Sunday, April 22, 2012
X-Wing Helmet for Vacuum Forming
Almost a year ago I began working on some Pepakura X-Wing helmets (seen here).
To create them I used paper, cardboard, fiberglass, resin, glue, primer, spray paint, wood filler, bondo and spackle. They came out pretty great considering they were my first attempts.
Recently I began learning how to vacuum form things. I wanted to make some Vac Forms of my X-Wing helmets, but I do not think they would stand up too well to repeated attempts of Vacuum Forming.
So, I decided to make a new helmet, expressly for Vacuum Forming.
I have learned from my first attempts that vacuum forming an entire helmet does not work well.
So I am going to make the helmet, fill it with foam, and then cut it in half. Once I vacuum form both halves, I will put them together. I also want to try using Expanding Foam - which I have never done before and is something I saw someone else use once upon a time.
First step it to make the pepakura X-Wing helmet out of card stock.
Then I glued in some card board supports to help strengthen the helmet and keep it's shape when the expanding foam is applied.
The helmet is now ready for the foam.
The first bottle of foam I used was supposed to be for gaps under 1".
Looks like macaroni salad inside there.
That foam didn't cut it. My own fault for using the wrong foam.
Then I went out and bought foam for gaps over 1" and that did the trick.
Perhaps it did the trick a little too well...
Several hours later and the foam is still expanding. So much so that it is ripping apart the helmet at the seams.
But this isn't too major and can be fixed. I now know for my next attempt that 1 can of expanding foam is more than enough.
Once it dries I will cut the helmet in half.
According to the expanding foam instructions, the foam dries to touch in 15 minutes and fully cured in 8 hours. almost 20 hours later and there is still a little oozing out, but I believe that is because some of the foam expanded and covered up inner layers of foam - which then did not have air to dry.
Once it finally dried, I a serrated knife to trim the foam on the front and bottom of the helmet. It cuts very nicely.
Then I drew a line throughout the middle of the helmet to mark where I will be cutting it.
And began cutting. At first it was easy and then I discovered the inner layers were still curing.
This made the knife sticky and hard to cut. Using some lacquer thinner I cleaned the blade and resumed cutting.
Looks pretty gross, but now that the inner wet layers are exposed to air, it should dry in a few hours.
When everything was dry I added some wood filler.
So the next day when all was dried, I decided to see how the halved helmet looked on the vac form frame.
It's too big for the frame (insert sad trombone sound clip here).
But it should fit if I were to have cut it down the middle sideways.
I'm not sure how to glue foam to foam, so I may just have to make this helmet all over again. Sigh.
So, a few days later I remade the helmet. This time I made it out of cardboard. I did this because I noticed the foam sticks well to cardboard.
I then decided to cover the outside with plaster wrap. This will insure that there are no major gaps, and will hopefully help keep the shape while the foam is expanding.
Next step - foam.
Still looks like brains or macaroni salad to me.
And one can done. This should be more than enough.
Once it's all done curing I'll do what I did before and cut it in half.
Here's how it looks after 40 minutes.
Here we see Iron Man and a scout helmet curing and expanding.
I try to do as many helmets as I can at one time since the can of expanding foam is only good once.
A few hours later I added just a little bit more foam, paying attention to apply it to the sides and back.
So the next day I cut the helmet in half.
The insides are still sticky and uncured,
I cut this right after I cut my foam Iron man helmet, and I've learned that I should cut the helmet before adding the expanding foam. Lesson learned!
EDIT: You can cut your helmet in half prior to adding expanding foam, but make sure your helmet is strong enough to survive the cutting process and retains it's shape. If you make your helmet out of cardboard and cover it inside & out with plaster wrap you should be fine. If your helmet is simply cardstock with some glued on cardboard it will probably be deformed after the expanding foam is applied.
Next step is to apply some wood filler.
Next stop: sanding.
After sanding I used Wood filler to fill in the spaces between the expanded foam and the outer layers of the helmet.
I also glued pieces of cardboard to the bottom so that it will lie flat on the vacuum former.
Then I began filling in the rest of the foam areas with filler, and began to use more filler to smooth out the round parts of the helmet.
While waiting for everything to dry, I decided to work on the visor.
I edited the pepakura file so that the visor would be one solide piece, printable on one sheet of paper.
I then cut it out and glued it.
Next, I used expanding foam to fill up the bottom. Once it dries, I will use a knife to cut it even on the bottom so that it would lay flat in the vacuum former.
Once it dried I will cut the foam so it's straight.
While the foam was drying I sanded the 2 halves smooth.
At this point I wanted to give a test to see how well it'll vacuform.
The helmet is not completely shaped and primed, so I will not get upset if it doesn't come out well.
Came out pretty good!
Turning it around I see that the plastic doesn't form all the way to the bottom.
I will have to make a platform for it so that the plastic gets all of the helmet.
On to the second half.
Both halves look good with the exception of not having a platform so the plastic covers every part of the helmet.
The 2 halves together.
Using some duct tape I simply taped them together for now.
Not as pretty, but the next try out should go smoothly.
Back to the visors. I cut the foam once it dried. Looks good. These guys are ready to be vacuum formed. But before that, I need to perfect the rest of the helmet first. I didn't take pictures of it, but I added more filler to smooth out the helmet, and then let it sit to dry.
Taking the failed helmet pieces, I decided to put them together without the duct tape. I did this by taking some of the scrap plastic I had left over and glueing strips to the helmet parts.
Eh, not to bad. But definitely not the best I can do.
So back to fixing up my molds.
I cut some dense foam to use as a lifter for the vacuum former. I made them slightly smaller than the 2 halves so that the plastic creates a 'lip' which I can later use for glueing the 2 halves together.
Worked Pretty well!
And there you have it!
I should note that my cardboard and wood filler molds worked well the first few times I used them, but after the 4th or 5th casts they began to crack and crumble. Perhaps this was do to the unfinished molds themselves, or maybe because wood filler and expanding foam are not substantial enough to undergo multiple castings. Either way I'll have to come up with something a bit more long-lasting. But if you're looking to make just a handful, this worked pretty well.
Thanks for reading!