WoodCast 30 – 8kg

WoodCast 30 – 8kg is an optically clear commercial grade casting and encapsulation two-part epoxy resin system.

WoodCast 30 – 8kg – Physical properties

Application method

• Brush
• RollerSqueegee
• Pour/casting

Note
A Propane burner can be used to pop bubbles that appear on the surface.

Processing

Preheat the epoxy to 25°C – 27°C before mixing, this will reduce the viscosity and make pouring easier. WoodCast 30 can also be used to make River Tables.

WoodCast 30 can also be Blled with a variety of materials for different visual effects such as wood chips, Aluminum Powder, Marble Powder, Stone Chips, Pebbles, Iron Filing, Copper, Bronze or Brass Powders, Cast Magic Powders.

WoodCast 30 can also be pigmented. After preparing the mix, mix thoroughly for at least 2 to 3 minutes and apply using your preferred method. The “Dirty Pour” is one such application method with many YouTube videos on the technique. https://www.youtube.com/watch? v=MrVKifoQ0M0

Important
Do not exceed 10mm thickness per application, allow to cool before mixing & adding additional layers. It is advisable to do tests with fillers and pigments before committing to a job.

Safety & Handling

Epoxy Resins & Hardeners are chemicals. Normal Health and safety precautions apply when handling these products.

Ensure

• Adequate ventilation
• Use of gloves and safety glasses
• Use of barrier creams
• Use of a skin friendly hand cleaner

Never Use any solvents to clean your hands.

Always

• Measure Accurately (Preferably on a scale)
• Mix parts A & B thoroughly (Use flat paddle and mix for a minimum of 2 minutes)
• Allow Adequate time to fully cure before using

Avoid

• Applying on Oily or Contaminated Surfaces
• Apply to damp or wet surfaces
• Working in a Cold Environment below 18 °C

Storage and stability

The shelf life is 24 months in a dry place and in original unopened containers at room temperatures between 18 – 25°C.

Faq, Processing Tips And Ideas – Tips To Help Produce A Perfect River Table

Mix Ratio

Mix at the correct mix ratio. Use an Accurate Scale to do this. Scales are available at AMT Composites. Woodcast30 is mixed at 100 parts Part A plus 60 parts Part B–BY WEIGHT (100:60) Very Important.

Mixing

Mix the two parts together very well. Stir with a flat paddle stick for a minimum of 3 minutes, scraping resin from the sides and bottom of the containers into the mix. Then transfer the mix to another container, mix again and then pour.

Maximum Depth Per Pour

Do not exceed 10mm per pour. The chemical reaction that occurs, generates heat. Large volumes of resin can generate excessive heat, which can lead to an exothermic reaction, and cause the resin to discolour, crack and warp!

Time Between Pours

Each pour must be allowed to cool down to room temperature before adding additional layers. It is possible to achieve 2 to 3 pours per day, depending on conditions. Use an Infrared thermometer to measure the temperature.

Colour Consistency

In order to ensure even colour throughout the resin in a multiple layer pour, first calculate the total volume of Epoxy needed for the entire job, then work out how much resin and hardener is required and mix the colour into the resin portion only.
Then draw off the required amount of pre-coloured resin and add the hardener for each pour.

Calculating How Much To Use (use our calculator at the top of this page)

1. To calculate the volume of resin required, measure the length, breadth and depth and convert to liters.
   A table 2met x 900mm x 50mm deep is:
   200cm x 90cm x 5cm = 90000cm³ 90000/1000 = 90Lts. The Specific gravity of the material is 1.05.
   So 90Lts x 1.05 = 94.5Kg is total amount of Resin and Hardener required.
2. b. To calculate the separate amount of resin and hardener required, divide the total Kilograms by 1.6 and that will give you the amount of resin required
   94.5/1.6 = 59.06Kg Resin (Mix Ratio is 100:60)
   59.06 x 60% = 35.44Kg Hardener Total weight = 94.5Kg Mixed Total
   For tables with wood and live edges it is sometimes difficult to calculate the exact amount of resin required because of the irregular shape of the wood.
   To do this see the example illustrated below:
   Length x Average Breadth x Height
   Average breadth is the sum of the measurement divided by number of stations e.g. 10,5cm + 13.6cm + 11,4cm + 19,4cm + 20,2cm + 14,6cm + 11.8cm + 8,3cm = 109.8/8 = 16,3cm

Casting Box

Build your casting box from Melamine chipboard. Glue all joints with a liberal bead of White Wood Glue in all joints and screw the box together. Then wipe off the excess glue with a damp cloth and let dry. Optional additional safety, glue the outside of the joints with a Hot Melt glue gun.

Release Agent

Use Ram wax as your release agent. Apply a coat all over the box and edges, allow to dry for 20minutes then buff off with a soft cloth.

Wood Will Float

Wood will float in the resin so it must be clamped or screwed down to prevent this.

