Why Braided Biaxial Fiberglass Sleeving?
Braided sleeving is a great way to reinforce masts, booms, yardarms, paddle shafts, oars, whiskerpoles - just about anything round. It goes on just like any other kind of fiberglass - put it on dry over wood and then wet out with epoxy. The video below has more information. The big advantages are first, neatness - no seams - and second, strength - the stuff is biaxial so all the strands are adding to the strength.
What size do I want?
For spars, oars, or any long, round piece of wood that you want to strengthen, You want sleeving with a nominal size that is the same or larger than the piece to be covered. Any of the sleeving sizes will stretch down to half its nominal diameter. More on this below.
How Much Will I Need?
This is where it gets complicated. The length we sell this stuff at is nominal. That means that, like a 2 x 4, you can't really take an inch or foot for granted. One of the great things about braided sleeving is that it assumes the size of whatever you put it on. That is great for tapered masts and baseball bats, but it makes it hard to estimate how much you need. Why? because as the diameter of the thing to be covered grows, the sleeving covers less distance.
We played with the materal quite a bit and found a rule of thumb that we can apply to all sizes: When covering an object that is the same diameter as the sleeving, a nominal foot will cover only 8 inches. When covering an object that is half the diameter of the sleeving (about as far down as you want to go), a nominal foot will cover 12 inches. For anything in between, you can extrapolate as the change is somewhat linear. At any rate, I would always add at least 10% for error.
There is one more thing you may want to consider and that is the orientation of the strands. While it is true that the sleeving is, by nature, biaxial, the angles change as the material is stretched. So, if you have two choices of size, it may make sense to get the larger diameter sleeving and stretch it more to get the strands running more along the length of the spar for greater strength.
If you are interested in trying some of this stuff but are unsure about what size to use, feel free to write to me at: firstname.lastname@example.org
Experimenting with some biaxial FG sleeving. Followed along with the demo video and got very good - better, really, than expected - results with the first experiment.
Maybe another experiment with the larger, heavier sleeving... and then try to figure out how much epoxy I'll need to do an 18' mast!
Thanks for these products Chuck.