how important is Epoxy resin in the construction to you?

[GordMay]

A composite is a thing composed of a number of parts - a complex material (compound), in which two or more distinct, structurally complementary substances or elements, combine to produce structural or functional properties not present in any individual component.

[noelex 77]

Epoxy resin is far superior to polyester. Why do expensive yachts such as HR IP Swan etc use non epoxy resin ? The cost of the hull is only a small fraction of the finished yacht. To pay $1 million for a yacht made of second rate materials Is maddness.
Just my opinion
Cheers John
See my blog at amzerzo.blogspot.com

[Weyalan]

Doing erfit work on my boat: Last winter I used vinylester resin because it is significantly cheaper, but this winter I am generally using epoxy, even with the added expense. The bottom line is that epoxy seems a lot easier to work with, such that the time you save outweights the additional cost. I have found that the vinylester is fine for straight glass-work, but it is not at all good for glueing and is a real pain in the butt for fairing. So, unless I am doing a whole heap of straight glassing, I'll be sticking with epoxy.

[Redbull addict]

Originally Posted by noelex 77

Epoxy resin is far superior to polyester. Why do expensive yachts such as HR IP Swan etc use non epoxy resin ? The cost of the hull is only a small fraction of the finished yacht. To pay $1 million for a yacht made of second rate materials Is maddness.
Just my opinion
Cheers John
See my blog at amzerzo.blogspot.com

I don't think HR is using polyester.

[noelex 77]

Originally Posted by Redbull addict

I don't think HR is using polyester.

HR dont use any Epoxy resin in their construction.
From their detailed brochure

"Hallberg-Rassy has over 43
years experience building
GRP (Glassfibre Reinforced
Polyester) hulls. All hulls
are hand laid up in GRP
under careful quality control
procedures by a subsidiary
company owned by HR.
Hallberg-Rassy has full control
over the complete production
cycle. No other hulls than
Hallberg-Rassys are built there.
The outer skin of the hull is
Optimal GRP hulls
made in isophthalic gelcoat.
Isophthalic polyester is also
used. Both are very resistant to
water penetration."

I think many companies are a bit ashamed that they make expensive yachts out of these materials and tend to burry the information so I can understand the confusion.

[never monday]

Originally Posted by Redbull addict

that's my undestanding also. I have Tartans brochure for the 4300 and it makes a big deal over the hull strength and the fact that they use epoxy. C&C seems to use epoxy on some of their hulls also.

When some manufacturers say their hulls are a composite, does that mean it could be any combination of resins, core, etc, right?

I believe Tartan & C&C are under the same management now. At least they have the same address.

[Redbull addict]

Originally Posted by noelex 77

HR dont use any Epoxy resin in their construction.
From their detailed brochure

"Hallberg-Rassy has over 43
years experience building
GRP (Glassfibre Reinforced
Polyester) hulls. All hulls
are hand laid up in GRP
under careful quality control
procedures by a subsidiary
company owned by HR.
Hallberg-Rassy has full control
over the complete production
cycle. No other hulls than
Hallberg-Rassys are built there.
The outer skin of the hull is
Optimal GRP hulls
made in isophthalic gelcoat.
Isophthalic polyester is also
used. Both are very resistant to
water penetration."

I think many companies are a bit ashamed that they make expensive yachts out of these materials and tend to burry the information so I can understand the confusion.

Wow, nice catch!

That is real surprising. So can the application technique, quality control or amount or addition of any substance to a polyester resin make it better (ie - stronger, absorb less water or any other benefits Epoxy have)?

[delmarrey]

Just as an example of the difference between epoxy and polyester, the last couple of weeks I have been reworking one hatch and installing a new one amidships behind the mast.

I've been using polyester because of the dry/work time is much quicker. Usually within a couple hours I can sand and form. Epoxy I have to wait at least 4-6 hours. or it gums up the sandpaper and files.

The point is when I work with epoxy and drip a little on the deck I usually have to go through some work to get it off. Working with the polyester, the drips I can just stick a knife under them and they pop right off.

Epoxy has a much better bond, even to a dirty surface like the decks. So anything structural I surely use epoxy and would luv to have a whole boat made of the stuff............................._/)

[noelex 77]

Originally Posted by Redbull addict

Wow, nice catch!

That is real surprising. So can the application technique, quality control or amount or addition of any substance to a polyester resin make it better (ie - stronger, absorb less water or any other benefits Epoxy have)?

Yes the care put into the layup, quality of resin and quality control can all make a big difference. I am sure HR do these things well. They produce some fantastic yachts. I had drinks recently on a 54 footer, very impressive.
However the resin used is still a second rate product. Polyester is much worse than epoxy in many important areas such as water absorption micro cracking etc etc. careful application cannot makeup for these deficiencies.
One fiberglass expert reported that GRP was a good boat building material, but for long term durability boats should be dried out for at least 3 months every year!. The loss of shear strength of GRP, immersed in water, with time is also quite frightening.
If they left off their teak decks and put the savings into epoxy I might have been tempted to buy a HR.
Many people cruse successfully in GRP and fiberglass has got some wonderful properties, but I have concluded aluminium is better material.
Yes I am biased, apologies and no offense is intended. The important thing is to enjoy cruising in any boat.
Cheers John
See my blog at “Amzer Zo” Yacht Blog