Upscaled LEGO Classic Space Helmet - DIY

Some people have asked how I made my upscaled LEGO Classic Space helmet. For those interested in making your own, here you go...

In the past I have worked with printing out ready made files that allow you to build a 3D image, but I wasn't happy with the file I found online. I needed to come up with something better. I found a digital 3D file of the classic helmet in the LEGO building software L-Draw support files. I was able to open the DAT file in Google's Sketchup application. Within Sketchup I was able to modify the 3D object to clean up unneeded parts. Mainly removed the interior of the helmet that made it fit a LEGO minifigure head. I then exported the 3D object to a DAE file. I imported the DAE file into an application called Pepakura Designer. Pepakura Designer allowed me to unfold the 3D image into 2D parts. The initial unfolding is not in the most ideal layout and requires some editing to get the file ready to print out onto cardstock. (I am going to save you some time and provide you with the Pepakura file that I created. Link)

After cutting out all the pieces I then glued them together to create the 3D helmet.

(Note: Most of the pics will be from when I made my first helmet.)

I Coated the outside of the helmet with fiberglass resin. 

Next I added a layer of resin to the inside of the helmet, add a layer of fiberglass matting and another layer of resin. Trimmed the excess fiberglass/resin from the opening of the helmet. (A dremel tool is excellent for this.) Add another layer of resin to the inside of the helmet to smooth out the rough fiberglass. 

Now I added a layer of General Purpose Bondo putty to to the outside of the helmet. I did this in small patches so the putty I was working with didn't harden before I was able to apply it.

Once I had a layer of Bondo covering the helmet it's was time to start sanding. I started with 60 grit sandpaper. The first round of sanding was to start getting the helmet to look round. The Bondo layer helps to even out the areas between the sharp angles. I didn't worry about getting the helmet completely smooth, because I knew I was going to need to add another layer of Bondo. 

The second layer was to fill in holes and build up areas that needed to be rounded out more. Then more sanding. Then more Bondo and the more sanding. I eventually move to a 120 grit sandpaper once the helmet had the look I want.

At this point I add another layer of resin to the outside of the helmet. The resin filled in most of the small holes or scratches that I had missed while sanding. 

Once the resin dried I sanded the resin to smooth out any problem spots or used some more Bondo, if needed, and sand again. Took a damp cloth to clean up the dust and let dry. 

(New helmet)

Add a layer of primer paint. Once the primer layer was dry, I went over the helmet with 300 grit sandpaper to smooth it. 

Now I add a 2 coats of helmet color. (I took a minifigure with me to the hardware store to match the color as close as a I could.) 

Once the helmet was dry, with a hot glue gun, I added a string of yellow battery operated LED lights around the inside of the helmets face opening. To finish up I added a layer of foam around the inside of the helmet. I adjusted the foam so that the helmet fit on my head at the correct height and to keep it from jostling around when I move.

This may not be the most ideal example of a "how to", but it should get you moving along the right path to making your own helmet... air tanks... blaster....