Beyond The Sprues
Modelling => Tips, Tools & Techniques => Topic started by: kitnut617 on May 21, 2012, 06:58:14 AM
-
Well I took the plunge, I'm attempting to copy some engine nacelles for the very first time.
I've made myself a casting box, in this case a short length of ABS pipe which I can use over and over again for various things. Next I cleaned up the part I want to copy, attached a lump of modeliing clay to create a pour lug, then attached it to my base with a screw. I had drilled a small pilot hole in the part so the screw would self-tap into it.
I'm using an Aluminite casting kit (which is made by Corning) and so far I've mixed up a quantity of silicone rubber and it's now poured over the part I'm copying.
In the next 24 hrs I'll find out how it turned out ----
-
Good luck!
-
If you're going to get into casting your own parts, but a small Legos bucket. You can build a mold box of just the right size for your masters and the rubber doesn't stick to the Legos.
-
Thanks for the tip Frank, down in the crawlspace, we still have all our son's toy boxes. There's a big box of Lego down there so I might give that a go.
The mould has cured and I've extracted it out of my mould box, and got the master part out too without any problems. Looking as best I can inside the mould, it looks pretty good, can't see any bubbles (something I was warned about) and the relatively simple detail to the air intake seems to be OK. I am now going to try to cast a replica ----
-
Another tip - pour some talc into the mold before pouring the resin in. Shake it up to make sure the inside of the mold is coated in talc, then pour out the excess. Now when you pour the resin in, the talc will suck the liquid in towards the surface of the mold, eliminating many surface bubbles. It's the poor man's (or hobbyist) equivalent of pressure casting, in therms of results.
The talc won't affect the resin in any noticeable way.
-
Success !!!
but only after a couple of problems to begin with.
I had bought a casting kit quite a few years ago and when I went to start this I found the tub of rubber was just that, a tub of rubber. Over the years it had set itself. So I bought a tub of fresh silicone rubber and a bottle of catalist, the mould turned out very well considering it was my first attempt. But the 2-Part resin material had also 'gone-off', it would turn itself into resin when you mixed it up but the consistancy was like porridge, so back to the store to buy some fresh stuff.
Instant results when I used this new stuff --- the grey nacelle in the pics below is the original part.
-
Cool! Casting is something I haven't tried yet but eventually I would like to.
-
Looking good. So when do you start taking orders?
-
This is instructive as I find myself looking to "clone" some vac-formed parts for a few efforts.