Monthly Archives: January 2015

decayed wood on a small boat

Borate Salt Treats Decayed Wood

by Tom Pawlak — GBI Technical Advisor

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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A properly engineered Scootboard chassis. Even without the resources of a well-equipped test lab, Bill Bertelsen, GBI’s test engineer, was able to gather useful composites data using the equipment at hand—in this case, a spring clamp, a ruler, a digital camera, and an 8-year-old girl.

Fortifying a Spare-Parts Scootboard

by Bill Bertelsen, GBI Test Engineer

Above: A properly engineered scootboard chassis. Even without the resources of a well-equipped test lab, Bill Bertelsen, GBI’s test engineer, was able to gather useful composites data using the equipment at hand—in this case, a spring clamp, a ruler, a digital camera, and an 8-year-old girl. ,

“Daddy, can we build a scooter from these old pieces of wood?” Continue reading →

Figure 1—A completed L-7 at the dock. Multi Marine’s new 23' folding trimaran kit features manufactured hull pans. The builder attaches plywood topsides to the pans.

Developing Multihulls

A folding trimaran for DIY boat builders

by Michael Leneman, Multi Marine

Above: A completed L-37 multihull at the dock. Multi-Marine’s new 23′ folding trimaran kit features manufactured hull pans. The builder attaches plywood topsides to the pans.

What is the simplest way for a home builder to build a good, light hull for a catamaran or trimaran? A few years ago, we set about looking for an inexpensive way to construct a small trimaran that we had developed as a prototype. The answer we came up with was unique: to combine a fiberglass molded “pan” with plywood/glass/epoxy topsides. Continue reading →

pot repair

One-Shot Pot Repair

by Tom Pawlak — GBI Technical Advisor

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 →

metal door repair with 410 Microlight

Metal Door Repair

WEST SYSTEM 410 Microlight® to the Rescue!

by Jim Derck—GBI Technical Advisor

Above: Jim Derck describes how he used 410 Microlight in a metal door repair. Image: A knocker on a metal door. Photo by Felix Luo on Unsplash 

At the end of moving day, after many large items had passed through the doorway, our house’s metal door was left with a nasty crease about a foot long. The door was made of steel and had a foam core. The needed repair was just a fairing application with no structural component. Continue reading →

Scheherazade under sail.

Scheherazade Update

Courtesy of Hodgdon Yachts

Above: Scheherazade is a 155′ Bruce King-designed ketch built by Hodgdon Yachts in Boothbay, Maine and launched September 27, 2003. Photo by Onne van der Wal.

Epoxyworks #23, Spring 2006

Cover Photo: Scheherazade, a 155′ Bruce King-designed ketch. Image by Onne van der Wal.

Hodgdon Yachts of East Boothbay, Maine launched the 155′ ketch, Scheherazade. She is a beautiful union of wood/epoxy technology, elegant design, and superior craftsmanship. Continue reading →

1—Statue repairs: Shep after being knocked off his base.

The Limitations of Statues

Statue Repairs with Epoxy

by Bill Bertelsen, GBI Test Engineer

Above: Statue repairs are underway on “Shep,” a molded fiberglass figure that was knocked off its base and belongs in the outdoor nativity set of St. Luke’s United Methodist Church in Essexville, Michigan.

Creating lasting outdoor art has challenged humans since the dawn of time. One has only to think of the pyramids (still there), Stonehenge (mostly there), the Colossus of Rhodes (long gone), or the Easter Island monoliths (surviving, but then two heads are better than one). In more recent times, there’s Mt. Rushmore, Stone Mountain Georgia, and the Statue of Liberty. The goal is nothing less than perpetuity. But of course, outdoor sculpture needs to be done right or it won’t last. Making statues, e.g., permanent structures that look like people, is particularly difficult. Continue reading →

he nearly finished masthead fitting with a duplicate of the foam mold. After the inside was cleaned out, additional fabric was applied to achieve the final exterior shape. The outside was faired and shaped before the topping lift and sheave were installed.

Building a Masthead Fitting

by Captain James R. Watson

Above: The nearly finished masthead fitting Captain Watson fabricated using the lost foam method of creating custom parts.

Here’s another use of the lost foam method to produce a custom part with a molded interior cavity. In this case, the part was a masthead fitting to hold an internal sheave and provide a route for the halyard to pass. This method can be adapted to a variety of other applications, as demonstrated in Fabricating an Airscoop. Continue reading →

This test apparatus is used to determine the effects of high temperatures on cured epoxy. It holds multiple test samples in a bath of heated oil while a three-point load is applied to the samples.

If You Can’t Take the Heat…

Understanding Epoxy and Heat Deflection Temperature

By Bruce Niederer — GBI Technical Advisor

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.

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International 110 sailboat restored

Rebuilding an International 110

By Tim Botimer

Above: Tim’s International 110 sailboat. After winning the National championships, he gave her a new coat of paint.

I first got into International 110 sailing 15 years ago and soon bought an old fixer-upper boat. After sailing it for a couple of years in a decrepit state, I made the decision to fix it right. I had worked with WEST SYSTEM® products before, and I was pretty familiar with the product line. I had done significant repairs on a 1965 plywood Thunderbird and a 1950s vintage Flying Dutchman, which incidentally was one of the original test boats when Jan and Meade Gougeon first came out with the product. I had never tackled anything on the scale of the 110 project, and at the time it was the only boat I had. Continue reading →