During a recent inspirational hardware store visit, I discovered a rotary wire brush made by Norton™ called the Rapid Strip Brush™. It is used with an electric drill and produces results comparable to bead blasting or a needle scaler. The package says it can be used to abrade metal, masonry and fiberglass. I immediately thought of a fiberglass application that I wanted to try it on. Continue reading →
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 →
Gougeon Brothers recently did R&D testing for a manufacturer who wanted to know if WEST SYSTEM® epoxy could effectively repair injection-molded parts made with fiberglass and dicyclopentadiene (DCPD) blended polyester resin that included an internal mold release. The hoods and decks for many jet skis and snowmobiles are made with this material.
DCPD blends in polyester cause it to cure rapidly and cross-link thoroughly. This feature helps to reduce emissions from the resin but makes it difficult to repair Continue reading →
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. We first looked at Scheherazade in EPOXYWORKS 17, Spring 2001, before she was rolled and set on her 153,000 lb ballast keel. On a March, 2002 visit, Scheherazade was resting on her massive keel (cover), while far above, surrounded by multiple levels of staging, work continued on her interior and deck (below). Continue reading →
We recently completed adhesion testing for a boatbuilder who was concerned about surfaces being contaminated by workers who use protective skin creams. The builder wanted to be sure that residue from the protective creams did not contaminate objects touched by workers throughout the day. We tested five products: Derma Shield™, Gloves in a Bottle™, Unique Skin™, SBS 46 Protective Cream™ and SBS 40 Medicated Skin Cream™. Continue reading →
Since so many projects in Epoxyworks incorporate plywood, we felt it might be valuable to discuss briefly the types of plywood and some construction methods best suited to it. It’s easy to understand why people like plywood and choose it for so many projects: it is readily available, comes in convenient sheets (typically 4’×8′), is pretty light for its stiffness and strength (1/8″ plywood weighs about 11 lb per 32 sq ft panel), and is a bargain when compared to the price of many composite panels. However, plywood also has its weak points. There are limits regarding shape development because plywood can be compounded (bent in two directions at once) very little. In addition, plywood contains end grain on all its edges, Continue reading →
Before you begin a project, it is a good idea to consider all of your options. Information about products or methods you may want to use is often available on product labels, from manufacturers, or your own experience. However, many times the information you need to make good choices is just not available. Then your best option is to test. In our most recent renovation, we had to figure out what to test for and how to do it. Continue reading →
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. Corian and Wilsonart are similar solid surfaces in that they can both be cut with conventional tools, then wet sanded and polished to a nice shine if they are damaged during installation. They are also available in thinner forms alone, or laminated over Continue reading →
Are flexible epoxies better than stiff epoxies? How stiff is too stiff? How flexible is too flexible?
By Bruce Niederer
Read the title of this article again. Could a statement be more confrontational? I sure didn’t think so when my ex-wife laid it on me! The issue of “flexible” vs. “stiff” epoxies seems to have become a battleground in a continuing debate among adhesive manufacturers, wooden boat builders, restorers and repair yards. Who’s right and who’s wrong? Is it even a “right or wrong” argument? Continue reading →
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 →