Category Archives: Materials Testing

yellow glue vs epoxy

Yellow Glue VS Epoxy

By Rachael Geerts—GBI Composite Materials Engineer

When should you use yellow glue (also called wood glue or carpenter’s glue) and when should you use WEST SYSTEM® Epoxy? This is common question epoxy users ask, especially when trying to choose the best adhesive for their woodworking projects. Let’s look at when one is a better choice than the other, and why. Continue reading

A GBI lab technician hard at work.

Quality Control: It’s what we do

By Pat Dammer – GBI Lab Technician

At Gougeon Brothers Inc., customer service and support are paramount. Throughout the decades (five strong and counting), we’ve built our WEST SYSTEM® product line on a model that places customer satisfaction at the forefront. Many WEST SYSTEM users know first-hand that we strive for customer success no matter the project. Our customers’ projects range across an extremely wide spectrum. What many users may not know is the extent of product support that grinds away behind the scenes before a batch of our epoxy even hits the retail shelves. I’ll provide a look at just one of our churning gears that isn’t so obvious at first glance-quality control (QC). Continue reading

penetrating epoxy sample blocks

Penetrating epoxy: legend or myth?

By Bruce Niederer — GBI Technical Advisor

I’m fast approaching my 22nd year of working here at Gougeon Brothers, Inc. From my first day on the job, I have lived the controversy surrounding penetrating epoxies vs. high-solids epoxies in general and WEST SYSTEM® Epoxy in particular. I have met with the formulator and founder of a popular brand of penetrating epoxy and talked to him many times over the years. He is a nice fellow and passionate about his product, but in the end we had to agree to disagree. Continue reading

Azek® PVC Deck Boards

An option in boat construction or repair?

By Bruce Niederer — GBI Technical Advisor

Wood has always been used in fiberglass boat construction, in stringers, and oftentimes as core in high compression areas such as under cleats, stanchions, and winches. Wood works great in these applications but we all know that the big problem with wood is the fact that it rots if it gets wet. Here at Gougeon Brothers, Inc. (GBI), we have spent long hours writing manuals and training people to use proper techniques using epoxy to keep wood dry and strong. Continue reading

Warm Temperature Bonding

By Don Gutzmer – GBI Technical Advisor

During warm summer months, WEST SYSTEM Epoxy working time and other handling characteristics will be different than at other times of the year. Our cure times are based on an ambient temperature of 72°F, but in warmer temperatures, the epoxy will cure faster. There are some steps you can take to extend epoxy working times and ensure good results when using WEST SYSTEM Epoxy in warm environments. Continue reading

Applying Polyester Gelcoat over Epoxy

By Mike Barnard

There are some myths out there as to whether you can apply gelcoat over epoxy. Andy Miller addresses the issue. He has a great understanding of WEST SYSTEM Epoxy, having used it for years as owner and chief repairman of Miller Boatworks in Herbster, Wisconsin. Andy knows his stuff. What’s even better is that, when he’s unsure about a detail, he contacts us for the right answers.  Continue reading

Aluminum Adhesion

By Tom Pawlak — GBI Technical Advisor

Because a newer epoxy formulation we offer is great for aluminum adhesion, we stopped offering the 860 Aluminum Etch Kit in the WEST SYSTEM product line in 2015. Before making that decision we ran a series of tests that compared bond strength of 105 Resin/206 Hardener and G/flex 650 Epoxy on aluminum surfaces prepared a variety of ways. As usual, we used the PATTI (Pneumatic Adhesion Tensile Test Instrument) to test aluminum adhesion. Continue reading

Common Errors in Fiberglass Laminate Repair

By Jeff Wright — Vice President of Technical Services

While most of our customers are successful when using WEST SYSTEM Epoxy to repair a damaged fiberglass laminate, we have become familiar with some common errors that are easily preventable. These mistakes are made by both professionals and amateurs. The information discussed in this article is available in our Fiberglass Boat Repair Manual and WEST SYSTEM User Manual, and on the WEST SYSTEM website. Continue reading

Advantages of 879 Release Fabric

By Mike Barnard

Much ado is sometimes made regarding amine blush but it’s easily avoided and easy to remove— especially if you use 879 Release Fabric.

When most epoxies are exposed to the atmosphere (especially cold and damp conditions) a secondary chemical reaction can occur at the surface of the epoxy, leaving a waxy-looking by-product called amine blush. This water-soluble film appears only at the end of the cure cycle, and never at all when WEST SYSTEM® 207 Special Clear Hardener is used. Continue reading