DIY Forged Carbon Fibre and Resin River Table

The incredibly cool Forged Carbon River Table is a mash-up of two very popular trends of the last few years - the resin river table and forged carbon!

We love both looks and came up with this amazing project to showcase them both. It's all down to personal choice whether you see this project as a small coffee table, a dining table for an F1 lover or even a large boardroom table to suit a hi-tec business. This design can be scaled up or equally scaled down to make a small side table or even a serving board.

At GlassCast Resin HQ we receive lots of calls from customers interested in the look of resin river tables but also looking for something completely new to create a real talking point in a room, so we're back with our latest main project tutorial and accompanying free downloadable eBook and of course this Instructable!

The step-by-step instructions described here, demonstrated in the accompanying Forged Carbon River Table Tutorial video and in more detail in our free downloadable eBook: covers all the information needed to produce your own unbelievably cool forged carbon river table.

Using GlassCast 50 casting resin and Chopped Tow Carbon Fibre from Easy Composites along with the additional materials listed, professional makers and DIY'ers will have everything needed to produce their own Forged Carbon River Table.

This Instructable covers all the information you'll need to create a forged carbon fibre river table. If you like this Instructable please check out our other Instructables; DIY Resin Countertops, Resin Penny Floor Project!, DIY Resin River Table, DIY Designer Epoxy Resin Floor and the DIY Neon Resin Plank Table! We hope you enjoy our latest offering and we look forward to hearing from you if you have any questions or comments, please don't hesitate to get in touch ...

What you'll need:

Materials

• GlassCast 50 Epoxy Casting Resin (includes hardener)
• Chopped Tow Carbon Fibre
• Wood of your choice - we sourced the Sycamore slab from our local exotic wood supplier

Ancillaries

• Polypropylene Sheet to make the mould form
• Bristled Roller
• Resin Release Tape 50mm width
• Abrasive Paper
• Disposable Paint Brush
• Reusable Resin Mixing Stick
• Calibrated Mixing Cups and Large Buckets
• Nitrile Gloves

Tools

• Wooden Battens, Blocks and Clamps or Weights
• Legs for the table and Danish Oil for finishing
• Eye Protection and a vapour mask (in case of insufficient ventilation)

Preparation

The first thing to do is select your wood.
There are a few things to consider when choosing the wood for the project and the aesthetics of the slab is very important. We selected a piece of sycamore with it's naturally pale appearance and fine grain detail which will contrast well with the dark, complex forged carbon fibre.

It's all down to personal preference, so whichever wood you choose - make sure that it's well seasoned and has a low moisture count. Wood is affected by environmental factors and can be prone to expanding and contracting in varying levels of humidity.
We're lucky enough to have a saw room at GlassCast HQ and have access to the tools needed on site, if you don't have access to this machinery, it is possible that the timber merchant you sourced your wood from could do the following for you;

• Cut the slab down the middle
• Put the slab through a thicknesser to reduce work later and flatten any twisting in the piece

IMPORTANT SAFETY INFORMATION:

GlassCast 50 Resin is a chemical product.

Before storage or use you must download and read the accompanying safety and technical datasheet, available on the GlassCast 50 product page.

A Summary of the most important information is as follows:

•Always wear nitrile gloves when handling the resin or hardener

•Never touch uncured or partially cured resin with your bare skin

•Wear suitable eye protection when handling the resin or hardener

Although GlassCast 50 Resin is solvent free and has almost no odour you should still work in a well ventilated area or wear a vapour respirator mask.

Ambient Temperature, Pot-Life and Cure Time

Epoxy resins are highly sensitive to ambient temperature and moisture.

To achieve the best results, we recommend working in a room temperature of 20°C.

GlassCast 50 can be used in temperatures from 15 to 25°C but higher temperatures will reduce the pot-life of the resin significantly; at 20°C the pot-life is between 30 and 45 minute and the curing time is 48 hours.

Epoxy resins are very susceptible to moisture and humidity so it's important to make sure the environment is dry and heated.

Airborne Dust and Contamination

Whilst the resin is still in the early stages of its cure, it is important to keep airborne dust and contamination to a minimum. Before you begin you should ensure that the area you’re working in is as free as possible from dust and dirt. Although you need good ventilation whilst working on the project, in order to minimise airborne dust and contamination, we recommend covering the piece if possible during the cure.

Epoxy Resin For Your Project

The resin used in this tutorial is GlassCast 50, this is specially developed for use alongside natural wood to create professional quality projects. To ensure the best possible appearance for projects like forged carbon fibre river tables this resin is highly UV resistant, designed to degas itself during cure and can be cast in thick section in a single pour.

