Anyone using it...? I can't find what I need to know with googling so here we go...
I have 400 mesh aluminium dust that I am mixing with West resins to cast and fill. I make it into a paste with quite a lot of aluminium.
Now I want to use it as a gelcoat in a mould - so it will be my first coat onto the plug before I glass it. I have not done that before, I have only used it for casting where strength is irrelevant.
West 420 additive is designed to increase abrasion resistance so it is ideal, but if it is aluminium dust with 1% other crap (seems it is) then I will stick with what I have.
West 420 specs say to mix it at 5 - 10% by volume. Umm, I've been using aluminium dust at about 50% when casting and it goes off fine.
Usually the maximum mix is because any more filler added and it won't go off properly. In this case I know I can add sh!tloads more and it will go off just fine and set rock hard.
Maybe max abrasion resistance is acheived at 5 - 10% though - as any more and it is too much alum, and any less it is all resin.
Anyone know why they specify such a low amount of 420 additive? I am guessing you CAN use heaps more, but 5-10% is max abrasion resistance?
I want to mix it as thick as I can to make it not sag on the plug - but not if I lose the benefits of the alum dust (namely abrasion resistance)
Are they specifying that % in order to retain a certain strength of the epoxy itself? In other words, is that the maximum abrasion resistance, while achieving a certain minimum strength?
Good point - never considered that it may be the amount of additive giving maximum effect, whilst maintaining flexibility and/or tensile strength etc
Of course I can't find any of this - only a ratio .... and not why
Sounds like you're doing something interesting!
What sort of things do you make Mark?
Geez Doggie it's obvious he's making moulded and casted Epoxy and aluminum dust things.
nothing exciting fellas :)
Epoxy and alum dust made up thick basically makes die cast metal - like dinky cars.
It is nice and hard.
I am making a new mould for a product and you want the mould to be nice and hard and scratch resistant to turn out lots of individual items from it. Usually you use "tooling resin" but West only does that in 5L at about $200, smaller qty's is not available which is bullsh!tfarkin 
so I am going to use epoxy alum dust for my first coat.
I know it will make a mould better than straight resin but have only ever used epoxy / alum for filling and in special cast applications.
so I am going to use epoxy alum dust for my first coat.
Dogster, yes the new mould is for a stock.
(Sold the last two)
I have used epoxy and alum dust for certain applications on the inside of said product, which is a trade secret :)
