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Cone hardening methods?
Hello All,
I'm getting ready to order a few parts, including various BT-5 conical balsa nose cones, to build a few scale and scale-like models of test vehicles and sounding rockets such as the Argentine Tronador I and several Indian sounding rockets. What is the most effective way to harden conical balsa nose cones (particularly to strengthen the nose cone tips)? I know that thin CA (or maybe even thin epoxy) could be "wicked" into the wood and then sanded when cured, but for pulmonary reasons I'd prefer to avoid them. Would white glue and/or yellow glue (perhaps thinned a bit with water) work? Also, are there any carpenters' wood-hardening products that would work on balsa? Many thanks in advance to anyone who can help.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR Last edited by blackshire : 03-23-2011 at 06:48 PM. Reason: This ol' hoss done forgot somethin'. |
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Check out this thread on TRF about Teamwork Filler. I think it might be the solution for which you are looking. I was hoping to get the ingredients to test it this past weekend, but the washing machine had other ideas.... Cheers, Jon
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BAR 2007 |
#3
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Quote:
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
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For over 40 years I have been using white Elmer's glue on my nose cones. Straight! squirt it right out of the bottle onto the nose cone and brush it smooth. Let it soak in and dry. Sand with 220 grit then 2 coats of primer. It gives me a plastic smooth finish.
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"I'm a sandman. I've never killed anyone. I terminate runners when their time is up." Logan from "Logan's Run" http://sandmandecals.com/ |
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BT-5 sized balsa nose cones aren't all that prone to incidental damage to begin with, most likely because the rockets that use them are pretty low in mass. I don't think that any of the more advanced methods of balsa hardening are really necessary for them because they don't need such strong armoring. Something like Delta Ceramcoat All Purpose Sealer or Pine-Pro Sanding Sealer ought to work fine for sealing, filling and hardening the wood. These products are water-based and don't emit any noxious fumes. They don't really penetrate into the wood all that much, but as I said I don't think that is really needed for parts at that scale. A surface treatment really should be enough. This is usually what I use on my smaller (under BT-50-sized) nose cones.
If you want to use something that is a bit more penetrating and you can handle the fumes, butyrate dope-based fillers and sealers (such as Aerogloss) work well, too. Their primary purpose is to prepare the surface of the wood, but they do penetrate easily into it and after they are fully dry they do have an incidental effect of hardening the surface a bit. Dope products won't harden balsa to the same extent as the full-bore hardeners will, but they'll probably be all that you need. I use dope filler and sealer on my smaller-pattern fins without any other reinforcement, and they do a fine job of protecting the surface.
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Mark S. Kulka NAR #86134 L1,_ASTRE #471_Adirondack Mountains, NY
Opinions Unfettered by Logic • Advice Unsullied by Erudition • Rocketry Without Pity
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I use the Minwax Wood Hardener. Let it dry and hit it with two coats of filler primer and it is smooth as plastic.
When I first started to build plastic models, I was hesitant to go at it with real coarse sandpaper. Once I learned to hit with 220 then 400, things started to pick up. What I've learned with balsa is to not "over sand" it. Mark, I do like the idea of water based sealer/hardeners. I'll have to give it a try.
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Bravo52 -------- Jerry Little TRA #11767 Level 1 |
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I dip mine in future.....let it soak in and dry.
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Don NAR 53455 "Carpe Diem" |
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MixWax Wood hardener to begin with. Unlike epoxy, it penetrates. It does swell the wood a bit, but then I was going to sand it anyway, right?
Hmm, I bet Future would work. Not as penetrating as the wood hardener, but much less obnoxious. Sometimes I'll brush on a very thin coat of finishing epoxy, but not often. Sometimes I put a flat-headed pin into the tip of a nosecone with a very narrow tip. Just push it right in until the head of the pin caps the nose cone. I cover this with epoxy + microballoons and sand to make a smooth transition. Something I often do, to cones and balsa bulkheads: Add an inch or two long coupler to the cone's shoulder. This prevents "cranking" and thus protects the top of the body tube. I chip a groove in the rear of the balsa shoulder and slip the coupler over this. Sometimes I epoxy strips of fiberglass on the inside of the coupler to the bottom of the shoulder. |
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I thank you all very much for your replies! I think I'll first try un-diluted Elmer's glue as Sandman mentioned. After sanding, it should hold lacquer or enamel (or even acrylic) spray paint fine. Since some of the nose cones are pretty sharply-pointed, their tips might be more prone to breakage or "erosion" from point-down landings (even in grass, with properly-deployed recovery systems) due to their small size.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
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Finishing materials devoid of "noxious" organic solvent fumes are NOT legitimate finishing methods, no matter what anyone else tries to claim.
Chances are if the finishing method meets Commiefornia VOC compliance, it SUCKS ! Multiple coats of thinned (at lease 50% thinner to sealer ratio) Aero Gloss Sanding Sealer will result in a HARD balsa nose cone. Small cones can be dipped directly into a can of the thinned mixture and allowed to soak for a few minutes. Epoxy/Microballoons is however much harder and more durable. Have zero experience with the Minwax wood hardener, but others really like it. I do know it has an obnoxiously long dry time though.
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When in doubt, WHACK the GAS and DITCH the brake !!! Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't ! Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY. ALL systems are GO for MAYHEM, CHAOS, and HAVOC ! |
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