Alternative to biaxial sleeve?

[paulk5]

I am using a glass biaxial sleeve to cover a wood pole (<2in diameter). Problem is that the lightest wgt these sleeves seem to be available in is about 10oz cloth. This is more bulk than I want. I'd like a 3-5oz cloth. I've tried roll wrapping and spiral wrapping (using tape), but I struggle with handling/positioning the wet layup, and can not achieve the ease and seemless look of a sleeve. Any suggestions on material, source, and/or method? Needs to be on the cheap, as I'm not ready to pay for custom material, yet. Thanks!

 

[Compositepro]

Table rolling fabric would seem your best alterntive. This will give a 0-90 fiber oriention rather than the bias of a braid. This should a lot stiffer. Success will depend on getting the details right. Prepreg the fabric and let the viscosity increase so the tack is right for rolling on your mandrel. You need a really flat table to get good pressure at the nip between the table and mandrel. Cut the ply to length after prepregging and before rolling.

 

[paulk5]

Thanks Compositepro. I've tried this a half-dozen times now without success. My tube is actually an octagon, and this makes roll-wrapping more challenging. I can get it wrapped, but it needs compaction, and that has left me with wrinkles. Compaction is via a vacuumed latex sleeve (seamless, with a breather strip). Again, the process works with a pre-formed fabric sleeve, but I want a lighter weight than std sizes. I've tried making my own sleeve by taping the seem of a biaxle (45deg) strip of cloth. With electric tape (stretches), this shows some promise. Any other ideas?

 

[Compositepro]

As I said, it is all in the details. Cylindrical shapes are challenging because the circumferential fiber length is set during wrapping or rolling the fiber. Compaction after rolling only reduces diameter and the extra fiber length will wrinkle. Fabric is more forgiving than uni because the weave creates a regular wave than can become a little more wavy rather than wrinkling.

Table rolling is not just rolling by hand on any table. There are manufactured rolling tables that roll a mandrel between two plattens. This can still work for octagons but adds some challenges.

How are you compacting your tube? Shrink tape will only apply pressure at the corners unless you use cauls to apply pressure to your flat surfaces. Perhaps this is your problem.

You could do a wet lap-up of fabric around your wood core. You will need a fixture to hold the core horizontally. Let the fabric hang down as you rotate the core incrementally and roll it with a grooved roller to impregnate. Keep the fabric tensioned as you wrap. A weighted bar at the bottom of the fabric can help keep tension and keep the fabric straight, axially. A spiral wrap of peel ply at the end could be used for compaction and to remove excess resin.