We recommend limiting pour depth to 25mm when poured into or alongside wood, it can be layered to achieve a greater depth if your river channel is deeper. GlassCast® 50 is highly polishable and can easily be buffed to a glass-like finish with it’s tough formulation making it hard wearing and less prone to scratches.

1. Flip the planks so that they create a river channel - placing the two live-edges to face each other
2. Remove any loose material from the live-edges, like bark
3. Key the live-edge with coarse abrasive paper (120 grit) this will ensure a good bond with the resin
4. Clean up the wood using a vacuum cleaner or brush and if needed, damp cloth

It's now time to construct a mould box around the planks, to do this you will need to lay out the planks and decide how wide you would like your forged carbon river to be. Remember the wider the river is the more resin and carbon fibre you will need;

1. Use polypropylene sheet (or similar - you need a surface that resin won't stick to)
2. Stick the polypropylene sheet to a flat smooth surface with doubled sided tape
3. To create the barriers around the perimeter of the slabs, use some wooden battens coated in resin release tape - you can use an alternative tape but you need one the resin won't stick to
4. Stick the tape to the batten leaving an overhang of tape creased, use this to stick it to the sheet of polypropylene
5. To seal the corners simply cut the tape and crease at a 45° angle to fit it snugly into the corner to complete the seal
6. Once the barriers are all in position, set up some bridging timbers and blocks to use with clamps to hold the slabs down to prevent them floating in the resin.
7. To make the demoulding process easy, cover the bases of the small blocks of wood with release tape and use below the bridging timbers, this will stop the blocks sticking to the resin
8. Then clamp the slabs, battens and blocks into position, this will also help to take out some of the gentle curvature in the planks if present

It's worth noting that the place you set up the project needs to be a suitable place for the pour and where it can remain until the resin is fully cured.

To work out how much resin and carbon fibre chopped tow you will need you will first need to calculate the area of the river section between the two planks.

In the tutorial we used a 133cm length plank. To work out the area of the river channel take an average width along the river channel using a measuring tape - the project river measured an average of 16cm.

To work out the area we will convert the measurements from centimetres to metres as follows:

1.33 metres X 0.16 metres = 0.213 square metres

The depth of our river channel is 25mm so a simple way to work out the volume is to multiply the 0.213 sqm by the depth of 25mm:

X 25mm (depth of channel)

This equals a total of 5.33 litres, we can roughly think of a litre as being a kilogram of resin which means that we would need 5.33kg's of GlassCast 50.

5.33kgs

The optimum ratio of the chopped tow to resin is 20%, having conducted lots of testing we found that this ratio gave the best results. Giving that real 'solid' forged carbon fibre look without the mix becoming too thick and hard to work with.

Having already calculated how much resin will be needed for this size project, adding 20% of the chopped tow carbon fibre will bulk up the mixture substantially. We could adjust the resin accordingly to account for this, but in this case we rounded the resin down to 5kg as the calculation was 5.33kg's. We can simply calculate 20% of 5kg as 1kg and use 1kg of chopped tow carbon fibre.

To achieve the best forged carbon fibre effect on this type of project we have found that the best method is to work upside-down. This means that the bottom of the wood and the bottom part of the river (against the polypropylene sheet) will become the surface of the table so do make sure that you place your favourite side of the planks face down in the mould frame.

It is also worth noting that to achieve the best results you need to concentrate on the first layer/or pour which will become the visible surface of the table.

The first pour will be the surface layer and as mentioned previously needs to be executed correctly to ensure the best results on the table.
For the first pour you need to mix up a fifth of the overall quantity.
In the tutorial the project uses a total of 5KG of GlassCast 50 and 1KG of chopped tow. So, this first mix will need 1kg of GlassCast 50 and 200g chopped carbon tow.

The recommended mix ratio for GlassCast 50 Resin is by volume, the resin to hardener ratio is 2:1, this means 2 parts resin (part A) to 1 part hardener (part B). Calibrated mixing cups are really useful for measuring by volume as they already have the 2:1 scale printed on them.

