Category Archives: Plastic

Royalex Canoe Repair with G/flex Epoxy

By Bruce Newell and Stan Bradshaw

Above: Stan and Glenda Bradshaw in the Mad River Freedom 16′ Royalex canoe repaired with G/flex Epoxy in August 2007 on the Blackfoot River near Ovando, Montana a couple of miles downstream of the Roundup Bar.

The wooden gunwales of Royalex canoes can rip a hull apart if left out in bitter cold temperatures. Somewhere south of freezing, the plastic body of the canoe shrinks while the dampish wooden gunwales expand. Unless the screws affixing the inwale and outwale are backed out, they pin a shrinking hull to an expanding gunwale, and something will give. That something is always the hull. Continue reading →

D-Ring Pads and G/flex Epoxy

by Tom Pawlak — GBI Technical Advisor

New Possibilities for HDPE Boats

D-ring pads are often attached to flexible surfaces with urethane adhesives to gain load-carrying capacity where there otherwise wouldn’t be any. They are used on waterproof fabric cargo bags, heavy tarpaulins, and inflatable boats. They are also sometimes used on the decks of canoes and kayaks to hold cargo in place on long trips. D-rings are not typically used on polyethylene canoes and kayaks because the urethane glues are not recommended for use on HDPE (high-density polyethylene) plastic. We experimented with gluing D-ring pads with G/flex 655 Thickened Epoxy Adhesive to HDPE plastic with that end-use in mind. Continue reading →

8—The finished hatch.

Installing a Removable Hatch

by Tom Pawlak — GBI Technical Advisor

Above: Meade’s removable hatch, installed on the Gougmaran.

Meade Gougeon installed the original hatches on his Gougmaran, but he wasn’t convinced he had selected the ideal locations. Prior to installation, he thought about how difficult it would be to remove and relocate them if he used one of the flexible adhesive/ sealants made for this purpose. There had to be a better way, one that would allow hardware to be easily removed yet seal out water. Continue reading →

WEST SYSTEM Launches G/Flex Epoxy

by Tom Pawlak — GBI Technical Advisor

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 →

Bonding Fasteners in High-Density Urethane Foam

Tips for Sign Builders & Everyone Else

by Bruce Niederer — GBI Technical Advisor

Above: Bonding fasteners in high-density urethane (HDU) foam calls for drilling an oversized hole slightly shallower than the fastener length and setting the fastener in an annulus of thickened epoxy.

Many of our readers who are familiar with WEST SYSTEM® Epoxy products for building and repair already know the benefits of fastener bonding techniques. WEST SYSTEM Epoxy has been used in other industries for many years as well, and these folks apply knowledge and techniques developed in the marine and aerospace industries in their work. A good example is the sign industry, a huge industry in the U.S. with companies ranging from mom & pop garage operations to multimillion-dollar corporations. Continue reading →

Testing DCPD Blend Laminates

By Tom Pawlak — GBI Technical Advisor

Above: A DCPD blend laminate repaired with WEST SYSTEM Epoxy is tested to failure. The laminate required gross deformation before it failed, meaning epoxy is an appropriate repair material for the type of laminates common on jet skis and snowmobiles.

Gougeon Brothers recently did R&D testing on DCPD blend laminates for a manufacturer who wanted to know if WEST SYSTEM® Epoxy could effectively repair them. DCPD blend laminates are injection-molded parts made with fiberglass and dicyclopentadiene (DCPD) blended polyester resin that included an internal mold release agent. The hoods and decks for many jet skis and snowmobiles are made with this material.

Continue reading →

Plastic Boat Repairs

By Tom Pawlak

Editor’s note: this article was written in 2000, years before we formulated G/Flex 655 epoxy which has superior performance with plastics. The basic plastic boat repair methods described here still represent best practices, but for optimal results use these methods with G/flex 655 epoxy on plastics.

Molded plastic canoes and kayaks are incredibly tough and durable. Occasionally though people damage them and call us for repair recommendations. Considering that plastic film is often used as a mold release for epoxy, you can see what we’re up against when we try to bond to it. Continue reading →

Bonding a Skeg to a Polyethylene Kayak

By Chris Maples

Editor’s note: this article was written in 2000, years before we formulated G/Flex 655 epoxy which has superior performance with plastics. The basic plastic boat bonding methods described here still represent best practices, but for optimal results use these methods with G/flex 655 epoxy on plastics.

The hull shape of a white water kayak is not designed for tracking well in open water. Since I do most of my kayaking on open water and flatter rivers, I decided to mount a skeg on the hull to make it track better. This is pretty simple if you own a wood or fiberglass boat, but can be more challenging on a polyethylene kayak. Continue reading →

Gluing Plastic Dimensional Lumber

by Patrick Ropp—GBI Technical Advisor

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 →

Garbage Disposal Repair with Epoxy

By Bruce Niederer — GBI Technical Advisor

If your kids are like mine, they manage to break stuff you didn’t even think could be broken—constantly. As parents, we can either get inventive at repairing things we know little or nothing about, or we can get second jobs and pay someone else to fix everything. I like the first option better. Continue reading →