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Ben Lipman Goo Roo SA Soarer TT manual, plus TT track car, plus a spare shell
Posts: 3464 Reg: 04-2006
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Saturday, August 03, 2013 - 08:10 am, by: Ben Lipman(Ben12a)
The first mould came apart easier than that, which is why I set up the video.
Essentially there is a vacuum between the two parts, so you have to overcome atmospheric pressure, as well as a slight chemical bond between the PVA, part and mould. The PVA is very flimsy, but it stops the gel coat bonding to the part in which case you would never get separated. More significantly, wherever gel coat has bled through joins, imperfections, or any 'undercuts' then a mechanical lock is formed and you need to break it. That is why it is important to get the plug finish as smooth as possible- otherwise every scratch will turn up in the mould, and allow the gel coat to 'key in' to the plug and lock the parts together.
The 50mm is a guess, but it would be close.
What s nasty about the rear over fenders? The style or condition? Post up a pic. Thinking about the work I did on these front guards, it might have been quicker to simply paint a flow coat over the lot and sand that down. That way you get a nice hard polishable surface in one step. Mind you, gel coat/flow coat is much harder to sand than bog and spray fillers.
