New to scratch building!
 

I'm new to scratch building and I have a huge problem I need solved. I'm building a custom airplane that has a cylinder shaped fuselage. I'm using balsa wood sheets as covering for the fuse and I need help!! How do I bend the wood to make it fit the fuse? And what's best to glue the balsa sheeting to my fuselhe frame? I heard boiling the balsa is great for making it bend but glueing wet balsa is almost impossible! Someone please help!!!

RE: New to scratch building!
 

You dont have to boil it, I personally have never heard of that. What I think is most common is to soak the balsa wood in regular old water. Once it has been soaking for a little while you can pull it out and bend it anywhere you want. When I have balsa that is already partially glued onto the fuse and it still needs bending, like around a round nose or whatever, you can grab a cloth or a big wad of paper towls and soak it in water. Just go back inforth over the area that you want to bend and shape with the wet cloth or towl and it will slowly start to bend around a curve. As for glueing wet balsa, the only thing I have used to glue it while wet is CA (cyanoaccylate) glue and kicker. I think if you use any other kind of glue that is slower drying you will need to get clamps and secure it in place until it thouroughly dries.

If you have to do some serious bending around really tight curves, the best chemical to use is amonia. If you soak wood in amonia for a little bit, that is the best chemical I think that will soften the wood to bend it anywhere you want. Windex is a good second or substitue because it has amonia in it.

David

RE: New to scratch building!
 

The front half of this plane was sheeted with 3/32 and from behind the cockpit I used 1/16. I used a squirt bottle of water blended 50/50 with ammonia, then rubber banded the wood and let it take it's own shape. I used medium CA for my sheeting. Before I glued it down I shot it with my squirt bottle again so it bends well for final gluing. There are a number of ways but damp wood and CA work pretty well. If you posted in the scratch builoding forum a lot of guys will have different ways of doing things but this is my old stand by.;)

RE: New to scratch building!
 

Hey Gene who is that ugly guy in the first picture. :D:D:D

RE: New to scratch building!
 

I 2nd the amonia + water treatment. I use sometimes ace elastic wrap doing the turtle deck. A little wider than rubber bands and doesn't have a tendency to dent the balsa. Either way works and I have used both. I enjoy scratch building and then seeing that sucker actually fly.

RE: New to scratch building!
 

Actually, vinegar is better than ammonia. Think back of the chicken legs you softened as a child in science class by soaking in vinegar. Pat the wood dry with a paper towel, then bend around the bulkhead. About the only glue that will attach wet balsa quickly and easily is CA and kicker.

RE: New to scratch building!
 

Well wasn't aware of the vinegar thing. I will certainly give that a try. Smells better than amonia. Never did the chicken leg thing in HS. I went to a city school:D:D:D

RE: New to scratch building!
 

Do you use the vinegar full strength?

RE: New to scratch building!
 

I do. Keep testing the wood until it has the flexibility you need. I simply use a 1" brush to wet the wood on both sides. Don't soak it. An alternative to trying to glue wet balsa: form the balsa into place and tape it down. Come back a couple days later when it's dry, take the tape off and glue.

RE: New to scratch building!
 

Do you have to have kicker for the CA? Can i just use regular superglue and wait the 3 minutes?

RE: New to scratch building!
 

The kicker gives you the instant set for the CA. That way you don't have to wait the three minutes.. :D Once formed and glued, you can move on.

CGr.

RE: New to scratch building!
 

I've found bleach-water (about 3:1 water:bleach) to have a rather nice ancillary effect:

Not only does it work well for softening/forming the balsa...but it also kicks the CA. :)

RE: New to scratch building!
 

I think you could definately try that. The only reason you use the kicker is so it will immediatley cure. If you dont use it you just half to hold the balsa wood in its shape until the glue dries which might take a little longer. You can check it every now and then by releasing a little pressure and if it starts poping back up, keep holding it.

RE: New to scratch building!
 

CA does not like to cure in wet wood. The kicker helps it along.

RE: New to scratch building!
 

i have never used kicker so im sorry if im kinda lost:D. How much is the kicker usually?

RE: New to scratch building!
 

Cost wise or the amount?

Cost.. just about the same amount as the CA.

If the amount, it's a spritz sort of spray. You join the two pieces of wood (three.. whatever) then hit it with your few drops of CA then immediately spray it with the CA Kicker spritz. You can almost watch it zap and set.

CGr.

RE: New to scratch building!
 

One note of caution about using the CA Accelerator/Kicker....

Be careful not to have any CA on your hands, or get your fingers into the CA in the joint.   It gets HOT....burn your skin hot.  Go ahead...ask me how I know.  :eek:

RE: New to scratch building!
 

"Be careful not to have any CA on your hands, or get your fingers into the CA in the joint. It gets HOT....burn your skin hot. Go ahead...ask me how I know. "

A big +1 there! Also, let the CA soak in for a second or so before hitting it with the kicker. And don't soak it, all you need is a light spritz.

RE: New to scratch building!
 

