Tag Archives: adhesion

Common Errors in Fiberglass Repair

By Jeff Wright

While most of our customers are successful when using WEST SYSTEM Epoxy to repair damaged fiberglass, we have become familiar with some common mistakes 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.


Typical Repair

fiberglass repair

A typical fiberglass repair in cross section.

This diagram illustrates how we recommend laminating a repair after the damaged Continue reading

G/Flex Keel Repair

By Don Gutzmer

Early in March of 2012, a local boat owner called our technical line and asked about repairing his cast iron wing keel with WEST SYSTEM® Epoxy. He asked if a technical advisor would be willing to take a look at the cracks on his keel and recommend the best way to repair it. After looking at the boat I gave the customer a call back and recommended using G/flex® Epoxy. The advantage of G/flex is that it is a toughened system that has a tensile elongation of more than 30 percent, which would prevent cracks from reappearing in the fairing compound. The boat owner then asked if I Continue reading

Will It Stick?

By Mike Barnard

Many times each day we get questions about sticking to various substrates.  Most questions are on something that we have already tested, so we check our large database and advise on how best adhere to the surface.  Other times the request is unique and we are unsure if WEST SYSTEM® Epoxy will stick to it or not.  In the event we do not have any experience bonding to a material, we recommend testing adhesion.  Many times this means gluing a wood block to the surface, then pulling the Continue reading

Letters to the Editor – White Oak

By Bruce Niederer

We consider ourselves students as well as tech advisors and so are always open to learning something from others. Our readers are generally pretty savvy people, and when they take the time to write us a thoughtful letter, we feel compelled to share what we learn from them with the rest of our readers.

My article, White Oak Redux (Epoxyworks 34) generated two responses we wanted to share. The letters, along with my replies, follow. Continue reading

Adhesive Bonded Structures

By Jeff Wright

Fiberglass reinforced plastic and other composites influence the design of many products manufactured today. Boat hulls, sports equipment and airplanes can easily take new, complex shapes when composites are used in place of traditional materials. Reinforcing structures also benefit from the versatility of composite materials when prefabricated components are bonded with a high-strength adhesive. This article will discuss some of the engineering aspects to consider when designing or repairing an adhesively bonded composite structure. Continue reading

White Oak Redux

White Oak Redux

By Bruce Niederer and Bill Bertelsen

Building stuff, especially boats, with wood is much like a religious calling; once you hear the call, there’s no turning back. Those who’ve heard the call will not suffer fools willingly, so when I decided to conduct some white oak adhesion and shear testing and report the results in Epoxyworks 31, skeptics and believers alike took to the internet wooden boat forums-and had no problem speaking their minds! Having healed from the pummeling I took in some quarters, I’m back again to report the promised follow-up test results. Continue reading

Shop Floor Testing Methods

Shop Floor Testing

By Jeff Wright

Boat builders or advanced hobbyists often want to learn more about the characteristics of the fiberglass laminate they’ve just created. But sending samples to a professional testing laboratory can be expensive and impractical. Fortunately, there are some tests you can do in the shop that yield reasonably accurate results.

Before you begin to test laminates in your own shop, it’s important to understand the difference between shop tests and standardized tests. Many organizations such ASTM, ISO, or UL provide established test procedures defining a specific test method. These may specify things like sample preparation methods, equipment and acceptable environmental conditions. These standards allow the test to be repeated by different people at different locations all over the world.
Continue reading

So Stands the Mighty Oak

By Bruce Niederer

People have been building boats using white oak for centuries, sacrificing blood, sweat and tears to engineer wonderful and enduring vessels of all shapes and sizes.

Oak was often used because of its desirable properties and behavior. It is dense, strong, rot resistant, holds fasteners well and can be steam bent. In the days before glues and adhesives, oak planking was used because it would swell considerably which resulted in tight and sound hulls, meaning little leaking and dry interiors. Of course, time marches inexorably forward and eventually builders began using adhesives to augment or, in some cases, replace mechanical fasteners.

We’ve been debating the issue of gluing oak ever since. Continue reading

Understanding Six10 Properties

By Jeff Wright

WEST SYSTEM® Six10 is a two-part, pre-thickened epoxy adhesive formulated with properties that make it perfect for many adhesive applications. Compared to other ready-to-dispense adhesives, its particular physical properties make it ideal for stitch and glue boat construction, fiberglass laminate repair and general bonding. This new formulation has a good balance between the elongation and toughness of G/flex® and the strength and stiffness of our 105 Resin-based epoxies. You can use it with as many materials as possible including wood, metals and composites. The long working time with fast thru-cure and unique shear thinning are additional characteristics formulated into Six10 that contribute to its ease of use. Continue reading

WEST SYSTEM Launches G/Flex Epoxy

By Tom Pawlak

G/flex Epoxy is a toughened, resilient two-part epoxy engineered for a superior grip to metals, plastics, glass, masonry, fiberglass, and wet and difficult-to-bond woods. Introduced in June 2007, G/flex Epoxy is currently available in two consistencies: G/flex 650 Epoxy, a liquid epoxy, and G/flex 655 Epoxy Adhesive, a pre-thickened epoxy. Both have a 1:1 mix ratio.

G/flex Epoxy gives you 46 minute pot life and a long open or working time of 75 minutes at room temperature. It will reach an initial cure in 3–4 hours and a workable cure in 7–10 hours. Wait 24 hours before subjecting joints to high loads. Continue reading