1. Fill the resin to line A and the hardener to line B.
2. Then combine the resin by mixing slowly and steadily to minimise bubbles for 3 minutes, ensuring that you periodically scrape the sides and bottom of the cup.
3. Then pour the mixture into a 2nd clean cup and repeat the mixing process for a further 3 minutes. This process is called double-potting and is to ensure that any unmixed resin from the bottom or sides of the pot do not make it on to the project. If this process is missed it can cause problems to the curing process and the finish.*
4. You are now ready to pour the resin into the river! Pour the mixed resin into the river channel, then allow it to stand for a short while to release any bubbles that may be present in the pour from mixing, check the edges to make sure no bubbles are clinging to the sides.
5. While waiting for the bubbles to disappear weigh out the carbon fibre**.
6. Spread/sprinkle the carbon fibre evenly along the resin river - with the aim of blocking out the surface below with a dense consistent layer.
7. Once all the carbon fibre is distributed, use a combination of a brush and a bristled roller to wet out the fibres and consolidate them. By adding the carbon fibres in this way it helps to ensure that the cosmetic side of the table is void free and has little to no air entrapment
8. Adding the chopped tow using this method is a much more gentle way of working with the carbon fibre and helps to keep the individual tows separate, which is key to achieving that perfect forged carbon fibre look. If you identify any areas that require more carbon fibre, just add the extra in and repeat the wetting out process with either a brush or roller and make sure that you check that all the fibres are consolidated down, paying close attention to the edges of the river against the side barriers and where the resin meets the wooden river edges.
   As this layer will become the cosmetic face of the table, take the time to make sure that any trapped air is forced out through the carbon fibres. Allow the project to sit for a while before revisiting it with the roller to push out any more bubbles that may have appeared.
9. We recommend that when you think this layer is complete, give it another roll over with the bristled roller just to be sure. At the end of this stage, the critical surface layer of the table is completed and wetted out sufficiently, it's now time to move on to the main pour of the project.

* A useful way of knowing when your resin is fully mixed is that it will return to it's perfectly clear state, any cloudiness or oily effect indicates that it is not thoroughly mixed.

** When handling the chopped tow it is very important to wear the correct PPE including gloves, eye protection and a respirator.

The mixing process for the main pour is done in the same way as the surface pour:

1. Measure out the remaining resin and hardener into a large bucket. If you are using the remainder of a 5kg kit as done in the tutorial you can safely pour out all of the remaining resin and hardener into the bucket, ensuring to drain the containers properly.
2. If you are not using a full kit make sure that you accurately measure out the parts again using the calibrated mixing cup at the 2:1 ratio.
3. Mix the 2 parts together slowly and steadily and use the double-potting method, then set aside the the mixture to allow the bubbles to rise and pop out of the mixture.
4. Pour the clear resin on top of the previous layer, filling up to approximately 5mm below the top of the planks.
5. Save a small amount of the mixed resin in the bucket for top up's.
6. Now add the majority of the remaining 800g of the carbon fibre chopped tow, again keeping a small amount in reserve for top ups.
7. Then using a combination of brush and roller mix the tow into the resin making sure that you evenly distribute the tow in the resin and ensure that the tow is completely wetted out.
8. Once the main pour is fully wetted out, leave it to sit for a few minutes to allow bubbles to rise out of the mix, then as with the surface pour use the bristle roller and brush to give it a final roll over. At this point you should see that the fill level is level with the top of the slabs but not over it.
9. If the pour has come up a little short, use the previous steps using the spare resin you set aside and top up as necessary.
10. Repeat the stippling and use the roller as required.
11. Once you are satisfied with the fill level, leave the project to fully cure for 24 hours*.

NOTE: it is worth pointing out that when working with GlassCast 50 Resin the maximum pour depth advised (when pouring into wood) is 25mm at a time.

*This project is at the upper limit of the 25mm pour, so to air on the side of caution we set up a fan at the end of the workbench to drive excess warm air away from the project and the curing resin and make sure that we keep the temperature of the room around 18-20°C .
To help keep the temperature at the correct level we used a desk fan to drive the heat away from the surface.

The reason it's important to limit the pour depth is because the wood acts as an insulator and if poured too deeply the resin could overheat and lead to problems through overheating. To avoid the possibility of this happening, limit pours to a depth of 25mm and if you require a greater depth of pour you need to allow the first layer to partially cure to the B-stage.
The B-stage is where the resin has firmed up but still has a tackiness to the surface - you can test this with a gloved finger - you should be able to make an indent but no residue will stick to the glove. GlassCast 50 will reach this stage between 8-12 hours then pour the next layer of resin. If you miss this stage you will need to key the surface with abrasive paper before pouring the next layer to achieve a strong bond.

After 48 hours have passed the project should be fully cured.
To check the cured surface, put on your nitrile gloves again and press your fingernail firmly on the surface it shouldn't leave any impression. If you do find at this stage that it is a little soft, leave it for a further 24 hours to fully harden.