Cold Weather

In cold weather it is advisable to heat your resin and hardener to at least 27°C before mixing and casting. To do this, place your resin and hardener bottles in a bucket of hot water. Shake the bottles to mix the resin before measuring the temperature. Use an Infrared thermometer, available from AMT composites.

Surface Tension Issues

Casting thin layers (<5mm) of epoxy over wood, can lead to surface tension issues, where the resin cures with dimples on the surface. We recommend a minimum of 5mm or more to try and alleviate the surface tension.

Bubbles in the Casting

There will always be bubbles present in the resin after mixing. These will rise to the surface after a while and they can be popped with the aid of a gas flames. Mini Gas torches are available at AMT Composites.
Some woods are very porous, and air will continue to escape from tiny holes when under the resin. In order to avoid this happening, it is advisable to first seal the wood with a coating or two of resin. Place the wood in the sun and paint on a layer of Woodcast30 and let dry. The sun will help heat the surface, open the pours and thin the resin so it penetrates the wood.

Gas Flame vs Heat Gun

A gas flame if the preferred method to pop surface bubbles. A heat gun can be used, but it does create waves, which can distort the surface.

Adding Pigments

When adding pigments, be very careful not to add too much as they are very strong. For small batches, use a toothpick to add small amounts of pigment and stir them well into the epoxy. A maximum of 2% to 3% by weight is normally sufficient.

There are also many different glitters and pearl essence powders that can be used in these Epoxy resins, it is impossible to go through them all and a subject all on its own. It is advisable to do some tests of your own to get the affects you desire.

UV Stability

Woodcast 30 is not UV stable. It works extremely well for indoor applications but is not suitable for outdoor use. However, the addition of UV stabilised pigments will greatly improve the UV stability of the resin system, so much so that it could even be used outdoors. For clear castings where UV stability is required, you can use the Kristal range. But even that will not be able to withstand full exposure to African sun for extended time. The only true UV stabilised resin systems are Polyurethanes. We stock the Crystal Clear Polyurethane Resin system.

Woodcast 30 Sanding and Polishing Recommendations

There is a reasonable amount of work required therefore we have developed a sanding and polishing process that gives good results:

Planing or Routing wood/epoxy to achieve flat surface

(This step is not always required as the casting may already be very flat and smooth)

What to take off the top?

• We advise a minimal cut of 1mm or less. Be careful; if you cut too thick, the epoxy will grab the planing knives and throw the piece. A thicker cut can also generate excessive heat that will affect the surface finish, or
• With a router sled remove 1mm or less per pass.

Drum sanding

Drum sanding can even out the top or both sides of the piece, depending on the machine. Feeds should be medium with grits of less than 120. Finer grit paper of 220 or higher should be used at slower speeds. Sanded depth will vary, but 0.5 to 1mm per pass should be the maximum. Be careful to make sure sandpaper is clean and free of material as the epoxy can leave a residue on the paper and gouge the material on the next pass.

Random Orbit Sanding

• Use a step-up dry sanding method beginning at 80 open grit and proceeding in finer open grit paper increments: 80, 120, 180, 240, 320, 400, 600, 800, 1000, 1200 and 1500.
• Wet sand using foam backed sanding pads at medium speed at 2000 grit. Clean all residue between sanding steps.
• Wet sand at low rpm using 4000 grit foam backed sanding pads, making sure surface is always wet.

Material should be clear and slightly hazed. Do not overwork or overheat.

Polishing

Use a variable speed Rotary polisher. (IMPORTANT)
We recommend Mirka Polarshine 10 – P1500 compound with a Lamb’s Wool polishing Bonnet at low speed so as not to heat the surface, taking time to polish and keep pad lubricated with Mirka compound.

• Using a lamb’s wool polishing bonnet, buff at 2000 rpm until surface imperfections disappear. If you don’t have a lamb’s wool polishing system, high quality foam polishes pads can also be used with a Random Orbital polisher. They are formulated to be used at specific speeds.
• Using a 2000 grit foam polishing pad, buff at 1800 rpm and
• Using a 3000-grit foam polishing pad, buff at 1600 rpm.

Finishing

Hand buff surface with a clean cotton terry towel or clean microfiber cloth to a brilliant finish.

Important:
Follow safety precautions on the technical bulletin when mixing and pouring WoodCast30. When machining, sanding or polishing fully cured epoxy, wear a NIOSH approved respirator, protective eyewear and clothing to minimize skin contact. Results may vary depending on how closely directions are followed, quality of equipment and aptitude/experience of artisan. In all cases, AMT Composites is not responsible for the outcome due to the above variables. If results are in question, we recommend testing on a small test epoxy casting before scaling up to a large project.

Nourishing/Coating Oils

Odie’s Oil is an excellent wood finishing oil, which can be use over the wood as well as the epoxy to get a beautiful sheen finish associated with a sanded finish.
We have had excellent results finishing the epoxy and wood surface to P600 with Abranet sanding discs on a Random Orbital Sander and then coating with Odie’s Oil on both the wood and epoxy surface.