Trade Secrets: TRADE SECRET: Sheathing with WEST SYSTEM epoxy
Sheathing is the process of applying an additional surface to your boat’s structure to help increase its strength and durability. Done in the correct way, using the right materials, this can significantly improve your boat’s water resistance and help to protect it against any nasty scrapes or knocks.
If you wish to form the strongest bond and the most durable protection, then the best solution is to sheath your boat with a combination of glass fabric and epoxy resin. However, when using these materials, it’s important to think about working conditions. The epoxy will be easiest to work with if it’s kept in a warm, dry environment, so the ideal situation is to carry out your sheathing in a heated room. But it is perfectly possible to carry out this type of work outside under a tent or cover just as long as the temperature is kept between 18 to 25°.
Follow these simple steps to make your boat surface stronger.
1. Surface preparation
The surfaces you’d like to sheath should be clean, dry and thoroughly abraded with 80-grit paper.
2. Filling and fairing
Your surfaces also need to be filled and faired using 105 WEST SYSTEM Epoxy and 407 Low Density Filler mixed to a peanut butter consistency. Applying an epoxy/filler mix to any external angles will allow the fabric to be more easily applied. When the epoxy filler has hardened, sand thoroughly before applying the epoxy/glass sheath.
3. Applying the glass cloth
For the application itself you will need to combine the 105 WEST SYSTEM Epoxy Resin with WEST SYSTEM 205 Fast Hardener® at a ratio of 5:1. For an accurate ratio, it’s a good idea to use a measuring system such as the WEST SYSTEM® 303 special ratio Mini Pump
Once this mixture has been thoroughly blended, it can be applied using two methods: the ‘dry’ method or the ‘wet’ method. The dry method is more commonly used with lighter fabric and is where the glass fabric is temporarily held in place by tacks and then ‘wetted out’. For the wet method, a thick layer of the epoxy mix is rolled onto the surface to be sheathed and the dry fabric is then unrolled into position over the wet epoxy.
4. Protecting the surface using peel ply
Adding peel ply over glass sheathing will help to protect the epoxy/glass laminate. It also prevents the need to sand a cured epoxy-coated surface which will save you a huge amount of time. The peel ply can stay on the surface of the sheathing for a long period of time and still be easily removed so you can keep it on there until you’re ready to reveal your new surface.
Now your boat is safe and protected – ready to take to the water whatever the weather.
Find out more about the benefits of this method by having a read of last month’s sheathing blog.