Once you are satisfied that the surface has fully cured, you can remove the barriers.
You may need to use a mallet and some wedges to help remove the barriers and lift the slab off the polypropylene sheet it should come away really easily and leave an amazing surface straight from the mould.

Remove all the excess bridging timbers, clamps and blocks and turn the slab over on the polypropylene sheet. You will now be able to remove any tape that has pulled away with the cured piece and inspect it more closely.

When you inspect the surface you may be able to see some tiny pinholes, this is to be expected due to the nature of the chopped tow material and can be easily rectified. The next step is optional depending on the type of finish you wish to achieve on your project.

OPTION 1 - natural wood look with a polished forged carbon fibre river

OPTION 2 - full hi-gloss coating over the wood and forged carbon

If you would prefer the option 2 hi-gloss finish over the entire surface of your table please go straight to the Alternative Hi-Gloss Finish step. Or, to produce a table with a polished forged carbon river and the natural wood slabs follow the following instructions.

OPTION 1 - Natural wood finish with a polished forged carbon fibre river

1. Flat the surface of the table - we used a router set up on a bridge and made multiple passes over the whole surface area.
2. To get rid of the lines in the table surface left by the router, sand using 120 grit abrasive paper until you reach a smooth surface. If you have access to a hand-held sander this will speed up this stage of the process.
3. Once smooth thoroughly clean the surface and most importantly using a clean brush and a vacuum cleaner remove all dust and debris from the pin holes, voids and surface.
4. Before we move on to the final sand and polish, this is the time to fix any pinholes or voids on the surface of the river.
5. Apply strips of the resin release tape along the river edge as close as possible to the edge of the wood, this will save time on the final stage.
6. To fill the pinholes and voids, any of the GlassCast Resins* would be suitable. Simply measure out and mix up a small amount of resin and hardener (according to the stated ratio) and using either a brush or a resin spreader work the resin into all of pinholes and voids. The brush is really useful for breaking the surface tension and work the resin into any hard to reach areas using a stippling action.
7. When you are satisfied that all areas are fixed allow to cure for the time stated.

* In the project GlassCast 50 was used to fix the pinholes (this requires a 48 hour curing time) if you need a faster turnaround or have some GlassCast 3 or GlassCast 10 available either of these would also be suitable and would be fully cured in 24 hours rather than 48 hours.

Check the resin is fully cured again by putting on your nitrile gloves again and pressing your fingernail firmly on the surface, it shouldn't leave any impression. If you do find at this stage that it is a little soft, leave it for a further 24 hours to fully harden.

You're now ready to flat the table and finish it up to a perfect finish.
Firstly remove the tape from the river edges and trim the slab edges/sides using a table saw or power planer.

To flat the high spots left by the resin from the last stage, sand using a coarse 120 grit paper to a level surface then work through the grits from coarse to fine over the whole surface - ideally up to 1200 grit.

Working up through the grits properly is worth the time it takes as it will expose the beautiful grain in the wood and the incredible detail in the forged carbon fibre.

The final step to achieving a beautiful finish is to apply a couple of coats of danish oil which will make the detail in the contrasting surfaces pop - simply apply this with a clean soft cloth.

OPTION 2 - Full hi-gloss coating over the wood and forged carbon

What you'll need:

Materials

• GlassCast 3 Epoxy Coating Resin (includes hardener)
• Notched Resin Spreader
• Flash/Release Tape
• Digital Scales
• Disposable Brush
• Mixing Cup and Stick

If you prefer the look of a hi-gloss surface finish all over your table top, this is easily achieved. By following the steps in this guide up to STEP 5 (on page 12) - Removing the barriers, the process is the same. At this point you would need to follow the steps listed in this section.

First, flat the surface of the resin to remove any high spots using 120 grit abrasive paper, if you have access to a Dual Action Sander this is the best way to achieve this.
Then thoroughly clean the surface including any voids or pinholes this process has exposed. The most thorough way to do this is by using a dry brush and a vacuum cleaner to make sure that all dust and debris is removed followed by a wipe over with a damp cloth.

The next step is to apply a sealing coat of GlassCast 3* coating resin. The GlassCast 3 mix ratio is 2:1 by weight, so you will need to weigh out the quantities using digital scales.
The mixing method is the same as the GlassCast 50 mixing process - mix the resin and hardener together for 3 minutes before transferring to a 2nd clean pot and mix for a further 3 minutes.

