Differences between Resin... Specifically House/Layup/General Purpose

[74bayliner]

I have been confused lately about the differences between the House , Layup, and General Purpose Resins. It seems each company calls it differently.

I am not talking in regards to the difference between vinylester and polyester resin.

So I have a few companies that Sell :
CompositesOne.com - Polyester House Resin,
Fiberglasssite.com - Polyester Lay Up Resin,
Fiberglasssupply.com - Boat & General Purpose Resin
Uscomposites.com - EB General Purpose Polyester Resin

I have the MSDS and Technical Data sheets for the first three and i am currently waiting on an email from USCOMPOSITES for their resin.

In comparing the first three, most of what i found is the biggest differences are in how much percentage the ingredients are mixed to make the resin. But they all use a general mixture of these ingredients:
COBALT NEODECANOATE
COBALT 2-ETHYL HEXANOATE
STYRENE MONOMER
SILICA, AMORPHOUS

Now my question would be... I contacted the companies (mfr) listed on the MSDS and tech data sheets i received and asked them the difference between "General Purpose, House Resin, Layup Resin" and they told me essentially the same thing... "They are the same resin just mixed differently" and i asked them if any of these would work for fiberglass cloth and mat in a boat interior and i was given the "Go ahead you should be fine"

Just wanted to gather some intelligence from the Iboater community. Does anyone know anything different from what i have gathered?

Some companies like Uscomposites sells both the EB General Purpose Resin and the Marine Grade.
But from googleing the difference between "Marine Grade and General Purpose" i could not find much information.

Please assist.

I am not too worried about the price but i just want this for my knowledge ... So yes if you feel like you need to tell me "Just play it on the safe side, get marine grade resin that is 18 bucks more than the general purpose"
Than please feel free because it is a forum for a reason
But if you know, and can provide some information as to the difference i think it would be beneficial to me and others asking the same question.
Thanks

 

[ondarvr]

Re: Differences between Resin... Specifically House/Layup/General Purpose

A “GP” or “House” resin would typically be a DCPD and ORTHO blend (2 difference resin bases) designed for lower cost and ease of use. A “Marine” grade should be a straight ISO base, it will be a bit stronger and more water resistant than a GP resin.

A typical boat will be about 99% GP resin, but frequently they will use a Marine grade, or VE skin coat right next to the gel coat for better water resistance. The more time the boat spends in the water can determine which skin resin is used, more time requires a better resin.

When it comes to what a company calls their resin it is totally up to them.

 

[74bayliner]

Re: Differences between Resin... Specifically House/Layup/General Purpose

Thanks for the reply ondarvr, can you explain what DCPD and ORTHO Blend Mean as far as ISO base?

 

[ondarvr]

Re: Differences between Resin... Specifically House/Layup/General Purpose

Within what might be called the polyester line of chemistry there are different formulas and ingredients, DCPD, ORTHO, ISO and VE (plus others) resin bases all have things in common, but the ingredients vary depending on what the resin is designed to do. Without getting too deep into the chemistry it’s hard to explain the differences. The base resin is what you start with to make the finished resin or gel coat, different resin bases may be blended together or used alone, then silica, promoters, wetting agents, air releases, styrene or other solvents, pigments and fillers too for gel coat, plus other things, are added to make the final product you buy.

 

[74bayliner]

Re: Differences between Resin... Specifically House/Layup/General Purpose

That sounds like great information. Thanks ondarvr...