The RAZOR

Phill, great picts. thanks for keeping us updated on you project. In the last picture where the hull halves are being joined up, could you post a picture of the underside of the hull? I am interested in the way you shape them, is there a cutout piece, like an outside bulkhead, to hold the shape? And are the two narrow strips across the bottom stitched to the side panels, like a stitch and glue kayak?

Also, on a completely unrelated topic, our media finally picked up on your wild fires, awful picture, 130+ dead, etc. My thoughts and prayers are with you all down there, I hope you get some rain soon, they did mention it was flooding in the north but no relief down south.

Tim,
There are 4 frames made from scrap timber. These are used to sit the panels in while they are wired together. The frames are not the shape of the hull but they are designed to make sure the panels join at the correct angle for the intended shape which is formed later when the bulkheads and subdeck are added.
It looks very box like right now but hopefully that will change.
It is stitch and glue like building a kayak.I think the photos you are asking about are in the catsailor photo albumn
and the link below should take you there.
http://www.catsailor.com/gallery/index.php?cat=10302

Let me know if they don't cover what you want to see.
***
The fires are bad news.
The people of NSW and Vic are all hoping for rain. Victoria is in flames and will be for weeks- already it is the worst natural disaster in the countries history in Victoria.

On the other hand the people in Queensland want the rain to stop- with record 12 metres of flood waters in places.

Regards,
Phill

Ahh yes, those are great pictures and answer most of my questions, worth well more than 1,000 words! Now, are the hulls fully symetric, as in, you build port/starboard exactly like the other, or is there a separate port/starbord hull and frame set? It looks symetric in the photos but I wasn't sure.

I really need to clean out my garage, get rid of all the kid's old bikes, trikes, etc. and start a project like this, but I think (since I already have a Blade) I would like to try a 20' trimaran. Build the center hull only, and use old Inter 20 hulls for the amas and rig/sails.

Tim,
They are symetrical.
You could always dig up a set of plans for a Farrier Trailer Tri 680 (22ft) and just build the centre hull or better still build the lot. The amas on those were a very simple shape and would be pretty simple to build. I have a friend with a 720 and he and his family get a lot of use from it. Although his later designs are much faster. Having a boat that you can sleep on and rig in 20 mins would be a great family boat. I know you have a lake house so the rigging may not be an issue but it may open up other options.

Regards,
Phill

Phil,

I am fascinated with what one can do with stitch and glue.

Some question...

why did you butt strap the bottom panels after stitching instead of scarphing them before?

why is this a faster method to build than the standard Blade method?

or are you just expecting better speed because of the chines?

regards

xuraax (currently building my own version of the Blade)

xuraax,
The Razor is about simplifying the building and the butt strap joint is simpler than the scarf. The keel panels are flat and do not need a scarf joint. In hindsight I think the side panels will take a butt strap joint too. The curve will not be that great and the joint can probably be made of after curve is induced.
Along the same lines the chines are easier than steaming the hull to coach the ply to take the intended shape. This design is much less stressful for both the builder and the ply.

Regards,
Phill

i actually did not need to steam the panels to coax them to bend. What I did was to bend the hulls as far as I dared and then left the wood to settle into the new shape for some hours. then i squeezed some more.

Thank you so much for designing this! As soon as I get out of grad. school and resume having a

real

income, I'm building one. By the way, I vote for butt joints all the way! They're so easy.

I built two stitch-and-glue boats from Bateau.com, and I've been incredibly impressed with that method. I don't have the patience or attention to detail required for tortured ply, but stitch and glue is right up my alley.

Folks,
I've not touched the Razor since February.
I've been busy with outside home improvements.
But since it has been raining so much lately I thought I'd take the opportunity to get back to it. So I put a couple more pics into my albumn. Just some shots of the keel glassed. It starts to give a bit of an idea of the under water shape.

Regards,
Phill

Phill,

it will be interesting to see your approach for putting the sides on, or are they already in place? Pretty hard to tell much from the picture really, but it do look kind of flat <img src="<>/grin.gif" alt="grin" title="grin" height="15" width="15" />

Folks,
I shelved the RAZOR project for quite a while. Just too many other projects going so it has been sitting in my workshop gathering dust.
A few weeks back I decided to get back to it.
I undercoated the hulls today.

