Monthly Archives: June 2015

Testing Epoxy to Determine Physical Properties

by Mike Barnard

In this article, I’ll describe our standards for testing epoxy and how we go about testing epoxy to determine its handling characteristics and cured physical properties.

Epoxy Testing Standards

These are the standards we follow no matter which epoxy we are characterizing.

Two-week room temperature cure

After proper metering and thorough mixing epoxy will continue to cure after it has solidified until all amines have paired up. Over years of testing epoxy, we have found that two weeks of curing at room temperature, which we define as 72°F (22°C), is a good indication of its full strength. Continue reading →

Repairing JESTER’s Cabin Sole

Who’s Laughing Now?

By Greg Horvath as told to Bruce Niederer

The following photos detail some recent cabin sole repairs made by the owner and crew of Jester, a 2005 C&C 99. Jester is well equipped and has been meticulously maintained by her skipper and only owner, Greg Horvath. Jester has only sailed in fresh water and is stored indoors during the winter. She is also the boat I’ve raced aboard here in Saginaw Bay as well as around the Great Lakes including the Port Huron to Mackinaw Race and the Ugotta Regatta in Harbor Springs. Continue reading →

Letters to the Editor – White Oak

By Bruce Niederer — GBI Technical Advisor

My article, White Oak Redux (Epoxyworks 34), generated two responses we wanted to share. We consider ourselves students as well as tech advisors and so we’re 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. Continue reading →

Stray Cat Strut

Restoring a Gougeon Tornado Catamaran

By Andy Davidson

I have just about finished restoring a Gougeon Tornado catamaran. I’ve always had and loved catamarans, and this one had been sitting out in the sun at the Oklahoma City Boat Club for years. Bob, a fellow club member, offered some parts. His plans were to “chainsaw the hulls tomorrow” and put the pieces in the club Dumpster. That was the push I needed. In a moment of insanity, I told him there was no way I could let him do that. Continue reading →

A Base Relief Sculpture in the Modern Bronze Age

By Kirk Williams

In 2010, I was given a commission to do a base relief sculpture for the Pioneer Care Center, a new retirement home in Fergus Falls, Minnesota. The sculpture, called “Creation of Life” was to be mounted on a wall about 14′ off the floor. I knew I had to make it strong and lightweight. The method I used was to sculpt the design in oil based-clay on a large wooden easel. Then I covered the finished clay sculpture with several layers of clear silicone, occasionally adding cheesecloth for build-up and strength. When the silicone was thick enough, I built a mold cradle, made of plaster and gauze reinforced with heavy metal wire over the silicone. When the mold cradle had dried, I removed it and the silicone mold and laid them flat.

1.) Williams first created the base relief sculpture in clay on a wooden easel.

2.) Epoxy/bronze mixture was buttered into the silicone/plaster mold.

3.) The silicone mold was peeled from the base relief sculpture.

4.) Buffing the sculpture with steel wool exposed the bronze powder.

4.) Buffing the scuplture with steel wool exposed the bronze powder.

I made a mixture of 105/205 epoxy and added bronze powder until it was the consistency of chocolate frosting. 105/205 gives me enough time to mix and spread it into the mold, but sets up within about an hour, making it possible to start another application. The epoxy/bronze mixture was buttered into the mold by using two fingers (gloved) to an eggshell thin layer, to avoid any possibility of air bubbles. When this cured I built up reinforcement layers using epoxy mixed with chopped fiberglass and Christmas tree flocking. For additional reinforcing, I embedded heavy wire and small iron rods.

After the final epoxy application had cured, I attached the base relief sculpture to a wooden frame with wires embedded in the back of the sculpture. With the frame standing vertically I gently pulled the silicone mold from the sculpture. I trimmed the rough edges with a Dremel® tool. Buffing the surface with steel wool brought out the metal, and gave me control over the amount of contrast. Olive oil rubbed over the surface gave the sculpture a smooth patina.

The 8′ long sculpture weighs less than 150 lb and was lifted using a scissor lift and hung 14′ above the floor level with ease.

