Tag Archives: Tom Pawlak

Varnish over epoxy

Testing House Paint Primers

By Tom Pawlak — GBI Technical Advisor

Gougeon Brothers, Inc. regularly engages in testing to support those who use our epoxy in architectural applications, both in new construction and repairs. In the past, we have tested the compatibility of house paint primers over WEST SYSTEM® epoxy and found that a variety of primers worked well. Latex primers especially performed well when applied over cured epoxy, even when the epoxy was marginally prepared prior to painting (Epoxyworks 7, Spring 1996). Continue reading

Mold Release, PVA and Hairspray

By Tom Pawlak — GBI Technical Advisor

PVA (polyvinyl alcohol) is a water-based liquid plastic that can be applied to waxed molds to prevent molded parts from sticking. PVA is not always required. Often laminators rely solely on mold release wax to create a surface contaminant on the mold that allows parts to be removed. However, on complicated molds and on new molds, when the risk of sticking a part in a mold is greatest, PVA can be applied over a waxed mold to minimize the chance of sticking a part. Continue reading

Porch Railing Coating Analysis

By Tom Pawlak — GBI Technical Advisor

My porch railing at home was badly in need of painting even though I had painted it the summer before. After just one Michigan winter, the paint had cracked and lifted. I wondered to myself if coating the top rail with WEST SYSTEM® epoxy would improve this poor situation and decided to turn the top rail into a small R & D project. Continue reading

Hardware Bonding

By Tom Pawlak — GBI Technical Advisor

My first experience with hardware bonding occurred shortly after starting work at Gougeon Brothers in 1980. Having just been hired into the wind turbine blade plant, I was excited to be part of this interesting company. Continue reading

Sandpaper Tricks for Random Orbital Sanders

By Tom Pawlak — GBI Technical Advisor

I recently ran out of sandpaper for my 5″ diameter random orbital sander, and needed only a few more sanding disks to finish the project. While my sander is equipped for the hook-and-loop style sanding disks, I had only PSA (pressure sensitive adhesive) style sanding disks. These did not stick well to the pad on the sander, and within a minute or two they would fly off, leaving me frustrated. I finished my project by gluing the PSA disks to worn out hook-and-loop disks with contact cement. This actually worked quite well. Continue reading

Rudder Repair

By Tom Pawlak — GBI Technical Advisor

A typical spade rudder for sailboats is made up of two fiberglass skins that define the shape of the rudder, a metal mandrel that is an extension of the rudder post, and foam core which bridges the space between the skins and mandrel. In order for a rudder like this to work properly, its fiberglass skins must be attached to the core and the core must be attached to the metal mandrel. Side loads on a rudder exert compression loads on the core which transfer into the mandrel. If the components become detached, the rudder can deflect excessively and eventually develop cracks in the fiberglass skins. Continue reading

Techniques for Fiberglassing Overhead

By Tom Pawlak — GBI Technical Advisor

The prospect of having to fiberglass the bottom of a hull can be a bit ominous. Any type of overhead work can be frustrating, but the thought of trying to hold fiberglass in place while applying epoxy can produce nightmares for some people. This is especially true if you will be working alone. Continue reading

Repairing Fiberglass Powerboat Transoms

By Tom Pawlak — GBI Technical Advisor

Transoms are major structural parts of fiberglass powerboats, especially outboards. Transoms not only support the weight of the motor, they maintain the shape of the boat, they are a mounting point for holdowns, towing eyes and other accessories. And, they must be able to let water out of the hull, without letting it back in. Continue reading

Edge Gluing Fixtures

by Brian Knight—GBI Technical Advisor

Rectangular or square edge strips tend to get out of alignment between mold stations, especially where the bend is tight and the planks have to be forced into position. You can build intermediate mold stations in these areas to support the planks in more places. Continue reading

Holding Strip Planks in Place

By Tom Pawlak — GBI Technical Advisor

There are many ways to hold strip planks in place while the adhesive between them cures. The best method for your project depends on how you plan to finish it, what fastener equipment you have on hand, and how much holding power you need to keep the strip planks in place. Continue reading