Good morning, all. It’s almost Christmas, so I hope all of you have been very nice. 
I am about to begin building the plugs for a set of hand guard ferrings for a friend of mine.
The ferrings I am refering to look something like this:
They protect the hands from the wind as the rider is going down the road.
The aluminum structural guards/bars are alredy attached to the handlebars. The ferrings will simply screw onto the front of the aluminum bars. and wrap backwards creating the wind shield.
The following is the plug development process that I have in mind:
-cut plywood template that represents the profile of the aluminum hand guards. One for each side.
-glue a stack of four pieces of 1" foam above and below the ply template.
-roughly shape the foam to give a close representation of what the ferrings might look like.
-use oil based Clean Clay to create detail and smooth transitions in the foam in order to create a final representation of the ferring.
This is when I question what I should do next.
I would like to use clay to finish the detail and transitions of the plug, but maybe an oil based clay, or clay at all would not be the best material to do this. Of course I could use Bondo or a similar material to smooth transitions and fill the pours of the foam, but I would not be able to create detail as well with this kind of material.
The reason I question which type of material in which to smooth and create detail is because after this step is done, the final step would be to apply Duratech 2K primer, sand, polish and create a mold. The material under the Duratech would need to allow the primer to adhere to it well and not pull up when the mold is pulled off the plug.
With this information in mind, I would love to hear what feeback you have on the process, and any imporvements, changes, different materials I could make or use to give this project a better chance of success.
Once I get past these planning stages, I’ll be sure to post some good pics of the process as I work my way from start to finish.