Anchors Away Boat Yard About Blisters

Blister Facts

What are blisters?
Blisters are the result of water molecules squeezing between the spaces separating the fiberglass molecules. Even though most think their hull is completely watertight, water does get into laminate. It typically takes between 7 or 8 years before a new hull develops blisters. The exact time depends on many factors such as types of resins used, gelcoats, and the amount of resin in the layup.

The following is a summary of our complete twelve-step restoration program. Though, there are other less strenuous techniques adopted by many repair facilities around the country, this is our format of choice. It is the only format under which we can offer the level of guarantee that each of our restored vessels leaves our yard with.

Once your boat is in the water, moisture will tend to concentrate in small voids and air bubbles in the laminate. Voids can be microscopically small or as large as in inch or more in diameter. Many tiny voids are unavoidable as air is introduced into the resin in the mixing and rolling process. It does appear that hulls with a large quantity of resin in the laminate are less prone to blistering than dry or resin starved laminates. This is one reason why pre-1970 hulls do not blister as easily as newer boats.

What should you do if you have blisters?
In some cases nothing. Water has already penetrated the laminate. To spend money on preventatives such as barrier coating without first removing the wet and damaged laminates will not stop the process. If you are not planning on selling the boat soon and simply want to sail it, your best plan may be to do nothing but monitor the situation.

In other cases, the blistering process may be no more than a failed barrier coat. A simple process of stripping the bottom and applying of a new barrier coat may be all that is required to remedy the blistering process..

In many cases the blistering process may have progressed to the point where the hull has been damaged. The only correct solution in this case is a complete removal and re-lamination of the damaged layers.