If you want to learn more about the different types of sealants/adhesives, I would suggest that you go to the following website: Http://en.wikipedia.org/wiki/Sealant
Halfway down the page, under types of sealants, there's a link-for more information visit- Http://adhesives.org. This will give you a good starting point. You can then explore from there.
In general, the marine industry uses polysulfides, polyurethanes, and silicones.
Silicones can effectively be used for sealing and bedding applications, both above and below the water line. The acetoxy cure products do not have great adhesion to fiberglass. The neutral cure products have very good adhesion, strength and UV stability. Also, they can be easily removed with the use of DeBond 2000. Do a google search for this product. After the use of DeBond 2000, wipe the area with acetone to remove any remaining residue.
Polyurethanes like 3M 5200 or 4200 have good adhesion and can be used for below the waterline applications. They however have poor UV stability properties. I would use these if you want to bed or seal hardware, but not if the sealant is going to be exposed to sunshine. The 3M 4000 on the other hand has very good UV properties. However, it is messy to work with. Unless the cartridge specifically states that it contains UV inhibitors or will not yellow, you can be assured that the product will yellow. The DeBond 2000 will break the bond of 5200-trust me.
Polysulfides cure by moisture adsorption. The thicker the bead or bondline the longer the cure. In effect, once the product forms a skin, it greatly retards the cure mechanism. If long cure times don't present a problem, they are excellent for above or below the water applications. They also have good UV properties.
Personally, I use 5200 and 4200 for bedding applications and for applications where I want to distribute stresses if I'm attaching two substrates with screws or mechanical fasteners.
The 4000 is used for UV exposed joints, if a lot of tooling isn't necessary. It's difficult to work.
For bead type applications which need to look good I use either BoatLife Lifeseal or neutral cure silicones with added mildewcides. There are only a few silicone manufacturers. Most silicones are privately labeled.
I can't stress enough the importance of having clean substrates or joints when using any sealant/adhesive.
Halfway down the page, under types of sealants, there's a link-for more information visit- Http://adhesives.org. This will give you a good starting point. You can then explore from there.
In general, the marine industry uses polysulfides, polyurethanes, and silicones.
Silicones can effectively be used for sealing and bedding applications, both above and below the water line. The acetoxy cure products do not have great adhesion to fiberglass. The neutral cure products have very good adhesion, strength and UV stability. Also, they can be easily removed with the use of DeBond 2000. Do a google search for this product. After the use of DeBond 2000, wipe the area with acetone to remove any remaining residue.
Polyurethanes like 3M 5200 or 4200 have good adhesion and can be used for below the waterline applications. They however have poor UV stability properties. I would use these if you want to bed or seal hardware, but not if the sealant is going to be exposed to sunshine. The 3M 4000 on the other hand has very good UV properties. However, it is messy to work with. Unless the cartridge specifically states that it contains UV inhibitors or will not yellow, you can be assured that the product will yellow. The DeBond 2000 will break the bond of 5200-trust me.
Polysulfides cure by moisture adsorption. The thicker the bead or bondline the longer the cure. In effect, once the product forms a skin, it greatly retards the cure mechanism. If long cure times don't present a problem, they are excellent for above or below the water applications. They also have good UV properties.
Personally, I use 5200 and 4200 for bedding applications and for applications where I want to distribute stresses if I'm attaching two substrates with screws or mechanical fasteners.
The 4000 is used for UV exposed joints, if a lot of tooling isn't necessary. It's difficult to work.
For bead type applications which need to look good I use either BoatLife Lifeseal or neutral cure silicones with added mildewcides. There are only a few silicone manufacturers. Most silicones are privately labeled.
I can't stress enough the importance of having clean substrates or joints when using any sealant/adhesive.