The building has been fun. Really just like the 2 CLC 18 kayaks I built a few years back.

Regards,
Phill

Photos or it didn't happen!

It used to be easy to add photos now it is a pain in the butt!
I'll see what I can do.

Razor Hull1

Razor Hull2

Razor Hull3

Hobie might love you but I don't.

Phil- Right click your photo on Flickr, select properties, then highlight and copy the address. Put the address between this:

That's nice. I DO like those bows Phill!

How flat is the run aft?

John,
It's one thing to design something on a computer screen but quite another to build it and see it unfold in the flesh.
One of the joys that I will never tire of when prototyping designs.
I'm quite excited by what I'm seeing in real life and it will be great to see the Razor in full flight. I've sent you some pics. If you want any others just let me know.
I'll post some more pics once the hulls have some proper paint on them.

Regards,
Phill

Hi Phill
Congratulations. Those hulls look extremely impressive and can't wait to see more photo's.
I just 1.5 questions;
What are the main design differences between the Blade and Razor and what are the major construction differences when building in Ply.

Mark,
Was that 1 or 5 questions? <img src="<>/smile.gif" alt="smile" title="smile" height="15" width="15" />

This is a chined version of the second generation hull shape.

It is considerabley more bouyant than the earlier Blade shape particularly forward of the front beam.
The relatively flat bottoms of the hull are now converted to chines.
This should deliver even more dynamic lift off the breese. The additional fore/aft stability will allow the crew to trim upwind for min drag and the sharper bows will slice very efficiently through the chop. There is no steaming required to achieve this shape and very little fairing so building can be from either ply or foam glass sandwich. The insides construction has been significantly simplified. It is no harder than building a pair of kayaks. I found it all just good fun. But I like this type of stuff.
Regards,
Phill

Brilliant Phill, I had feared never seeing the Razor build but I'm very happen to see otherwise. I feel this design is an excellent development.

Well done indeed, looks good.

Wouter

Phil,

do you see this method being useful for building to the 8.5M class or bigger using thicker ply?

regards

What many forget is ply was the most advanced high tech solution, (and with the correct skills, still is), up till the Kiwi's (Jennifer Julian) started using cores in glass boats.. The US & Europe were at that time using solid glass boats or cold molding.. The impoverished kiwis and Aussies builders could not afford the expensive materials of resin and glass. er But what they did have is many learnt the trade of building Aussie and kiwi WW2 planes. And good supplies of quality ply.

If you look around there are pages and pages of historical documents of well build offshore races built out of ply.. So the answer.. is yes a 8.5 meter cat could be built from ply if the builder has a good skill set and ply is available.. Its no longer as available as in the 70s and quality has become an issue as well..

Like Stewart says!
Apart from basic skills the biggest problem would be getting good quality ply. The stuff coming out of China may not be so good but there is a French company still making the good stuff. You really would be better off getting BS1088 quality ply. Read the specs and check the ply yourself to make sure it conforms before buying.
Alternatively you could use the same method and build from foam sandwich.
Good luck.

Don't mean to thread hijack but ply 8.5s are still being built, from reading the forums at crew.org.nz a ply boat 'atttude' is one of the fastest and lightest.

You don't fancy designing an 8.5 Phill, I hear there is some interest in Oz!

An 8.5 would be fun.

I need no convincing that good ply is still a good way to build boats. I own a self build Micro and despite the fact that it is now 15 years old it requires very little maintenance.

The reason I wrote earlier is that I would like to build a larger more modern design but I would prefer to avoid double diagonal or strip building.

Indeed I do know about the efforts in NZ and am particularly impressed with

Attitude

which I understand is built from stressed ply.

Unfortunately I could find very little info about their building methods on the WWW so if Phil decides to take on the project I would very likely be interested.

Regards

http://perverted-moth.blogspot.com/

basically a ply construction, but with carbon foam sandwich panels instead.

There was a boat here (think she is in Sydney? now) called wings. a 36'foot stressed ply river racer.. Basically a ply 18' skiff with the wings stretched to 36'. Very quick..
The only issue with ply is compound curves..