5. The completed base relief sculpture weighed only 150 lb and hangs 14′ above the Care Center floor.

Pleasant Bay Columns

By Suzanne Leahy

Cover Photo: The finished 24′ front columns built by Pleasant Bay Boat & Spar Company.

In 2006, I was contacted by a wood consultant whose client was looking for a shop to turn solid Ipe architectural columns. He’d found out about our company through the Federal Reserve project. STA Architectural Group was the principal designer of a private residence under construction in South Florida. Their trademark motif was tropical hardwood architectural columns resembling palm trunks. This design called for unusual dimensions for eight columns.
Continue reading →

Building a Custom Stained Glass Lampshade Mold

With G/5 Five-Minute Epoxy Adhesive

By Tom Pawlak — GBI Technical Advisor

A few years back Mary, my better half, suggested I make a custom stained glass lampshade for our den at home. There are molds commercially available for making glass lampshades. They hold glass pieces in position in the desired curved shape until the soldering process is complete. Unfortunately, the shape I wanted was not available. I wanted something similar in size and shape to the fabric-covered lamp shade in the den. In the end, I decided to make a custom mold. Continue reading →

Skeg Construction for SPARKS

Lesson 3 in our series on Strip Planking

by Ted Moores

Designing and constructing a successful skeg for Sparks (our 30′ hybrid electric launch featured in Epoxyworks 32) took some head-scratching. But in the end, it was just another combination of wood and WEST SYSTEM® epoxy. Our skeg needed to be functional and age gracefully, yet be reasonably quick and easy to build and install. This project was an ideal opportunity to explore the limits as well as the advantages of combining wood with epoxy to engineer simple solutions to complex problems. Continue reading →

The Coupe de Ville of Epoxy Caddies

By Mike Barnard

Inspired by an old Boatbuilder article by Captain James R. Watson, my father and I built our own deluxe epoxy caddy, which we call the Coupe de Ville of Epoxy Caddies. My dad has grown very fond of WEST SYSTEM® Epoxy and his box of epoxy-related items has been growing at a steady rate. The overflow of his box in an already “treasure” packed garage emphasized his need for an organization and storage system for these materials. We have had several requests for this same type of solution lately. Continue reading →

Bubble-Free Epoxy Coating

By Mike Barnard & Don Gutzmer

WEST SYSTEM® Epoxy has long been a popular choice for clear coating tabletops, and for these applications, you’ll want a bubble-free epoxy coating. Epoxy works great as a buildup coat and a moisture barrier. It also showcases the beauty of wood grain and fiber weaves. Formulated with boat building in mind, WEST SYSTEM Epoxy is not intended as a final finish coating. You may find it a bit more difficult to achieve a perfect surface with epoxy than with a coating formulated specifically for final finishing, such as varnish. Here’s how to make sure your epoxy coating is bubble-free.

However, WEST SYSTEM offers some distinct advantages. It builds up quickly: a single coat of 105 Epoxy Resin® with 207 Special Clear Hardener® offers about four times the thickness of a typical coat of polyurethane varnish. WEST SYSTEM epoxy is also an excellent moisture barrier, stabilizing the surface so your final finish coat will look beautiful longer.

When coating a surface that will be used outdoors, it’s important to put a UV-resistant clear coating over the epoxy. While 207 Special Clear Hardener contains a good UV inhibitor, it will still need additional UV-resistant coats to withstand the degrading effects of sunlight on epoxy.

Since you will need to sand down the epoxied surface and coat the epoxy with varnish, getting a perfect coating isn’t strictly necessary. But the better shape it’s in, the more easily you will achieve a beautiful, bubble-free finish. The key is creating the smoothest, flattest epoxy surface possible. This will save you a lot of sanding later.

Last summer here at the Gougeon shop, we laminated a 35-year-old conference table with carbon fiber and WEST SYSTEM 105/207. We experimented with different methods of achieving a smooth, even, bubble-free epoxy coat to reduce the need for sanding prior to the final finish coating. (Editor’s note: 10 years after this article was written, that carbon-fiber conference table still looks terrific.)

