Category Archives: Bonding

Mixing G/Flex with Other WEST SYSTEM Epoxies

by Jeff Wright — Vice President of Technical Services

Above: Mixing G/flex with other WEST SYSTEM Epoxies increases the versatility of these epoxy systems.

WEST SYSTEM 105 Resin-based epoxy is a very versatile system. For years, experienced users have been mixing and blending the various product combinations in countless ways. For example, users may blend 205 Fast Hardener and 206 Slow Hardener to make a hardener with a modified cure speed. Different uses of 410 Microlight® Fairing Filler provide a further example. Many customers assume that the only use of 410 is to make a fairing compound—it is added to thicken epoxy to a peanut butter consistency to create a light, easily-sanded filler. Continue reading

Bonding Fasteners in High-Density Urethane Foam

Tips for Sign Builders & Everyone Else

by Bruce Niederer — GBI Technical Advisor

Above: Bonding fasteners in high-density urethane (HDU) foam calls for drilling an oversized hole slightly shallower than the fastener length and setting the fastener in an annulus of thickened epoxy.

Many of our readers who are familiar with WEST SYSTEM® Epoxy products for building and repair already know the benefits of fastener bonding techniques. WEST SYSTEM Epoxy has been used in other industries for many years as well, and these folks apply knowledge and techniques developed in the marine and aerospace industries in their work. A good example is the sign industry, a huge industry in the U.S. with companies ranging from mom & pop garage operations to multimillion-dollar corporations. Continue reading

Epoxy's adhesion to metal is affected by surface treatment

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.

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

Testing Bolts Epoxy Bonded into Concrete

by Brian Knight—GBI Technical Advisor

Above: The final version of the test Brian devised to determine the holding power of bolts epoxy bonded into concrete. When the load cell registered 4000 lbs, he stopped the experiment.

The email exchange with Bob Warters in the article Installing a basketball goal is typical of the process we sometimes go through to answer a technical question. Most questions do not generate laboratory testing, but, in this case, the data we had available was limited. I was able to give Bob some shear strength data on concrete block from previous tests but was unable to find specific data on fasteners bonded with epoxy into poured concrete. I suspected poured concrete would hold a bolt better, but another data point would be reassuring. Continue reading

G/5 Adhesive Tips

Working with G/5 Resin & Hardener

By Tom Pawlak — GBI Technical Advisor

Above: To simplify mixing G/5 Resin and Hardener for a large project, Grant made a carrying pallet with sixteen holes, sized to hold 1-ounce mixing cups (pill cups purchased at a food service outlet). The pallet was covered with duct tape so glue drips could be peeled away. Note that a mini cupcake pan could be dedicated to this kind of task as well.

Many of us at Gougeon Brothers experiment with WEST SYSTEM® products on personal projects at home as well as at work. We often push products and techniques beyond the limits recommended in our literature. Sometimes the experiment fails, sometimes we discover something very useful. Continue reading

Scheherazade under sail.

Testing Large Bonded-In Fasteners

by Brian Knight—GBI Technical Advisor

Above: Scheherazade, the 154’7″ yacht that required testing of large bonded-in fasteners.

Epoxyworks 19

Cover Photo: The 154’7″ Bruce King-designed Scheherazade resting on her massive keel at Hodgdon Yachts in East Boothbay, Maine.

Scheherazade is a 154′ 7″ Bruce King-designed ketch under construction at Hodgdon Yachts, in East Boothbay, Maine. Scheherazade is 60% larger than Antonisa, the last Bruce King/Hodgdon Yacht collaboration, and is the largest sailboat under construction in the United States. 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

Gluing Plastic Dimensional Lumber

by Patrick Ropp—GBI Technical Advisor

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