Category Archives: Sports Equipment

Light as a Feather

How I made a composite fender for my bike

By Tom Pawlak — GBI Technical Advisor

Last Father’s Day I received a new light and sleek bicycle from my family. It is by far the nicest bike I’ve ever owned. I enjoy riding it to work in the spring, summer, and fall. Because it is so nice, I decided I didn’t want to bolt on the aluminum bracket used previously over the back wheel on my old bike. The bracket had served multiple purposes. It supported my travel bag and it acted as a fender to keep road water off my back while riding. I decided I would ride with a backpack instead to reduce bulkiness and thought it would be nice to make a lightweight composite fender that I could snap on for those rainy days. That would allow me to remove it for longer trips and on nice weather days. Continue reading

Improve Wooden Paddles with G/flex

By Tom Pawlak — Retired GBI Technical Advisor

Wooden paddles and boat oars are known for getting dented in service. While G/flex 650 is not optimized for use as a coating, we found it was worth the extra effort it takes to apply to wooden canoe paddles and boat oars to deflect impact and prevent cracking the wood beneath.

G/flex epoxies weren’t developed with coating in mind, but early on in applications testing, we discovered they were excellent at dealing with impact. This became evident when we used G/flex 650 (the unthickened version) as a coating and when we used G/flex 655 (the thickened version) as a protective buildup. Continue reading

Time is Everything

A last-minute ski repair

By Grant Hilger

On the evening of March 19, 2013, I inspected my 217cm Atomic™ downhill race skis in preparation for race day. Because of the early ending to winter in 2012, these skis have not seen the light of day in almost two years. The only real chance I get to ski with them is at the annual Boyne Highlands Downhill Race in Harbor Springs, Michigan. This late March tradition is usually the grand finale of Michigan’s ski racing season.

This year the weather was shaping up perfectly for outstanding conditions, and I was chomping at the bit to ski fast! Much to my surprise, when I picked up one ski I found that a section near the tail was delaminating. On the inside edge of the left ski, a 1.5″ x 0.5″ area of the top skin was bubbled up from the ski’s sidewall. The bubble was 3/8″ of an inch high. I was less than impressed with this find, knowing that in order to race I’d need to repair the ski.

Delamination area on the ski.

Delamination area on the ski.

Some of the steel inside the ski’s core corroded, causing the top sheet to lose its bond and bubble up. This corrosion was most likely accelerated by salt, which is often used in late-season ski races to keep the snow from softening in the intense sunlight. The salt and water must have made their way into the ski’s core during the 2011 race. It then had almost 24 months for the corrosion to occur. With the issue identified, it was time to plan a repair. The clock was ticking.

I had a cartridge of WEST SYSTEM Six10 Epoxy Adhesive in my repair kit, and I thought that this would work for the application. I rounded up acetone, pipe cleaner, mixing stick, mixing cup, small flathead screwdriver, paper towel, gloves, safety glasses, wax paper, wood blocks, and a C clamp to complete the repair. My plan was to attempt to salvage the top sheet and re-bond it to the ski’s core. This is the procedure I followed:

Step 1: I gouged out the corroded metal from the bubbled-up top sheet. I was careful not to damage the top sheet because then I’d need to repair that as well. I used a shop vac to help suck the metal shavings out of the hole in the ski. Once all the corroded metal was removed, I blew out the void in the ski with compressed air.

Step 2: I used a pipe cleaner and acetone to clean out both the inside of the ski’s top sheet and the ski’s core to aid bonding.

Step 3: Once the area was dry, I mixed a small amount of Six10 adhesive and brushed it into the void on all surfaces with another pipe cleaner. I then used the plastic mix stick to fill in the void as much as possible. This probably added more epoxy than was needed, but it was such a small area that I wasn’t too concerned with waste when it squeezed out. I was more concerned that the repair was robust.

Step 4: I applied wax paper to the skis so that the epoxy wouldn’t get anywhere that I didn’t want it to, and then I clamped the ski as shown in the photo.

The ski repair, clamped and curing at 68°F

The ski repair, clamped and curing at 68°F

Step 5: I allowed the epoxy to cure for 24 hours before removing the clamp.

