When I posted this model way back, I got a number of questions about how I sculpted the Chaplain skull helmet. That meant a tutorial was in order. I have to be honest, the pics for this one aren't the greatest... my camera just would not work with me on this one. Nonetheless, the idea is here and with a little work, you can have one of these in no time at all.
You'll need a suitable skull obviously.
They come in all sizes, but I prefer these here for some reason. They're just the right size and have some nice angles to them. Most skulls you find will be "smaller" than actual helmets but that's perfectly fine since you'll be adding to it with greenstuff. Just be careful not to get one that's too small.
You'll need an old helmet that you can cut the neck portion away. That's all you need from the helmet so it doesn't matter what condition it's in, you just need the base.
And greenstuff for the rest of it.
First thing is to clean up your skull and cut the neck away from the helmet. Make sure the top of the neck piece is flat along with the bottom of the skull jaw.
Take the skull and glue it to the neck piece allowing a slight bit of the jaw to hang over the front of the neck.
Next you take a bit of greenstuff and fill in the void on the backside of the skull.
The first portion of the helmet we'll be adding is the part that goes around the back of the skull. Take a piece of greenstuff and wrap it around the skull. You keep working it until it's the same thickness around and a consistent height. You don't want to come much higher than the eye sockets and not much lower than the start of the collar. If you go too low onto the collar, you'll prevent the helmet from sitting properly in the torso opening.
And it obviously doesn't go all the way around the skull. I cut it off about halfway up the side of the skull. There's no exact place to do it, whatever looks best to you. You want to leave enough skull visible so that you can tell what kind of helmet it is.
Next up is the ridge vent. Adding another piece and flattening it out like you did the horizontal portion, you trim it down until you have something that suits your needs.
And last but not least, the cables that run along side the jaw. Take a thin roll of greenstuff that is about the length of the space you have between the front face of your horizontal portion and his teeth and press it into place. Once you have it in place, you carefully cut grooves into it to simulate the ribbed cables. This part can be tricky as it can be tough to get the greenstuff in position without damaging it. Then repeat for the other side.
This conversion really only works on power armoured models. You can see how it just does not fit into a terminator torso. And, if that wasn't enough, you'll notice the neck is exposed on this guy. It's because his face doesn't extend forward like regular power armoured helmets do.
You can solve the problem by adding a collar to the torso or even using the plastic Sergeant chestplate on your conversion to save the need to sculpt a new one.
Here's how it's done for a terminator armoured Chaplain