I have never used kicker as a general rule. Medium CA is fast enough for me. When I glue, the wood isn't dripping wet but it is very damp, I only spray the outside. Rubber bands do tend to dent the wood so if you come up with something wider like Gene mentioned and it works for you then you would be better off. I have only used the ammonia and water so I can't coment on the other brews. Ugly I can take, just watch the old jokes!!!:D I showed the photo with me in it to show the planes size and to show that you can sheet a round fuse without too much trouble, even with thicker wood. As shown, that plane was boned up for use with a 1.20 four stroke, after the photo was taken I added hard wood stringers from the fire wall to behind the cockpit because I went with a gas 2.4 Brison so there was a need for some added strength. I love sheeting and like the looks of a plane that has been sheeted, just something about the way they come out so smooth. Maybe I'm just silly but I like to glass them too, the Sukhoi was just sheeted and covered though.

RE: New to scratch building!
 

You can always lay the fuse up with balsa strips about 1/2" wide. Sand to suit.

RE: New to scratch building!
 

This is true, I have a couple of those way cool strip cutters and you can angle the cuts so the sheets line up without the flat gap. Strip sheeting is something I do on very tight curves. With the cutter angled you use almost no filler.

RE: New to scratch building!
 

soak it with rubbing alcohol...bend and rubber band it on,,the alcohol will dry quicker than water or vinegar will.. then just glue it where it is with ca when it dries....Rog

RE: New to scratch building!
 

Vineager works on chicken legs by removing calcium. Did you notice the chicken legs never reharden. Personally I wouldn't use it. I use plain water.-BW

RE: New to scratch building!
 

Nope, never knew that. You contry boys in Millington had all the fun. Us Grand Blanc boys were city slickers.

RE: New to scratch building!
 

Never had no chickens out here in the boonies...got some cows though. But we did have alotta fun...You city slickers couldn't launch rockets in your front yard like we could...lol.-BW

RE: New to scratch building!
 

I may be the only doing this but...

Water in a spray bottle and an old clothes iron set pretty high. Spray one side of the balsa, get it good and wet. Place wet side out wherever it's going and slowly start working at it with the iron occasionally spraying it down. It may not be the quickest, but I don't feel right about getting the wood wet on both sides and applying glue after. How much of the ca can the balsa suck in (capillary action) if the wood is already full of water?

My 0.02

RE: New to scratch building!
 

Most curves you only need to wet the outside, that will swell the outside making it concave and leave the inside dry. When I do big curve's like wingtips I soak them. Hear are some pictures of a rudder I did by soaking. Sorry about the quality.-BW

RE: New to scratch building!
 

That rudder looks amazing! How long do you leave the pins around the wood until its ready to hold its shape on its own?

RE: New to scratch building!
 

I think thay call that Planking a fuse !! I personally use the water and amonia trick !! Planked a fuse on an F3F navy Gruman bipe once !! wish i had it back !! or had plans for a 3rd scale one !! Like the Gulfhawk !! that would be so SWEET !!! Dale

RE: New to scratch building!
 

Never glue wet wood to a framework! What happens is the wood swells when wetted. If you glue it down the wood eventually dries and un- shrinks. The wood will pull in bewtween fromers and you will get an airplane with the classic 'starved horse' look. The best thing to do is custom fit lengths of wood to lay along fuse formers or wet the wood to bend around formers and then just rubber band it it place until it dries. Once the wood is dry remove rubber band for fitting and gluing. Then you will be more apt to fit the wood where you want it to go.

RE: New to scratch building!
 

The form is just 1/4" foam board. I used a large zip tie on the outside to protect the soft wood from the pins and left it to dry overnight. The next day I used thin CA and pulled it off. I think I found the technique here on RCU.-BW

RE: New to scratch building!
 

City??

RE: New to scratch building!
 

Now thats what I call a "Picture" window.-BW

RE: New to scratch building!
 

That's neat. We have hundreds of turkeys around our farm. Lots of deer. but not as friendly as yours. Nice picture, mom and her boy.

RE: New to scratch building!
 

I use rubbing alcohol and get it to start bending as much as I can. I glue that part with CA and accelerator. Then I take a rag and it soak in water then rub the wood, bend and glue. I repeat this until it bends all the way around. What I've also done is do planking. You can take a wood stripper like the one from master airscrew and strip 1/6" strips for small planes and maybe an 1/8" or 3/32" planks. Just glue the planks around the fuse until you get all the way around. Then sand smooth

RE: New to scratch building!
 

What sucks more than anything is im 16 years old so money isn't an endless pool. I need balsa wood for my custom jet that im framing and my lhs sells balsa wood streamer ( balsa sticks) for almost 1.50! Thats cheap alone but in bulk thats a ton of dough for me. My engineering teacher has at least 1200 streamers at his disposal that we never use and he won't give me 8! I hate it when im impatient to finish a plane and my resources have run dry![&:] Anyone else have this problem? ( oh and could i possibly use fiberglass to cover the wood cheeting on my plane? Or would monokote be better?

RE: New to scratch building!
 

Google Lone Star Balsa and break away from buying wood in hobby shops. They sell Mid West wood and it's really high dollar stuff. You won't find any scratch builders buying there wood from a hobby shop unless they need a size that they don't have in stock, that happens quite often and I can go to Hobby people or Michael's and get a stick or two. Just have to pay through the nose for it. Balsa USA is another good wood sorce but a bit more money.;)

RE: New to scratch building!
 

It was a bummer when Lone Star had their fire. I forgot how much balsa I was buying until they were gone.

RE: New to scratch building!
 

but you do know they are back now and you can buy from them again.

RE: New to scratch building!
 

No I didn't. I took it off my bookmark. have to add it again. Thanks