Category Archives: Materials Testing

Low-Tech Adhesion Testing

by Jim Derck—GBI Technical Advisor

Before beginning a project, it’s a good idea to test the adhesion between epoxy and the materials to be used. Preliminary adhesion tests can help you choose the best materials and surface preparation methods. It can also help to avoid a surprise bonding failure.
At Gougeon Brothers, Inc. we use a Pneumatic Adhesion Tensile Testing Instrument (PATTI) for adhesion tests. After the PATTI test stud is bonded to the test surface, the stud is pulled in tension until it releases. The instrument gauge gives a precise pounds per square inch reading at failure. Continue reading →

Minimizing Amine Blush

By Tom Pawlak —GBI Technical Advisor & Tim Atkinson — Senior Chemist

I recently built a double-ended paddle for my kayak. The blades were made of thin mahogany plywood coated with epoxy. I had coated all the paddle parts with two coats of epoxy the day before, and overnight a thin oil-like film had formed on the surface of the epoxy. This is amine blush. To ensure a good bond between the blade and the shaft, I removed the blush with water, dulled the surface with an abrasive pad, and dried the surface with paper towels. I’m confident using my new kayak paddle because the mating surfaces of the shaft and blade were properly prepared prior to bonding. Continue reading →

Bonding PVC Plastic with Epoxy

Editor’s note: This article was originally written in 1994, long before we developed G/flex epoxies which offer vastly superior performance in bonding to plastics including PVC. A much more current article on this subject is Gluing Plastic with G/flex Epoxy by Tom Pawlak and Jeff Wright. If you’re interested in gluing PVC with epoxy, we suggest you start there. The following article is published at Epoxyworks.com for historical purposes only.

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cold-temperature bonding

Cold-Temperature Bonding & Coating with Epoxy

Strategies for successful application and curing of epoxy at low temperatures

Epoxy behaves differently in cold temperatures. These handling tips can guide you in obtaining optimum performance from epoxy in this fall and winter.

Epoxies reach a higher percentage of their potential physical properties when mixed and applied at temperatures above 60°F. However, you can use epoxy at lower temperatures and still obtain a dependable bond. The key is adapting your handling and application techniques to cold temperatures. Whether you live in a Northern or Southern climate, it is helpful to know how temperature affects epoxy chemistry, how epoxy handles differently in cold conditions, and what steps you can take to assure dependable bonds in cold weather. Continue reading →

What All Those Tests & Numbers Mean

by Captain James R. Watson

If you were to inquire about the physical properties of WEST SYSTEM® epoxy, you’d receive a physical properties data sheet. To some, the information is very meaningful, but I was having a hard time figuring out what all those tests and numbers meant and how they applied to my projects. After I found out for myself, I decided to write an article explaining how the tests are performed and what the resulting numbers mean. Continue reading →

Air Quality

VOC Testing, epoxies, and your shop

By Tim Atkinson — Senior Chemist & Glenn House — Director of Product Safety and Regulatory Compliance

Many materials used in large manufacturing processes and even small do-it-yourself jobs, emit volatile organic compounds (VOCs) and other air pollutants. Paints and other coatings, adhesives, resins and cleaning solvents are all sources of air pollution. Each product emits different types and varying amounts of air pollutants. Federal, state and local governments have passed legislation (e.g., the federal Clean Air Act) to reduce air pollution and prevent the depletion of the ozone layer by regulating the emission of air pollutants. Continue reading →