Now brush apply the resin in a thin but even coat and leave to fully cure for 24 hours.
Once the resin has fully cured, flat the entire surface using the 120 grit paper and clean up ready for the main pour. Brush towards the edges of the table to stop resin running down the sides.

Then check the surface of the table is completely level before leaving to fully cure for 24 hours.
*GlassCast 3 Coating Resin is perfect for creating stunning glossy coatings due to it being hard wearing, self-levelling, self-degassing and scratch resistant due to it's suitability for use on floors, bartops, countertops and tables.

Once cured, sand the surface again all over with 120 grit abrasive paper and thoroughly wipe clean.

Then apply resin release tape around the entire table top. This will act as a retaining tape around the edge and prevent the GlassCast from flowing off the sides.
Make sure that the tape edge stands proud of the table top by a few millimetres, it's advisable to pour the resin to a depth of 2mm. The resin needs to be at least 2mm deep for its self-degassing and levelling technology to work.

The table in the tutorial measured 1.33m long by 0.64m wide and we need to pour a depth of 2mm which can be calculated as:
1.33m x 0.64m x 2mm = 1.7 (1.7kgs) The 1.7 can roughly be equated to 1.7kg's of GlassCast 3 so for this project 2kg would be more than enough to apply the sealing coat and cover the main pour and will use 1133g resin and 567g hardener. Mix in the usual way for 3 minutes, scraping the sides and bottom of the pot before transferring to a 2nd bucket (double potting) and mix again, then allow to stand for a few minutes before pouring.

Pour the mix all over the surface of the table, then using a notched resin spreader move the resin around the surface.
Use the spreader to push the liquid up to the taped edge and check for bubbles. Sometimes bubbles will try and cling on to the tape around the edges so use a spreader or mixing stick to dislodge them. Do not use heat to remove bubbles around the tape as this may shrink the tape and damage the retaining tape and could cause leakages.

Finally leave the resin to fully cure, if possible place a cover over the surface to keep out any dust or debris and make sure that the environment stays at an ambient temperature of 20°C. This will need to cure for 24 hours before moving on to the final step.

Check the surface is fully cured by testing with a gloved finger then the barrier tape can be removed.

To remove the meniscus left around the edges and neaten the sides of the table, the table top was trimmed on a table saw to take off a few millimetres.
Alternatively you could use a power planer if you have access to one and on a table of this size the right result could be reached quite easily and quickly.

Follow up the trimming by sanding the sides of the table (taking care not to touch the top surface of the slab), work up through the grits from 240 grit all the way up to 1200 grit.

Don't move on to the next grit until all marks are removed from the previous grit. When sanding it is always worth taking the time to do a thorough job to achieve the best results.

The final step is to flip the table over and apply the legs, we chose these boxed industrial legs in a matte charcoal grey to compliment the forged carbon fibre.

As always with a project like this the style of legs and finish all comes down to personal preference.

Now that your GlassCast® Forged Carbon River Table project is complete you’ll want to keep it looking great for years to come.
Here are a few important things to keep in mind when looking after your epoxy resin table:

• Hot Objects - You should not place hot objects directly on to the resin (pots, pans, plates or mugs) as this may mark the surface. Instead use coasters or heat proof mats. If you do find that hot objects have marked the surface it can be flatted and polished again to remove any marks.

• UV Light - GlassCast® 50 and GlassCast 3 has been designed to have the best UV stability of any epoxy resin on the market and should withstand years of indirect sunlight with very little effect. However, common with just about all materials of this nature, prolonged exposure to UV light, particularly direct sunlight, can eventually cause some change in the appearance of the resin. For this reason, finished GlassCast® projects are not recommended for outdoor use and should be kept away from direct sunlight where possible.

• Scratches and Marks - GlassCast® 50 and 3 are very hard wearing plastics and will hold up to the rigours of light daily use without marking. However, accidental damage can be caused by sharp objects scraping over the surface of the resin or from things being dropped onto it. If this occurs, these can be polished out using the same process that was used for the initial sanding and polishing ; i.e. abrasive paper (for coarse scratches) followed by polishing compound to restore the gloss.

So, project complete and the results are awesome!

Both finishes look incredible - the polished river against the natural grain of the wood complement each other beautifully and the super hi-gloss surface really turns up the natural definition in the grain of the sycamore and amplifies the light reflections with the forged carbon fibre is incredible.

The only thing for you to decide is which finish you want for your project?!

We would love to hear what you think of this project, be sure to let us know what you think and if you have any questions don't hesitate to ask.

Thanks for reading our Instructable :-)