Monthly Archives: April 2014

Minimizing Amine Blush

By Tom Pawlak —GBI Technical Advisor & Tim Atkinson — Senior Chemist

I recently built a double-ended paddle for my kayak. The blades were made of thin mahogany plywood coated with epoxy. I had coated all the paddle parts with two coats of epoxy the day before, and overnight a thin oil-like film had formed on the surface of the epoxy. This is amine blush. To ensure a good bond between the blade and the shaft, I removed the blush with water, dulled the surface with an abrasive pad, and dried the surface with paper towels. I’m confident using my new kayak paddle because the mating surfaces of the shaft and blade were properly prepared prior to bonding. Continue reading →

Ticonderoga: Testing for the Toughest Deck Coverings

by William D. Bertelsen

Ticonderoga is a 220 ft. sidewheel steamboat built in 1906. She carried passengers on Lake Champlain until 1953. The Shelburne Museum wanted to replace the decks and cover them in a way that recreated the appearance and texture of the original canvas sheathing. But it was equally important that the authentic looking decks be durable enough to survive the unrelenting foot traffic inevitable for such a magnificent museum centerpiece. Continue reading →

Composites You Can Build

by Captain James R. Watson

Composites have been on the automobile motor sports racing scene for some time now. Indy cars, Formula 1, IMSA GTP (International Motor Sports Association Grand Touring Prototype), and others employ composites to the fullest limit of the imagination (and budget). Engine builders are even beginning to use composites for internal components. Autoweek, Advanced Composites and similar magazines write about composites constantly. But most of these applications involve sophisticated techniques, tooling and materials such as autoclaves and resin-impregnated materials (pre-pregs). These require aerospace-level technology not commonly available or economical for the amateur builder. Pre-pregs and other advanced composites employ adhesives that require an oven to promote curing (post cure). Continue reading →

Gelcoat Blister Repairs

by C. Joe Parker, Michael D. Arndt & Tim Atkinson — Senior Chemist 

In Epoxyworks #3 (Fall 1993), Robert Monroe discussed the idea that polyester is subject to degradation in much the same way as wood is affected by rot. Many cases of blistering are actually much more than a blister directly under the gelcoat. These blisters may be the first sign of laminate degradation. Once this degradation begins, it may be as difficult to stop and just as damaging as rot is in wood. Continue reading →

Big Shoe Repair

by The Restoration Clinic staff

The Restoration Clinic of Fort Lauderdale, Fla. completed major repairs on the Cartagena Shoes statue, a pair of seven foot by four foot shoes weighing one ton each. In Coral Gables’ Cartagena Plaza near the University of Miami, the shoes are a well-known fixture. They were smashed by a falling tree during Hurricane Andrew, and appeared to have been ruined. One shoe was broken into several large pieces, and the other was crushed. Continue reading →

A Build-It-Yourself Drill Guide

by Brian Knight—GBI Technical Advisor

Bud Hauschild, from Hastings, Michigan, sent us this idea for a drill guide used to accurately drill holes through irregularly shaped surfaces. Additionally, you can use this guide to drill from both sides of a thick beam and have the holes line up. Orthopedic surgeons use a similar device to drill holes in bone for screws or pins. Continue reading →

Bonding PVC Plastic with Epoxy

Editor’s note: This article was originally written in 1994, long before we developed G/flex epoxies which offer vastly superior performance in bonding to plastics including PVC. A much more current article on this subject is Gluing Plastic with G/flex Epoxy by Tom Pawlak and Jeff Wright. If you’re interested in gluing PVC with epoxy, we suggest you start there. The following article is published at Epoxyworks.com for historical purposes only.

Continue reading →

Stitch & Glue Details

by Captain James R. Watson

You may have read my articles about how to build mail boxes, canoe paddles, wheels, tillers, how to get glue off clothing and so on. Somebody called the other day and asked, “You ever build a boat?” Well, it so happens I’m building one right now and it’s a good example for describing the latest stitch and glue techniques. Continue reading →

Making a Deck Crown Tram

by Captain James R. Watson

A deck crown tram is a device used to describe a specifc curve or crown of a deck regardless of the deck’s width. To make a deck crown tram, begin by laying out a baseline on a piece of plywood. Make the line the length of the largest (widest) deck beam. Drive a nail at either end of the baseline to represent the beam ends (points A and B). Draw a centerline between points A and B. Continue reading →