foam build - rocker by heating foam

[merl]

Success. I have H75 25mm thick foam (from easycomposites, likely very similar to divinycell) and I put a 450x540 piece in a domestic oven for 12 minutes at 110C. There is no drama here - the foam is not visibly affected. I quickly clamped it down and let it cool for 15 minutes. I got 5cm of rocker. I repeated the process and added a few cm more.

The main surprise was that the foam shrank by around 1cm.

The first time I couldn't shut the door so I used foil to keep in the heat.

[Herman]

Nice job. If I remember correctly most (maybe even all) materials based on long carbon chain molecules will shrink with heat. Cross linking of the molecular structure can greatly reduce the shrinkage. I think basically the molecules like to curl up and cross linking of covalent bonds only reduce this effect. Old style crisp packets used to come out not much bigger than a postage stamp if given a bake. I presume this would be applicable to dyneema as well.