Category Archives: Composite Fabrication

Fabricating an Air Scoop

Using the Lost Foam Method

By Brian Knight

I used lost foam construction to fabricate a fiberglass air scoop for my son’s Formula Continental C race car. Our project started because a modification to the shape of the race car body necessitated the construction of a new air scoop. The air scoop is bolted to the car body so if either the air scoop or the body is damaged (a very likely scenario), the repair will be simpler. To fabricate the scoop, I made a Styrofoam male mold, surrounded the mold with fiberglass, and then dissolved the Styrofoam to leave a hollow part. I used Styrofoam to build the male mold for several reasons. It is readily available at most lumberyards, it is easy to shape with files and sandpaper, and it is easy to dissolve with lacquer thinner.

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Build What You Can’t Buy

By J.R. Watson

Do you sometimes need a replacement part for your boat, home or recreational vehicle and find out its no longer available? Discontinued. Source unknown. Can’t be found. Maybe the price borders on insanity or, you need a part that simply does not exist and never did.

“Okay,” you say, “I need it, can’t get it, my only option is to make it.”

As soon as you reach this decision, two thoughts pass through your mind. “How will I make it?” and “What materials shall I use?” You may have a third question like, “Am I the only one that has these problems?” Continue reading

Testing for Damage Tolerance

By Jeff Wright

Ted Moores and his company, Bear Mountain Boats, build wood epoxy strip plank canoes, manufacture kits and publish books on building strip plank canoes and kayaks. This method of construction provides a very light yet stiff structure and also enables the hull shape to have compound curves. Moores has 30 years of experience and his designs have logged many safe miles. He understands the forces boats are subjected to when paddled on the water and during transportation. Continue reading

Building Composite Tubes

With WEST SYSTEM and braided fibers

By Captain J.R. Watson

Tubes are used on boats for hard tops, T-tops, Biminis, dodgers, bows, bow and stern pulpits, rails, canoe and kayak paddle shafts, boat hooks, and so on. Composite tubes built with epoxy and reinforcing fibers offer advantages over metal in terms of light weight, custom shapes and sizes, and corrosion resistance. Composite tubes can be faired and painted to produce a seamless appearance to match the boat, or left to show the carbon fiber. I’ve been experimenting with approaches to building a variety of composite tubes. Following are some things I’ve tried (some that worked and some that did not) that you may find of value if you want to produce composite tubes yourself. Continue reading

Building a Masthead Fitting

by Captain James R. Watson

Here’s another use of the lost foam method to produce a custom part with a molded interior cavity. In this case, the part was a mast head fitting to hold an internal sheave and provide a route for the halyard to pass. This method can be adapted to a variety of other applications, as demonstrated in Fabricating an Airscoop. Continue reading

Chopped Strand Mat

Chopped Strand Mat and Epoxy

By Tom Pawlak

Chopped strand mat, in fabric form, is sold on the roll and in small folded packages. It is made up of 1″-2″ long fiberglass strands that are randomly oriented and typically held together with a styrene-soluble binder that acts like glue connecting the fibers. The binder is designed to dissolve upon contact with styrene in polyester resin or vinylester resin. Once dissolved, the fabric softens, allowing it to drape around curved shapes. It comes in a variety Continue reading

Building Photographic Darkroom Sinks

By Spiros Polemis

We built two darkroom sinks using WEST SYSTEM® epoxy: one for tray developing, the second to hold our Jobo film processor and two archival print washers. The two sinks are end-to-end on one wall of the room and fit flush with waterproof caulking, the taller sink sitting on top of the side of the shorter one. Continue reading

Testing DCPD Blend Laminates

By Tom Pawlak

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

DCPD blends in polyester cause it to cure rapidly and cross-link thoroughly. This feature helps to reduce emissions from the resin but makes it difficult to repair Continue reading