Gelshield Application, Gelsheild protection, Protecting your Gelcoat

GRP hulls will start to absorb moisure through the gelcoat as soon as the vessel is launched and this will gradually increase the longer the vessel is afloat. The moisture penetration causes very little damage as it passes slowly through the Gelcoat barrier. This is why it is recommended you store your vessel on land at the end of a season to allow the moisture that is still working it’s way through the Gelcoat to evaporate before it becomes trapped behind the Gelcoat and blisters begins to form.

A GRP boat hull is usually a mixture of polyester resin reinforced with glass fibres. This is due to more cost affective build prices, in a process where layers are placed on top of one-another which forms the laminate. This laminate will have very small voids, air pockets within the resin and fibreglass.

Water may pass slowly through Gelcoat but eventually water molecules can collect and condense within these voids and air pockets. Within the laminate are various water soluble components. These are solvents and unreacted cemicals from the manufacturing process.

The water within the voids dissolves and reacts with these components. (Hydrolysis). The ongoing hydrolysis will continue within the voids enlarging the cavities and forming a solution. The solution is water absorbing (“hydroscopic”) and once the solution is released in the voids it accelerates the rate of water absorption into the laminate.

At some point the pressure may become too high for the surrounding material to support and a blister is formed. As this process continues, moisture continues to be absorbed, the laminate break down accelerates and more blisters are formed. In time some larger blisters may develop within the laminate as well as those more commonly occurring between the gel coat and laminate. To rectify this extent of damage is very costly and more often than not costs more to repair than the vessel is worth in most cases.

Osmosis can become noticeable, in most cases in the form of small lumps in the surface of the Gelcoat that when broken open have a distinctive vinegar like fragrance. It is a race against time at this point as this process will work it’s way through the laminate compromising the strength of the GRP, exponentially increasing repair costs.

Epoxy barriers such as GelShield help to drastically slow the prosses of osmosis before it can advance to the condition described above. 

With nearly 2 decades of experience you can have peace of mind the work being done on your pride and joy is of the best standards available.

 For more assistance or any enquiries please contact me through the link below.