How to Use:
GLASS CAST EPOXY has been designed to be as easy-to-use and reliable as possible. It does not require degassing or any other special equipment and in fact will thoroughly degas itself during cure, resulting in a perfectly clear, bubble-free casting. Ambient Temperature: Like most epoxy resins, the way that Glass cast will cure is very dependent upon the ambient temperature. The system has been designed to work in ambient temperatures between 15°C and 30°C. For best
results, an ambient temperature of between 20°C and 25°C is recommended. The resin and hardener also needs to be used and cured at an ambient temperature between 20°C and 25°C to achieve optimum results. If the product is over 25°C or falls below 20°C it can affect the performance of the resin.
Whilst Glass cast is curing it can absorb moisture from the air. In higher humidity environments this moisture absorption can affect the surface finish and therefore, for best results, avoid pouring the product in humid environments (relative humidity of 70% or more). This becomes particularly important in lower ambient temperatures where a slower cure leaves the
uncured resin exposed to humid area for longer. Surface Preparation: In much the same way that Glass cast can be adversely affected whilst curing by moisture in the air, it will also be affected by any moisture in the surface onto which it is poured. Whatever surface you are
pouring onto, it is important to ensure that the surface is as dry and stable as possible. This is particularly relevant when working with natural materials like wood and cork or concrete where moisture levels within the substrate can be high. When working with wood that is either freshly sawn or reclaimed/salvaged from a damp environment it will be necessary to dry the wood thoroughly – which could take days or weeks indoors – before use. Failure to ensure that wood is
properly dried and stabilised can result in a surface reaction with the resin as well as ‘bowing’ or distortion if the wood starts to dry after the resin layer has been cast.
Moisture in Wood:
Glass cast has excellent tolerance to modest levels of moisture but can still be adversely effected by higher moisture content in wood and other substrates. Wood with a high moisture content is also liable to move (shrink) as it dries out which can cause ‘bowing’ or distortion of the piece if the wood starts to dry after the resin layer has been cast. Ensure wood is properly seasoned and dried before use. Sealing Coat – Required for All Porous Surfaces: When working with porous substrates such as wood, chipboard, concrete or ceramics it is highly
recommended to first seal the substrate with a thin application of Epoxy Sealer. Doing so will seal and stabilize the surface, greatly improving the flatness of the final pour. The sealing coat must be allowed to fully cure and then ‘keyed’ before proceeding. The sealing coat can be applied with a disposable brush.
Just as with the surface preparation, it is important to ensure that any materials that are going to be embedded within the resin, such as pennies, crushed glass, bottle tops, corks, leaves etc. are thoroughly dry. Any embedment may also require being glued/fastened down to stop them floating in the resin once it is poured.
Depending on the ambient temperature, Hayper Glass Cast will take around 48hrs to become touch-dry. During this initial 48hrs it is essential to keep all dust and dirt away from the uncured pour. Once the surface is ‘touch dry’ it is much less susceptible to contamination from dust but it will still be quite soft and easy to mark and so you should avoid touching or using the surface for as long as possible. The time it takes for the resin to cure fully will depend
very much on the ambient temperature; at 20°C you should allow at least 72hrs before remolding (if casting into a mold) or attempting to do any work on the resin (such as sanding or polishing). The product will take around 7 days to reach full hardness.
Trapped Air – Heat Gun or Blow Torch Required?
Glass Cast includes advanced technology to help it to expel air that has been entrapped by the mixing and pouring process and so in many cases the resin will fully release any trapped air to leave a beautiful bubble-free finish. After pouring, it usually takes the resin around 5-10 minutes to expel trapped air. Factors such as ambient temperature, mixing action, pouring thickness and the substrate you’re pouring onto can all influence the appearance of trapped
air (bubbles) within the resin. After around 10 mins, if you find that you can still see trapped air bubbles with this resin then lightly passing over the surface of the resin with a heat gun or blow torch on a low setting will help to dispel any bubbles. In both cases only ever use a light pass and wait for any heat in the surface to dissipate before repeating.
Work in a well-ventilated area. Whenever weighing, mixing, pouring or checking the state of the cure of the resin, you should be wearing suitable protective gloves and eye protection as a minimum precaution. Always wear gloves when you are ‘testing’ to see if the surface has cured. Do not touch or handle the surface without gloves until you are sure that it is fully cured.
How Much Resin?
