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Aug 21, 2019, 08:50 AM
'Douglas' to his friends.
Quote:
Originally Posted by mybad
I would imagine that not using CA would greatly increase the build time.
I use Titebond in similar fashion to that descibed by Bruce, above. I've had the current bottle for a couple of years, now; it's gone down by nearly half, so I can say that it's economical. I use a small brush to coat just one surface to be glued, after pouring a drop or so into a little plastic 'dish', gleaned from some old chocolate box packaging (I don't really remember...). The glue starts to 'turn' after about ten minutes or so, and, after clamping up the parts, sets in roughly one hour in normal clement conditions (longer in cold winter conditions, when the 'den' is not heated...). I pop the brush back into a small bottle of water, which keeps it clean and supple. Whilst the parts are setting, I get on with the next step, usually, and get back to continue a bit later on in the evening. To me, glue drying time is not really a problem; waiting for paint to dry is much, much longer. I use CA, but rarely, and only when it's material that requires it, such as plastic-to-plastic or -wood, or metal-to-wood. Any wood-to-wood is always Original Titebond. In very rare cases, when necessary, I'll use epoxy, but I hate the messiness of the stuff. I much prefer Gorilla Glue, if the foaming expansion is not detrimental. Titebond, even in the tiny quantities I'm applying, produces wood-to-wood joins far stronger than the wood itself, and takes little extra time, in my humble experience.
Hope this helps.
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Aug 21, 2019, 11:14 AM
B for Bruce
BMatthews's Avatar
Yes, it does take longer to dry. But I work around that by having a handful of building boards so I can work on building up the wing or some major portion of the fuselage and then leave it to dry while I do the fin or stabilizer or prepare the next set of parts or do some other related job. So the drying time isn't as bad as it might seem at first glance. I can't say that it's really slowed me down all that much.
Aug 21, 2019, 11:18 AM
B for Bruce
BMatthews's Avatar
Oh, I should also mention that I'm not artistically or emotionally bonded with the plans for the model. So I tend to cut away the wing and tail portions to more easily allow working on multiple building boards in this manner. After the model is done the pieces all go into a big envelope to keep them together.

Even if you can't bring yourself to commit such disfigurement with a bit of planning you could still work with either one very large building board or multiple boards sitting in key spots under the plans to allow working on a couple of parts at a time.
Aug 21, 2019, 05:56 PM
If it flies - I want one!
Petem's Avatar
Strongly agree with the previous three posts - a good aliphatic wood glue is king for wood to wood joints and does not slow things down at all for me.
And regarding weight of glue, I did some experiments years ago when playing with electric indoor free-flight, making lattices of balsa strips with joints of either CA or thinned Weldbond white glue. The CA added 50% more weight than the thinned white glue - suspect the root cause is that all the CA remains on the airframe as a solid resin, while around half the white glue evaporates as water in the drying process.
Had to chuckle at your thoughts on plan cutting, Bruce - I have been a shameless plan cutter-upper all my life, till last year when my Introduction F5J kit arrived.
It included a full size, rolled, full colour plan and I found myself artistically and emotionally unable to cut it up.
Fortunately, a friend in the printing game came to the rescue with a cutupable black and white copy - phew!
Back to the topic: as well as using minimal glue, check out the wood quality, sizes and design towards the rear of the aircraft as you build. You can save a lot of nose weight by substituting some nice light balsa where appropriate, reducing the size of some bits or leaving them out, and sanding down anything that can be sanded without compromising strength.
Enjoy your next build MyBad, but caution, is addictive.
Cheers,
PeteM
Last edited by Petem; Aug 21, 2019 at 06:06 PM.
Aug 24, 2019, 07:43 AM
Sure, I can fly after sunset!?
Thread OP
I really appreciate all the suggestions and encouragement.

I don’t understand the process of using glues that take an hour to set. Take the fuselage frame for instance. You have to cut out a bunch of 1/16 inch square sticks and scratch build the frame on top of the plans. With CA, you pin the assembly of about 20 pieces down and then hit each joint with CA.

With wood glue, do you apply the glue to each stick first, and then pin it down in place, then put glue on the next piece before pinning it down and then the next piece, and so on and so on?

How about when you’re glueing down the many stringers along the fuselage. With CA, I dabbed a bit of glue on each “bulkhead” and then placed the long stringer in place. It sets instantly.

