Tomorrow from college I am going to get a large peace of foam to shape out a micro cat hull. It has been advised to go over 21 inches. The foam will be about 25 inches by 15 inches by about 4 inches.
I will be running 6-8 sub-c cells in the hull and a 19t double motor. i want to get the most speed possible.
After the shape has been shaped I am going to coat the foam to strengthen it or fibreglass it but I would prefer to just coat it but could be swayed.
What would be lighter out of coated and fibre glass and which would have better results?
Also any tips on shape of hull and anyone got any plans? (i say plans a while back for a small cat on here but cant find them)
Also any tips on setting up surface drive?
And any general tips that will help me out and stop me making a hash of it would be much appreciated.
Sorry if any of this has been covered before but if it has if you could post the links it would be very helpful.
Thank You
Alex

when fiberglassing, you should use either epoxy resin, or cover the hull in aluminum tape to keep the foam from melting (polyester resin eats up foam, but epoxy resin dont..)

i think i will go for fibreglassing it as it will be stronger and easier to mount the hardware to.
thanks

could someone explain the different shapes of cat hulls and the benifits and so on also?

If you want a micro cat go to BBY or Blew By You Boatworks I got one and love it. You can take a look at it on RumRunner Racing.

I have just built the XSCat by J. Turner plan available fro Traplet https://sslrelay.com/s84068217.onean...dex.shopscript

The sponsons are foam cores covered with 1/32 ply but glass would work too, you could probably cut the center section from foam as well. I shortened it to 24in too fit my foam and widened the center section to take a 700 and 12 cells, as I plan to race in a restricted class (SWAMBC F4). Last weekend I ran it with a Mega 22/20/2 and 12 GP3300's to find the limits of the handling, it was quite rapid (mid 30's) and I found the rear limit for the c of g !

PINZA - Nice looking Cat. Love the scratch builds. I also built a Jay Turner Cat (XL Cat)... well 2. It is basically the same overall design as yours but it is built lighter and a little smaller for 6-7 cells. I also added steps to the design, which made it noticably faster than my other one without steps. It is an excellent handling boat.

nice cats, thanks for the tips you 2.
i started work this morning and have got a lot further that i thought i would.
i have taken picture as i go, so under here is the pics in order of what i did.
i used a table saw for all of this work, as advised by my dad which i was very please with as it saved me loads of sanding.
and yes i know, it does look like a tunnel hull at the moment, i thought that but i promise it will soon look like a cat.
i am taking different parts from all different cats, like i am having the cockpit like jdoug(raised a bit) and trying to copy the front of PINZA cat, as it looks smooth but have not started the main shaping yet, any how, heres what i have done so far:

heres were i am up to now:

p.s. i have to do dam revision now so will have to wait till later.

Very nice!!!.
SO you don't need my plans any more ?

no, sorry, i thought i would just give it a go. it still needs lots of work.
What do the think of the shape of the sponsons?
will they cut the water ok?
thanks

Judging from the picture.
They are nice and wide. SO it will hold up nicely. the length is Ok. and .
I would add one strake to each of the sponsors to keep it more straight and hold better in the turns.

strake?

Look on the bottom of a V hull. You will see 2 or 4 lines on the hull that protrude from the V of the hull, and the run about 1/2 length of the boat
Those are strakes

you can see 4 stakes along the bottom of that hull

ah thanks, sorry i am new to this hobby, so dont know all the terms.
if you have got time could you put on some strakes on the picture of the hull upside down, showing where you would put them?
if not could you describe where?
thanks

how far from the inside edge would you say and also, how would you do it, either add a bi on or sand the rest down?
thanks

i don't know the hull you made so it would be hard to determine. Try just in the middle .

ok, is there any way of telling where to put them?
how would you do it, either add a bit on or sand the rest down?
thanks alot

I don't understand.
There is no really way of how to put them on. But they are only effective when they are in the water. So find a place that they will touch water most of the time and then mount them their.

ok,
what i meant was, how would you add strakes, would you add something, or sand the bottom away and leave the strakes?
sorry for bad wording, it made sense to me, as i was writing it. but i dont think anyone else had a chance.
thanks for all this help

i have done most of the finishing touches on the hull now, i just need to add a stake on each sponson and it will be ready for fibregalssing.
i have set a myself a 3lbs limit to keep to, rtr. (1.4kg).
the hull at the moment only weighs 5oz. i wish i could keep it that low, with fibreglass on. i am going to use fibreglass tissue, as it is very thing and i am going to leave most of it in anyway. hopefully i will keep under 12oz. for the hull, wihout any gear.

cool.
But why is the hull rounded ?
Most hulls are straight they preform better and tack straighter.

dam, i didnt know

will it make it alot slower?

it wont make it slower it will just skip and slide in the turns

ah, ok,
so shall i make the egdes sharp again?
just the bottom ones though yeah?