building mold and boat from scratch need help

[marbleman]

I am planning on building a boat for my son I wont have a problem with building the plug or the mold but, as I build my own molds for my shop, but I have a few questions as far a the actual part. I am building a 14ft. pirouge for my 12 year old son to play with also hoping that he takes intrest in it. How many layers of fiberglass do I use and what type and size mat do i go with. should i start wit a 1/2 oz mat? and gradually get bigger? I dont want the boat to get to heavy. Also I use ccp resin with my shop is their fiberglass resin as good in quality? probably a dumb question!! Do I use mat or woven? Thats all the questions I have for now. Any insight or advice would be greatly appreciated.

[JEM]

That's a lot of trouble just for a simple pirogue. But it sounds like you have a shop set up for that type work.

Anyway, a lot depends on if you plan to use any sort of stiffening ribs in your hulls because stiffness will be the key in this type paddle boat. I'd think woven will offer a little more stiffness in this application. Maybe you'll need to just experiment. Some woven sandwiched between 1/2 ounce mat would be a good start. (woven for stiffness and mat for finish).

Let us know your results!

[lewisboats]

http://www.bateau.com/freeplans.php

Small pirogue...it takes about a weekend to knock together, will be lighter (about 35 lbs) than a frp molded one and cost many bucks less, specially ifn he don't take to it. Kinda like my son...built him a ScoutCanu (see pics) and he/we used it a couple of times then there was no interest.

Steve

[marbleman]

Thank you for your replies.
What size woven should I use? Two bench seats will strenghthen the sides of the boat. I know it is a lot of trouble to build, but I have six other people who want one if I build it. More than being interested in the just boat I am hoping my son would take interest in making them.

If I sandwich woven between two layers of mat making it 3 layers should that be sufficient? To me that doesnt seem like it would be strong enough, but like I said this is not my area of expertise. I overbuild my molds because I dont have the expierience to know when it is strong enough.

[JEM]

Disclaimer: this is not my area of expertise. :p I'm more of the experimental type. A lot will have to do with what you have on hand, cost trade offs, etc.

I'd think 2 layers of 18 ounce woven between layeres of mat would be stiff enough for the sides. You might need a 3rd layer for the bottom.

Before you get too far into it, do a some experiments. Lay up a couple of flat panels of varying thickness that have the same width as the hull bottom. See how much it flexes and if you think the bottom will oil-can or flex inward. Incidently, you could help this by adding a slight V. It'll be easier (and cheaper) to get your need hull stiffness.

Also, I'm not sure how easy it is to get woven to go around corners. Someone else will have to offer opinion about that.

[Jeff Therrell]

My layup schedule for this boat would be 2 layers of 1.5 oz. mat 1 layer of 18 oz.woven boat cloth and another layer of 1.5 oz mat.I agree with Matt you may need another layer of woven boat cloth in the floor and maybe a few strips of core foam or for cost savings you could use strips of wood.I'm no expert on this hand lay-up either but from my experience with racing bodies I think this should work fine.
Thanks
Jeff Therrell, Performance Engineered Composites

[marbleman]

Thanks that is what I was wondering about. I will let you know how it goes