Musings on balsa vs. coroplast.

Andrew, I had thought of doing that.  I was going to clean and flash the coroplast, then glue with thick CA, then use a sheet of coroplast on the joint like I would use a piece of triangle stock balsa on the joints.  But that's a pain, and the glue would have to fill a large gap that I didn't want to deal with.  The slot for the wing is just the flute cut out in the right position.  Unfortunately, the flute is a little wide, and it's also not perfectly square, so there is a small gap where the wing and the stab slide through the fuselage.  I will tack it in place with CA, then use the heavy duty glue stick to glue in the wing and fill the gap.  I don't want to use too much reinforcement because that will add more weight, and one purpose of the experiment is to see how light I can build this.

The Sticky Mark

batjac wrote:.......I will tack it in place with CA, then use the heavy duty glue stick to glue in the wing and fill the gap.  I don't want to use too much reinforcement because that will add more weight, and one purpose of the experiment is to see how light I can build this.
The Sticky Mark

I think you've got a good plan.

The newer glue sticks are formulated so much better than the older sticks and a small fillet may very well be just the ticket. I just recently bought one of the higher capacity high temp glue guns and a pack of the better sticks, but have not used it yet. Your results may well be the nudge I need to put it to work.

a--

Hi Mark,  (nice thread !)
From my coro combat days,  ( I flew against them with wood/foam)
The best glue for coro was medCA and kicker. (need the kicker for some reason)
-Gorilla PU and Goop worked good too.
-rubbing the surface with 120 grit, acetone wipe was the key, and the rub. (pun intended)
-1/16th  bamboo skewers are your friend.
I think,
A 1/2A coro plane, has all the advantages of,
A balsa plane with many crashes/ repairs.
Coro is close. And needs,
Just as many props...
Take care,
Have fun,
Dave

The glue sticks that I bought were the premium Arrow Slow Set sticks (here).  At $1.21 per stick, they'd better be the best.  I got the sticks recommended by a user on the S.P.A.D. forum on RCG.  I messed up and didn't notice the glue gun I got was not dual temp.  The reviews said it heats up pretty high and works great, so we'll see how a couple of test runs work.

The Spendthrift Mark

Hi Mark,
All my coro info is 20yrs old...
I am familiar with Tig/Mig welding...
If you can weld coro together,
Is it called,
Pig welding?
Take care,
Have fun,
Dave

HalfaDave wrote:
If you can weld coro together,
Is it called,
Pig welding?
Take care,
Have fun,
Dave

that's oinking funny!

Here's a pic for inspiration that I ran across the other day.  

That RC plane looks awesome! How does coroplast resist the hot castor the BB is slinging?

That RC plane just gave me an idea....


The Idea Man Mark

The pic was posted in RCG under 1/2A Model Aircraft Restorations.

The RC plane is, I believe, a modified Guillow Flying Eagle 48" foam glider that has been converted to RC and COX power.  I don't think this particular type of foam is damaged by fuel or oil, however, I have seen some that were discolored to light brown from the castor.

The C/L plane is a coroplast Baby Ringmaster (?).  Coroplast is pretty impervious to 1/2A fuel, but I don't know how well the glue joints would hold up.  I suspect the hot glue that Mark has sourced will not be affected.

a--

Well, I bounced back around to this to finish it off.  I glued it all together, put in wood dowels for reinforcement, and put on the engine.  Then I weighed it against the balsa Skyray.  I’m not sure where my numbers were off, but the CoroRay is almost an ounce heavier than the Skyray.  But, 6.25 ounces is still plenty light for a Bee engine.






Having done this once, there are a couple of things that I’d do differently.  But as an experiment, it turned out pretty good.  Now to just get out and fly it.

The Plastic Fantastic Mark

Hey Mark what are the safety pins? for sticking out the fuse ? And what paint did you use ? Thanks

getback wrote:Hey Mark what are the safety pins? for sticking out the fuse ? And what paint did you use ? Thanks

Eric, the safety pins are for using a bladder, as it previously had a TD on it. No paint, Monokote.

The Bladder Control Issues Mark