Found Dreaming

The Navy Loves Propellers, Screws in nautical terms, so I have several request for the "standard" Stylized screw plaque.
I used a technique I have not used Myself, so I will share



start at the lower left, and follow along clockwise

I carved a single blade of the propeller out of a piece of poplar. I glued it to a piece of ply, and wrapped that with tape and filled it with Aeromarine 125 silicone RTV rubber. and made a beautiful blue mold. I cast three blades using specialty resin model-pro. Work Fast this stuff gets hard quick at 90 degrees. you can slow it dowm a bit by keeping the 2 parts in the fridge to cool it.

In the past I have used the silicone calk and acrylic paint, and thinned bondo. I rescently ended up in the ER urinating blood. so I have went to the above products which are non toxic and all but odorless. . BTW the Bondo, or the fiberglass resin , or the combination of the two where the offending problem, the silicone. was just a pain to use compaired to real castable rubber



I made up a hub, and fitted it all together on a matchplate. Now I'm ready to Gate it, I would like to hear all your ideas on the best manner. I will start with one No Go. if you cast a real screw, you horn gate it into the hub. I'm not horn gating a plaque, now remember the leading edge of the screw is 3/8 IN thick, the trailing edge is 3/32IN. the hub is 1/2 IN thick with a hole half way through

Looks good
I guess you could put a ring around the outside and feed into the edge of each blade, it will be easier to clean up then feeding into the side of the hub. will the other bits is the pic be added?

Will you be casting it in brass / bronze?

Nice, does it lat flat on the back side? I have always though screws would be a great place to make use of a follower especially if casting more than a few to eliminate coping down. In your crowd you should make them on hitch receivers... probably sell as many as you can make especially if you personalized them with a ship or group name on the hub.

it's flatbacked for wall mounting

I would just pour down a big sprue/riser right on the hub. Since its flat backed, it will be all in the drag, so the sprue will be attached at the back. It will make it very easy to cut off, and you wont have to worry about making sure its machined off beautifully, since it will be against the plaque board. Id use a riser extension to get max head pressure to make sure you fill out the blades 100%.

4cylndrfury wrote:I would just pour down a big sprue/riser right on the hub. Since its flat backed, it will be all in the drag, so the sprue will be attached at the back. It will make it very easy to cut off, and you wont have to worry about making sure its machined off beautifully, since it will be against the plaque board. Id use a riser extension to get max head pressure to make sure you fill out the blades 100%.

Top gating is not used with nonferrous alloys, which form large amounts of dross when agitated. additionally there is a high likelyhood of mold erosion, directly in the casting