photoniq

Guys - I have been reading lots of 'build' threads because I feel it is helping me get my head around what you have to go through in a build. Consequently I have a couple of quick questions.

1) When you pin your wood to the building board over the plan do you pin AROUND the wood or THROUGH it?

2) When you dry fit pieces of wood to make sure everthing fits do you just wick CA in to the dry fitted pieces of wood or do you take them apart, apply glue and then refit the parts?

Cheers,
photoniq

MinnFlyer

My Feedback: (4)

1 It depends on the piece. If it's structural, like a wing spar (or hard wood), pin around it. If it's something like the leading edge of the rudder, I'll pin throught it.

2 This depends too. If a part fits so nicely that wicking in a little thin CA will work, great. OR if I have all of the ribs lined up with the spars in place, I'll add a dab of Medium where the spar and rib meet. But in some cases, you may need to remove the part - glue - and replace. There's no set rule really.

As far as which CA to use, I only use Thin and Medium, and I rarely use thin (Except on hinges of course). I will usually go through a 2 oz bottle of Medium but only use a little bit of a 1/2 oz bottle of thin for a 40 - 60 size plane.

And to save a little money, I'll use carpenters glue on large areas, but tack them down with CA

photoniq

Thanks minn.

Carpenters glue is that white PVA wood glue right?

Mechanos

"Carpenters glue" generally refers to any of the aliphatic resin glues. Usually yellow in color. Tite-Bond it one popular brand name.

blw

My Feedback: (3)

I always pinned thru wood when building rubber powered planes as a kid. You could always see the pin holes after covering with fabric, but I didn't know any better back then.

I was pinning across the wood on rc kits, but I now pin thru after reading about making pin holes before covering to allow hot air to escape. This is supposed to help prevent bubbles in the covering.

I was mostly gluing and then putting down the parts, but a friend builds Sig Something Extras often and he can build one in a few days. He puts the pieces down and wicks thin CA in to hold the pieces. It only takes a few seconds per rib to align properly and tack. He can build a wing in a few hours this way and his SEs are build very strong. For instance, he tacks down all of the ribs, spars, edges and then goes back and wicks it all properly. It makes sense the way he does it. He hardly ever uses medium CA without hitting it with kicker after setting the pieces. I've watched him go and go on several repairs to my planes this way. It would have taken me days and he did it in hours.

Bax

My Feedback: (11)

If you're using carpenter's glue for laminating, it's usually a good idea to weight the parts to keep them flat. I've had pieces curl apart because the water in the glue expands the wood on one side, and the two parts warp away from each other. The CA tacking sounds like it will keep that from happing, though. Haven't tried that. I usually use a gelled CA for laminating.

Pacer's Zap-Gel is wonderful stuff!

bax

Mike in DC

I almost always pin through, even if, for hard wood, if I have to drill a tiny hole. The reason is that I've found that the tighter you can get the wood to the building board, the straighter your parts come out. Before I discovered this, I would build a wing or something, pin it down, and everything looked fine, but when I took the part off the board, it wasn't as straight as I'd like. I found if I really pinned the parts down solid, it made a huge difference. I'm not saying that the slightly unstraight parts didn't fly just fine, just that the pinning seemed to make a difference.

If you're building a kit, I'd follow the instructions as far as dry fitting and gluing. For one thing, it depends on the wood. Light ply pretty much has to have a fillet of medium CA for a strong joint. Wicking works fine for soft balsa parts that fit very well.

Like MinnFlyer, I use very little thin CA. For one thing, it is much worse on my sinuses and eyes than medium, but mostly medium seems much more appropriate for most joints.

blw

My Feedback: (3)

Any CA hurts my nose and sinus. I usually use a fan to blow the fumes away. CA isn't for everything, of course.

When epoxy is needed, I try to use 30 min epoxy so that it has more time to soak down into the wood fibers before setting.