Sorry AndyMan
To simplify my sager.
Yes the Rocksolid is created using Epoxy and Polyurethane. This is the same as many of these kits where Epoxy is use by itself as a coat.
Epoxy is solid and the thicker it is used the more risk of fracturing. It actually becomes brittle over time. It is the fibreglass, Carbon Fibre or Kevlar that hold the epoxy together and as a combination less epoxy, less thickness less likely to fracture. It does as I stated will eventually fail as a resin only product. West Systems who were the largest manufacture of Epoxy and Epoxy systems admitted that if used by itself or the layup [material and resin together] is to resin rich will eventually become brittle and fail [hence the yacht masts.
Vinyl Ester was created to take over from using a resin rich or straight resin only applications.
Polyurethane Now your talking is the bonding resin. It has been used for many years and is used in the same manner as an Epoxy resin. STOP. Epoxy and Polyurethane are a two resin mix always called an A and a B monomer [resin and hardener].
Polyurethane is better known as a Foam. When mixed you have a short time before it begins to react [foam up] and the solidify. If you get it on yourself or any surface you can remove the foam but not the actual resin the bond is permanent. Now you get it the Bond [it is the proverbial **bleep** that sticks to the blanket]. But polyurethane as a laminating resin wont work it is meant as a foaming agent.
Now I do not understand the chemicals used that will bond these two completely different resins with two different hardeners work. It has always been my interpretation of these resins that you cannot interchange the hardeners. so how they have managed it is pure science.
Now the problem always arrises the actual mixing process. You cannot always use a drill or motorised mixer as it creates tiny bubbles that require another chemical to disperses. I am not going into that now. These tiny bubble are a danger sign if you have a clear mix but you do not in this kind of application the mix is coloured. These bubbles are filled with air, air expands and contracts just like everything else in these bubbles but air during its expansion grows the tiny bubble until one bubble join another bubble and so on. hence the brittle reaction has begun. and will not stop.
One of the problems you will get is areas or patches of either a milky white or a yellow as stated in the article. This will happen it is the Russian Roulette Factor in other words it is not the users fault all the time it is in the manufacturing process one batch will be fine and look marvellous and the next shoddy and motley. This could be either the air moisture, the sun [UV], cold and i could go on and on, [ this is the short version] if you cannot understand this then you cannot follow the directions properly.
I could go on and on but if you cannot read this then get someone who has had experiance as it my give you a couple of extra bullets in your game of Russian Roulette. Let the buyer beware. The manufacturer in this case has the odds of in his favour in this case.
