VIDEO TUTORIAL

How to Use Sheet Wax to Create Moulds for Cover Components

WHAT YOU WILL LEARN

How to use calibrated sheet wax to create an offset mould
How to use our Epoxy Mould Making Starter Kit to make a simple fibreglass mould
How to use EG60 Epoxy Tooling Gelcoat and EMP60 Epoxy Laminating Paste

In this video tutorial we explain why offset moulds are needed when making cover components and how to use sheet wax to create an offset mould. We then use our Epoxy Mould Making Starter Kit to make an offset fibreglass mould which in a follow-up tutorial we use to produce a carbon fibre frame protector/cover component.

INTRODUCTION

Composite materials such as carbon fibre, Kevlar and fibreglass can be a good choice for making close, accurate fitting cover components such as frame protectors, clutch covers, mirror covers, bash-guards and more.

To make a properly fitting cover components such as these, the first step is to create a mould that is slightly larger than the original component to allow for the thickness of the cover itself, known as offsetting. This offset will allow the inside of the cover to be a correct fit for the outside of the original component.

In composites, one practical way to create this slightly larger (offset) mould is to use calibrated sheet wax. Calibrated sheet wax is a type of flat wax sheet, often with adhesive on one side, that is available in accurately calibrated and consistent thicknesses. The sheet is gently manipulated and applied directly onto the surface of the original component.

A traditional composite mould making process can then be followed, taking an offset mould off the outside of the sheet wax which can then be used to produce accurate, snug fitting cover components using of a variety of composite reinforcements. Sheet wax can also be used to produce an offset mould suitable for use in RTM/RTM light.

The key to creating a snug-fitting cover component is to use sheet wax with a thickness that closely matches the thickness of the cover component. For example, if you want to make a 5mm thick Kevlar sump guard, you should use 5mm thick sheet wax. In our example, we are making a 2mm thick carbon fibre frame protector and so a 2mm sheet wax is used.

TUTORIAL BREAKDOWN

1. Applying the sheet wax

The original component is measured, and the sheet wax is cut to the correct size. In this tutorial we will be using the sheet wax to create the 2mm offset and also to form barriers off the sides of the part, that will in turn form the flanges around the edge of the mould. The sheet wax is cut oversize to allow for this.

The sheet wax available from Easy Composites has a self-adhesive backing meaning it can easily and securely be applied to the original component/pattern. When applying the sheet wax to the part, a heat-gun can be used to soften the wax slightly, making it easier to conform to the contours of the original part.

Where the sheet wax is being used to form the mould flange, filleting wax is used to add some temporary support to the sheet wax. Simple tools like dibber/laminating tools can be used to add definition, as required, to the sheet wax.

2. How to join sheet wax

For larger or more complicated shapes is if often necessary to join multiple pieces of sheet wax together. To do this, the different pieces of sheet wax should be cut so that they join together as closely as possible. You will find that gently and repeatedly pushing the two sections of sheet wax together at the join will usually close the gap quite effectively.

Having closed the gap between the pieces as much as possible, filleting wax can be gently pushed into any remaining gap and the excess carefully scraped off before finally buffing the join smooth with a cloth to leave an almost seamless finish.

3. Epoxy Mould Making Starter Kit

In this tutorial, we make the mould itself using an epoxy tooling gelcoat and an epoxy laminating paste (or putty). By using an epoxy-based tooling system to make this fibreglass mould we ensure that the mould is fully compatible for use making epoxy-based components, such as the carbon fibre frame protector will use the mould to make in a subsequent tutorial.

Another advantage to using epoxy-based resins when working with sheet wax is that epoxy gelcoats and resins contain no solvents and so they don't attack, soften or stick to the sheet wax in the way that styrene-based resin systems (such as polyester and vinylester) can. This makes it easier to remove sheet wax from epoxy-based moulds.

For simplicity, in this tutorial we use our Epoxy Mould Making Starter Kit which includes the EG60 Epoxy Tooling Gelcoat and EMP60 Epoxy Laminating Paste. The kit also includes the mould release wax, along with ancillary items such as gloves and mixing cups.

The materials included in the Epoxy Mould Making Starter Kit are almost completely odourless.

4. Applying EG60 tooling gelcoat

The EG60 Epoxy Tooling Gelcoat is mixed carefully and fully according to the instructions. In this tutorial we will be 'double-gelling' whereby the gelcoat is applied in two, even applications.

The first application of gelcoat is thoroughly mixed and applied directly onto the sheet wax at a thickness of approximately 500g per square metre, or around 0.5mm.

The first application is then allowed to cure to the 'B-stage', where it is firm but still tacky. The exact timing of this will vary according to temperature but at 20°C this will be around 3hrs.

Once the first application has cured to the B-stage, a second application of gelcoat is applied. The second application is mixed and applied just the same as the first, aiming to keep the gelcoat as smooth and even as possible. This second layer of gelcoat is now also allowed to cure to the B-stage.

5. Applying EMP60 laminating paste

As soon as the second application of gelcoat has cured to the B-stage, the main reinforcement for the mould can be applied. It is very important to not allow the gelcoat to cure past the B-stage otherwise it will become to hard and dry and the laminating paste will not be able bond properly to it.

EMP60 is an epoxy-resin based laminating paste. The paste contains resin, filler and chopped glass fibre strands for reinforcement and so can be used on its own as the main reinforcement for the mould. The advantage to a laminating paste is that the fine, paste-like material is very easy to work into corners and details, reducing the risk of air-voids and providing a fast ad reliable means of reinforcing an epoxy-based mould.

