Vinyl Ester or Polyester Resins

Boater's Chat Boat Buying Information Muskoka

 

 

Looking for a best buy fiberglass boat at the 2015 Toronto Boat Show in January?  How do I know superior hull structure….brochure….salesperson….Google it or just how important is hull structure and how do I find out about the hull structure?  You have to know what to look for and the right questions to ask.  Hardly anyone ever asks they just assume its okay.  Recently I read an article that stated that 9 out of 10 new car buyers do not even lift the hood to see what is in there!  Most buyers I have dealt with do look at the engine compartment on an inboard powered boat.  I always show it regardless as it is in the case of a stern drive (inboard/outboard) about half the cost of the total price.  The added benefit is that in this area you get the only at least partial view of the lamination.  I am at the Toronto Boat Show or a dealerships and see all these shiny white boats with blue and black accents….are they built all the same?  In a word…..”NO”  not even close! In the article on ” Are Fiberglass Boats All the Same” we started into this subject and today we continue into the hull laminate.

I am going to start with an example of how we achieve lower laminate costs but at what costs to the buyer.  A major brand in the 2014 model year in order to get competitive price advantage decided to not use an approved IBBI product in the lamination schedule.  The savings were not insignificant to the builder so it was decided by management to go this route….we save costs which may make us more competitive in the marketplace.  The non IBBI approved product was used in top deck lamination schedule.  Boats were sold to dealers and retailed to the public.  Then what happened? Gel Coat Cracks!  Lots of gel coat cracks!  That shiny new toy that you dreamed about for years is full of gel coat cracks.  Then the doubt starts creeping in…did I do my homework….is it just my boat….what did the dealer know who sold it to me…can this be fixed….will they come back….will the repairs show?

Just What is Good Hull Lamination?

There are four main types of fiberglass lamination schedules.

  • Traditional hand lay up using either a vinyl ester resin  (best) or polyester resin (cheaper) based system.
  • Chopper Gun lamination which can use either of the resin bases.
  • Combination of hand lay up augmented with chopper gun strand.
  • VEC lamination used exclusively by Larson Boats.

Resin Base Systems and Their Importance

Think of the resin base system as the glue or cement that holds the hull structure together and remember that the hull is what interacts with the water and forms the foundation for flooring, seating , windshields and the engine.  There are three main types or resin systems utilized in boat construction.  These are vinyl ester, polyester and epoxy.

Vinyl Ester Resin System ( Superior )

Vinyl Ester Resin systems simply cost significantly more…way more!  This system has two main advantages:

  •  Vastly more capable of resisting cracking due to flexing of the components.  A boat hull bends or flexes perhaps millions of time in its lifetime as each wave, bump or shock causes tiny flexing movement and this will result in fatigue and this fatigue is cumulative over time. Vinyl Ester are therefore 1000’s of times better in a marine application.  On a hard impact Vinyl Ester resins are more tolerant of stretching than polyester resins and are less likely to show stress cracking.
  •  Vinyl ester resins have fewer and smaller micro cracks and open sites in the lamination which provides vastly superior resistance to osmosis and overall water ingression into the laminate.

Polyester Resin Based System ( 50% Cheaper ) 

Polyester resin systems are used in some cases exclusively in up to 95% of the lamination schedules for craft under 60 feet in length.  Why….polyester resins are 50% cheaper than vinyl ester resins and the resin component of a fiberglass boat can 40 to 50% of the laminate structure.  This the builder can represent a very significant cost savings on his bill of materials.

  • Polyester Resins are significantly less cost to utilize and can represent a savings in the hundreds of dollars for a builder.
  • Polyester Resins are more prone to osmosis blistering and water absorption and is more prone to secondary bonding failure.
  • Polyester Resins demonstrate significantly more shrinkage during curing which can result in weaker lamination and voiding.

 

VEC Resin Based System

The VEC patented system is unique in the marine business with the resins being a totally different animal.  The VEC system is state cutting edge technology exclusive to Larson Boats utilizing patented and secret resin and epoxy formulas developed in combination with Boeing and 3M.  Polyester and Vinyl Ester systems are open mold systems which is explained in more detail in lamination.   VEC is a closed mold system and the result is a 100% composite boat.  For more detailed information click on VEC Technologies.

Campion Boats Envirez Resin System

The Campion lamination and Envirez Resin system is a unique application of renewable resource resins in an open mold lamination schedule.  As this is proprietary property of Campion what I can tell you is that it utilizes a isopthalic resins in combination with a dcpd resin blended further with chemical compounds made from corn and soya oils.   Of note in an open mold situation of which over 90% of todays recreational boats are constructed with, the Campion system could be considered the most expensive lamination schedule of all brands.

Gel Coat Cracking

Unfortunately in the 29 years in the marine business I have seen lots of gel coat cracks.   Boats made in the 70’s and 80’s typically do not have gel coat cracks.  Some of the old Grew, Doral, SeaRay if you found one today in a field probably does not have on gel coat crack!  Why do most of the older fiberglass boats not have problems with gelcoat cracking?  It has to do with the type of gelcoat utilized at that time.  Environmental regulations were not as strict and VOC ( volatile organic compounds) emissions essentially were not regulated in combination with thicker and stronger lamination schedules.

Todays fiberglass boat designs which try to maximize interior space have added to the gelcoat crack issue.  What are the factors contributing to gelcoat cracking?

  • Too much or excessive stress related hull flex particularly in the areas at the base of the windshield and mid bow areas
  • Additional widening of the entry from the cockpit to the bow seating area reducing strength and increasing flex at this point
  • Boat builders not predrilling or not using proper counter sink type drill bits.
  • Boat builders not scribing top decks at the main hull deck joint with cracks then radiating off the screws holding the two hull pieces together.  Scribing stops the continuation of a crack beyond the boundary of the scribe so that it does not radiate past the gunnel molding.
  • Boat builders thinning our top decks to a point of too little strength and too much flex
  • Boat builders utilizing a polyester lamination system instead of a vinyl ester system

How do we as a buyer eliminate or reduce our chance of a gel coat crack problem?  Unfortunately it does come down to money.  As I stated before in the boat business you get what you pay for and you do not get more for less!  Ask questions….go deeper than that lifestyle brochure shot!  Most sales people will not tell you and in many cases product knowledge about construction is so poor they cannot tell you.  If you only sell one brand of boat…that is what I must try and sell you that!  Its your money…demand more and get past the emotional attachment to just style.

Which lamination system sounds like the best value for you and your family and where you want to place your trust and investment in again in consideration that this is a long term purchase.  In the boating business today there is no more for less there is only less for less.