Just wonderin what, if any, experiences people have had using something other than fiberglass cloth for the bals/whatever to foam using epoxy lamination?
I know peopl on here have use alternatives (e.g., hemp), but I am wondering at using light alternatives for these beneath-the-wood-only lamming. And still using fiberglass+epoxy over the timber.
I’ve had a really hard time finding light fiberglass cloth locally. best I can do is 2oz - but I have to drive 90 minutes each way to get that. The alternative being mailorder
You can use all sorts of stuff instead of glass - aramids,polyester, polypropylene or hemp fabrics. Thing is you’d have to be careful about matching up the properties of all your sandwich ingredients otherwise one component will fail if not supported by the others. Those cloths will stretch more than glass so you’d have to use more flexible resins and a core that could bend more as well. My compsand board uses e-glass, core-cell, and Bote-cote epoxy all have 4~6% elongation. Skins are tied to balsa rails with lapped 4 oz outside. - it has a really nice feel, responsive but not stiff.
The fabrics mentioned above have way more elongation than glass, if you just used them under your skin and the skin was something like core-cell you might end up with the glass shattering or delamming if something hit it, because on impact the core and the composite under it would stretch more than the glass. Balsa might be able to take more flexy materials underneath, as it is stiffer and springier than the man made core foams. Be interesting to try on the bottom skin.
Hi doug! Have been thinking of using hemp and bamboo for the sandwichconstruction over 1 pound eps, since we have got tons of bamboo growing everywhere here in japan.
In the back of my mind I am wondering about using silk. I don’t mean the processed stuff from clothing (which is probably too light and has been adulterated with dyes). I mean clean 1oz or 2oz plain silk cloth off the roll - available from sewing supply stores everywhere.
Silk has a very high strength:weight ratio, stretches very little and wets out very well. I used to back wooden bows with this stuff with fantastic results. But the stresses involved there are different - tension rather than sheer. But instinct tells me this could work very well indeed.
I have actually run a 2.3oz paper backed silk through my printer and then done a test lam. It takes ink well and laminated easily (RR epoxy), but wasn’t nearly as clear as glass. I’ll take some pics this evening and post tomorrow. This is the stuff:
I believe the custom sailboard manufacturer Proof (Canary Islands) uses a silk for there epoxy reinforcement on the inside of the sandwich. It makes sense as it’s only there for it’s tensile properties and nothing else. Ive had one of these boards and it held up well.
I thought silk was worth trying, but I couldn’t find informations on the mechanical properties of the material. I think I heard it is stronger than steel, but I don’t know how it compares to fiberglass. Many different qualities seemed to exist and they all have very specific names which I don’t understand, so I couldn’t make a choice. I didn’t spend enough time on it though, anyone had a good try at this? In my opinion, balsa sandwiched with silk would be extremely nice to have, only epoxy resin would be the last “non green” material, EPS being recyclable, wood and silk being organic matter.
Hi doug! Have been thinking of using hemp and bamboo for the sandwichconstruction over 1 pound eps, since we have got tons of bamboo growing everywhere here in japan.
hi doug , my wife is a florist and they use a material called spiders web , its for wrapping around vases etc,comes in different colours, i have tried laminating with this and its really tough and very light weight it costs something like £6 for a roll, cheap, might be worth buying your wife some flowers and getting them wrapped in the spiders web material, i am going to try it under balsa at some point, another good florist material is the clear flower wrap ,its like a very shiny celophane, its good for laminating on to give very shiny finnished surface, pete