With wood glue, how do I attach the perhaps 20 long stringers and keep them in place until the glue sets an hour later? These 1/16 inch sq balsa strips break just by looking at them too hard! I can see no way to “clamp” one in place, let alone 20.

Again, we’re talking about 17” wingspan planes here.

So, I think I understand what you’re doing, but not how.
Aug 24, 2019, 07:55 AM
Sure, I can fly after sunset!?
Thread OP
By the way, the further I got into building that model, the more frequently I had st step away from the table because of my eyes burning from the fumes. I tried opening a window for some ventilation but the breeze just blew the loose balsa around. I’ve heard of people developing an intolerance to CA. Hope that’s not happening here.
Aug 24, 2019, 08:12 AM
Sure, I can fly after sunset!?
Thread OP
I picked up a good CA tip elsewhere.

After a little use, so much CA would crystallize around the nozzle that I couldn’t get the cap fully back on.

I bought a jar of nail polish remover. I removed the tip and nozzle from the bottle and soaked it 24-48 hours. The CA turned into a gelatinous glob that came right off. Amazing.

Out of curiosity I set the CA glob aside to dry out. Once dry, rather than being a hard bead, it crumbled to pieces between my fingers.
Aug 24, 2019, 10:54 AM
'Douglas' to his friends.
Perhaps I have more patience than some (although that's not proven...), but I don't mind pinning down a part after gluing and waiting for it to set. I do other stuff while waiting (I don't just sit there twiddling my thumbs...). For formers, I often clamp 'em in place with Lego blocks...



I also use a fuselage jig on occasion, which works well for 'stick' construction ...



For ribs, I have sets of what I call 'soldiers': little 3D-printed supports that keep the ribs upright while the glue sets ...



... and I hold stringers in place with elastic bands...



I bought specially a small bottle of CA the other day, just for the undercarriage legs seen here, to glue 1mm piano wire as reinforcing, for a 16" SE5a biplane kit ...



Other than that, I've not used CA for ... well, even longer than that. To each his/her own, of course, but I really don't find glue drying time a handicap at all.
Aug 24, 2019, 11:29 AM
Sure, I can fly after sunset!?
Thread OP

We Came. We Flew. We crashed!


My grandson is back, so we took the plane out to test.

First the test glides. She had a tendency to go right. How do you correct for this without movable control surfaces?

We tried flying but only had an extended glide even with three hundred turns.

Well, we had a nice glider anyway.

So, we headed for a nearby sled hill. The winds were about 10 mph. You see where this is going. I tossed it first, but too gently and it only glided about 30 feet. Now, my grandson wanted to try. Unfortunately, as he tossed the plane forward he swung a bit to the side, resulting in a nice nose dive down the hill. Good thing we took along a plastic bag to take the plane home!

OK. He wasn’t upset. He told me: build fly crash repeat. And he was supremely confident that PAPA would have it back together when we met again in two weeks!!!

Any suggestions on how to fabricate a new cowl? I was thinking stacking and gluing balsa into a hollow cone shape, then sanding the exterior to shape. Sort of like how we built the wheel pants.
Aug 24, 2019, 11:34 AM
Sure, I can fly after sunset!?
Thread OP
Wow! Thanks dad3353. A picture is worth 1000 words.

I must have a thousand LEGO blocks in boxes in my garage.
Aug 24, 2019, 12:28 PM
'Douglas' to his friends.
Wow..! Your pictures are quite telling, too..! The kid's right, of course : Build, Fly, Crash... Repeat...
No magic secret for restoring your 'plane, unfortunately. I think, if it were mine (and it does resemble some results I've had from bad launches ...), I'd suggest cutting back to sound stuff and rebuilding the front end completely. Those busted stringers and formers could be used as templates, but aren't fit for re-use. As for the cowl : It could serve as model for a new one made of sheet balsa, suitable curved and carved.
Two weeks, eh..? Still enough time for Titebond to set.
Aug 24, 2019, 12:36 PM
B for Bruce
BMatthews's Avatar
Quote:
Originally Posted by mybad
I picked up a good CA tip elsewhere.

After a little use, so much CA would crystallize around the nozzle that I couldn’t get the cap fully back on.

I bought a jar of nail polish remover. I removed the tip and nozzle from the bottle and soaked it 24-48 hours. The CA turned into a gelatinous glob that came right off. Amazing.

Out of curiosity I set the CA glob aside to dry out. Once dry, rather than being a hard bead, it crumbled to pieces between my fingers.
Some years ago I needed to buy some Teflon spaghetti tubing for a project. When I ordered up the size I needed I also picked up a roll of the small size that is suitable for jamming down into the openings on the CA bottles.

