if you are looking for structural stuff then there is plenty of books about aerospace composites and design. Lots and lots of equations and not a lot about the practical side of it, the rest of the information with aerospace is in documents but the public dont get access to them.

Ok mate. Think I'm looking fo a education into composite materials. In particular the structural side of things. I want to learn more about the material and it's properties. 

I don't know if you'll find a copy online but ISO 12215-5 is the ISO Standard for hull construction of small craft.

So is there a website that would have this information? The examples you have do sound familiar. In a lot of situations I've found in boat building you appear to over compensate with adding extra Matt in areas/situations that probably don't require it. 

However, the boat building industry is backwards in coming forwards in terms of materials and technique advancements - panel thickness for example can be dramatically decreased by manufacturing under vacuum - a wet laid panel will be 20-50% thicker than a panel produced under vacuum but in the marine industry, thickness is key so despite producing a panel of at least equal strength for less weight and better consolidation, you would (in many marine cases) need to increase the number of layers to achieve the same thickness as you would do without vacuum which starts to somewhat defeat the object.

In the boat building industry, composite production points such as overlaps, number of layers and fibre orientation is driven by specific rules and regulations; under 24m in length, this will generally reference the Recreation Craft Directive which in turn will draw on specific ISO codes of practice/standard or in the event of Commercial Craft will draw on the rules of one of the certifying authorities such as Lloyds, Bureau Veritas or DNV GL as examples. The rules determine the construction requirements but give leeway for things like panel size versus panel thickness; i.e. you can opt for less structure within a hull if you increase the shell thickness or by virtue, decrease the skin thickness and increase the amount of internal structure which gives a fine balancing act to find the optimised weight.

Yeah I get that, in this industry you often don't learn why you just learn how. For me it would just be nice to know why we use certain weaves in a certain order. Or can you butt join Matt as long as your overlapping with another layer. Or minimum staggers over joins in lay ups. It's difficult to get answers because everyone has different ones. As I've only worked in the boatbuilding industry it's hard becuase aerospace and motorsport have a very different standard it seems. Was just looking for more of an education on tolerances and why we do certain things. 

As mentioned, Hexcel do some good guides to general material properties, nomenclature etc which can be useful - albeit based around their own product ranges as you would expect. Gurit do another very good introduction guide.


A good point Scott has mentioned is that a lot of the knowledge is rules of thumb and passed down experience as to what works.   Although that will rarely give you a precise technical answer when in a structurally critical application, it is often a good starting point from which you can make changes from.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Most of the learning is actually doing the job, very little is written down on the applications of it. Theres lots about lamina theory and design specs and material data sheets but a lot of the knowledge is in people heads.

Cheers for the reply,