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Building Tips and technical articles. => Building techniques => Topic started by: kevin king on January 01, 2023, 01:53:41 PM
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Experts, do you think its worth the extra weight to fiberglass the nose on a os max LA 46 powerd Vector?
Kevin.
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Experts, do you think its worth the extra weight to fiberglass the nose on a os max LA 46 powerd Vector?
Kevin.
Yes, it's negligible once you consider how much filler you are not going to use.
BTW, while it is probably OK in this case, you really want to cover the entire wing tip-to-tip before installing it. Covering it afterward causes a stress concentration at the root.
Brett
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What is it that you fear if you do not fiberglass the nose? Have you had some type of structural failure in that area on another plane?
I have never fiberglassed anything. I never saw a need for it, especially on a built-up fuselage. If you constructed the nose properly, it will survive normal use.
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Thanks Brett.
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What is it that you fear if you do not fiberglass the nose? Have you had some type of structural failure in that area on another plane?
I have never fiberglassed anything. I never saw a need for it, especially on a built-up fuselage. If you constructed the nose properly, it will survive normal use.
Jim, I guess the whole Fiberglass the nose thing came from the days of the ST 60. Some people are rough on planes so they like the extra durability of the glassed nose. Longevity, and a consistent motor run too. This was going to be the first time i omitted the fiberglass, so i have no experience on planes that dont have it to compare. Actually, that phrase "Our planes are over built" was stirring up the thought of skipping the glassing of the nose.
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Jim, I guess the whole Fiberglass the nose thing came from the days of the ST 60. Some people are rough on planes so they like the extra durability of the glassed nose. Longevity, and a consistent motor run too. This was going to be the first time i omitted the fiberglass, so i have no experience on planes that dont have it to compare. Actually, that phrase "Our planes are over built" was stirring up the thought of skipping the glassing of the nose.
In this case, it gives you a consistent surface to finish over, instead of the usual mix of balsa, plywood edges, maple, and a bunch of glue joints, for almost no cost in terms of weight. I am fiberglassing my electric for the same reason, it just ties everything together.
People were fiberglassing the nose long before people were using ST60s, mostly for the same reasons. It ends up being almost no weight, all you are doing is replacing the filler you would otherwise have to use to smooth it all out, and the dope or whatever to seal it.
Brett
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Definitely glass the nose, but use as light a cloth as you can get. I like 0.58 oz/yd2 and EZ-Lam epoxy. Really easy to work with.
Much less susceptible to handling rash and print-thru of the underlying structure. Paper used to do the same thing, just not as well.
I had to rebuild the nose on a Legacy ARF that was pulled around by a Saito. The glass in that case was very necessary to unify things.
Dave
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I accidently brushed one coat of clear butyrate dope on the raw wood nose section of the vector 40 yesterday. Will there be any compatibility issues with applying finishing resin and fiberglass over the dope? The 2 types of finishing resin choices the hobby shop has is Zpoxy and BSI finishing epoxy. Which one should i use? In the past ive had issues with butyrate not sticking to finishing resins as well. I am suspicious that the Z poxy has a brown nitrate color and the the BSI doesn't. Which one should i use? Is the finishing resin ok to apply over the one coat of butyrate?
https://webstore.eliminator-rc.com/zap-z-poxy-finishing-resin-12-oz
https://webstore.eliminator-rc.com/bsi-4-5oz-20-minute-epoxy-finish-cure
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Went with the z-poxy. On with the show! 😁
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I accidently brushed one coat of clear butyrate dope on the raw wood nose section of the vector 40 yesterday. Will there be any compatibility issues with applying finishing resin and fiberglass over the dope?
No, it's much better with a coat of dope as the doped wood will absorb less epoxy than raw balsa. L
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No, it's much better with a coat of dope as the doped wood will absorb less epoxy than raw balsa. L
Very true. I use that method for sheeting foam wings. After that coat of clear dope, you can get the minimum amount of epoxy on the sheeting, a thin film, and still have a very good bond line with the foam. A little bit epoxy goes a long way now and you are not adding needless weight.
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I accidently brushed one coat of clear butyrate dope on the raw wood nose section of the vector 40 yesterday. Will there be any compatibility issues with applying finishing resin and fiberglass over the dope?
I probably wouldn't have done that, although it probably won't hurt anything in this case. The issue is that now you have a self-destructing material (dope) where all the fuel will be, and you didn't wait nearly long enough for it to completely outgas before sealing it up.
One coat is so thin that there will be relatively little solvent trapped under the epoxy, and it will still be porous enough to not affect the adhesion too much. This is a very different situation from sheeting a foam wing - there you need nearly no adhesion and there's no way for fuel to get in. For the nose, you *want* it to soak up epoxy, the weight is negligible, but the more glue that soaks in, the better it protects from fuel.
Brett
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Thanks Gentlemen. I read after the fact last night dope thats not totally dry and still shrinking can be a problem to put epoxy on top. But it was a very thin 70/30 dope mix, and i started with the cowl and wheel pants. I will give the nose a couple more days to dry, give it a good sand and then glass the nose. All 3 methods will work. Fiberglassing is
actually quite fun, (said no one ever) 🙄
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Glassing the nose refresher. Windy adds 3 to 4 grams.
Glassing starts at 11:09.
https://youtu.be/GXaiFrTevvc
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Done. First glass job in 15 years. I forgot how to do it. Now scuff sand when dry and continue with the "Tinted" Brodak Butyrate dope, And hope it sticks
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Glassed and trimmed
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Nose glassed.
Vector 40 Baby! Randy Smith OS LA 46!! ;D VD~ VD~ >:D
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I probably wouldn't have done that, although it probably won't hurt anything in this case. The issue is that now you have a self-destructing material (dope) where all the fuel will be, and you didn't wait nearly long enough for it to completely outgas before sealing it up.
Brett
Well, if all the fuel is there, then you have another problem. I guess the main thing here was to make a good surface laminate with minimum resin. L
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dont think it will be a problem if the dope is gassed off good,Windy glues his wings in the fuselauge while its in silver dope with epoxy with no problems...