Composite portable playscape

I’m in a Live Action Roleplaying Game. It’s kind of like playing Dungeons & Dragons like paintball with foam padded swords. We play in public parks and often rent out private or public campgrounds for large events.

Here’s the thing. I’d like to make a transportable castle which we can fight on. The challenge is going to be a tower platform. Ideally I’d like a 5 ft x 5 ft platform up 8 ft high, with some additional protective wall around it. It should hold two people under aggressive movement and with no wobble. I also would like to make a walkable span over the gate if it all possible.

I want this not only light, but the parts should lie as flat as possible for transport. I do have some composite experience. My initial plan is for a core of 1" styrofoam wallboard, faced with fiberglass. I’ve used 8 oz cloth before, but now I have found a deal on lots of 24 oz woven roving.

Does this sound strong enough for a platform? Is the 24 oz a good idea? Is thicker glass even useful, or will the glass separate from the core under high impact negating the benefit of stronger glass? I don’t vacuum bag, will the coarser nature of this thick weave create poor contact on the bond line?

Having corner joints I can disassemble is another issue. I’m sure bolts would be too much of a point load and tear through the material. I came up with the idea of doing corners just like a door hinge, where loops on each side mesh together and a pin is dropped in. The overall geometry of the structure would need to prevent the hinge from hinging around. Anybody got a better idea? This type of joint is going to be a great deal of work to make.

Vacuum bagging is not necessary. I would recommend polyurethane foam over styrofoam however. 24oz should be fine if you encase the foam board completely. To keep it from delamination, just drill perforated holes into the foam board. The holes do not have to be big.

Why polyurethane? Due to the large areas involved, and the possibility that it won’t work the first time around, I’m trying to keep the costs down.

Drilling holes? I’m not familiar with that one- could you provide a reference on the web for this procedure?

I assume we’re talking about drilling the core material before putting the glass on top, to give it more features to grab onto? How far apart should they be? Is it really that good at prevent delam?

If you’re using vinyl ester or polyester resin then the styrene content in the resin will melt away your styrofoam. The only thing styrofoam is compatible with is epoxy. Yes I was referring to drilling the holes in the foam board, not the final laminate. This allows resin to bleed through and bridge. You can also score valleys into the foam blanks as well.

Here’s a good example of the scoring. Of course you don’t need to score it that deep.

I would drill the holes (1/8" diameter) about 1.5" apart. Drilling and scoring might be excessive. Just choose what might work better for you. I would do a small 4’x4’ test panel and go from there.

I’ll be using epoxy. It’s what I know best. Do the holes go all the way through? It seems like this would constitute an awful lot of extra resin, plus just the 5 ft square platform would be 1600 holes.

Does 1" styro core sound good for a platform of this size? I might be able to go thicker if necessary, but it is less desirable.