Aircraft ply? Well the in between of ply and balsa is Basswood, much easier to finish because of the tight grain configuration.Personally, I don't. That being said, if I, theoretically, were going to add fiberglass, I would go with one layer of .6-.75 oz. Fiberglass in such small sizes is never necessary, use either label paper over balsa or just aircraft ply. If your fins are popping off, fiberglass isn't the answer; have someone check your glue technique and/or your recovery systems.
I've never fiberglassed a fin for a D-G size rocket. Actually I've never fiberglassed fins for H or I sized rockets either.What weight fiberglass do you guys use to make the fins stronger on d-g motor rockets ?
After all of the discussion about fiberglassing on another thread in the last couple of days, I realized that one of my dormant projects could probably benefit from tip-to-tip fiberglassing of the fins, and it is in that range, at least partly. It's more in the F to H (possibly I), range. I was building an upscaled Estes Super Flea that was based on 2.34" diameter tubing. If you don't quite recall what the Super Flea looked like, see here. Note the long swept fins. For my upscale, I made them out of 1/4" basswood, which worked fine and wasn't at all heavy. Because I was also making the rocket with an interchangeable motor mount, the fins were surface-mounted.Typically none. In the vast majority of cases, D-G powered rockets do not need any fin reinforcement.
If it is needed, a single layer of 0.6-0.75oz would be perfectly adequate. Why do you want to use fiberglass for a D-G powered rocket though?
I would suggest that taking parts of the body tube with the fins is an indication that tip to tip was NOT needed. Tip to tip is good if you are going near or over Mach and need to prevent destructive fin flutter, but for joint strength, is sounds like you already achieved what you need. Or maybe you need to stop testing the structural integrity of the rockets with your desk chair! :bangpan:Two fins broke off, taking chunks of the airframe with them. Sure enough, the bond was much stronger than the parts that were bonded, but that wasn't good enough in this case. A tip-to-tip veil of lightweight FG would seem to be indicated here, ...
I use "Fibatape" fiberglas wall repair tape for fin strengthening for midpower. It's not as strong as glass cloth as it's an open weave and I usually coat it with several layers of white glue. It also requires filling to get a smooth surface. Depending on the fin span/size I don't generally cover the whole fin. It's a lot of work to do it right but I think the results are worth it as I can pick up my rockets by the fin and give them a good shake with no ill effects. Paper laminating as suggested will be easier and probably all you'll need. TedWhat weight fiberglass do you guys use to make the fins stronger on d-g motor rockets ?