Category Archives: Techniques & Tips

Screw strip out of particleboard furniture

Furniture Repair with G/5

A good method for particleboard furniture repair

by Tom Pawlak — GBI Technical Advisor

Above: Particleboard furniture repair can be tricky when screws strip out. G/5 Five Minute Epoxy Adhesive offers an easy solution to fixing inexpensive furniture when this happens.

I recently broke the leg off an old workshop table. The tabletop was made of particleboard covered with Formica®. The screws holding the leg in place had pulled out and taken chunks of particleboard with them. Continue reading

Testing Bolts Epoxy Bonded into Concrete

by Brian Knight—GBI Technical Advisor

Above: The final version of the test Brian devised to determine the holding power of bolts epoxy bonded into concrete. When the load cell registered 4000 lbs, he stopped the experiment.

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

Bonding surfaces should be as dry as possible.

Avoiding Surface Contamination

For Good Adhesion

by Brian Knight—GBI Technical Advisor

Above: Sanding the bonding surface is important to good adhesion with epoxy.

“Cleanliness is next to Godliness,” the old expression goes. This is certainly true when preparing a surface for an epoxy application. The surface has to be clean to begin with or there may be adhesion problems. But often, our good intentions with respect to cleaning a surface result in contaminates deposited on the surface. Below are some potential surface contaminates, ways to avoid them, and an almost foolproof method to determine if a surface is clean or contaminated. 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

G/5 Adhesive Tips

Working with G/5 Resin & Hardener

By Tom Pawlak — GBI Technical Advisor

Above: To simplify mixing G/5 Resin and Hardener for a large project, Grant made a carrying pallet with sixteen holes, sized to hold 1-ounce mixing cups (pill cups purchased at a food service outlet). The pallet was covered with duct tape so glue drips could be peeled away. Note that a mini cupcake pan could be dedicated to this kind of task as well.

Many of us at Gougeon Brothers experiment with WEST SYSTEM® products on personal projects at home as well as at work. We often push products and techniques beyond the limits recommended in our literature. Sometimes the experiment fails, sometimes we discover something very useful. Continue reading

Scheherazade under sail.

Testing Large Bonded-In Fasteners

by Brian Knight—GBI Technical Advisor

Above: Scheherazade, the 154’7″ yacht that required testing of large bonded-in fasteners.

Epoxyworks 19

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. Continue reading

protective skin creams

Protective Skin Creams

Do they interfere with adhesion?

Above: Protective skin creams. Photo by Nati Melnychuk on Unsplash

By Tom Pawlak — GBI Technical Advisor

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

The putty knife scraper used as a push scraper.

Scrapers—Versatile Tools for Working with Epoxy

By Tom Pawlak — GBI Technical Advisor
Above: A putty knife scraper is being used as a push scraper.

My first experience with cabinet scrapers occurred shortly after hiring into Gougeon Brothers. Bill Slaby, a wood/epoxy technician who specialized in mold building, routinely used cabinet scrapers to remove irregularities on cured epoxy coatings. Continue reading

estimating epoxy amounts for fiberglassing

Estimating Epoxy Amounts

By Bruce Niederer — GBI Technical Advisor

Above: The layout of an Optimist pram provides an example of how to go about estimating epoxy amounts.

This formula will help you estimate the amount of mixed epoxy needed to wet out fiberglass cloth (assuming a resin-to-fiber ratio of 50:50) and apply three rolled epoxy coats to fill the weave of the cloth, i.e. “fill coats.” Continue reading