1973 BMW R75/5 Rebuild: Using Plast-aid To Attach Electric Connector in Windjammer Fairing

After I took my first ride on the bike, in parking it I had occasion to turn the handle bars all the way to the left and heard a loud “cracking” noise. I kept the stock turn signal stalks on the fork tubes. It turns out they hit the wiring harness connector that I had repaired as I describe here.

46 BMW R75/5 Repair Windjammer II Fairing, Strip Paint-Reattach Fairing Wiring Connector

Now I know why one of the stalks had the tube the turn signal would mount on bent upwards, so when I straightened it, I set myself up for this surprise. 🙁

I originally used a piece of ABS from the fairing repair kit Craig Vetter supplies as an internal bracket to hold the end of the white plastic connector inside the fairing and tried Epoxy Plastic adhesive to attach it on the inside of the fairing.

ABS Patch Attached with Epoxy to Fairing Wire Connector

ABS Patch Attached with Epoxy to Fairing Wire Connector

ABS Plastic Patch Epoxyed Across Connector Hole in Side Pocket

ABS Plastic Patch Epoxyed Across Connector Hole in Side Pocket

The ABS patch separated from the inside of the fairing wall.

Plasti-aid(R) Multi-purpose Repair Plastic

I read in Motorcycle Consumer News a short article about Plasti-aid, a product produced in Estes Park, CO which is at the entrance to Rocky Mountain National Park, and a nice ride from my house along the front range of the Rocky Mountains.

Plasti-aid Kit-Large Size

Plasti-aid Kit-Large Size

Dale Greenawal, a fellow Airhead who lives in Boulder, told me he wanted to fix a broken fairing lug that attaches the lower part of his R80-RT fairing to the frame, and wanted to know if I have any ideas. I told him about Plast-Aid and that it sounded interesting, but I hadn’t used it yet.

So, Dale called the company and spoke to the owner, Randall Amen. Randy invited him to come up and take a tour of his operation and talk about how it can be used. When Dale invited me to come along, it was a no brainer. I had the week off and was finishing up Grover in preparation for the first ride around the block. The ride from my house to Estes Park is one of my favorites up Coal Creek Canyon and then along what is called the Peak-to-Peak Highway. So Dale, my wife and I set out on a day ride to the Plast-aid HQ.

When we arrived it was lunch time. Randy came over as we got off our bikes and said they were having lunch at the restaurant next door, the Mountineer. So, we had lunch (good food) right next to the Plast-aid’s office/factory, and then got a personal tour with technical background and tips about how to use the product from Randy. His wife and daughter (wo)man the front office while Randy handles the R&D and manufacturing.  Dale and I were nerding out and even my wife was thinking of several problems she faced at home where Plast-aid could be a solution.

Randy was very gracious and gave all three of us free samples. So, a few days later when I heard that “crack”, I decided it’s time to try Plasti-aid.

Securing Windjammer Electrical Bulkhead Connect with Plast-aid

I removed the gas tank as I decided to remove the turn signal stalks from the front forks rather than bend one of them. I put some towels along the frame tubes near the rear of the tank and the removed the wing nuts securing the rear of the tank.

Protecting Frame Tubes when Removing Gas Tank

Protecting Frame Tubes when Removing Gas Tank

I put another towel on the front of the tank and then carefully lift the rear over the bolts and slide the tank back. Then I lift the front past the steering head chrome cover. This is not so easy with a full tank and 5.8 gallons.

Protecting Gas Tank From Steering Head When Removing Tank

Protecting Gas Tank From Steering Head When Removing Tank

Then I removed the fairing and carefully put it on the work bench.

I put some Plast-aid powder in the supplied mixing cup (the cup is made from a plastic that Plast-aid doesn’t stick to, so it’s easy to clean up and reuse).

Plast-aid Powder in Supplied Measuring Cup

Plast-aid Powder in Supplied Measuring Cup

I add a little liquid to the powder and stir with a popsicle stick (included in the kit). I want a pancake batter consistency. I let the mixture sit for a bit so I can mold it. I use a small paint brush and paint some of the Plast-aid liquid around the edges of the electrical connector. Randy said this is a good idea when you mold some Plast-aid and want to attach it to another piece of plastic. The liquid component softens the part a bit to ensure a tight bond to the molded Plasti-aid when you attach it.

By now the Plast-aid is acting like taffy. I take it and make a rope of it in my hands and mold it around the plastic of the electrical connector. I press that into the hole in the fairing filling the gap between the fairing and the electrical connector with Plast-aid. I dab a bit more Plast-aid on the edge of the fairing and over the top of the Plast-aid filling the hole and then hold the electrical plug steady for a couple more minutes.

After Applying Plast-aid In Its Moldable State

After Applying Plast-aid In Its Moldable State

Plast-aid gets hot as it sets and then cools off when the reaction is about done. I wait for it to start cooling and then let go of the plug. Wow. It’s solid as a rock.

I remove the turn signal stalks from the fork tubes and mount the faring on the bracket. Then I install the tank using the cloths to protect it and the frame tubes. I plug the wiring harness into the Plast-aid repaired connector inside the fairing and check out the electrics. It’s all good and the connector seems nice and solid.

The next morning, I check everything again before I go to work. The connector is Rock Solid and I don’t have an ABS plastic patch inside the pocket of the Windjammer to snag stuff on.

I’ve got some other ideas of where I can use Plast-aid. It will stick to metal as shown in one of the videos on the Plast-Aid site. I’ll post more about my experiments with Plast-aid when I get that far.

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