glass layup

[conyermud]

Hi, I've just bought a mould for a 10' pram dinghy. I am experienced in wooden dinghy construction and am looking to try out a glass number. Can anyone advise on the correct weights of cloth to use and suggest how many layers etc.?? I envisage around 6 hp. outboard and a max load of around 450lbs gross. I will be laying up with polyester resin. Cheers all.
conyermud

[makeitfly]

Hi have you had any reply's as to the glass to use ?

[conyermud]

hi, no, had no replies as yet, thanks for your interest.
Gordon Inwood

[rxcomposite]

Originally Posted by conyermud

Can anyone advise on the correct weights of cloth to use and suggest how many layers etc.?? I envisage around 6 hp. outboard and a max load of around 450lbs gross.

What is the breadth? Is it a flat bottom or is there some amount of deadrise? I will try to run some numbers for you.

Rx

[conyermud]

Hi, thanks so much for the offer of help. The mould is around 48'' wide at the lowest chine, it is a very shallow vee, noticeably rockered along its length. Do you need anything else??
conyermud

[makeitfly]

A simple lay up for a dinghy
1 -GEL COAT ALL OVER 2 COATS IF BRUSHING
2 -1 450 GRAM CSM TO COVER GEL AS THE FIRST SKIN
3 -1 450 GRAM CSM + 760 GRAM WOVEN CLOTH OR A FABRIC OF THE SAME WEIGHT ALL OVER . OVERLAPS ALONG THE CHINE AND ALONG THE LENGHT OF THE KEEL . DO THE BOTTOM FIRST AND LAP THE TOP SIDES AND TRANSON INTO THE BOTTOM
ALL OVER LAPS SHOULD BE 50MM OR MORE
4 -A SECOND LAYER FOR THE BOTTOM ONLY -1 CSM 450 + ANOTHER WOVEN MATT TO FINISH
WOVEN MAT HAS A 150GRAM SCM ON ONE SIDE SO MAKE THE CSM FACE UP WHEN YOU LAY THE LAST ONE .
THE TRANSOM NEEDS PLY TO HOLD THE OUTBOARD .
WILL GET BACK TO YOU WITH THAT ONE

[conyermud]

You star.. thanks so much for the help. I can start working out areas and getting a buying list together now!!
Conyermud

[makeitfly]

Originally Posted by conyermud

You star.. thanks so much for the help. I can start working out areas and getting a buying list together now!!
Conyermud

Woven matt has a 150gram csm on one side ,this saves time and resin when doing a series of layups .
Stitched fabrics are inclined to shear between the glass layers under hard impacts
The transom need to be strong with a finished thickness of around 40mm +. It needs to be robust enough for a 10 hp outboard at least . Build it strong so it will last the distance . Never underbuild a small boat