2 replies to this topic

[midridge2]

many times on the forum its said the f/g is stronger than steel in relation to flip fronts.
the genera theory is weight for weight f/g is stronger than steel.
weight wise a 1 foot square sheet of f/g would need to be really thick to be stronger than the same size of 21swg steel.
i presume a flip front is made with one layer of 3ounce matting, this over the gell coat gives about three to four times the thickness of the 21swg steel, how thick would the f/g need to be to give the same weight as the steel?

[l_jonez]

not sure on the actual strength but i'd prefer steel if the worst where to happen as it crunples which absorbs energy rather than splinter like fibreglass

[The Matt]

Simple answer:

There are that many different manufacturers of flip front that it's hard to call it. I've seen some really shoddy glassfibre panels in my time from people that call themselves "experts".


I wonder what testing has gone into the people's opinions that state that a GRP front is stronger than a steel one? My GRP front is wobbly as hell, not anywhere near as stiff as a steel variant and that's a good 6mm thick, but then again, it's closer to 10mm thick in places.

I've seen a lot of test data for GRP shells, but that data was analysing a cloth layup, with (IIRC) 3 layers on different biases.

I don't think that a lot of the "experts" are actually experts when it comes to it! I think they're people who do a good job of laying up materials and making them look pretty, but I don't think much design or testing goes into it at all.