FAQ about aluminium boats and powercat attributes

Alloy as a building material

How much of a problem is corrosion in alloy boats these days?

In a properly built boat it shouldn’t be a problem at all – provided:

  1. The electrical system is professionally installed and fitted anodes are tested regularly. (This actually applies to all boats whatever their construction)
  2. Paint applications are done exactly to manufacturers specifications. (even a hand print on a prepared surface can leave a smudge of sweat/oil which can cause corrosion later)
  3. The boat is maintained and underfloor areas in particular are kept dry and free from salt build up and accumulating dirt/leaves/scales etc.
  4. All closed or inaccessible areas are sprayed with a suitable barrier product like Prolan. At Alloy cats we seal all underfloor areas with Prolan, especially inaccessible buoyancy compartments

What are the finishing options for alloy hulls

  1. Clearcoats. There are several brands of clearcoats (like Nyalic) that can be applied to hull. This is a specialist job that can entail acid washing first.
  2. Wet on wet paint. A properly prepared hull can have several coats of the required paint layers applied in a short time. Not all paint manufacturers offer this procedure. This method is popular over unfaired surfaces.
  3. Faired and painted. This can be taken to any level of finish required. Being labour intensive, costs can rise very quickly.
  4. Graphic film. Here at Alloy Cats Ltd we are using this method more and more, especially on trailer boats. It is becoming popular because it is relatively cheap and very quick to apply. You can even have photographic images set on the film for spectacular appearances. The film (like signwriters use) is self adhesive and we are yet to find any problems with it relating to corrosion. Scratches can be quickly patched over.

Are all aluminium sheets suitable for boats?

There are literally dozens of different alloys created with aluminium. Each has different properties relating to strength, weldability, corrosion resistance and so on. The most common one for boats is the 5083 alloy as it meets most boatbuilding criteria.

I have found quite a few corrosion holes under the floor of my tinnie. Can these be fixed?

Generally, yes. We once tigged up 128 holes in a hull! The thinner the hull (under 2.5mm) the less likely they can be welded. Sometimes the alloy is too oxidised and weak to withstand any form of welding.


How does the cost of a new alloy boat compare to the same boat built in composites?

Our research has shown our alloy boats cost approximately 15% less, Of course this will vary from builder to builder and assumes the boats are of very similar specifications.

On the water

Alloy hulls are known for being noisy. How can this be overcome?

On trailerboats there is not a lot you can do. However on our powercats we normally install engine type sound insulation along the chines and closed cell foam under wall carpeting along the hull interior.

Advantages of alloy over fibreglass

What are the advantages of an alloy boats

The main advantages is the ability to customise to a clients specifications.
For a full article on this topic see The advantages of Powercats