battyone wrote:
Richard,I think you're actually missing quite a bit,I'd suggest getting some books on fibreglassing or doing some online research.The principles apply to epoxy/carbon laminating just the same.
Pva release is used over multiple layers of wax not just on the mould and you are moulding the wrong way round,you should be making female moulds of your parts.
The other problem is that not all plastics are the same,some react rather badly to resins,although in my experience epoxy is very friendly compared to polyester.
Resins will not stick to a plastic sheet,but if you vac bag your male mould,any folds in the bag will show badly in your finished product.Better way to do it is produce a thin female mould and vac bag that onto your male and laminate.
Thanks for your very useful input Nige.
There's no doubting that, when making a laminated part, the best results in terms of strength and surface finish are to be achieved by first carefully preparing a suitable female mould / former - the inside surface of which will form the outer surface of the part being made as the still wet laminated layers of material are forced against it by higher external air pressure acting against the vacuum bag, peel-ply and wicking cloth.
I guess my point is that quite acceptable parts can be created quite simply by using a male mould ( as a release agent, I applied several layers of beeswax disolved in white spirit to make a thickish paste to the outside of the mould when making my air box ) or even the original part ( where size isn't critical ) albeit the quality of the outer surface will only be as good as the degree to which the maker has been able to get the layers of laminated material to conform to the shape of the underlying mould / former and to squeeze out excess resin.
Anyhow ....... I still haven't been able to find anything on line which properly explains how and when the peel ply and wicking cloth should be removed from the part being created ( when using a vacuum bag to achieve proper conformity of shape against a male or female mould / former and, in the case of a male mould, then using wet and dry and further resin coats to obtain a satisfactory final outer finish ) but the only thing that would seem to make sense to me is if the resin is allowed to set to the extent that the shape of the part is "fixed" but not to the extent that it will not let go of the peel ply and wicking cloth which would otherwise become an inseparable part of the laminated structure.
As an aside, I'm pleased enough with the results of my recently created male moulded parts to want to have a crack at building a sculpted male mould over which to create a carbon fibre cover for the battery and front / top of the oil tank on my X1. On the one hand, the oil in the oil tank will no longer enjoy a "cooling frontal air flow" but, on the other hand, the tank is only inches behind the rear cylinder and exhaust header so this cover may even serve to cool the oil in the oil tank on a long journey by sheilding it from hot air as well as tidying up this part of the bike . Any thoughts on this from anyone would be most welcomed.
Richard