Ok, so the hemp threads have been rattling around for a while now, and we’ve had very few hemp boards posted as far as I can tell. After all of Chipfish’s input, and searching threads with ‘hemp’ here’s what I’ve come up with.
The Story:
I was driving by the lane on the way home from work a while back and saw the nose of a longboard impaled on a ‘no parking’ sign. Looked twice, and saw the rest of the board next to the trash can at the base of the sign. I whipped around, pulled up to the board, and asked the gentleman in the wetsuit, with no board, if it was his. After a little banter, he said I could have it, since he was throwing it away, but that he regretted taking the nose off the sign, since it looked so cool. Yes, I replied, it does look cool.
Here’s the board when it got to my front yard “shaping lawn.”
All the fin boxes were smashed to the same side. A friend commented that it looked like someone had run it over with a car, or smashed it with their feet. I think he’s right about that. I mean, wouldn’t you be ticked if you broke you relatively new board on a midsized day?
More carnage shots:
Here you can kind of see that the center finbox is cracked:
The board was by Iverson. Dimensions were 9 feet x 22 1/2 wide by 3" thick. Pu/Pe construction. Two layers glass top and bottom, not sure what weight. Since I wasn’t sure about doing the repair with glass/epoxy on a Pu/Pe board, and Ben’s hemp thread had just shown up, I decided to try something different. Stripped all the glass off. Cut out the side fin boxes easily. Had to use the router for the center fin box, which was a huge mess. It took me a while to get all the plastic out of the lawn.
I put the board back together following some of Benny1’s advice from another post about using roof rack straps on a flat surface. No reinforcement, just really held everything in place and loaded gorilla glue into all the gaps. Oh yeah, took out the shredded stringer part first. It foamed up about 3" above the deck, and took a little effort with the sureform to get it back into shape. Not sure I’d recommend that technique, I had a hard time getting the shape smooth. Anywhere else there was a big gouge I squared it off, and glued a block of foam in place with gorilla glue. Added a balsa tail block just to help even everything out, and widened the tail by 1" with a little foam added on.
Next I wrapped a 10" wide strip of 6oz s-glass around the break on the bottom of the board, using RR epoxy, after sealing with epoxy/filler. I didn’t extend it all the way onto the deck, just wrapped the rails.
Tail shot:
The main break:
Note my fancy new shaping bay… .a 10’x15’ standup tent.
Please note that I’m not going for looks here, so all those lines were drawn with a sharpie marker right on the blank.
The shipment I got was the same weight, although it was semi-bleached instead of fully bleached which suited me fine.
The cloth was a pretty tight weave, no bumps or irregularities. It had a minimal amount of stretch. Thought about washing and ironing the cloth, but didn’t in the end since I can’t ever iron wrinkles out of anything.
Didn’t really take any photos of what happened next, but will outline it here.
Decided to add a balsa deck after talking with Christian (cj3) about the project. Couldn’t have done this without his advice. Milled some balsa down to just over 1/8" thick on the table saw. Cut out a 1/8" inlay on the deck. Cut out a hemp inlay for under the balsa, and cut the balsa to shape. Vac bagged the balsa onto the deck over the hemp. Wet out and vac bagged one layer of hemp for the bottom, one over the top of the deck, then one more on the bottom. So the rails have 3 layers of hemp, plus that strip of fiberglass around the break. Hopefully it should be more than strong enough.
very difficult. I’ve only done one lamination of any type before, and that was with cotton on a boogie board, and it was easier. Oh, and that little 10" band of 6 oz, which was really easy to bend around the rails compared to the hemp. This needed a lot of release cuts around the rails. And, it’s very hard to sand smooth. It seemed to want to come off in chunks rather than feather into a smooth edge. So, in some of the less critical areas, I left the seams less than smooth, but that was all on the deck. Sanded everyghing with 80 grit, then did my fill/gloss coat.
One other thing, I used the 2020 epoxy on the advice of Greg Loehr, who was really helpfull. He said that with hemp, due to it’s longer elongation, the 2020 was needed. Aparently he tried hemp with 2000 and found that the resin cracked.
Thanks Benny! We’ll see how functional it is this weekend, once we find a fin to go with it. I ended up post curing this afternoon, so it’s all set to go.
Final Cloth Schedule: Bottom Deck 2 layers of 4.6 oz hemp. Top Deck: 4.6oz hemp/balsa/4.6oz hemp sandwich.
The only fiberglass used was one band of 6oz on the bottom/rails where you can see the black lines drawn on.
Thanks to everyone who’s tried hemp before, the stuff in the archives was great. I’ll have a ride report within a week or two, depending on when we get out to cowells. If the swell keeps up, it will probably just be shortboards for a little while.
