Board one was Clark/Epoxy/S Cloth with a 3/4 carbon deck. Board two was the same. Board 1 was tweeked in the beach break plus some delams so skinned it, re-shaped and vacuum bagged with 5oz. carbon 2 on deck and 1 on bottom. I re-inforced the nose (bent part) with carbon rail stringers.
I LIKE BAGGING!!
Board three I hotwired (pic 1) EPS. Actually bought a piece 1’x2’x10’, got three more blanks out of it (pic 2). Board three is for my Chiropractors daughter. I’ll be experimenting with carbon rail stringers (pic3) and working on decorating it/being more artistic than the first two.
There have been some questions, mine also, about “how does EPS differ from poly?”. Seemed to be pretty much the same to me! I used my Harbor Freight planer, was gentle with the cheese grater and smoothed it out with 80 grit dragon.
I made the cut for stringers with a hacksaw blade. I figured the roughness would be OK as it would be compressed by the vacuum bagging while epoxy was curing.
Other questions I had about bagging:
Can you re-use the material… Peal-Ply and Breather - NO
I have used the same bag three times so far… I’ll keep
using it till it doesn't work any more.
As you should be able to tell from the pictures… I do
things VERY low tech. ie..ShopVac with tubing for
the vacuum. HotWire.. Car battery charger set on 12
volt, 10 amp. with PVC frame for wire, worked GREAT!
More pictures and updates as I continue on it… if you like.
Might I suggest making longboards at least 2.85" thick, with at least slight crown deck, and apply some V or bottom roll to the bottom…tube technology.
Carbon is cool, but possibly not necessary. All theory, works for hollow construction, but only really good for anti dents.
Thanks Lee, This board is 8’5", 3 1/4" thick, crowned deck, front 1/3 is concave, middle is flat and last 1/3 is V (about 3/8" total at the tail, 3" tail rocker with 3 3/4" nose rocker. Those suggestions are GREAT for most ALL of my surfing, easy wave catching, good turning, love it!
So… with out a middle stringer I feel I need a little extra support for the fin box.
I’ve decided to re-enforce it, both deck and bottom, with extra carbon cloth extending out to the rail stringers.
Seems you’d need about 4 layers of tightly placed carbon to ensure durability on impacts and side bending, but that would be very thin and the resin on the outside would not hold up, as it sits against the foam. Any solid resin thicker than 1/8" would crack under load.
I’d go with woodie reinforcement myself, because it flexes naturally just a little, is proven for years in stressed finboxes, laminates with just one layer of saturated glass, is cheap and easy, and only needs to be 2" longer than the box, on both ends, and 1/8" deeper than the box. The ends are aligned just like the sides, butting into the front and back of the box.
YOu mean add two 1/8 wood 'stringers on each side of the box extending forward and back an extra 2"? And/or add connectors at the front and back of the box to the wood ‘stringers’?
In styrofoam, you’d need at least 1/4" medium density wood…better yet, tied to the deck under the finbox also.
In poly blank, no less than 3/16" high density.
Didn’t see you pic.
Just stick a fin in your box, lay it on a table, fin up, and twist the fin around. That pressure is generated with your hand! Possibly your two legs might generate some twisting forces also.