I cut off the tube to be around 1/2" long and make the cuts with a long angle to them. In use I put the glue on by letting it flow out of the long slash cut and only the very tip of that long slash touches the work very lightly. So any dust that contaminates the glue and cures into a ball tends to be right at the end of the slash and is easily pinched and pulled off the end of the tubing. This being for the thin CA.

As for working with longer drying glues for doing the work you're describing? Well, that's what dress maker's pins are for if needed. For my own scratch built models I have a slotting saw made from hacksaw blades glued together that forms a slightly snug fit on the strip wood. I put a little bit of glue in each notch then push the strips into place and friction holds them until the glue dries. On kits or other situations where the notch is more generous in size I'll wedge the strip in place with a pin and leave it there until the glue dries. It's not as slow as it sounds. Or perhaps I got used to doing it that way as a kid when we didn't have CA.

The fumes are always bad when they kick off. It's noted in the MSDS sheet for CA glues as being a "minor eye irritant"...... yeah, right..... I learned to turn my head away for the most part. But a fan at the end of the bench on low can also help a lot. But it's these fumes that has encouraged me in recent years to shift to using a combination of CA, Sigment and aliphatic glues in my building. And there is something to be said for old style cements like Sigment and Duco and if they were still making it Ambroid. Namely that these glues sand very much like balsa and make it easy to get nice finishes clean of ridges. And for folks like me there's a bit of nostalgia in working with them.

I'm sorry to see the damage from the crash. But such is the risk with a biplane or a parasol wing with cabane struts to hold the parts together. That's always going to be a weak point. And sadly repairs to put it back together are going to increase the weight of an already rather heavy for the size model. I hate to say it but you're on a downward spiral where the repairs are going to just make it even more likely to do further damage.

I'd suggest that if you want to pursue rubber flying that it's time to shift to a high wing monoplane design of some sort. And preferably one intended from the outset as a flying model and not a scale model. They can still look like a proper airplane but with a little longer nose to make balancing easier. I can offer up a lot of options for your consideration if you feel it might be easier. In the meantime to get in some flying with only a little time investment I'll point back to the link for that Peter Chinn Project 3 I posted earlier. You could likely build one of those in less time than it takes to do the repairs on the Hawk. And you'll have a lot higher chance of good flights with it.

First thing to do though is get some rubber, lube, props and a winder on order from one of the online suppliers so you have them on hand for the next flying session regardless of which way you go with repairs or building anew.
Aug 24, 2019, 08:23 PM
If it flies, I can crash it.
rocketsled666's Avatar
The only way not to crash is not to fly. If you fly, you will eventually crash. It's just part of "game". The way I always looked at it, a crash is an excuse to build something new. You learned something building this first one so I bet you do a better job on the next and it flies better because of it.

My first RC airplane was a Goldberg Electra, a ~7' span polyhedral rudder/elevator electric sailplane. Stick built, not foam or an ARAF. I'd done rubber powered and control line so I had the requisite building skills. Took it to my high school athletic field to fly it for the first time. The field at my high school was huge, and it bordered a river wetland so it extended out for miles with no trees. However, way out in the middle of the field was a steel pole for tetherball. The plane flew beautifully, but I was afraid to gain altitude (beginner mistake). Basically the only obstruction for 1000' in any direction was that metal pole and I hit it 2 minutes in to the first flight. Snapped the wing and tailplanes. Took it home, peeled off the covering, rebuilt the wing making it 20" longer and converted the tail to a V tail. I still have it ~40 years later and even fly it now and then.

Even though my first RC experience was sub-optimal, I was hooked and have been flying RC ever since.
Aug 25, 2019, 11:36 AM
Sure, I can fly after sunset!?
Thread OP

Scratch Build Cowl: Proof of Concept


As proof of concept, I made two “Quick and Dirty” cowls.

Method 1: Dollar Tree Foam Board.

I used the plans to make multiple copies of the cowl base. I cut, stacked, and glued them together.

I then whittled them down and lastly sanded them.

Not too bad. Weigh nothing and very strong.

Broken cowl shown for comparison.
Last edited by mybad; Aug 25, 2019 at 11:50 AM.
Aug 25, 2019, 11:40 AM
'Douglas' to his friends.


Beware, though, to not end up with a foam 'plane..!

...



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