Prepare the surface

Proper surface preparation is one of the most important steps in using epoxy. Make sure the surface is clean of contaminants such as wax and paint. Sand the surface smooth. Avoid using solvents immediately before applying the epoxy.

Eliminate dust

Getting a perfectly smooth surface starts with clearing the air of small particles. These particles may seem harmless, but once they are on a glossy surface it will not look nearly as good as it could. Avoid using tack rags. Vacuum the surface before coating.

Understand outgassing

Before coating bare wood, heat the wood and apply the epoxy while the wood is cooling. During cooling, the air in the wood contracts, drawing the epoxy in for a bubble-free epoxy coating. The opposite happens if you coat wood as it’s warming (such as in the morning, in the sunlight, near a heater or anytime ambient temperature is rising). The air in the wood will expand and “outgas” while the wood’s temperature is rising, resulting in bubbles in the curing epoxy coating.

Applying over stains

Be careful when using WEST SYSTEM Epoxy over commercial stains. Some stains prevent epoxy from penetrating into the wood. The result can be epoxy that fisheyes or peels off after final cure. Always perform a test before using epoxy over a stain.

Avoiding blush

It’s easy to avoid the inert, waxy residue that is sometimes a byproduct of the curing process and is commonly called “blush.” Simply use WEST SYSTEM 207 Special Clear Hardener. It cures blush-free. It’s also formulated for excellent wet out and self-leveling. It cures extremely clear and without color.

If you are using WEST SYSTEM 205 Fast, 206 Slow, or 209 Extra Slow Hardener, blush might develop on the surface, depending on working conditions. It’s easily removed after the epoxy cures with plain water and a light scrubbing with a Scotch-Brite™ pad. These hardeners are not normally recommended for clear coating.

Rolling and tipping

The only recommended way to coat vertical surfaces with epoxy is the roll and tip method. Roll the epoxy on with a foam roller, then “tip” by dragging another roller across the surface to smooth the epoxy layer.

Tip off wet epoxy with a roller cover brush using long, even overlapping strokes. This will leave a bubble-free epoxy coating.

Flow coating

This is the best method for encapsulating items in a bubble-free epoxy coating. The fewest bubbles result if epoxy is poured from the bottom of a container. A word of caution: Never pour a single layer of epoxy thicker than ¼”. Thicker amounts can quickly overheat or “exotherm” during cure, resulting in quite a mess on your lovely surface. If you want a final thickness greater than ¼”, wait until the first layer is cured to the point where it’s firm and about as “tacky” as masking tape then apply the next coat on top of that.

If encapsulating items such as coins, medals, bottle caps and photos on a flat surface, affix them in place with decoupage glue such as Mod Podge® (readily available at craft stores). It’s compatible with epoxy and will prevent your items from floating around. Use it to pre-seal photos and other paper items.

Propane torch

This method of achieving a bubble-free epoxy finish has been used for years by technical advisors at Gougeon Brothers. Not only is it effective for removing air bubbles from the surface, it also lowers the viscosity of the surface and flattens it out a bit. Be very careful when using this technique because leaving the flame over one spot for too long could cause bubbles to appear. We don’t recommend using a propane torch over epoxy-coated bare wood. Doing so may cause outgassing into the epoxy layer.

A thick coating of epoxy with bubbles in the coating.

Pass a torch flame quickly over wet epoxy to warm the surface, reduce the surface tension, reduce viscosity slightly and release air bubbles, resulting in a bubble-free epoxy finish.

After a quick pass with a torch, the bubbles are released and the coating begins to flow out.

Denatured Alcohol

Spraying a fine mist of denatured alcohol over the surface will pop air bubbles as well as lower the viscosity of the surface and flatten it out. There is little risk in this method because denatured alcohol evaporates fairly quickly and does not cause air bubbles to propagate. A fine mist is critical. To get the fine mist we purchased a bottle of hair spray with a push button pump (a Windex™ sprayer is not fine enough) and replaced the hair spray with denatured alcohol.

A fine mist of denatured alcohol will reduce surface tension and release air bubbles, resulting in a bubble-free epoxy coating.