The very nature of a “live-edge” on a piece on wood makes it difficult to calculate exactly how much resin you will need for the project. There are some practical methods that can be used to actually measure the exact volume an irregular shaped cavity – such as pouring rice or sand into the gap and then measuring the volume – but in most cases it is probably more a case of estimating the volume of the gap and then allowing a little extra. Areas that are to be filled with resin (for example the gap between the two live-edge planks on a river table) should be measured approximately in length, with and depth to find the cuboid volume, as follows:
Length (in cm) x Width (in cm) x Depth (in cm) 80 cm (Length) x 40 cm (width) x 5 cm (depth) = 16000 CM³ 16000 CM³ = 16 ltr (approximated 16 kg) Mixing Instructions: Weigh or measure the exact ratio of resin and hardener into a straight sided container. Using a suitable mixing stick begin to mix the resin and hardener together to combine them completely. Spend 3 minutes mixing the resin and hardener together, paying particular attention to the sides and base of the container. Remember: Any resin that has not been thoroughly combined with hardener will not cure. Once you have finished mixing in one container, it is good practice to transfer the mixed resin into a second, clean mixing container and undertake further mixing for another 3 minutes using a new mixing stick. Doing so will eliminate the risk of accidentally using unmixed resin from the bottom or sides of the original container.
Step by Step Guide:
Depending on your requirements (and artistic ideas) there are many different ways in which you can work with the product to achieve some really stunning effects. The following step-by-step guide describes the most standard way to work with Hayper Glass Cast which is a sealing coat (for porous surfaces) followed by a single main pour.
Step 1 – Sealing Coat:
If the material you are pouring the product onto is not porous, for example plastic, metal, marble or granite then you do not need to seal the surface and you can skip to Step 3. If the material you will be pouring the product over is porous such as wood, chipboard, MDF or ceramic then it is highly recommended to apply a sealing coat before the main pour. Doing so will improve the flatness of the final surface and help to eliminate warping of the substrate after cure. This will also minimize air entrapment.
Mix around 500g of Epoxy Sealer per square meter of surface you need to seal.
Don’t worry if most of the resin seems to be absorbed by the substrate; this is
normal for the sealing coat. Allow the ‘sealing coat’ to cure before proceeding
to Step 2. Depending on the ambient temperature, this is likely to take around 24 – 48hrs.
Step 2 – Prepare the Sealing Coat for the Next Pour:
In order to ensure that the next layer of the product bonds well to the sealing coat it is necessary to ‘key’ the surface of the sealing coat using some coarse abrasive paper. This will also help to flatten off any slight raised texture where the substrate has absorbed some of the sealing coat. Having checked that the sealing coat is well cured (it should feel hard and not at all tacky), use a sheet of coarse abrasive paper (such as P120) to ‘key’ or scratch the entire surface. Don’t worry that the surface then looks scratched and light in color – this will
disappear as soon as the next layer of resin is poured.
Step 3 – Adding Barriers:
Because most river table designs feature unsupported areas of resin (which it’s possible to look straight through) these areas of resin need supporting and containing somehow whilst the resin cures. The material we use to contain the resin is referred to as baseboard barriers and side barriers. It’s very important that the barriers are totally sealed, otherwise the resin could leak out and spoil the project (not to mention waste resin). We strongly recommend choosing a
barrier material that the epoxy will not stick to and which will leave a smooth finish on the cured resin – we use polypropylene plastic sheet in the project. We suggest starting with a flat sheet of chipboard or MDF as a base to work on. The sheet should be just slightly larger than your table to allow clamps to reach around it when clamping down the planks.
Step 4 – The Main Pour:
Ensure your work area is as free of airborne dust as possible. Ensure the ambient temperature is between 20°C- 25°C. Calculate how much resin you will need for the main pour using the information in the ‘How much resin?’ section earlier in this guide. Follow the instructions for measuring and mixing the resin making sure that your mix ratio is very accurate and that you’re mixing is very thorough. Once the sealing/base coat of the resin has cured to the B-stage it is important to continue straightaway with the first stage of the main pour, otherwise the two
layers will not bond properly to each other (see preceding notes on the B-stage). When you do the main pours, it’s likely that you will need to be mixing quite large quantities of resin (anywhere between 5 and 15+kg for a typical table). This means that mixing in multiple smaller batches is highly recommended. After around 10 minutes, take a careful look over your resin casting. If any trapped air bubbles still persists, you can use a heat-gun or gas blow torch lightly over the surface of the resin to lift any remaining air bubbles out of the resin. Once you are happy with the casting, cover it as soon as possible to prevent any airborne dust or contamination from landing on the surface. Leave the surface to cure fully before handling; this is likely to be around 48hrs, depending on the ambient temperature. Please see the Curing Time section earlier in this guide for full information. Now the pouring is complete, we must allow the resin to fully cure to give us the hard finish desired. The resin will achieve an initial cure in approximately 48 hours – temperature dependent. You must not touch or attempt to use the casting during. This period and avoid opening doors and windows to reduce the chance of dust and debris contaminating the resin. The resin will continue to harden to full strength over a period of 7 days.
