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. Continue reading
Above: The notched-beam test for creep stress determines flexible properties.
The Technical Staff at Gougeon Brothers, Inc. regularly discusses material properties in a variety of applications. For example, it is not uncommon for us to discuss with a customer how to use carbon fiber to stiffen a structure, such as the shaft of a kayak paddle, and then within minutes discuss with another how to bond a dimensionally unstable wood, such as oak, and ensure precautions are taken so that the relative movement of the wood will not cause a failure. Continue reading
Above: Measuring epoxy is easier with positive displacement pumps.
For measuring epoxy accurately, Gougeon Brothers, Inc. has introduced high-volume epoxy pumps that are extremely robust. These pumps dispense epoxy faster than any pump the company has previously offered. The 303 and 305 Positive Displacement Pumps work by trapping a fixed amount of resin and hardener, then forcing (displacing) that trapped volume into the discharge pipe or system. The mechanics of this setup mean that increases in resin viscosity due to temperature changes will not slow dispensing speeds. Positive latching lids help prevent contamination of resins and hardeners.
The 305 Metering Pump is an excellent tool for measuring epoxy.
The new 303 Positive Displacement Pump is calibrated for WEST SYSTEM 3:1 ratio epoxies (105 Resin with 207 Special Clear Hardener or 209 Extra Slow Hardener) and is easily identified with a red base. The new 305 Positive Displacement Pump is calibrated for 5:1 ratio epoxies (105 Resin with 205 Fast Hardener or 206 Slow Hardener) and has a blue base.
Positive Displacement Pumps are also available with drum fittings. These connect directly to WEST SYSTEM Resin and Hardener drums so there is no need to decant materials. This setup conveniently streamlines the metering process for high-volume users, saving both time and money.
Several manufacturers offer high-volume pumps that deliver epoxy at upwards of several gallons per minute. Several well-respected pump manufacturers are listed at the end of this article. Their pumps are specially designed to meter epoxy resin and hardener simultaneously at specific ratios. Some of these pumps can meter resin and hardener through a static mixer, so additional mixing isn’t required.
For more information on mixing larqe quantities of epoxy, read Tom Pawlak’s Big Batch Mixing Methods.
Above: Batches of epoxy samples awaiting accelerated testing in the hot water bath.
We are constantly testing our products to fully understand and characterize them, and this is important both for ourselves and for our customers. A test method will usually produce results in a timely fashion, but there are times we must use an accelerated testing method so we can get the results before we take that last lonely boat ride across the river Styx. This article describes some of the accelerated testing we do here. Continue reading
Above: Safely removing uncured epoxy from your tools starts with a citrus-based hand cleaner. Photo by Mariya on Unsplash
Removing uncured epoxy from tools used for applying epoxy often involves solvents that have strong odors and are flammable. A WEST SYSTEM® user suggested an alternative that does not have these problems: a solution of citrus-based hand cleaner and water. This solution will remove uncured epoxy from tools and can remove epoxy that has started to gel if the tools are allowed to soak for a few hours.
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Above: Decayed wood on a small boat. Photo by Chester Ho on Unsplash
Sodium borate is used in a number of commonly used household products from laundry detergent to hand soap. It is also used to treat wood against insect and fungal attacks. Sodium borate is refined from borax, a natural mineral, which is mined throughout the world. One of the largest deposits is in the Southwestern United States. (Think 20-Mule Team Borax™, Death Valley Days radio and TV shows).
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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
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.
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
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.
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