pacifier

My Feedback: (4)

I just finished framing a hull and getting ready to plank it. This is actually the second time I've built this project. The first time I planked the hull with 1/16x 1/4 balsa strips. With the glue used, and two layers of fiber glass, I think that model hull weighed just a few pounds less than the prototype with all it's accessories. So I decided to rebuild it and ask for expert help that would help to improve my sadly lacking skills. I would be very glad for any help anyone could give me in this endeavour. Thank you, Marc


P.S. The length of the hull is: 32 3/4". The beam is 9". So far just the keel, formers, and stringers are glued together.

LtDoc

A very simplified and basic generalization is that the planking gives shape, and the fiberglass seals, and gives it strength. A boxcar full of sandpaper seems to be a good investment too.
Any generalization is almost always 'wrong' to some extent. That definitely goes for this one! But, it's also fairly close to being one of those "truths" people are always talking about, you know?
A few more of those 'truths'...
If it break when you look cross-eyed at it, it ain't strong enough, use more of whatever you made it from. But if it weighs more than the water it's supposed to displace, it's too strong. That's where that sandpaper comes in.
Strength is nice! As in being strong enough to stand on. But do you really ever plan on standing on the thing, or run into something that hard? Gotta keep things at least part way reasonable.
It depends a lot on your point of view of things in general. A little bit more never hurts if you're sort of 'frugal' in attitude. If you're normally sort of 'extravagant' in nature, a little less probably won't sink the thing quite as fast. Sort of like having a 'hemi' in a Volkswagen. If you keep your foot off the accelerator and gear the thing properly, it ought'a do okay. If you like planting your foot in the floorboard all the time, you just ain't gonna get very far without new tires and lots of gas.
That's about the most outlandish analogies I can think of at the moment, and if you can't get at least a sort of general idea from them, you just ain't trying very hard (stop laughing and it'd help too). Whatever works.
- 'Doc

TCHedOff

Pacifier: Balsa is light but lacks strength, and by the time you add carbon fiber or fiberglass for added strength you'll be overweight again.... balsa is best for cosmetic things like a scoop, windshield, or to make a driver.

For an RC boat you need higrade (birch) plywood (some call it aircraft plywood) that you can get online or at your local hobby store. Typically they use 3/32's ply for the bottom and top, 1/8" for crossbraces and 1/4" for the transom - especially if using an outboard engine.

You COULD try 1/16 ply for top & bottom, but when your at your hobby shop, you'll see how flexible it is.... stick to 3/32; if you are using a bigger engine .45 and above you could go 1/8" - the extra weight wont matter really (set up will be more important than a couple oz's) and give you a very strong hull. Post some pics of your build & best wishes.

todd

TCHedOff

BTW I am ASSUMING you want a nitro or gas boat... if you want to build a something that goes slower - like 1-15 MPH - then you can use other materials, including balsa. I have kit for a sailing boat that uses 1/16 by 3/16 mahagony strips for planking.