Category Archives: Techniques & Tips

Estimating Epoxy Amounts

Estimating Epoxy Amounts

By Bruce Niederer — GBI Technical Advisor

This formula will help you estimate the amount of mixed epoxy needed to wet out fiberglass cloth (assuming a resin-to-fiber ratio of 50:50) and apply three rolled epoxy coats to fill the weave of the cloth, i.e. “fill coats.”

The formula includes a waste factor of approximately 15%; however, more (or less) may be needed depending on the job and personal application technique. The epoxy is applied at standard room temperature, approximately 72° F. Continue reading →

The Scarffer is a tool for cutting plywood

Plywood Basics

By J.R. Watson

Since so many projects in Epoxyworks incorporate plywood, we felt it might be valuable to discuss briefly the types of plywood and some construction methods best suited to it. It’s easy to understand why people like plywood and choose it for so many projects: it is readily available, comes in convenient sheets (typically 4’×8′), is pretty light for its stiffness and strength (1/8″ plywood weighs about 11 lb per 32 sq ft panel), and is a bargain when compared to the price of many composite panels. However, plywood also has its weak points. There are limits regarding shape development because plywood can be compounded (bent in two directions at once) very little. In addition, plywood contains end grain on all its edges, Continue reading →

Product Highlight: 804 Reusable Mixing Stick

Reusable Mixing Sticks are practical mixing, application, filleting and cleaning tools have found many places in our workshop toolboxes, and we believe they will in yours, too. The squared, beveled end reaches into the square corners of the 805 and 806 Mixing Pots for thorough mixing of epoxy and blending of fillers. Continue reading →

Comparing Surface Preparation Techniques for Paints and Primers

By Joe Parker

Before you begin a project, it is a good idea to consider all of your options. Information about products or methods you may want to use is often available on product labels, from manufacturers, or your own experience. However, many times the information you need to make good choices is just not available. Then your best option is to test. In our most recent renovation, we had to figure out what to test for and how to do it. Continue reading →

Bonding to Corian™ and Wilsonart™ Laminates

By Tom Pawlak — GBI Technical Advisor

We recently did adhesion testing to Corian and Wilsonart surfaces with WEST SYSTEM 105 Resin and 206 Hardener at the request of a composite panel manufacturer. Corian and Wilsonart are mineral filled acrylic panels that look like granite and are often used as countertop material in kitchens and offices. Cabinetmakers and contractors typically use the panels in ½” thickness for residential applications. They are quite heavy, though not nearly as heavy as actual granite. Continue reading →

Research Chemist Bruce Niederer

“If You Were Just More Flexible”

“…you’d see things my way!”

Are flexible epoxies better than stiff epoxies? How stiff is too stiff? How flexible is too flexible?

By Bruce Niederer — GBI Technical Advisor

Read the title of this article again. Could a statement be more confrontational? I sure didn’t think so when my ex-wife laid it on me! The issue of “flexible” vs. “stiff” epoxies seems to have become a battleground in a continuing debate among adhesive manufacturers, wooden boat builders, restorers and repair yards. Who’s right and who’s wrong? Is it even a “right or wrong” argument? Continue reading →

Gluing Plastic Dimensional Lumber

By Patrick Ropp

More people are using recycled plastic/wood composite lumber for decks and other various projects. Although each manufacturer of recycled plastic lumber has his own blend, we found that most are using very similar ingredients: an equal amount of melted recycled plastic mixed with recycled wood chips or sawdust and then extruded in the form of dimensional lumber. Since the wood is encased in plastic, the plastic/wood composite boards are supposed to last longer than traditional decking materials and carry a good warranty. Many of these boards are not intended for use as structural members, but they Continue reading →

Varnish over epoxy

Testing House Paint Primers

By Tom Pawlak — GBI Technical Advisor

Gougeon Brothers, Inc. regularly engages in testing to support those who use our epoxy in architectural applications, both in new construction and repairs. In the past, we have tested the compatibility of house paint primers over WEST SYSTEM® epoxy and found that a variety of primers worked well. Latex primers especially performed well when applied over cured epoxy, even when the epoxy was marginally prepared prior to painting (Epoxyworks 7, Spring 1996). Continue reading →

Mold Release, PVA and Hairspray

By Tom Pawlak — GBI Technical Advisor

PVA (polyvinyl alcohol) is a water-based liquid plastic that can be applied to waxed molds to prevent molded parts from sticking. PVA is not always required. Often laminators rely solely on mold release wax to create a surface contaminant on the mold that allows parts to be removed. However, on complicated molds and on new molds, when the risk of sticking a part in a mold is greatest, PVA can be applied over a waxed mold to minimize the chance of sticking a part. Continue reading →