[TowerTalk] [Antennas] Carbon Fiber Boom

[Roger (K8RI)]

> >Carbon fiber
>>probably demands special methods of attachment, drilling, fittings,
>
> Who needs drilling and fittings?
>
> Buy some carbon fiber fabric, some epoxy, and really good gloves.
> Sand the boom a little.
>
> Make a jig to hold your aluminum element center section at a right
> angle to the boom and just wrap the joint in epoxy coated carbon
> fiber.
>
> Let it cure ... done.

But if you ever want to disassemble it, that's one expensive joint to cut 
apart.
Also, just wrapping it up doesn't give the best strength and with large 
antennas this is important if you want maximum strength with minimum weight. 
Fiber orientation and type of cloth is very important for maximum strength 
with the minimum of materials.

Typically for this type of joint fiberglass and resin is more than suficient 
and a whale of a lot cheaper. The carbon fiber boom is where the light 
weight and strength really would come into play.

If a person has the equipment or skill with hand tools hard wood blocks can 
serve as molds for building element to boom mounts/clamps. For me, lacking 
the skill with hand tools, a milling machine works wonders at making molds. 
Cut to shape, sand smooth, give several coats of Verithene (sp?), let cure, 
coat with mold release (non silicone car wax) and have at it.  It's a little 
more complicated than that as it takes two halves for each and they have to 
properly fit the boom and element, but if one likes to experiment it can be 
fun.

Roger (K8RI)
>
> Go to the local fancy bike shop if you need ideas on how to attach
> aluminum to carbon fiber ;-)
>
> Dan