| I think it's a good idea. I've been thinking about it as well. But it's a lot of manual work, and maybe this stiffness isn't needed.

I think it is a silly idea. No offence intended, but we don't even know what problem we are trying to solve.

While a cheap substance like XPS might work as a filler material for a fiberglass shape that might have enough compressive strength and other material parameters, we don't really know what those are and how to begin designing them.

I can also imagine laminating a full foam sheet both sides with Uni glass, and cut 'thickness of core' mm slices off the ends, leaving upright uni glass. Rack that in a sandwich with unglassed foam, leaving glass perpendicular to the final surface at regular intervals.

That's got to have awesome compressive strength!

But its a lot of guessing for what gain? You are trading a known and proven system for a guess at a system that might be cheaper in cost, but certainly not in time.

If you reexamine the boat design thread linked in the XP thread, it gives a link to a design guide that shows H100 is way higher spec than we need. Groper shows that at
https://www.boatdesign.net/threads/extruded-polystyrene-xps.24213/page-3#post-501739
The 700kpa cores should be good for 50' cats.

The whole advantage of a foam core it is contiguous. Its the same all along. While ribs can be used, the problem is the structure must be correspondingly over built, because BETWEEN the strong spots is weak. This is what must be done with honeycomb. One makes the skin stronger to bridge the gaps. But note making the skin stronger costs however much more, doubled. Once for each side. My point here is these extra costs soon outpace the cost of better foam.

It is entirely possible for such a structure to be lighter and stronger than a foam structure. But it is often found to not be, and to be much more expensive when it is.

Intelligent infusion is way cheaper than any other boat building system I know of. But I know nothing. Also, Rob builds boats cheaper than anyone. Afaik.

Now Rob is looking to drop that cost by a significant amount, going so far as to acquire a material from for in lands, not easily available to him to look at testing to save builders money. If you are looking to build a cheap boat, I would bet on Rob.

Now I love yammering about boats. And probably about how to build boats better and cheaper even more. But the idea that there is a cheaper way to build them appreciably better than II is silly. But I will talk all day about it. Anything is better than thinking about babies in concentration camps.

My only problem with the current discussion is the lack of math being used to actually quantify the discussion.

Do i need to send that hexel composite design guide again?

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