Glue to adhere monofilament to balsa?
 

Can anyone advise what kind of glue can be used to attach monofilament to the leading edge of a glider's wing? I think fishing monofilament is nylon but I can't find any online reference to what kind of glue will work with both balsa and monofilament.

IIRC, the old method from the 1970's was to use "Ambroid" glue, which is no longer made. Perhaps Testor's "wood glue" would work well enough.




I do not recall for sure if I ever tried doing that, or not. Maybe once. Pretty hard to glue a round thing to a leading edge and not affect the airflow. And I didn't have the patience/skill to try to cut a tiny angled notch into the LE for the line to fit into, or not badly mess up the shape of the leading edge which is usually the most important shape of a wing airfoil.

For those who wonder why even do it, it's an old-school F/F model plane method to provide some "ding resistance" to a leading edge of small balsa wing gliders (usually hand-launch type).

Would some thin CA soaked into the leading edge work about as well? I'm not sure how much of the reinforcement was actually the monofilament vs the glue that was used.

Is SIG's Sig-ment similar enough to Ambroid to work? And yes, I thought I'd give monofilament a try as I keep getting serious dings in my glider leading edges. Was also under the impression HLG/DLG builders used monofilament to reinforce the LE as well?

Interesting thought. I've tried CA on my larger heavier gliders (which are primarily the ones getting most of the leading edge damage) but they still get dinged and dented. May work better on my smaller and lighter gliders much better though, they pack less mass so tend to come down a bit slower/gentler.

Don't use Ambroid for anything. Was the the worst glue on the planet when I was young. If they still sell it, it has to be worse.

Allen

Sig-Ment is a much better replacement for Ambroid and is better than Testors green or yellow tube wood cements.

Are you trying to build one of Guppy Youngren's R/Gs? There may be other plans that use it, but mentioning the use of monofilament to reinforce the leading edge of a wing - in a model rocketry context - reminded me of that plan.

http://georgesrockets.com/GRP/GLIDE...IT-Scans223.jpg

If you examine plans from those days, they seemed to favor replacing the leading edge of the wing with strip of hard balsa or spruce. I think this wasn't done to just toughen up the leading edge of the wing. It would make sanding a nicely shaped leading edge into the wing easier.

The monofilament might have been experimenting with a turbulator on a low drag airfoil. I can't imagine a thin little line of monofilament "reinforcing" anything. It certainly worked - he set a world and national record with that wing.

Not specifically Guppy's, but I've seen several early glider models that used monofilament attached to the LE (for example the Longhorn-16 BG by Tony Williams: http://www.oldrocketplans.com/narco...RN-16_PLANS.PDF) whose function, I gathered, was to strengthen and protect the wing's leading edge. I've also seen HLG/DLG-type free flight models that employ a hard balsa or basswood LE, and honestly the monofilament seemed a much easier solution for my limited crafting skills.

Thanks for sharing the glider plan. I'm not going to argue with Maddog about why he recommended monofilament on the leading edge.

In this link:
https://books.google.com/books?id=c...bulator&f=false
...the author describes how to apply the monofilament with model cement.