I do not understand your ShoeGoo reference, are you saying that would be better or worse than Silicone caulk?
I'm sorry I was not clear in my writing, George. Yes, I tried ShoeGoo and no, it did not work well for me long-term. It turned yellow and dried out out, then became brittle and lost adhesion in this application after about three years. In this way, it was about the same result for me as silicone caulk (I used black to match the fender in one case, clear in another instance). Both failed for me after awhile (some few years) but they failed in different ways.
The super super glue gel you cited does scare me a bit, I am less than enthusiastic about that as I would rather not glue my fingers to anything.
I buy either 5mil or 7mil gloves in bulk from Harbor Freight and wear them while gluing so if I get stuck, it is the glove and not me. For many years, I did not use nitrile gloves for tasks and one day realized I was absorbing a lot of chemicals through the skin of my hands. I was also spending more time on cleanup than on the task, so the change made sense for me and has worked well for minimal cost.
As for the task itself, I made a dry run the first time, arcing the wire along the inner bead edge of the fender and holding it in place with the clothespins. I then removed everything and did the same again with the gel glue. The gel gives a working time of 5-15 seconds depending on humidity and it can be pulled free for up to about 20 seconds. Long-term, it can be peeled off with dedicated effort because the wire is elastic to a degree and the hardened gel is not.
Sandpaper, what grit do you think would work best? I was thinking something pretty fine like 400.
That is what I used initially, though in later efforts, I used a 3M green scuff pad because it resulted in less dust that had to be cleaned off. I found it sufficient to simply remove the surface gloss, so a quick swipe or two with the scuff pad was enough. Be sure to clean up the dust afterwards. I find 99% isopropyl works best, but it does temporarily soften the clear cellulose-based coating in ESGE Chromoplast (now SKS) fenders on first application.
I think you should use the materials you are most comfortable with. It is just that having tried a number of materials, the super gel glue is a) what worked best for me on application and b) has held up best over time. There are different formulations, too and this can affect results. Your experience might vary of course. Much of the success is dependent on humidity at the time of application and I found this true for all the adhesive materials I used. This is why I take care to emphasize what worked for me; local conditions do have a marked influence and it can make a difference whether you work inside a house (A/C reduces humidity, a humidifier increases it) or work outdoors/in a garage. Cyanaoacrylates in particular catyalyze in the presence of water and water vapor, moreso in humidity or fog. By the way, if you need to create acrylic plastic to reinforce end-points or do a field repair of some plastic part, baking soda added to liquid super glue works very well as an accelerant/filler and water can trigger catalyzation if humidity is very low and it would not cure so well otherwise. Conversely, vinegar will loosen super glue.
I would suggest you ask a local bike shop for a piece of used/broken fender and then try gluing a piece of the same wire you intend to use to it to see what works best for you before diving into the same thing. Experimentation is worthwhile. I've had good luck using the 2-conductor "zip" wire leads provided by Busch & Muller, the bike-light people. Some other brands of wire have insulation that reacts poorly with some adhesives, becoming ever-sticky dust magnets.
Best,
Dan.
