Guy Helmet Build Part 2
This continues the second part of my Guy helmet build. I know I had promised to have additional imagery for the Thomas helmet but my friend whom is building it isn’t comfortable with using my camera and wanted to do his own. I have not heard word of whether he has done a blog or not but will post when I find out. I had intended to have my build finished before October 31st for obvious reasons, but failed at that miserably. I missed that deadline and basically put the project on the back burner. I guess going out of town twice, 2 weddings, a bachelor party, a new job, being lazy, and some major setbacks – needless to say, I didn’t get much work done. Since things have somewhat slowed down I have been able to jump back into the mix and been powering through the next step of my build.
Part 2 includes completing the original busts painted and sanded, molded, mother molded, casting. I was hoping to get the vacuum forming included in this update as well but decided to just do an entirely different post, which is already posted. Explained at the end of this entry should explain what happened in the setback and will just mean more postings before this project is completed. Thanks for being patient and waiting and hope you enjoy this post!
Again, if things become unclear or need futher explanation, please feel free to ask, email or message. I will again try to do my best to be as thorough as possible..Ok here we go…
So where I left off from the last post I had just completed the main bust and was ready to start painting. We went through a number of different types of paints and decided the best primer/filler was the rustoleum. Valspar sucks and the 1-2-3 sanded like shit and got super gummy. the grey 2in1 rustoleum dried quick and sanded great! highly recommend it.
Another great thing about the rustoleum is it dried super quick. we were able to spray and apply a second coat within 30 minutes of each spray. Sanding we waited till the next day I believe. Below are the some imagery during the spray.
After the paint dried I went through a butt ton of sanding slowly moving up through the grits 150, 220, 400, 600, 800, and eventually up to 1500. I suggest using the sponge sanders, they are easier to hold, last forever and get around the corners more consistently without breaking up. Honestly this could go of forever. We could have spent days sanding it down making it look perfect but since its just for the mold all it needs is to have a decent surface so the mold doesn’t pick it up. Dont get me wrong, you’ll still be there sanding forever, but it doesn’t need to be a mirror surface.
After wiping and washing the excess paint off it was time to start molding. I had never used this material before and made me a little nervous since I didn’t want to muck up my bust. So again I went by Volpin’s word and used his recommendation for Rebound 25.
This shit is expensive! about 35 bucks for 2 pints. I was able to get a good three coats from this one batch.
It says this stuff is brushable but its like trying to brush with molasses. I used something like popsicle sticks it allowed me to apply it evenly and keep things under control, relatively. Once this stuff goes its got one gear, go. Rounded surfaces can be a little of a pain in the ass since it just keeps dripping off and you need to keep applying it for about 20 minutes. It does start to harden fairly quickly though, which is nice. Also you can reapply it in about an hour after your first coat.
If you want a thicker coat, I would recommend getting double and going to town with stupid thick coats but remember your mold will only last to so many pulls from casts. If you go lighter you won’t need as much and will be able to save some cash. Its up to you.
So you really cant see it here but I made this pseudo stand to keep the helmet up allowing me to work on it. It really doesn’t matter what you use, just get it off the table or your work surface so you can get a decent bit on the underside.
This stuff is quite strong for how malleable it is. I was very surprised to see it continue to stretch under high strain. Im confident 3 coats from one batch is enough for about 6-10 casts before it really starts to degrade and break from pulling. I guess we will see.
Again I took Volpin’s advice and also made reference points from little trays. Parts of me were a little skeptical about how successful this will work, but I guess its ok. For a design like this, the ribbing is good enough referencing to begin with since its circumnavigates the entire body of the helmet anyways. Something else you can get is a hardener from Smooth-on, called Thi-vex. This allows you to make reference points and break lines that are much much thicker than the rest of the mold by adding it directly to the Rebound 25. But again you have to spend the cash for it and also find it.
The next step was to add the mother mold. We waiting a bit before getting this done since we were unsure what to use. What we ended up doing was just getting the same stuff Volpin used called plasti-paste. Its quite weird, like a wet fiber you mix with a catalyst. Again this stuff is also relatively expensive for what you get and only goes so far.
It was like working with a beginners version of fiber glass. either way I applied the same way i applied the Rebound using a stick and spreading it on. I cut a 1/4inch thick piece of plywood to create the break between the two halves of the helmets mother mold. I also made it really wide so I could spread it out along its surface.
After I got he main body covered I filled in the thinner parts and spread out along the mohawk like split giving me a nice flat surface for the other side. This serves 2 purposes. One is to be wide enough that I can drill through it and bold the 2 sides of the mother mold to itself instead of having a board or guide being mandatory. The other is to help break the two halves apart.
When your ready to pry apart I highly recommend getting a friend to help work them apart with you. It is NOT easy. Take your time and dont rush. You will break it if you pull too hard.
I did leave a single layer of aluminum foil between the two halves since they would fuse together otherwise. I also applied a coat of Release 200. You can use a spray cooking oil or Vaseline but this stuff sprays wide and leaves practically ZERO evidence its there. And it works great.
Since I only used one container of the Plasti-paste I did a small striping of fiberglass over the outside of the mother mold to give it some extra strength. This I recommend. Fiberglass is easier to find, cheaper, goes a lot further, relative easy to you use and is stupid strong.
I did a thick coat of fiberglass along the break in the middle giving added strength support and stability to the mother mold. After it dried I drilled directly through it. This worked great. also keeps the body light and relatively easy to work with.
After reading about the difficulties Volpin had removing a single mold from the bust, I was slightly nervous about what would happen when I was ready to pull mine, but after fiddling with it it I knew it would come apart nice and easy.
It actually came off with practically zero trouble. That Release 200 worked really well!
Ha, couldn’t help it.
Once the mother mold was dry, reinforced and bolted together it was ready to start casting. I spent a good amount of time cleaning the interior and exteriors of both the mother mold and mold to make sure there wasn’t any debris that may cause any flaws. If I did miss anything, I can just go back through and fix it with some more bondo. But I would like to not have to deal with a lot of that.
Time to start with the first cast!! Since we had tons of fiberglass resin laying around I went with that. But I am curious about slush casting. I think I may try that for the next cast.
Im doing this outside, as opposed to my shop since its in my basement and the ventilation basically includes my house. I don’t want my entire home smelling of strong toxic chemicals.
This first cast was a quick run through to play with materials and see how the mold works. I t was fairly satisfied with the outcome, but I had a few minor issues. I had a few places where the mold wasn’t staying in place or flush with the mother mold.
The second cast I made, I futzed with the mold to get it as smooth as possible to get the visor for the vacuum forming. It came out much cleaner then the initial test run but still with flaws. All of this was due to a thinner mold. This setback alone has delayed me probably a month between not being able to be productive and just being upset. On the upside, I found a solution! I drilled holes in the mother mold and created small silicone rubber pull tabs that can pull through and keep it flush. I did this so I could continue to mold using what was already made but have started a second molding process that is much more sturdy and will allow other molding methods.
The second run through I am making now, the mold is much thicker to help avoid this. I am also going to do the mother mold a little different to help keep accuracy of registration and ease of use. There is a large amount of time spent registering points between casting. Lesson learned, I guess. Either way, this major setback taught me a lot about molding and registration. The biggest reason for preparing a second cast, it will accommodate different methods of casting, like slush casting.