In my last haul out, I has a few blisters that were in need of repair. I ground out the area and had fiberglass cloth and west system ready to go, when the yard guy cam around and said that I should use csm becaues it is the best wtih west system. Any ideas on this? Is this just two ways of accomplishing the same task? Everyone has opinions..... Thanks for yours.
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epoxy does not get good adhesion on polyester resin for several reasons. Its best to use polyester resin for your repair work and then use epoxy for a barrier coat. The thicker the better also make sure the epoxy has the stoichiometric ratio on the paper work for constant proportions.
I forgot to mention epoxy does not wet out most cloth used in fibreglas layup very well.Since you are using west systems they should be able to supply you the proper material.
HUH???
Excuse me Rob, but exactly which planet did you just fly in from??? Maybe you haven't read any of the responses from our guest expert. Your quotes are laughable in this forum.
Excuse me Rob, but exactly which planet did you just fly in from??? Maybe you haven't read any of the responses from our guest expert. Your quotes are laughable in this forum.
There's alot of rumors and misconceptions
I would like to dispel some of the misconceptions Rob from Newburgh mentioned in his responses. Don't be too hard on him Eric - a lot of old school polyester guys still believe many of the same things. Polyester resin, which the vast majority of production boats are made with, is a perfectly fine resin system for new construction. The longevity of the hulls is a testament to that. But I can say with full confidence that polyester is not a good repair resin, and most competent boat yards know this and use epoxy for all structural repairs. Polyester simply has poor secondary bonding characteristics. We have done exhaustive research and testing to confirm this and published much of the data over the years. The aircraft industry has know this for a long time and specifies epoxy for repairs to aircraft. Epoxy wets out fiberglass very well, including CSM. Fiberglass is treated what is called a sizing when manufactured. The sizing is applied to promote and aid the wet out with resin. Yards that are used to doing repairs with polyester often have glass that is sized specifically for polyester and it's true that epoxy wets out this glass poorly. Glass can also be sized specifically for epoxy, but these days the overwhelming majority of glass is treated with volan, which is compatible with both epoxy and polyester. Also, while it is important to mix epoxy resin and hardener at the correct ratio, by using our calibrated pumps it becomes very easy. Our ratios are formulated to be a bit forgiving - a little bit off one way or the other is fine. (about +/- 5%) If you haven't read our 002-650 Gelcoat Blisters: Diagnosis, Repair, and Prevention manual you should be able to get one where you purchased you WEST SYSTEM. If not contact me and I'll see you get one. And maybe get one for the guys in your repair yard.
I would like to dispel some of the misconceptions Rob from Newburgh mentioned in his responses. Don't be too hard on him Eric - a lot of old school polyester guys still believe many of the same things. Polyester resin, which the vast majority of production boats are made with, is a perfectly fine resin system for new construction. The longevity of the hulls is a testament to that. But I can say with full confidence that polyester is not a good repair resin, and most competent boat yards know this and use epoxy for all structural repairs. Polyester simply has poor secondary bonding characteristics. We have done exhaustive research and testing to confirm this and published much of the data over the years. The aircraft industry has know this for a long time and specifies epoxy for repairs to aircraft. Epoxy wets out fiberglass very well, including CSM. Fiberglass is treated what is called a sizing when manufactured. The sizing is applied to promote and aid the wet out with resin. Yards that are used to doing repairs with polyester often have glass that is sized specifically for polyester and it's true that epoxy wets out this glass poorly. Glass can also be sized specifically for epoxy, but these days the overwhelming majority of glass is treated with volan, which is compatible with both epoxy and polyester. Also, while it is important to mix epoxy resin and hardener at the correct ratio, by using our calibrated pumps it becomes very easy. Our ratios are formulated to be a bit forgiving - a little bit off one way or the other is fine. (about +/- 5%) If you haven't read our 002-650 Gelcoat Blisters: Diagnosis, Repair, and Prevention manual you should be able to get one where you purchased you WEST SYSTEM. If not contact me and I'll see you get one. And maybe get one for the guys in your repair yard.
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