I had a wild hair yesterday afternoon and decided to start finishing some helmets. I had three good castings on the bench and one horrible reject that was just a little too good to throw away. Here's how they started out:
This is the inside of the ugly reject after rough-trimming the neck hole:
And here's the ugly reject showing the void that collapsed on the left side of the snout:
Trimming the eye holes was done with a tile cutting bit on the dremel:
I also rough cut the sink drain holes in the snout with the same bit:
So after a few minutes' work, here's four helmets with the rough trimming done:
Next, I smoothed out the neck holes with a sanding drum:
The ugly reject took a bit longer because I decided to grind out a lump on the inside:
Next, I smoothed out the eye holes:
Each cast has a tiny flaw on the left side of the chin from a bubble in the mold:
There's also a tiny blob on the underside of the snout (I know, I'm a failure):
Fortunately, a high-speed cutting bit makes quick work of these:
Dremel work done, I move onto sanding the neck hole by hand:
Eye holes too:
There's a tiny bit of mold flashing on the back of a couple of the castings where the mold seam was:
This goes away after a few seconds worth of love from a sanding block:
After that, I sand down the entire surface of the helmet to take the shine off:
This will give the primer a bit more "tooth" to grab onto on the surface.
That done, I drill a hole in the right ear to fit the bolt that will hold the sight arm:
The hole is 1/4":
The snout also gets a 3/16 hole for the little lever:
And finally, I drill a 1" hole everywhere the gas mask hoses attach:
Piece of cake:
Next I trim the cheek hose attachments:
The mold sprues get cut off with a cut-off wheel:
Then they get glued onto the surface of each helmet:
After bending some 1/4" aluminum rod to make the eye guard rails, I drilled holes to fit them and glued them into place. Then touched up the ends of the cheek tubes with spot putty to hide the seams and set the helmets aside to dry:
Since I had a minute to wait, I decided to add a bit more "damage" to the ugly reject helmet. It already had this big dent:
I figured I'd leave off the detail greeblies on the left nostril too, so I drilled out the spots that they would cover:
I also dug a bit of a hole on the right side of the snout:
And another hole in the forehead:
The forehead hole got a bit of love with some bondo and spot putty:
So did the one on the snout:
I also decided to add a bent section to the ridge around the sink drain on the snout:
After adding the headlamps, I decided to call it a day. As of last night when I was leaving the shop, this is how they looked:
The silver one in the top row was casting Number 1 out of the mold. I decided the picture looked better with more helmet in it.
Not bad for a few hours of relaxed tinkering.