need help with a assymetrical cat- plywood and other things

[assycat]

Originally Posted by AsterixDeGaul

Same way you would fair glass or wood ... Sand it hehe

Tomcats Boats has been working on an F32(?) all carbon with corecell.

did you see the trimaran built with the plascore on the plascore site?

check this beauty out!! all plascore...bet shes light!

http://www.plascore.com/pdf/Plascore...utions9.10.pdf

[assycat]

Marc- this is the pet foam one strike--easily holed it --but did not penetrate the other side

[assycat]

this is the nida core- same as core cell...double cut for countouring

[assycat]

this is the balsa core--its heavier but its mega stong and relatively cheap too..noahs has some. i hit that with a hammer without laminates and made only a dent. prob is its friable..meaning it can break up in the laminates..but thats only with heavy pounding over some time...

[assycat]

this is prefiberglass nida core- easiest to hole of all..but i think its only above waterline useage...

[assycat]

the first pic is the 1/8th inch ply without lmainates--i hand broke the piece- you can see how easy it is to break...the second one is sinle laminate--notice the exit marks of the hammer. but it stiffened it up considerably with the laminates- and it still took a good shot to hole...
the third is the double lmainate both sides--this was the strongest of all and at just under a lb per sq ft. not sure how you would use it for a design like yours other than strip planking. but notice the other side--the hammer didnt penetrate it at all--the one hole you see is a hammer shot on that side..its not holed at all from the hammer shots on the opposite side...it cannot be bent by hand or using my feet against the tree as leverage...great stuff...

[assycat]

finally--the plascore-here we have 1/2 inch single laminate--trust me-its strong stuff...this ha a single laminate both side. a veil which is attached to the core when you buy it bonds the laminates to the the core- and limits resin making it very light! the four holes i hd to really hit it hard to hole..the holes did not penetrate the opposite side of the core. imagine two layers!
its almost identical to the nida-core and in my opinion better. i needed no vacuum bagging...it easily layed up by hand...

[AsterixDeGaul]

Thnx for all the info . . . How is your project coming along ?

J've been a little busy with other things these days.

[assycat]

Hi- sorry its been so long--my project is still waiting until i get the plascore.
I am finishing off another boat i built this spring. I am hoping to have it launched by august 1st. This boat is a 24 x 9 ft power shanty. using a very small diesel(10 hp) eventually it will be steam powered.

cant wait to start my sailboat though...i may build my p 95 with some mods of my own...

how bout you??..your design was nice..the round D sectioned hull is trusty and proven...

[catsketcher]

Gday Asterix

I was looking through this thread and saw that you were considering using bead and cove strips in Corecell. I built a few tri hulls this way and whilst it built a good hull it was more expensive in materials and tooling than going vertical strip foam. (We tried strip foam but the foam was too thick to bend to the tight radius required so we had to go bead and cove) That being said it was still a nice method to use and produced fair and light hulls. I would put it way ahead of cedar strips. (But I still like working with Cedar - wood is nice)

I find 10mm foam nice and easy to work with. Vertical strips about 300mm wide are easy to bend. I used this method for a 7 metre cat and foamed the hull bottoms up in less than 6 hours. The good thing about foam is that you can fair it before you put the laminate on reducing filler weight. You save money on resin and money on buying strips. You just rip the sheets into 300mm wide strips with a saw.

There are lots of spots on the web that detail vertical strip foaming. Try one of Farrier's F22 building blogs.

cheers

Phil Thompson

[AsterixDeGaul]

Originally Posted by catsketcher

Gday Asterix

I was looking through this thread and saw that you were considering using bead and cove strips in Corecell. I built a few tri hulls this way and whilst it built a good hull it was more expensive in materials and tooling than going vertical strip foam. (We tried strip foam but the foam was too thick to bend to the tight radius required so we had to go bead and cove) That being said it was still a nice method to use and produced fair and light hulls. I would put it way ahead of cedar strips. (But I still like working with Cedar - wood is nice)

I find 10mm foam nice and easy to work with. Vertical strips about 300mm wide are easy to bend.
Phil Thompson

If I am going with corecell, I will make my own bead 'n cove with 12mm foam. I am not a big fan of the vertical strip method because of all the screwing needed to keep the foam in place(female mold). Now I'm wondering if i can use a male mold(plug) with the vertical strip method... Hmmmm? This may tip the ballance on the side of foam

Although Cedar is somewhat heavier, it's unbelievable how much the cedar adds to the overall strength and rigidity of a hull!! I need this thing to be able to sail offshore. I have worked with corecell and a few other foams before and like them well enough but i am really tending to go with cedar

A550-12mm CORECELL can be had in 4' x 8' sheets @ ~$5/square foot

What is cedar worth these days >?

BTW: Corecell can be heat-formed very well.

[catsketcher]

Don't worry about the holes in the foam. You have to put holes in both vertical and bead and cove strips so this aspect doesn't matter. The holes are easily plugged with filler in an hour and sand beautifully. Vertical strip will be easier, cheaper and lighter so it would be my choice unless you go cedar.

cheers

Phil

[AsterixDeGaul]

Originally Posted by catsketcher

Don't worry about the holes in the foam. You have to put holes in both vertical and bead and cove strips so this aspect doesn't matter. The holes are easily plugged with filler in an hour and sand beautifully. Vertical strip will be easier, cheaper and lighter so it would be my choice unless you go cedar.

cheers

Phil

Thnx, much appreciated

It's really looking like cedar @$6/brd foot = ~$4/sqr foot on the cat. I need to cover approx. 600sqr feet for 2 hulls

I have seen the verticle foam strip method done and didn't really like the result.

[redreuben]

If you wish build light and use wood I would use Paulownia (Kiri) rather than cedar and then use the foams or plastic cores for your interior fit out. Use high gloss melamine sheet as a mould and lay them all up. Kiri can also be purchased in laminated sheets or coved strips.
RR

[peterchech]

It is not easy to get your hands on kiri in north america, at least it wasn't a year ago when I tried to get some for a hollow surfboard I was making...