Composite Tube Fabrication Methods that Work!

On Rom's question, my internal antenna's (NAV antennas) on the outer wing panels would not work with carbon caps on the spars any more than they would work with carbon tubes for pass tubes and pushrods.

I use a center section main spar and a center section drag spar from BL50 on one side to BL50 on the other side, and those spars could have been graphlite rods - no antennas near enough to them. The outer panel spars are much lighter, and might not have benefited much by having graphlite caps.

Billski

I admit it, I'm not as smart as you guys are but I enjoy all of the great information I can soak up from these conversations. Regarding the push-pull tubes: Why not just glass over wooden dowels? Did I mis something in the post that's going to make me look like a moron for asking this?

FlyGuy,

For my push rods, it is primarily weight. My methods make for light parts. The most troublesome tubes had to be hollow, fuel-tight, and large (2-3/4" diameter). The pushrods were easy.

Bill

Hot Wings,

I would like to know more about how this gadget works.

It seems to be a vacuum pump made by running the sump pump to run water through a venturi to make suction, and plastic tote is there to catch and recirculate the water while allowing the air pulled from the bag to percolate off? Yes? No? Please explain...

Next, how much vacuum do you get this way and how much air does it move? In my experience, you never really get big parts sealed at the start. We turn on the pump and start chasing leaks by running our hands over the sealant, listening, etc. The pump and mold system have to be able to move enough air to make finding the leaks, which makes the rate of air removal important to us.

Do you have any techniques that allow you to really get the bag sealed immediately? Please share...

Billski