Step 5 – Polishing and Finishing Shaping and Polishing:
Once fully cured, Glass Cast can be shaped, flatted and polished up to a full gloss finish. This can be particularly effective in creating soft, radiuses edges on cast surfaces or when flatting the cast surface to be perfectly flush with surrounding material, such as a flat table surface when filling surfaces of reclaimed wood. To flat and finish Glass Cast, follow standard flatting and polishing techniques of working up through the grits of abrasive paper until you reach around P1000 grit before changing to a polishing compound and power polisher for the final gloss finish. This process can also be followed to restore surface scratches and dulling from continual use. You will now have a stunning casting that with care will last many years, amazing family and guests alike. If over time the surface picks up minor scuffs and scratches these can be polished out to restore the original high gloss finish.
It’s absolutely fine to use the product to create castings in a thick layers but to do this they should be made up in multiple layers with the resin allowed to at least partially cure between each layer. Pouring onto Partially Cured (B-stage) Resin The easiest way to build up the resin in multiple-pours is to allow the preceding layer to cure to what is known as the ‘B-stage’. The B-stage is the point at which the resin has firmed up, so that it is no longer a liquid, but it has not fully cured. When the resin is correctly at the B-stage, using a gloved finger you should be able to press a fingernail into it but no resin should come off on your glove. The advantage to pouring new resin onto partially cured (B-stage) resin is that no surface preparation is required and the new resin will bond chemically with the previous layer (known as cross linking). Pouring onto Fully Cured Resin If the first layer cures past the ‘B-stage’ (see above) then you can still pour a new layer on top of it however it then becomes essential to allow the previous layer to cure fully and then key the surface using an abrasive paper in
order to allow the new resin to mechanically bond to the previous layer. To pour a new layer onto fully cured resin use a coarse abrasive paper (80 to 120 grit) to fully abrade the whole surface of the cured resin. Don’t worry about the scratched appearance; as soon as the new liquid resin is added it will blend transparently with the layer underneath.
Inclusions / Encapsulation:
One of the stunning applications of Glass Cast is the inclusion of other materials within the resin. Such materials could be coins, bottle-tops, beer mats, playing cards, photographs, pebbles, crushed glass; in fact, just about anything. With so many different types of material that could potentially be encapsulated within your Glass Cast pour it’s essential to experiment first to ensure that you understand how your chosen material will behave when encapsulated in the Glass Cast. All materials will need to be thoroughly dry before you encapsulate them but others may require ‘sealing’, gluing down (to prevent floating) or some other preparation to get the best results. As a general rule, the inclusion of any materials within your Glass Cast surface will result in some slight effect on the surface caused by absorption of the resin into the material being included or simply by variations in the thickness of the resin where these inclusions occur. For this reason, when working with inclusions, it is generally best to do two pours; the first is your main pour and will encapsulate the inclusions completely, the second pour is a thinner pour intended simply to leave a perfectly flat surface. See the ‘Multiple Pours’ advanced technique for further information. Shaping and Polishing.
Pigments and Tints:
To achieve a range of creative effects Glass Cast can be tinted or coloured using a variety of tints, pigments and powders. It is essential to use pigments that are designed for or compatible with epoxy resin. To achieve a subtle ‘tint’ remember that you will need proportionally more tinting pigment for thin sections that you will for thicker sections. A transition from one color to another can be achieved using two pours of differently tinted resin, sloping the surface slightly for the first pour to create a thickness gradient for each pour. Always conduct a small test first to ensure compatibility with your chosen tint, pigment
Epoxy layers should be protected from moisture for 4-6 hours after application. Moisture may whiten the surface or/and make it sticky. It may also disturb hardening. Faded or sticky layers in parts of the surface should be removed by grinding or milling and laid again.
Use only where application and drying can proceed at temperatures above 5°C, and relative humidity is below 75%. Apply only on a dry and clean surface. Safety: Handle with care. Before and during use, observe all safety labels on packaging and paint containers, consult Hayperflex material safety data sheets and follow all local or national safety regulations. Avoid inhalation, avoid contact with skin and eyes and do not swallow. Take precautions against possible risks of fire or explosions as well as protection of the environment. Apply only in well-ventilated areas.