Are you looking to purchase a boat? Looking at a secondhand fibreglass boat? Concerned that there might be some nastiness lurking under the surface of the boat hull? Don’t let this put you off purchasing that boat. Sandwich construction is a popular method for fibreglass hulls. Its lighter, and usually stronger than those with a solid fibreglass hull, however this means that water can weaken the hull if it finds its way inside. Sometimes this can rot the timber core or delaminate the core, however it can be relatively easy to fix, if you know what you are doing or know the right professionals like the team at Advanced Fibreglass Techniques. The construction of your boat will largely depend on its use, if you are looking to purchase a speed boat, odds are the full hull uses the sandwich construction method, whereas normal weekender fibreglass boats might actually use a combination construction, where below the water line is solid fibreglass, and above and the decks might be the sandwich method.
Core materials will differ between manufacturer and usually are different foam materials, light timbers like balsa or ply and sometimes even an aluminium. Essentially anything lightweight, flexible but sturdy. Foam cores conform to curves and can allow for greater flexibility in the core, however most applications use the timber materials for a more stable inner core.
So how does a boat find itself with internal water damage? Surely when it comes to a boat, its pretty protected from water egress, being it spends the majority of its life on the water right? Well yes, that is true, however there are some places water shouldn’t go, but it finds its way there and the most common entry point is an unsealed drill hole. Boat manufacturers all have their processes for ensuring sealing the core around any hardware or components that need to be affixed to the core, however nothing is fool proof. Mostly caulking of some description is used to seal the drill holes or seal the area around the core that the hardware has been mounted to. However over time, these materials degrade, through age or movement. The most common place is the anchor. If you think about how much a boat rocks on open water, to have the weight of an anchor moving on a single point and the only material in between the core and the weight is caulking, over time the movement and the weight will degrade the caulking allowing for water to enter and start to rot the inner core.
The first problem with water egress is obviously rotting the timber core, the next is potential separation of the sandwich construction. Both issues cause structural problems, however both at the same time can cause serious structural concerns.
At least there’s a relatively simple solution, we have discussed fibreglass hull repairs previously, but this is a little different, instead of simply working back the fibreglass you need to get right into and remove the rotten core and epoxy in a new core to reinstate the strength. There are more advanced ways of completing these repairs, but we might leave these processes for another time.
Mark, Nigel and the team provide our clients across industrial, private and commercial fibreglass our professional design and development services as part of the project. We enjoy the challenges presented in boat restoration and take great satisfaction in achieving the customer’s desired result. We use the latest techniques to repair your watercraft, whether it be a small cosmetic repair or a structural modification. Contact Mark or Nigel today, on (08) 8182 4877 or drop in for an obligation free quote.