Category Archives: Techniques & Tips

One-Shot Pot Repair

by Tom Pawlak — GBI Technical Advisor

Above: The cracked polyurethane foam planter pot upon which Tom performed this simple pot repair with epoxy. You can see the household cling wrap he used to hold the cracked pot together while the epoxy cured.

My wife Mary and I recently went to the local building center to purchase a large planter pot for our patio. After we had agreed on a nice large terra-cotta beauty, I noticed another large pot that had a serious crack. I asked the associate for a price on it, knowing it would be easy to repair with WEST SYSTEM® Epoxy. He said I would be doing him a favor if I took it away. So we came home with two pots for the price of one. Continue reading →

If You Can’t Take the Heat…

Understanding Epoxy and Heat Deflection Temperature

By Bruce Niederer — GBI Technical Advisor

Above: The test apparatus holds five of the test samples shown below in a bath of heated oil while a three-point load is applied to the sample. It is used to determine heat deflection under load (HDUL) temperature and the effects of high temperatures on cured epoxy.

Among both professionals and amateurs in the world of composites, there are certain enduring misconceptions and rumors regarding the effects of elevated temperature on an epoxy bond. Armed with just enough misinformation to be dangerous, folks will make important decisions that can lead to costly or time-consuming mistakes that might have been avoided—if they had an adequate understanding of the principles that encompass epoxy structures and temperature. By defining some commonly used terms and briefly discussing issues surrounding epoxy application, we hope to dispel some of these misconceptions about epoxy and heat.

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Comparing Cost and Weight of Flat Panels

How to choose the best materials when building flat panels

by Jeff Wright — Vice President of Technical Services

Above: Jeff Wright, Vice President of GBI Technical Services, poised to take a deep dive into types, materials, costs, weight, and stiffness of flat panels.

Many WEST SYSTEM® customers appreciate the benefits of cored composite construction. They understand that it creates a part that is lightweight, strong, and stiff. We often receive calls from these customers inquiring about using a composite panel when building or repairing something that would normally be made of plywood. Such projects may include a new center console for a fishing boat or the replacement of flying bridge side shields. Determining the best material requires consideration of many aspects of the project, but often comes down to cost versus weight. Continue reading →

Practical Uses for Razor Blades

by Tom Pawlak — GBI Technical Advisor

Necessity is the mother of invention, and razor blades are often called into service for a variety of tasks around the shop other than shaving. Here are a few.

Mini-Spreader

Razor blades can be used in a pinch to apply caulks and thickened epoxies with great precision. They do a great job filling isolated pinholes and scratches, especially when the blade is laid at a low angle (nearly flat) when spreading the putty. Continue reading →

Effects of Surface Treatment

On Epoxy Adhesion to Metals

by Brian Knight—GBI Technical Advisor

Above: Surface treatment can make all the difference in epoxy adhesion to metal. Photo by Manny Becerra on Unsplash

We have performed tens of thousands of adhesion tests over the years and many of these tests were done on metal surfaces. Below is a summary of tests done on a variety of metal surfaces and done with a variety of surface preparations. As you look at the chart, notice the surface preparation that gives the highest number.

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WEST SYSTEM Epoxy vs. Polyester

for Fiberglass Boat Repair

by Tom Pawlak — GBI Technical Advisor

Above: Epoxy vs. polyester in a typical fiberglass boat repair cross-section.

Even though we’ve been promoting the use of WEST SYSTEM® Epoxy for repairing fiberglass boats (boats made with polyester resin) in our manuals and Epoxyworks for many years, we continue to receive inquiries asking whether it is appropriate to use epoxy for polyester boat repair. Because of the misinformation still prevalent in marinas, local yacht clubs and on the Internet, we felt it was time to restate the case for epoxy. Continue reading →

Polyester Gelcoat Over Epoxy

by Jeff Wright — Vice President of Technical Services

Most production fiberglass boats are made with polyester resin, and we’re often asked if it’s appropriate to use polyester gelcoat over epoxy. WEST SYSTEM® epoxy is a wonderful material for repairing polyester fiberglass boats. One reason for this is the ability of epoxy to form a stronger mechanical bond to a damaged laminate than polyester resin. Epoxy also provides a better moisture barrier than polyester resin. Continue reading →

There Will Be a Test

by Kay Harley

A research mentality and ongoing epoxy testing permeate all levels of Gougeon Brothers, Inc. We are committed to rigorous, long-term research on WEST SYSTEM products and their uses with other materials in wide-ranging applications. Studies include the basic chemistry involved, safety for users and the environment, formulation changes, product modifications such as adding pigments or UV additives, panel strength and stiffness with varying composite lay-ups, and the strengths of epoxy bonds, including hardware bonding. GBI commits capital investments to improve its testing capability and supports active ASTM involvement.

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Swift Solo

Building for Long-Term Competitive Performance

by Bram Dally

Above: The Swift Solo in action. The complicated rig is designed to be managed by one person while they hang from the side of the boat.

Swift Solo, a single-handed skiff built by Bram Dally.

When Meade Gougeon asked me if I’d write a piece about what I’m up to for Epoxyworks, I was honored. He had read the January 2002 article on my single-handed skiff in Sailing World and offered the assistance of GBI (Gougeon Brothers, Inc.) to do some extensive testing for us on several composite samples. Continue reading →

Epoxy’s Adhesion to Wood

Woods of the World Epoxy Adhesion Testing

by Tom Pawlak — GBI Technical Advisor

Above: Epoxy’s adhesion to wood is the focus of this study of dozens of wood varieties from Africa and the Philippines.

We recently purchased a 154-piece wood sampler from Eisenbrand Inc., Torrance, California. The 3″ × 6″ × ½” specimens originated from points all around the world. Each specimen was provided with its common name, scientific name, and country of origin. There were several specimens we’d never heard of in this study of epoxy’s adhesion to wood. Continue reading →