Vinyl Ester Over Epoxy

Cloth and polyester resin.

Vinyl ester over epoxy.

Many high strain repair areas and lightweight parts must flex and strain without micro fracturing. They are produced by the addition of α β unsaturated carboxylic acids to epoxy resins. Essentially they comprise a base of polyester resin strengthened with epoxy molecules in the backbone of the molecular chain. Epoxy vinyl ester resins ver are an important class of high performance thermoset molding resins.

Specifically proper cure of vinyl ester resins and a 15 year study of the effective use of permeation barriers in marine composites to prevent corrosion and blistering. To cover wood a laminate using epoxy resin and 10 oz cloth will yield a much better job than 10 oz. In the case where a part originally manufactured utilizing polyester or vinylester has yielded to strain and cracked a well reinforced epoxy repair will tenaciously hold to the substrate with 2000 psi strength vinylester. Vinyl esters also use peroxides e g.

Allow the epoxy to cure to the point where sanding produces a fine powder. Wash away amine blush with water and an abrasive pad such as a 3m 7447 hand pad. Using epoxy you can improve the laminate properties with a post cure almost always. Quality epoxy resins stick to other materials with 2 000 p s i.

Vinylester is essentially a styrene modified epoxy resin. Epoxy resin is an ideal resin for high performance and light weight parts. Cured epoxy tends to be very resistant to moisture absorption. Vinyl ester resins are produced by the reaction esterification between an epoxy resin and an unsaturated monocarboxylic acid.

Before coating a fully cured layer of epoxy with polyester gelcoat prepare the surface properly to remove any amine blush. The hardener catalyst for vinyl ester resin and polyester resins is mekp. For vinylester resins and even less for polyesters. Has some great papers on this which i am quoting from.

In areas that must be able to flex and strain with the fibers without micro fracturing epoxy resins offer much greater capability. Regarding costs vinyl ester resin is more expensive than polyester resin but cheaper than epoxy resin. Before applying gelcoat over epoxy. It is water resistant.