gussets and nails

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gicummo

Member
Joined
Nov 19, 2009
Messages
20
Location
montevideo / uruguay
Hello,

I am here again with the gussets. ... :ermm:

It is necesary, appart from the epoxy, put nails with the gussets?... If it yes.. why?

regards.

PD: I am steel thinking what to do with the gussets... I think I am going to use 3 mm (1/8) ply
 

Dan Thomas

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Joined
Sep 17, 2008
Messages
6,599
Nails hold the gusset until the glue sets. After that, the nails (or staples) are redundant. Some guys pull them out. If the glue failed, the nails would never hold things together under the strain, anyway. And nails tend to work themselves out with temperature changes; on some fabric-covered wooden airplanes you can see the nail bumps under the fabric. The nail lengthens as it warms up, pushing the head up, and when it contracts again it tends to pull the point upward rather than pull the head back down. Don't know why. It was bad with urea-formaldehyde glues; perhaps epoxy will stick to the nail and discourage that.

Dan
 

Franklin63

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Joined
Sep 26, 2010
Messages
45
Location
Central Texas
Nails hold the gusset until the glue sets. After that, the nails (or staples) are redundant. Some guys pull them out. If the glue failed, the nails would never hold things together under the strain, anyway. And nails tend to work themselves out with temperature changes; on some fabric-covered wooden airplanes you can see the nail bumps under the fabric. The nail lengthens as it warms up, pushing the head up, and when it contracts again it tends to pull the point upward rather than pull the head back down. Don't know why. It was bad with urea-formaldehyde glues; perhaps epoxy will stick to the nail and discourage that.

Dan
Speaking of staples, thats what I use, and I made this staple remover out of an old screwdriver. Just rounded it off real quick sharpened it and bent it so it can pry. Works good.

 

HumanPoweredDesigner

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Joined
Sep 6, 2009
Messages
1,030
Location
Arizona
It all depends on the size of your wooden members. Houses are made with very strong members sized for minimal deflection. The nails and gussets are no where near strong enough to withstand the full potential of the members. They are only strong enough to withstand the loads. Picture a huge plank under a second story floor. The nails just keep the ends from sliding off their supports. The plank is so strong so it does not bend noticeably.

With lighter wooden structures, like ultralight airplanes, the glue and gussets are designed to support the full loading of the members. But in this case, the glue is far better than the nails.

I think nails would weaken the wood. That is not a problem for house beams that are more than strong enough.

But it boils down to surface area and volume. Big beams have lots of volume and not much surface area by comparison, so it would be difficult to have gussets big enough to support their full strength.
 

Yogi

Well-Known Member
Joined
Jun 9, 2010
Messages
121
Location
Commerce Georgia USA
What Dan says is true . Nails/staples just apply pressure until the glue cures. My first wing, a Mitchell B-10, I used staples and spent a LOT of time pulling them and sanding. Just finnished building a set of ribs for a Fauvel 361 using weights (old ballasts/3 lb. xfmrs) to apply pressure .Worked great. Just had to be careful to set gussets firmly before applying weights so the gussets wouldn't slide around when putting the weights on. I prefer weights and clamps over staples and nails but it probably won't work for all gusset applications.
 
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