Hi folks

I am interested to hear from those of you that have worked with both types of resin and associated build materials when putting together your boat.

Personally I have always previously used the polyester types. My new gas boat is an epoxy boat so it is my first experience in working with epoxy resin. Despite being initially apprehensive about moving away from what I know and a bit of a learning curve, I am now delighted with the system (I am using the West System epoxy).

What in your opinion are the pros and cons of the two product types?

For my part the pros of Epoxy far exceed the cons in my experience so far.
1 Epoxy is far stronger and more durable.
2 I prefer the cure process as it simply thickens until solid unlike polyester that quickly gels.
3 No more gel coat fractures that happen with polyester/fibreglass lay ups.
4 The cure process does not mark or distort the outside of the hull when installing hardware which has happened to me with polyester resin.
5 No strong lingering smells after application.
6 Five to one ratio mix by weight with the West System gives a consistent strong setting using digital scales for accuracy of measurement.

As to the cons, I can only think of one that being Epoxy is more expensive. However I am a convert to the Epoxy system.

What are your opinions? I am interested to hear from your experience.

Cheers
Craig

Epoxy is the way to go. It lends itself to more things like carbon fiber, and vaccum bagging type apps... along with many of the pros that you listed... welcome to modern epoxy

Craig just remember when using West system epoxy you should always sand/scuff between applications. West System when cured has a very fine "wax" film on the surface that makes a poor bond between cured layers. Polyester resin and some brands of epoxy does not do this.

Thanks for your comment guys.
In respect of the “wax film” the 55 page manual makes reference to this as an Amine Blush. Thankfully it is water soluble so it says can be removed with a wet abrasive pad. Alternatively applying fresh resin to a partially cured surface gives a chemical bond and no issue with this film and no need for sanding.

In my learning curve, I did initially have a small 12gram batch that failed to harden properly. The cause as I suspected was that I was not getting the 5 to 1 mix accurate enough. The solution for me was to invest in a small set of digital scales with 0.01g increments.

Since using these I get the hardener accurate to one drop of resin and every subsequent mix has set consistently rock hard. So I can mix in 6 gram batches with absolute confidence that the ratios are sufficiently accurate.

Cheers
Craig

While I agree EPOXY lay ups are the stronger if sufficiently thick and more accurate ( Due to less shrinkage )
Still REALLY like those hulls layed up in Vinylester resin. * It is harder than epoxy, has minimal shrinkage unlike polyester resin and is much more stable in the heat of summer not getting soft and flexy like epoxy does.
Down side is it shatters like poly and does not tear with the cloth grain in an accident like epoxy hulls typically do