Dear All,

I have recently acquired 2 fibreglass kayaks.

Given our lack of storage space, I am considering shortening them.

Has anyone done this before?

I have done some research into glass fibre moulding, and if I was to do
it, was planning on making a male mould that I would leave wedged into
the cut ends and lay the fibre over it. My brother has some experience
of glass fibre moulding and is prepared to advise too.

One is 3900 long, the other 4200 long. The width is around 600mm.

I have calculated the volume of the shorter one as being around 360
litres.

Surely I can afford to lose some volume given that some modern kayaks
are as little as 180 litres and I'm not that heavy?

I read a little somewhere about people shortening plastic kayaks, so I
would have thought this would be more straightforward?

I know it could be quite time consuming and messy but it seems a shame
not to make use of kayaks that would otherwise have been destined for
landfill!

I have had some advice from another couple of forums advising that the
paddling efficiency could be reduced, this is not too much of a problem
as I will only be covering short distances on a placid local river.

I understand that bouyancy and waterline depth will be affected too.

Any thoughts/advice gratefully received!

Regards,

Nick

How about posting pics of them, are they sea kayaks...or perhaps old slalom
racing boats? Either way, if they are being trashed anyway, why not
experiment? From a face value POV, I would keep the ends intact as not to
drastically change the handling characteristics (although any alteration
will do this to some degree) and remove the volume from the middle say just
in front of and just behind the cockpit? Keep it symetrical.



wrote in message
ups.com...
Dear All,

I have recently acquired 2 fibreglass kayaks.

Given our lack of storage space, I am considering shortening them.

Has anyone done this before?

I have done some research into glass fibre moulding, and if I was to do
it, was planning on making a male mould that I would leave wedged into
the cut ends and lay the fibre over it. My brother has some experience
of glass fibre moulding and is prepared to advise too.

One is 3900 long, the other 4200 long. The width is around 600mm.

I have calculated the volume of the shorter one as being around 360
litres.

Surely I can afford to lose some volume given that some modern kayaks
are as little as 180 litres and I'm not that heavy?

I read a little somewhere about people shortening plastic kayaks, so I
would have thought this would be more straightforward?

I know it could be quite time consuming and messy but it seems a shame
not to make use of kayaks that would otherwise have been destined for
landfill!

I have had some advice from another couple of forums advising that the
paddling efficiency could be reduced, this is not too much of a problem
as I will only be covering short distances on a placid local river.

I understand that bouyancy and waterline depth will be affected too.

Any thoughts/advice gratefully received!

Regards,

Nick

Thanks for that, I hadn't thought of cutting them that way!

That might be an easier way of going about it. I'll have another look
at them with that in mind!

As for kayak type, one has Kiwi (Perception?) and Slalom on it so I'd
guess it is an old slalom one as you suggested. The other one is
unmarked.

As you say, I've little to lose by experimenting!

Cheers,

Nick

With the volume in mind, remember that the 180L modern playboats are
very different boats from what you are looking for. They have a flat
bottom, they are very hard to paddle straight (without experience), and
the ends can dive underwater.

That being said, 360L would be fine (I think). An older whitewater
kayak certainly had less volume and never had any buoyancy issues.

I think I remember reading somewhere about someone doing what Grip has
suggested. He cut a foot or two from the middle of his kayak (or
canoe). I'll try and find it.

Have a look at the pictures on these websites and see if your kayak has
a similar design:

http://www.canoeslalom.co.uk/
http://www.jacksonkayak.com/kayaks06/ricochet.cfm

wrote:
Thanks for that, I hadn't thought of cutting them that way!

That might be an easier way of going about it. I'll have another look
at them with that in mind!

As for kayak type, one has Kiwi (Perception?) and Slalom on it so I'd
guess it is an old slalom one as you suggested. The other one is
unmarked.

As you say, I've little to lose by experimenting!

Cheers,

Nick

wrote:

Given our lack of storage space, I am considering shortening them.

Sell them and buy the kayaks you want. I modify kayaks all the time, but
shortening the hull is just a waste of time and money.

Mike

Thanks for the input!

The kayaks are not too different to the ones on the webpages.

They are old though, perhaps 20 years? They came from a local army
cadet unit, so have probably had a hard life!

I'm not trying to create a playboat, just make something more
manageable for our circumstances. Our local river is an old navigation
and as such is not cleared and has many tight spots (fallen branches
and overhanging trees) where a long kayak could get stuck. Plus I enjoy
breathing new life into old things!

Whatever I do with them, they'll need some TLC. I'll continue to
think about it!

If it's generally believed to be a complete waste of time, I'll fix
them up and get rid. Any more information will be appreciated!

Cheers,

Nick

wrote:
Thanks for the input!

The kayaks are not too different to the ones on the webpages.

They are old though, perhaps 20 years? They came from a local army
cadet unit, so have probably had a hard life!

I'm not trying to create a playboat, just make something more
manageable for our circumstances. Our local river is an old navigation
and as such is not cleared and has many tight spots (fallen branches
and overhanging trees) where a long kayak could get stuck. Plus I enjoy
breathing new life into old things!

Whatever I do with them, they'll need some TLC. I'll continue to
think about it!

If it's generally believed to be a complete waste of time, I'll fix
them up and get rid. Any more information will be appreciated!

Cheers,

Nick

I have to agree with Michael. Shortening a kayak is simply not
practical. Bobbing the stem and stern won't work unless the boats have
long overhangs that could be shortened. Cutting a chunk out of the
center and re-joining the resulting pieces probably won't work since the
boats are not likely to have the same hull shape forward and aft of the
cockpit. It's simply not worth the effort as you'll just end up
destroying the boats. The time and money you waste on this project could
be better spent elsewhere. You would be better off to sell the boats or
give them away and buy what you need.

Michael Daly wrote:
wrote:

Given our lack of storage space, I am considering shortening them.

Sell them and buy the kayaks you want. I modify kayaks all the time,
but shortening the hull is just a waste of time and money.

Mike
Agreed as well. Assuming you get the right materials to effect the
repairs, there will still potentially be weaker spots and definitely
make a heavier (and probably quite ugly) boat.
Spiff them up, toss a coat of gelgloss on them, and sell them. Then buy
boats you can store and are usable as they were built.

Marsh

Cutting a piece out of the middle of the hull should be no great
challenge. Just be careful to choose the locations of the joined halves
that they match exaclty. Then sand off the inner surface around the cut
and apply a couple of layers of fibreglass soaked in resin through the
cockpit. Boat builders call it a "butt" join. I've used it in plywood
boats. While the boat is in pieces it should be easy to prepare the
inside, move the foot braces, etc.

The challenge would come in enlarging the cockpit. I don't see how you
can cut a piece out of the middle of a kayak without effecting the
cockpit, and they tend to have moulded coamings to keep out the water
and to allow a spray skirt to be tied on. Before cutting I'd want to
figure out what to do about the cockpit.