Hemp repair

A little while ago, Chipfish posted a thread asking about how some of these hemp boards have been holding up. I couldn’t find the thread, so here’s a new one. I wanted to give an update and repair report on the board from this thread:

http://www.swaylocks.com/forum/

gforum.cgi?post=289800;search_string=Hemp%20project%3A%20broken%20longboard%20rebuild;guest=16487665#289800

It’s been holding up like a champ, and I thought it was indestructable. Then I took an inexperienced friend out at a rocky point during one of the lowest tides of the year. After a poor takeoff in a very shallow area, the nose did a really good job of connecting with one of those rocks. Fortunately, only the board was damaged.

The damage:

The cracks on the bottom went through to the foam as well.

So I cut out the damage. You can really see how thick the 3 layers of hemp were here at the nose.

I let it dry out a bit, then went about the repair. First, I filled up the space with epoxy/q-cell. After sanding that down, I wet out two layers of hemp for each hole to be patched put them on the board. In order to get a good bond with the hemp, it really helps to use a vacuum bag. A little bit of window caulking for a seal and part of an old vac bag were used just in the area around the repair. This didn’t work too well, and I was chasing leaks in my miniature ‘bag’ for about 20 minutes. Eventually I had about 8" Hg of pressure going, put some heat on it, and walked away. The result was that some of the window caulking and breather material got incorporated into the repair. But it worked. Someday I’ll clean it up a bit, but this is really the beater board for our house. The black and yellow bits give it some more character.

Pat

thanks for posting that pat !

let us know how the REPAIR holds up , eh ?

[can anyone get a photo of you surfing the board , too, please ??

cheers 

ben

…hemp fins soon…

I’m going to subject the repair to a rigorous trial of sticking it behind the shed in the rain all winter. It seems like I’ve got longboards coming out the ears now, and this one is one of the less friendly boards at this point. I did ride it quite a bit after the repair was done for a week or so while doing repairs on the other boards. Despite the little black fuzzies and yellow sticky goop, I didn’t notice any difference in the way it surfed.

Pictures of me surfing are hard to come by on any board. With all the talented folks here in santa cruz, who would want to take pictures of me shuffling around and flapping my arms like a chicken?

Pat

Interesting subject…I’ve never worked with Hemp cloth. Why did you need to vac bag the repair? Would it be possible to use standard glass and epoxy resin with a hand lay up to do a repair like this over Hemp? Is Hemp cost effective? (how much does it cost per yard?) I have a Bio foam blank that I just shaped…I’m not a hippie or a greenie ,just having fun checking out different stuff…

Ray

Hi Stingray,

Lot’s of questions here, let me begin:

  1. Why did you need to vac bag the repair?

I found that I couldn’t get my hemp to bend over curves very well without the bag when I was first putting the board together.

  1. Would it be possible to use standard glass and epoxy resin with a hand lay up to do a repair like this over Hemp?

I don’t think that’s possible due to the different amounts that each flexes. Hemp will flex a lot. It would be like using suncure. Probably would hold for a while, but then begin to crack along the edges. You also need to use a very flexible epoxy (I used RR 2020.) This info was from Greg Loehr.

  1. Is Hemp cost effective? (how much does it cost per yard?)

Nope. Fiberglass is much cheaper. Prices vary a lot depending on what you’re getting. I think I paid about $10 per square yard? Can’t quite remember.

I don’t think hemp is a substitute for glass, myself, but it’s fun to play with. It can be VERY good for some applications, such as impact resistence. This board had been dropped on the rocks many times without a scratch, before being pile drived (driven?) this time. I think that bamboo is more promising, a la Garry Young, if you’re going to go glass free and want a light board. Or just make a wooden board like Stewart or Wegener, and don’t use any glass at all.

Pat

Thanks for the response Pat. I have a small interest in vac bagging but things are headed towards wood board. But that’s only because I have a guy that will pay for the materials If I build the wood board. My strong suit is repairs and I want to be able to repair any thing that comes my way!

Share the stoke…

Ray