I think there is some fear and trepidation from modellers regarding moulding their own fittings, and after I have posted similar threads I get a pm or an email asking whether it is as easy as I make it out to be............the only problem that anyone will have is wastage of resin, as the polyurethane resin that I use these days needs to be spot on weight wise AND so I use a small digital scale to get the weight exact per part, and the shelf life of the resin...........it can be dear, and I use CFS for my supplies and I make sure that I have all my fittings ready and ready moulded in rubber before I buy a two pack of resin, and then little is wasted before it goes off.
the actual making and cutting of the moulds is very easy so long as decent masters are made.........they don't have to be perfect, as they can be cleaned up once out as a moulding, ......
I do also have a centrifugal casting machine and melting pot for casting in white metal and in such circumstances just use a harder grade RTV rubber to take the heat of the metal.
so on to the mould today. the first half cured and so time for the second half.
over the years I used a release agent supplied by Tiranti's of Reading where I would buy my rubber, and it was in aerosol spray cans, but then all of a sudden they could not supply because they said their couriers and Royal Mail would not carry spray cans...........I spoke to the tech dept, and the guy said why was I wasting my money on spray cans anyway, as common good old Vaseline was a far better release agent than any they could supply when moulding the two halves together. And once you have pulled the masters from the mould halves, you never need to re apply a release agent again anyway........it is only used to stop the second half of the rubber mould sticking to the first half when making the original moulds.
so here it is, the finished mould for the two nozzles.