Fiberglass type

Hi all
Is Fiberglass fabric G390T2 good for bottom of 7 meter long and 1.8 m wide sailboat foam core?
TECHNICAL CHARACTERISTICS
Areal weight: 390 g / m2
Weaving style: Twill 2X2
Width: 1.26 meter
Warp type of yarn: Glass fiber EC13 272
Weft type of yarn: Glass fiber EC11 272
Warp reinforcement ratio: 52%
Weft reinforcement ratio: 48%
Warp thread count: 7.5 ends (threads) / cm
Weft thread count: 6.8 ends (threads) / cm
Best regards

Update, flowing my question, after reading your comment I decided to abandoned the thought of Fiberglass fabric G390T2 in my project.
Best regards.

 

Sounds like a fun project, but perhaps more questions before there are good answers:
How many layers of fiberglass on each side of the core?
What foam (type/thickness) for the core? Does the boat have structure like bulkheads, stringers, etc?
If boat was designed by someone else, what do they say?

 

Twill is an expensive cloth for finish or light structures like sailboards. A boat hull structure has to be designed for the expected stresses. There is no way to answer the question properly. As a designer, you have to decide how thick the laminate needs to be. From that, the amount of layers (depending on the fabric weight and type) will be specified. In general, the thickest possible fabric is used. That is the most economic and fast layup. Is this a sailboat you are attempting to design?

 

The boat is inspired from flatbottom skiff.
Pvc foam 80, 20mm at bottom and pvc foam 60, 15mm sides and deck. I didn't ordered yet because I want to order the materials together from the supplier in Greece called fibermax.eu
The boat has bulkheads and stringers.

 

It is a sailboat.
I was thinking to use pvc foam 80, 20mm for bottom and pvc foam 60, 15mm for the sides and deck,
What thickness would you think would be a good mach for this sailboat?

 

It all depends on the design. You have to calculate the stresses on the hull and deck, etc. first. That drives the laminate schedule and core selection. It is irrelevant whether it is a sailboat, a p0werboat, or a pool. As a designer, you need to do the calculations. Otherwise, you could copy the scantlings of a similar boat. That works for designs that are not at the extreme of light weight and heavy loads. Also, thicknesses vary according to the location. For example, the mast step and shroud/stays attachment points will probably need reinforcement and backing plates for the fasteners. I assume from you questions that you are attempting to design your own boat, and then build it.

 

I understand.
Yes, I did design my own boat because I could not find any sailboat that has the dimensions I wanted and I wanted to be flat bottom with wide transom that gradually tapering towards bow, with fine bow. With vertical sides.
If there is something 7 m to 1.8 m wedge shape I be interested.
I will try to calculate how wich fiberglass do I need and how heavy it should be.
Thank you so much for your information.

 

I guess it is easy enough to understand you are asking an impossible question with so few details provided. I am thinking something like this might help you to calculate your own schedule. Also there might be online resources specific to the materials you are using.
The Elements of Boat Strength: for Builders, Designers, and Owners. - cached - the Boat Design and Boat Building Directory https://directory.boatdesign.net/detail/517.php

 

Thank you for the link.
I have the pvc foam sheer strength and I have the data sheet of the deferent fiber glass , just I need to know which fiber glass to choose for the boat that I want to build with pvc foam 80, 20mm for bottom and pvc 60 , 15 mm for sides and deck.
The amount of strength that the boat need indoor will sailing in deferent speed and conditions.

 

To reiterate. You, as the designer, have to calculate the stresses that each part will be subjected to. Also, how much deflection is allowable. In smaller boats stiffness is one of the main driving factors. You, as the designer, calculate and define all that. Then, if you ask for a laminate that can deflect no more than x when a force y is applied, we can give you a relevant answer. Can you at least post a picture to understand what you mean by "wedge shaped"?

 

This is the Shape of the boat from top view. 7 m (23 ft ) long 1.8 meter wide at the water line flatbottom. 20 mm thickness pvc foam 80 for bottom and 15mm thickness for the sides and deck.

 

What is the reason behind the unusual shape?

 

This shape reduces wave making drag, increase stability , and planing downwind. This shape is common in Lenj and dhow also Mike waters arrowhead 40 concept is a similar shape, which I liked.
It is easy to build. With straight lines and flat bottom. I prefer to have good amount of space aft in the boat it will help more load caring capacity at the aft where the cockpit will be and my fishing geers.

 

You are absolutely wrong. But hey, prove everyone wrong. Build it and see.

 

Everything that I sail was rong or there was something that was right?
I appreciate if you point them out.