The repair seemed to be sound, and time was of the essence, so I prepped the skis for racing by hot waxing them with the race wax. I was concerned that adding heat to the ski this quickly after curing might compromise the repair. To my delight, everything held fine. Hurdle number one, cleared.
Now the ski had to hold up to the stresses, vibration, and temperature of a 38 second, 60+ mph run down an icy ski hill. The ending to this story is a happy one. The repair passed its first trial with flying colors. No ill effects were observed in the ski’s performance, and following the race run I inspected the repair. It looked like just as it had when I removed the clamp earlier that week. If you’re at all interested in the race, the skis allowed me to complete the race run in 37.99 seconds, hit a top speed of 66.1 MPH as recorded on GPS, and win my age class by 0.5 seconds (a significant margin in ski racing).

A timeline of the events:

• 3/19/13 (6 pm) – Discovered ski delamination
• 3/19/13 (8 pm) – Ski repair complete, epoxy clamped and curing
• 3/20/13 (7pm) – Hot wax skis for race day
• 3/24/13 (1pm) – Race

Ski repair complete, ready for wax, and then the race.

Ski repair complete, ready for wax, and then the race.

For this repair, time really was everything!

 

Wooden Bicycles, Seriously

By Grace Ombry

Renovo Hardwood Bicycles

Meade Gougeon was intrigued by the Renovo Bikes company of Portland, Oregon after spotting their wares on display at the Wooden Boat Festival in Port Townsend, Washington last fall. Meade has long been a serious cyclist and understands better than most the value of wood as an engineering material. He saw in Renovo an opportunity to combine two of his great loves, wood, and bicycles. Continue reading

Bicycle Frame Repair vs Wall Art

The Difference Between a Carbon Fiber Bike Frame Repair and Wall Art

by Randy Zajac

I will start by saying that, in my opinion, most carbon fiber bicycle frames that have sustained damage from an impact should not be repaired—there are too many damaged fibers that are typically unseen. The two repaired frames featured in this article had damage caused by operator error, not impact. The last two bicycle frames are prime examples of parts that should not be repaired for safety reasons. Continue reading

A graphite composite fly rod with all of the guides attached with G/flex to maximize the rod’s flexibility.

Attaching Guide Lines to Fly Rods with G/flex

By Tim Veale

Above: A graphite composite fly rod with all of the guides attached with G/flex to maximize the rod’s flexibility.

Fly fishing, particularly for Atlantic Salmon, has been my lifelong hobby. The fly rod itself has an ancient past but its technical prowess as an instrument to launch line and fly to a designated spot on the river was epitomized by the arrival of handcrafted split bamboo rods in the late nineteenth century. Continue reading

The repaired panel is back in place on the camper. A coat of Krylon Fusion™ textured, plastic- compatible paint completed the repair.

Camper Panel Repair

By Tom Pawlak — GBI Technical Advisor

Above: The repaired camper panel is back in place on the camper. A coat of Krylon Fusion® textured, plastic-compatible paint completed the camper repair.

Todd Lynch, one of our valued employees, brought in a damaged plastic panel from the back end of an 11-year-old pop-up camper and asked if it was worth fixing. It came from his hunting camper which had been rear-ended. He just wanted it to be functional. The impact had made cracks at nearly every screw hole for holding the panel in place, making it doubtful it would last another trip down the highway. Continue reading

pouring an air-free transducer base when installing a depth sounder

Depth Sounder Installation

Above: Pouring an air-free transducer base for installing a depth sounder. Draining neat (unthickened) epoxy through a hole in the bottom of the mixing cup will leave the air bubbles behind on the surface. A putty dam on the hull ensures the correct size and shape for the depth sounder base.

Jim Costello of Dallas, Texas, asked the Gougeon Tech Staff about a depth sounder installation that called for mounting a transducer to the hull of his 1983 Bayliner Capri Classic.

“The user manual for my new Hummingbird fish finder says that the transducer can be installed in the hull with a slow curing epoxy. It says to try to eliminate all bubbles. I have WEST SYSTEM 105 Resin, 206 Slow Hardener, 404 High-Density Filler, and 406 Colloidal Silica on hand. What if I just mix up some peanut butter thick epoxy paste and use that? Or do you have any other suggestions? I can mount the transducer on a part of the hull that is thin enough for the application, according to Hummingbird. Thanks.” Continue reading