EG60 is thoroughly mixed according to the instructions and then applied directly onto the B-staged EG60 gelcoat at a thickness of around 10mm before being left to fully cure for around 24hrs.

6. Demould and remove sheet wax

Once the mould is fully cured, it is removed from the pattern. Typically, the sheet wax will come away with the new mould. The sheet wax can then be removed from the new mould by hand, using plastic tools to avoid scratching or damaging the new mould.

Any residual traces of sheet wax should be cleaned off the new mould using mould cleaner.

7. Trimming and finishing the mould

The rough edges of the mould are removed and tidied-up using a slitting disc in an angle grinder. The finish left on the surface of the mould by the sheet wax will be quite smooth but quite satin. To give the mould a smooth, glossy finish P1200 and then P1500 wet & dry abrasive papers are used before polishing the mould using an NW1 polishing compound.

DISCUSSION (8)

Please share any questions or comments you may have about this video tutorial.

Dean7/5/2024

Is there any concern about the sheet wax affecting the surface gloss or finish of the part that you are forming it to? I'd like to make a part for my car but do not want to damage the painted surface or leave any blemishes.

Easy Composites› Warren

The sheet wax may well damage the surface as you often need to scrape the wax off the surface once the moulding process is complete. If the panel is especially fragile, you could try vinyl wrapping it or covering it in a PPF type product but there is always the risk of panel paint damage with a moulding process.

Truth1/6/2020

I've never had much success polishing epoxy gelcoat. Is this gel something special, or maybe it's the polishing compount?

Easy Composites› Matt

Epoxy gelcoat is normally just harder that a polyester or vinylester gelcoat. This does indeed make them harder to polish but certainly not impossible. The key would be making sure you've done the rubbing back properly with the abrasive paper (no underlying scratches) and then using a suitable polishing compound. The NW1 we use in this video is designed for very hard materials, like epoxy, and so does a much better job that most compounds.

29/5/2020

Will the epoxy and gel coat shrink or deform if you used a low temp oven (e.g. 75°C) to soften the wax? For a complex shape I can see the wax becoming difficult to remove.

Easy Composites› Matt

For our EG60 and EMP60, the 'Tg', i.e. the maximum temperature the gel and reinforcement can go to without any problems is 60°C. At 60°C the wax would not really have changed a great deal in terms of removal. It's probably more helpful to use more heat from the heat gun, aimed directly at the way, to aid with removal. Generally speaking, if you're using sheet wax with epoxy resin, like we are in this tutorial, then you're unlikely to have any trouble removing it. When using sheet wax with polyester or vinylester resin then it can be more of a problem and that's where sheet wax sealers can help.

Erosennincss27/5/2020

Nice! I guess the wax sheets technique could be use to make some nice carbon fiber mudguards for a bicycle by applying it over the tire?

Easy Composites› Matt

Yes, you could certainly do that. You'd probably need quite thick sheet wax to allow enough clearance but it can be layered if needs be.

Pushyhog27/5/2020

I put Mavcoat release agent and then airbrush PVA onto the sheet wax, I then spray a primer and then a polyester gel-coat. This way my parts are in primer straight out of the mould.

Easy Composites› Matt

Thanks for the info. Sounds like an interesting approach but I guess you're only wanting to make a single component using the wax mould though, which is unusual.

Χρήστος Βασιλείου25/5/2020

Can I use acetone to clean the surface from wax instead of mold cleaner?

Easy Composites› Matt

Yes you can but you need to be a little bit more careful with acetone because it can be more aggressive to the mould than mould cleaner. The other thing you'll find is that it's easier with mould cleaner but the mould cleaner solvent is less volatile (so, evaporates less quickly) and so it softens the wax more before it just evaporates away.

Sylvester Oziomek25/5/2020

Is this sheet wax reusable? could we transform it into some sort of filleting wax?

Easy Composites› Matt

No, not really. I don't know of a method or process for usefully reusing the sheet wax. It's to broken up to be used whole again and I'm not aware of a way to recycle it into another usable material. Filleting wax makes sense as a suggestion but the consistency and behaviour of these materials is quite different.

Neilon Abraham18/4/2020

Can any type of sheet wax be used?

Easy Composites› Matt

Hi Neilon, I'm not sure what other kinds there might be or what their properties are. The sheet wax we supply is specifically for composites, it's precisely calibrated for thickness (important for offset moulds, less important as a temporary flange barrier) and it's self-adhesive. If you can get these properties then it's probably the same material and of course, depending on where you're based you could always buy it from us to be sure!

VIDEOS IN THIS SERIES

How to Use Sheet Wax to Create Moulds for Cover Components

How to Hand Laminate & Vacuum Bag a Simple Carbon Fibre Part

USED IN THIS PROJECT

MATERIALS & CONSUMABLES

TOOLS & EQUIPMENT

STARTER KIT(S)

VIDEO TUTORIAL

How to Use Sheet Wax to Create Moulds for Cover Components

WHAT YOU WILL LEARN

INTRODUCTION

TUTORIAL BREAKDOWN

1. Applying the sheet wax

2. How to join sheet wax

3. Epoxy Mould Making Starter Kit

4. Applying EG60 tooling gelcoat

5. Applying EMP60 laminating paste

6. Demould and remove sheet wax

7. Trimming and finishing the mould

DISCUSSION (8)

LEAVE A COMMENT OR QUESTION

How to Use Sheet Wax to Create Moulds for Cover Components

How to Hand Laminate & Vacuum Bag a Simple Carbon Fibre Part

USED IN THIS PROJECT

MATERIALS & CONSUMABLES

TOOLS & EQUIPMENT

STARTER KIT(S)

DISCUSSION (8)

LEAVE A COMMENT OR QUESTION

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