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Hi,
I have just finished my first kit. A Pica Shoofli BI. How old is this kit?
It was given to me by a gentleman who has been flying 20 plus years. I am using Futaba radio gear and a Magnum 70. The top wing is 54"

How does one glue balsa sheeting together, on edge, and minimize the glue seam? I've used both CA and Titebond wood glue. The seam is always harder than the balsa and the finish sand always has the ridge of glue higher than the wood.

thanks,
RCS

RCKen

My Feedback: (9)

If you use the Titebond for the seam then the seam will sand easily. But to remove a ridge the best way is to not get one. Most people use too much glue (I'm guilty of that too) when they glue parts together. When you are gluing sheeting together put your glue on, then press the sheets together, wipe all of the glue that squeezes out, and then clamp them in place. But try practicing putting less glue on when you join the sheets. I use Elmer's Carpenter's Glue and what I do is put my bead of glue on the wood, use my finger to spread it out evenly and remove excess glue, press the parts together, and they wipe up what squeezes out before I clamp it down.

But at all costs try to avoid useing CA to join your sheets. No matter how much CA you use there will be a hard ridge or joint that is impossible to sand. That's just the nature of CA itself. This is actually one of the biggest reasons why I quit using CA and started using Elmer's.

Hope this helps

Ken

saramos

For good joints when joining sheets, there are several things that can help. Make sure that you have a good butt joint between the sheets. Sand or cut the edges with a good straight rule. Try and match hardness of wood from sheet to sheet. Butt the sheets together and tape them on one side. The tape will be like a hinge and allow you to open the joint. Apply glue to the joint and then lay the sheet down flat. Wipe off excess glue and make sure the sheets match up level along the entire joint. Weight and let dry. Once you have made up sheets wide enough for your application, sand both sides of the sheet while on the table, before applying to the model. Use a long sanding bar and 80 grit. This will be coarse enough to cut the glue joint. If you use a fine grit, you will only smooth a ridge, but not eliminate the ridge. Sanding both sides will make sure no ridge or irregularities will show up when you apply the skin to the model. Now sand one side with fine grit to get a smooth surface. Once applied, you will not have to do any more than touch-up sanding. I've read where some people like to use ambroid glue (wood model airplane glue) for gluing skins together because it sands easily.

Scott

BBW Walt

My Feedback: (11)

220 grit takes care of the ridge's..

Gray Beard

My Feedback: (-1)

NoGlo and I do it the same way, even have the same machine to do it with.

TLH101

My Feedback: (90)

Just exactly like Scott describes.

IronCross

One other thing that might help... Which Titebond are you using ?... I find that the "Original" indoor version sands pretty good.. The "Outdoor" and newer versions don't sand nearly as well..

saramos

I use and like the original Titebond formula. I have not personally tried ambroid glue. I tried Titebond II once, but didn't like it as much as the original (shorter working time and I found it gummier when sanding). I also use Titebond for applying the skins to wings using the iron on method. It's like applying a heat activated contact cement. Apply an even coat of alphatic glue to all the ribs, spars and stringers, and also to the matching surface of the skin. Let the glue dry (about an hour), then apply the skin with a covering iron. The heat will 're-activate' the glue giving an almost instant bond. This way, you don't have to have a million pins, bags of sand, or worry about working time like with CA. PVA glues (Elmers, Titebond II) work using this method as well.

Scott

d_bodary

My Feedback: (85)

I like using Sig-Ment myself. But if you use thin Ca it will work also. Now before i get flamed. read thru. Once the two pieces are squared up. lay wax paper down on the bench spray accelerator on the wax paper. yes the wax paper not the wood. Then using a Thin CA with an applicator tip glue about 5 inches together hit it with a 220 sanding block for a couple of seconds then move to the next 5 inches hit it with the sanding block then continue as before. It actually goes pretty fast that way. now the wood that is against the wax paper will be the outside edge that you would see . the ca side will be the inside. Now if you did all the steps right there should be no ca on the outside of the wood due to the accelerator setting it up.

Dennis

dbacque

My Feedback: (3)

Someone has a web site that has a very detailed write up on the best technique I've ever seen. But I can't find the link, hopefully someone will know it.

First, make sure both pieces of wood are the same thickness (don't laugh, they don't always match!) and true up the edges to be glued with a straight edge and X-acto.

Lay the pieces down as they are to be joined. Using a few pieces of low tack masking tape (blue tape) tape across the joint. Turn over and run a piece of tape the full length of the seam. This will act as a hinge. Turn wood back over.

Now remove the first pieces of tape and fold the joint open, giving a V shape at the joint. Run Ambroid into the joint and lay the pieces of wood flat. Wipe up any squeeze out and wipe again with a rag with acetone. Now you don't have any glue on the surface of the wood so you won't have to sand any glue!

Tape this side up again with numerous short pieces across the joint.

Turn over and peel off the long piece of tape. Clean this side with acetone too and tape with pieces across the joint.

Place on a flat, true surface and weight. Allow time to fully cure!!! Remove tape and lightly sand seam with a sanding bar. When done right you will not be able to find the seam.

Other glues and their proper solvent could be used but I love Ambroid and it sands beautifully. Plus it smells like my childhood!

Dave

Charlie P.

Flat surface, wax paper, lots of "T" pins. I pin one side down well and then use a soldering brush to apply Titebond II glue to the edge of the second piece. If you slide the piece in you will get glue on the back. Try to set it down right at the seam. Push them together hard and "T" pin them in place. Then, I wet my finger and smear all excess glue off the seam. Plan the parts so the upper side is outside on the model. If you're really sloppy with the glue, use a slightly wet rag over your finger. When it dries there is a discoloration, but no glue ridge. With 150 or 220 grit on a block I flat sand both sides.

In the first image I am also holding the pieces together with blue masking tape. I've found the tan/brown masking tape will stick to the Titebond II, making a mess to sand away.

mmattockx

Dave,

That is probably Terry Brox's page on pattern wing construction:

http://www.mackrc.net/patternwings2/index.htm


Enjoy,
Mark

dbacque

My Feedback: (3)

Mark,

Not the site I was thinking of but thanks for the link.

Dave

rc-sport

My Feedback: (12)

I use the tape and hinge method descibed above with wood glue. Wipe off any acces that oozes out and you will need very little sanding. I put the piece between to pieces of wax paper and place a heavy board on top while it cures so it doesn't warp.