Bowriders for Sale in Ontario…What Exterior Hull Gel Coat is Best?

Looking for a shiny new bowrider for 2016?  Thinking about The Toronto Boat Show?  Lots of models and tons of colours at the show…..are you going to look past the colour and the shine?  The outer colour of a fiberglass boat is made of a material known as Gel coat.  To properly understand the outside colour the purpose and bare in mind that gelcoat has a very important purpose other that look….think of gel coat in terms of armour platting to guard against the harsh marine environment and UV radiation.

A car or truck has depending on the manufacturer will have an automotive type paint finish over the steel body work which is intended to limits corrosion of the body steel plus gives it that colour that attracted you when you first saw that new vehicle.  Automotive paint finishes are in the range of 1.5 to 2.0 mils thick and with todays vehicle’s paint is protected by a clear coat finish on top.  Fiberglass materials used in boat building do not suffer the same corrosive effects steel unfortunately does when water, air and oxygen meet.   Fiberglass lamination can and will have deterioration problems with exposure to water!  But its a boat and it should be able to live in the water right for years?

What are the three main problems with fiberglass lamination techniques as they apply to bowriders?  For this article we are not going to discuss the main resin component Polyester or Vinyl Ester resins but stick to the outer gelcoat component that give the bowrider its colour and sheen.

  • Water absorption that results in osmotic blistering and premature failure of the laminate.
  • Cracking, crazing or patchy gelcoats
  • Damage due to UV radiation.

Good Gelcoat thickness is in the area of 20 mils or 10 times the thickness of an automotive paint finish. Too thin and normally you get what is called print through of the hull laminate cloth weave and too thick and gel coat cracking can be a problem.  The outer surface microscopically must be smooth or this will dramatically increase fading as the surface area exposed to UV radiation can actually be 200% to 300% larger.  Say what?  Think of it as hills and valleys verses a near totally flat surface like a farmers field. How can I tell…difficult because rubbing your hand on it will not tell you the actual definition.  I see people at boat shows pounding and knocking on hull sides as a measure of a good boat….no this does not work and has no basis in fact!  You cannot clear coat gelcoat like a car finish as it yellows very quickly and due to chemistry flakes off making a real mess.

An optimal gel coat surface will be extremely smooth at the microscopic level and this is affected in a positive or negative way by:

  • The base resin type utilized in the gelcoat and what materials are added to strengthen its chemistry
  • Length of time allowed to cure in the mold
  • The care and knowledge of the workers applying the gelcoats in the mold
  • How well temperature and humidity are controlled during the curing process in the mold

What is the poorest gelcoat:

  • The poorest quality gelcoat would be polyester based combined with Orthophthalic anhydride.  This combination is cheap for a boat builder, easy to work with but has serious associated problems with water absorption, cracking and UV fading.  This combination of polyester base can be improved by changing the Orthophthalic anhydride to Isophthalic to improve greater levels of water and chemical resistance.  The difference here is cost and not insignificant cost!

A bowriders best available gel coat would be:

  • Vinyl ester based and reacted with Isophthalic to provide best water impregnation resistance, highest strength, best finish quality as well as best resistance to cracking and fading.

There it is! Simple right!  I can tell you that over 90% of salespersons have no idea of what the chemistry actually is in that boat they are pitching you including the laminate and gelcoat.  All you hear is that there brand is hand laid.  Actually there is to my knowledge and research by the old standard no bowrider hull that is actually hand laid anymore.  Yes there are components that are applied or maneuvered by hand…but machine application of the resins is the norm and with machines computer controlled the ratios are consistent.  It is not the application so much but what materials are chosen by the boat builder and from what supplier and remember most of this information is not available to you.

This type of information goes to show you how say a Bayliner or Tahoe bowrider can be significantly less money to purchase than say a Monterey Boat or a Regal Boat.  This can also explain why a Glastron Boat or Four Winns Boat is likely less cash than a Chaparral Boat.

Application of gelcoat and the care that is taken can be accurately judged by the amount and placement of decals (flash).  How is that?  Most of today’s bowriders have an accent colour against the predominate white hull colour. This is done strictly for cosmetic look to attract you as colour have been shown to effect mood, sales and overall opinion.  For example purple is a royal colour, green represents the environment and black is luxury!   When two or three hull colours exist bleeding from one to the other is a problem.  Maintaining a clearly defined distinct line between the colours is time consuming and requires a great deal of expertise in combination with additional in mold time….in others word….costs the builder more time and money.  Bowrider and fiberglass boat builders eliminate or hide poor gel coat finish and poor separation of colour lines by plastering large amounts of rapidly deteriorating decals, stripe applications and tape on the hull.   All decal application flash potentially hiding poor workmanship!  A boat builder who puts little or no decals on the outer hull surface such as Monterey Boats, Regal Boats of say Chaparral Boats is showing that they know what they are doing and are prepared to do what is right.

The absolute best gel coat colour which maintains their actual intended colour over time is white.  So the best boat is like Moby Dick the great white whale of legend…apparently based in fact…who new?  Colours that seem to fade the most….yellow, red, browns and some greens.  Best dark colours over time as long as the correct gel is used are blue and black.

How do I as a boat builder get competitive price advantage on hull lamination.  Simple….apply lots of decals or stripping over a polyester based gel coat system with no barrier coat underneath and use polyester resins for the hull laminate in combination cheap cloths and lots of chopper gun fiberglass.  Get it in and out of the mold as fast as I can!

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