Will epoxy resin stick to gel coat?

Typically, gelcoat isn’t recommended over epoxy because they’re chemically incompatible and the gelcoat won’t adhere properly.

What causes gel coat to blister?

Fiberglass blisters occur because water passes through the gelcoat. Water soluble chemicals inside the laminate exert an osmotic pull on water outside, and some water molecules find a way through the gelcoat. As more water is attracted into the enclosed space, internal pressure builds.

How do I stop my gel coat from blistering?

To make sure you have an excellent waterproof barrier you must make sure the hull is clean and free of any antifouling paint. It is wise to use a generous amount of epoxy over the entire boat for maximum protection. Sanding and reapplying an addition coat will ensure that you hull will be safe from blistering.

How long before you can sand West System epoxy?

It has a minimum recommended working of temperature of 60°F. 209 Extra Slow Hardener, mixed at a 3:1 ratio with #105 Resin, results in a pot life of 20-25 minutes at 72°F, with 10-15 hours required for a solid cure….Overview of Hardeners and Cure Times.

Hardener 206 Slow
Min. Temp. 60°F

Can you Fibreglass on top of gelcoat?

No you should not lay glass on top of gel coat. If you want a stronger boat seperate the hull and deck and lay glass on the inside.

Does gel coat dry without hardener?

If the gelcoat does not get enough catalyst it will not “kick” or begin to harden. If the measurement is off even slightly, the gelcoat could start to harden but not cure completely, leaving a tacky, non-sandable surface.

Are gel coat blisters bad?

Poor quality gel-coat cause blisters on the boat hull If that layer prevents water from getting in, blisters will not occur. But, epoxy resin is better than polyester and good at resisting water. If the first layer (gel coat layer) resists water well, then blister will not form on the hull.

What is Pox boat?

It occurs when boats are left in the water for long periods of time and happens more frequently in fresh water. Once blisters start to show up, it is not necessarily time to panic.

What is osmosis on a sailboat?

Rod Twitchin, qualified surveyor and director of RTMarine, describes osmosis as “the blistering found on many GRP boat hulls”. A blister that is considered Osmosis is typically a result of moisture being trapped within the fiberglass below the gelcoat and or top coatings causing softening in those areas.

Can you mix West System hardeners?

One full pump stroke resin to one full pump stroke of hardener delivers the correct ratio. This can also be done for 207 Special Clear and 209 Extra Slow Hardener but at 3 parts resin to 1 part hardener. When mixing, stir the epoxy for at least two minutes to ensure it is thoroughly blended.

Can you spray lacquer over epoxy?

Lacquer can stick to epoxy.

What’s the difference between fiberglass resin and gelcoat?

Gelcoat is not a finishing coat; it is painted onto moulds/plugs and remains tacky after it cures. Resin and Glass are generally applied on top of the Gelcoat. It forms the hard, smooth shiny surface of the finished article and is usually pigmented. It paints on easily but does not drain from vertical surfaces.

Can you use polyester gelcoat over West system epoxy?

We know polyester gelcoat can be used over WEST SYSTEM Epoxy. As Jeff Wright wrote in “ Polyester Over Epoxy ” in Epoxyworks 22: “As with many products, the surface must be prepared properly: if it is not, then poor curing and adhesion may result.

What does gelcoat do to a fiberglass boat?

Gelcoat is the coating sprayed up against a highly polished mold at the beginning of the fiberglass layup process. This process results in the smooth, mirror-like finish typical of new boats. With the passage of time, unprotected gelcoat will oxidize and eventually take on a chalky appearance.

When to use Gelcoat or epoxy on glass?

Gelcoat is sprayed into a mold before the glass fabric and resin are applied to provide a smooth pre-finished surface when the part is removed from the mold. It is not often used as a post-production finish coating, but it can be applied over epoxy and is useful in some repair situations.

What is the catalog number for West system epoxy?

Catalog number 002-650 A guide for repairing and preventing gelcoat blisters in fiberglass boats with WESTSYSTEM®Brand epoxy. Thetechniquesdescribedinthismanualarebasedonthehandlingcharacteristicsandphys- ical properties of WESTSYSTEMEpoxy products.