Vinyl Ester Resin
Vinyl ester resins and polyester resins are very close in molecular composition. The difference is that the molecular chain is longer in vinyl ester resin. This helps it absorb impact better than polyester. It also helps the vinyl ester shrink less. There is less chance of de-lamination when using vinyl ester (VE) resin. Vinyl ester can be used as the final coat after polyester resin to create a better water barrier.
Vinyl Ester resin is more resistant to solvents and water degradation. It is typically used in gas tanks, boat hulls and other items that will be exposed to water or chemicals for extended periods of time.
VE resin is a tough resin that can withstand repeated bending better than both polyester and epoxy resin. Vinyl ester resin cures with a tack just like polyester resins without wax.
Vinyl ester resin is more expensive than polyester resin, but cheaper than epoxy resin. The hardener/catalyst for vinyl ester resin is MEKP (methyl ethyl ketone peroxide). It is the same catalyst used with polyester resins.
Epoxy resin is an ideal resin for high performance and light weight parts. It is water resistant and can be used with carbon fiber, Kevlar and fiberglass fabric. It is not compatible with fiberglass mat (chopped strand mat). It has great bonding capability and a fast wet out. Epoxies have a low odor compared to other resins. One of the downsides to epoxy is that it is more expensive than polyester and vinyl ester resin.
Epoxy resin comes in two parts. The resin side is usually designated as the ‘A’ side. The ‘B’ side is the hardener side. Our epoxy resins come in either a 2:1 or 4:1 mixing ratio. There is a choice of three different hardeners: fast, medium and slow. The speed of hardener chosen depends on the temperature in the work area, the desired working time and desired drying time. Epoxies dry with a full surface cure.
We carry the Pro Glas 1200 Series and 1300 Series epoxy. The biggest difference between the two is the 1200 Series is UV stable, extremely clear, tough and high gloss. It is UV resistant which reduces yellowing and surface degradation from UV exposure.
It is ideal to work in temperatures around 77 degrees Farenheit. Resin will typically not cure well in temperatures below sixty degrees and will cure too fast in temperatures above 90 degrees Farenheit.
Mixing the correct ratio of A:B is extremely important. Most problems that occur with improper cure is due to incorrectly measuring or not mixing the two components completely.
Liquid Properties of Systems
|Speed of hardener||Fast||Medium||Slow/Flexible|
|Mix ratio, Resin to Hardener by volume||4:1||4:1||2:1|
|Viscosity, cps mixed||450-550||275-325||650|
|Gel time, minutes at 77 degrees F.||12-15||25-30||25-30|
|Set time, hours at 77 degrees F.||2.5||4.0||6.0|
|Recoat time, hours||2.5-3.0||3.5-4.0||6.0-7.0|
|Recommended minimum working temperature ( degrees F)||40||50||45|
|Suggested uses: F=Fairing, L=Laminating, A=Adhesive||F,L,A||F,L,A||L,A|
Cured Properties of System
|Heat Deflection Temperature (HDT) Note: higher HDT’s attainable with post cure.||145||150||110|
|Flexural Strength, Psi||18,560||16,000||10,500|
|Tensile Strength, Psi||9,000||9,756||7,000|
|Flexural Modulus, Psi||360,000||360,000||400,000|
|Tensile Modulus, Psi||475,000||475,000||360,000|