thickness of the body

[bathtubbuilder]

I'M EXPIRIENCED WITH COMPOSITE MATERIALS BUT STILL HAVE PROBLEM.CAN MEMBERS HELP ME WITH AVERAGE THIKNES OF FIBREGLASS BODY , PLEASE.
I READ SOMEWHERE THAT THEY ARE BILD FROM 2-3 LAYERS OF VERY THIN LAYERS OF MATT NO MORE THAN 100 GRAMS IN ALL 3 LAYERS TOGETHER.
I KNOW THAT BODY NEEDS TO BE LIGHT -FOR BETTER PERFORMANCE - BUT THINER WOULDN'T BE GOOD.
HOW THICK IS BODY AT THE ENDS

THANKS


SORRY FOR SPELLING MY SPELLCHECK IS NOT INSTALLED.

[andy]

There is a balance, when you start making the body too thick it then needs extra strength to support the extra weight.

Then there is the pannel size and shape.... for instance a bath is curved etc so will have strength in the shape so could be thinner... however a flat panel will have little shape strength so may have to be thicker.

I guess I will make mine 3layers and go thicker where I think it needs extra.

[bathtubbuilder]

Thanks for your post.
Yes I realise that flat surfice will suffer from torsional moment - twisting
(more than different shape 3 dimensional) and I will use sandwitch construction for better resistant.
And you are right - in my opinion 3 layers are ideal for the job.

However 3 layers of 100gr and 3 layers of 300-450 gr matt is going to result with different thickness of laminate.
That's why I ask members for help , to see how thick proffesional body is.
And there, where you can see the thickness of laminate is for shure that - that is stronger part with 1-2 layers more than on the rest of the body (archers over the tires, hood asamble, etc) or if the kit is from "brand" kit car factory - thats is how this has to be done.

[Davi]

The clam wings my father purchased for his build (the only part he did buy) were about 2 - 4mm thick, being 4mm or so at the edges but rapidly narrowing to 2mm (ish) for the main panel bulk.

As to how many layers you build up of what, The panel will be MUCH stronger if you build up of a higher number of thinner layers than by just using 3 layers to make your required thickness. I tend to use a layer of 30 to 80gm plain weave cloth for the layer immediately under the gel coat, and like to total between 3 and 5 layers as average for general lay up, but can go to 7 layers or more. Of course it'll vary depending on complexity of shape as well. I find I can also build much lighter this way, and coupled to a vacuum bag you can reduce the weight of a panel by half or even more.

Something to bear in mind - if the panel allows it, using a hard foam insert between layers will allow you to build lighter and thinner. (I get mine from the local boat builders yard)

[JG]

Kitcarman would be a good one to answer this being an ex-manufacturer and all that.

I think it's pretty much what's been said already but I guess you just need to calculate/identify where there may be stresses and build those areas up accordingly.

My Sumo typically was around 3mm I would guess + gel coat but considerably thicker in certain areas (hinge points for example)

I don't know what layup was used but with any luck Den will see this and be able to offer a more detailed view.

John

Madabout-Kitcars