Hemp

[Bill Baillie]

I saw an advertisement on the internet a few days ago for a hemp grower in the UK. The ad said that hemp fibre's weight to strength ratio is comparable to fibreglas.
Has anyone considered using woven hemp fibre in place of fibreglas as a coating on a boat hull? For that matter, are there other fibrous substances that could be woven into a sheet and used for the same purpose?

[Ariel]

I think hemp is illegal in the US because folks try to smoke it....I read where Hawaii can grow it since 1999 when permission was granted. I think other states have applied for permits to grow it also. We will see...?

[Ken Hall]

I believe industrial hemp is now legal in Canada.

[Tom M.]

You can't smoke hemp.

Hemp and pot are different, even though they are the same species.

Hemp is bred to yield fibers, at the "expense" of a flower that you can't get a high from. Pot is bred for the flower, at the expense of good fibers.

The problem in the USA, apparently, is that law enforcement can't tell the difference. Of course, timber/paper/pulp interests in this country lobby against it because it threatens their markets.

Anyway, I don't mean to hijack this thread.

I don't think hemp mat would do well in resin. I think the fiber/resin ratio would be too low, and you couldn't get a nice surface.

That said, I just remembered that HENRY FORD built an all hemp body for a car in the 1930s I think. His gimmick was that he took a sledgehammer, hit the car as hard as he could, and the hammer just bounced off, with no damage to the car body. He probably had something there...

I wonder why THAT got swept under the rug??

[gary porter]

Bill, I'm thinking that hemp cloth would probably work , strength wise with epoxy as
the cloth gives strength to the epoxy although it would probably depend on how the cloth was woven. Hemp, as far as I know is not illegal in the U.S. just growing it. Many folks have hemp clothes etc. and our Oakum comes from other countries but is legal to have. No one wants to smoke that. As I see it one of the biggest problems with the hemp industry is that the folks who are pushing it are the same ones pushing pot. I guess it might be a problem for the agencies to tell what was growing at first, not sure.
Anyway I'm all for the hemp industry but would like some folks to talk about it without going into rants about smoking pot. They, in my opinion, are their own worst enemies.
I'd like to try some cloth with epoxy just to find out.
Gary.....

[hoz]

I read a book about the prohibition against hemp. It said one lobby against it was the synthetic fibre industry. They wanted to replace hemp ropes with nylon.

[L.W. Baxter]

Yeah, maybe if Woody Harrelson would just shut up for a minute...but no sane congressman wants Woody et al. showing up to cheer for him...

[Captain Pre-Capsize]

A related history lesson for this thread. The U.S. Navy got caught unawares during WW 2 regarding hemp. They had historically used hemp as anchor rope for their ships. The U.S. had one source for the hemp and that was the Philippines. When the Philippine islands fell to the Japanese during the war suddenly we had lost our only source of anchor rope.

After the conclusion of the war my grandfather was approached by the War Department to manage a farm in Honduras that would become the new source of hemp for the navy and their ships. My grandmother wouldn't hear of it - trying to raise two young boys in another country - and my grandfather decided against it. Good thing too. A few years thereafter the navy decided to go with chain for all ships and to heck with the Philippines!

[Bill Baillie]

Thanks for your responses. When I first saw the ad and wondered about using hemp fibre as a replacement for glass, I thought I would laughed off the forum as some kind of stoner.
Yes, hemp fibre and clothing are legal in Canada, but the one store that I visited out of curiosity, seemed to run by people that were just as confused about the difference between Pot and Hemp as the government.
I never thought about the quality of the finish a hemp covering. It might take a lot of filling to get a fair surface, which would defeat the strength to weight ratio claim the the UK grower was promoting. I looked a little farther into the issue and found out that the woven hemp mats are very stiff; much stiffer than chopped strand mat fibreglas, so I wonder if, with closely spaced moulds, a hull could be created of only hemp and epoxy.Probably too much work though.
One additional story: It is legal to purchase marijuana in Canada for medical reasons provided you have a special government license and a prescription from your doctor. The only marijuana that can be purchased legally is grown in an abondoned mine near Winnepeg, Manitoba. The first batch was released about two weeks ago, and the quality was so poor that the patients would buy the government Pot, empty the packages, and get them re-filled by their local pusher.
Thanks for the feed back

[Aramas]

I'm not sure why you think that hemp cloth would give a rough finish. It can be obtained in different weaves from rough burlap style to fine cotton. It really wouldn't be much different to using canvas.
However, that said, I've never heard of it being available in a random mat or biaxial style cloth with uncrimped fibres. It would be very interesting to see serious engineering tests done on appropriate designed cloths. I suspect that the modulus of elasticity might be a problem. The epoxy matrix could fail before the hemp took the load.

Wicca boats - lol.

[ 10-03-2003, 01:14 AM: Message edited by: Aramas ]

[Popeye]

good thread. As a quick aside, I recall a news story, some time ago, about a man in Canada who tried to distil his own methanol to use as fuel. The govt in their paranoia and gov't-like wisdom conficated his still.

Yes, Hemp is confused with cannabis leaves and flowers, this is like mixing up poppys and heroin. I think a marketing strategy is in order to rename hemp products into some benign trade name, say for example, i dunno, doobie-fiber or hash-lar.

By yet another example Kevlar is an organic material, yet has no stigma attached to its uses. Also, a little of topic, forgive me, has anyone seen bamboo used in flooring?

[Skiff Junkie]

One word - DuPont.

[Bill Baillie]

To Popeye:
There was a store in Toronto that sold bamboo processed into planks for flooring. I saw a sample and it was a very light colour, very stiff and hard enough to be walked on. Nice looking stuff too. It was laminated up from sections of large bamboo canes but the people in the store were unable to tell me what adhesive was used. I suspect epoxy or maybe polyester because there were no easily visible glue lines.
I wonder if laminated bamboo would have good properties for boat building? It is light and stiff, comes in long lengths and grows fast. However I have no idea about its' rot resistance, modulus of elasticity etc etc. Does anyone have any information?

[Johannah]

Another name, oddly enough: William Randolph Hearst. This important fibre has been surpressed for so long by pressure to reduce competition that people have come to believe the banning of hemp agriculture is related to drug problems. Only because memory is so short. But that relationship has made it difficult to reintroduce the industry. Very frustrating for farmers who could make a living from hemp. Look up the story of hemp agriculture in the 1700's.

Truth to tell, I don't miss the blisters from using manilla lines.

[ 10-03-2003, 02:03 PM: Message edited by: Johannah ]

[Andrew Craig-Bennett]

Manila is not the same as hemp - manila is musa textilis which is a different plant, yielding a different fibre.

In Britain we can still get both hemp and manila rope - made by Chatham Historic Dockyard's eighteenth century Naval ropewalk.

We have no ban on growing the hemp plant but it won't grow in our climate. Italian hemp was reckoned to be the best, but Indian was cheaper.

The Manila rope industry was pretty much shot to bits by the adoption of artificial fibre rope aboard merchant ships, in the 1960's.

[T.KAMILA]

How about Bamboo?

http://www.bamboosurfboards.com.au/boards.htm

Tom

[Johannah]

Oooooops, thank you Andrew! And me a botanist, oh well. redface.gif

[warwick]

I beleive the hemp for rope etc is canabis indica, the stuff that is smoked is canabis sativa.

[Andrew Craig-Bennett]

The Chinese use shredded bamboo for caulking; I have a sample, given me by Jerry Sousa last time I was in Hong Kong.