilise the colours and stop them from separating into each other. Again be careful and consider how much Resin is within the cup because this is within a small surface area meaning heat can not escape and the reaction will begin to increase rapidly. If left too long, you can lose workability with the Resin mixture all together often experiencing bubbling, excessive heat, distortion and even a flash cure! And remember, Rapids is a thick resin to begin with so you will not need to leave the mixed resin for a long period of time. 

For more information check out our blog post about how epoxy resins cure!

Curing Time
The curing time is dependent upon Total Heat. Total Heat = Heat of Reaction + Ambient Temperature. The Heat of Reaction is dependent upon the overall depth or mass of epoxy + curing properties of the Part B component.

For Rapids the Part B is fast curing therefore when added to a large mass and deeper than the recommended depth of 10mm the Resin mix will overheat rapidly. We recommend mixing small quantities.

The temperature of the room you are working/leaving your pieces to cure in does have a surprisingly big impact on the curing time. It isn’t a straight line between heat and cure time, so ass the temperature rises the pot life and cure time increases exponentially. And similarly, for a drop in temperatures the cure time will lengthen exponentially.

Adding heat in the form of a propagator, heat mat or other source of heat, you can expect curing times to reduce by up to 75% if you are concerned about cold temperatures. Typically Rapids used with the guideline parameters of 0-3mm, you can expect to de-mould in less than 24 hours.

Working in Layers
To achieve greater depths Vista Rapids is suitable for layering. Throughout the curing process of your first layer the epoxy mixture passes into an initial cure phase when it begins to gel off. The epoxy is no longer workable and will progress from a tacky, gel consistency to the firmness of hard rubber, which you will dent with your thumbnail.

Because the epoxy mixture is only partially cured, a new application of epoxy will still chemically link with it. It is at this stage you can successfully apply a second layer / pour / coating to an existing resin and create a monolithic bond. The next layer will be able to join without visible lines. Should the casting resin be allowed to reach full cure, we would recommend to mechanically prepare the surface of the bottom layer by sanding and then chemically clean using isopropyl alcohol.

Using with Pigments
When using our Vista Epoxy Pigments you can easily introduce some fantastic colours. And because the colour is already diluted into resin, the mixing process is quick and easy.

To create a translucent colour, simply add a small amount of colour and look by eye to ensure that the mixture is not going to turn opaque. For a full colour, it will depend on the depth of your application. A full colour at a significant depth is capable of being achieved with a small amount of pigment. For a very thin coating, you will need much more colour to ensure a fully opaque Resin mixture.

We would recommend to trial and sample get the right amount of colour saturation for your project. Each pigment is coloured naturally, and so you will find that a lot more pigment is needed for colours like orange than it is for black for example. For each colour you can trial and error until you know what to add by eye.

We know from experience it doesn’t take long to get used to the colours and they’re very easy to use.

As well as standard solid colours, we also have metallic colours – Metallic White, Metallic Bronze, Metallic Silver and Metallic Gold. In addition, we have a Metallic Boost which you can add to the solid colours to give them an injection of metallic. For a small change and hint of metallic, add around 25% to solid colour, for a strong metallic finish, we’d recommend to add up to 70%.