Silicone Mold & Model Prep:

Step1: Develop a plan

The reason I list this as a step is because I didn’t have one when I first tried to commando mold and I felt like I was flying by the seat of my pants the whole time. With that said, you will want to get a good idea of how you will do the subsequent steps in this tutorial (Ex. Mold Keys) before starting the process. I personally like to draw a design for mold key placement before I start so I know where they are going to go before I get to that step.

Step 2: Model Prep

When creating a mold, it’s important to first prep your model before you begin laying down the silicone.

-Add a base to the Helmet



-Fill in holes that can potential trap silicone molding material in the wrong area. Pay attention to detail areas & the visor. I put a layer of clay between the visor and the helmet shell to prevent the silicone from dripping into the inside of the helmet and connecting with any silicone at the bottom of the neck opening. You will also want to create a seal around the neck opening and the base the helmet is secured to (my base was made from cardboard & I used clay to seal it up).



-Spray down the helmet with a light coat of release agent before you begin step 3 (I used ease release for this and waited 15 to 20 mins before moving on)



Step 3: Silicone Print Layers & Keys

When I did the print layer for the Pilot I decide to use two layers of un-thickened silicone (No Thivex) to capture the detail better.

Layer 1 (Detail covering & Registration Key Creation)

This step is one of the most important layers. The basic idea is to get the helmets detail fully covered (possibly the whole helmet, but more importantly, the detail) and create the registration keys you will use in step 4.

Registration Keys: Created by taking a paper roll and hot gluing it to a base, or using solo cups. I used a wooden base and some left over cardboard roll to create the smaller keys and solo cups for my larger keys. Now let these setup (these will be used in step 4)





1st Print Layer: You are going to want to apply the silicone in a jabbing motion into the fine details to minimize air bubbles within the print layer (ex. carved in detail lines). Once your details are covered, brush on the remaining silicone over the helmet, hopefully you have enough to go over the whole model (If not don’t worry-see layer 2).



Layer 2

Now that the silicone has cured up enough to apply a second un-thickened layer, mix up another batch of your two part silicone rubber and start on the second layer fully covering any areas you may have missed in the first layer and fully covering the model one more time. You will know it’s ready because the silicone will no longer stick like super glue to your gloves (it will still be tacky, just not real sticky). Test the spilled silicone at the base of the model. (Not the model itself) so that you don’t disturb the silicone on the actual model (you don’t want to pull partly cured silicone from the model and trap air between the 1st layer and the surface of the model). Once you have completely covered the model and the dripping silicone has subsided, you can let the 2nd layer cure up. But first, take the cheese cloth you cut up in the beginning and lay it down the back of the model long ways. This cheese cloth help add in some security against the mold wanting to tear all the way to the front (Thanks Smooth-On for the advise).





De-molding the registration keys for Step 4. Check to see if your keys from your previous step are cured up before moving on to step 4. They should be firm enough to start de-molding from the solo cups & cardboard roll or ice cube trays. You will want to take them out of their forms and ready them for the first layer of thickened silicone in the next step.









Step 4 Thickened Layers (2X)

Layer 1: Now that the first two layers of un-thickened silicone are cured enough to begin the thickened 3rd & 4th layers, it is time to break out the thivex. I generally eyeball it. Keep this in mind, the more you add, the thicker it becomes (you will get the hang of it, if you’re breaking your mixing sticks, you may be using too much, or your mixing stick isn’t strong enough). Once the fully mixed & thickened silicone is ready, use your Bondo spreader to spread the rubber all over the helmet. You want to fill in any undercuts and create a nice even layer all around.

Applying the registration keys: Once the thickened 1st layer has been applied but before cured, start sticking your keys all over the mold (be sure to refer to your mold plan, your molding plan should have already outlined where you want your keys to go). Now let the silicone cure up enough for the final thickened layer of silicone.


(I actually cut the top 2 large keys in half later and used them in different areas, 1 up front on the chin and the other I cut in half and placed them over the vents)

Layer 2: Now that it’s time to apply the last thickened layer, you will want to mix a batch up again of thickened silicone. Once mixed apply and smooth out the surface of the silicone mold nice an even. Be mindful of any areas on the keys that may get caught in the jacket of the mold and try and cover & smooth those areas around the keys that could potentially create problems with the silicone seating properly with the Jacket/mother mold portion of the mold (Jacket has not been created at this point). Use some of the silicone rubber to create a sort of Mohawk style key down the back of the helmet area. It should be place right over the area you used the cheese cloth on. This Mohawk will help the silicone portion seat better with the jacket and create strength down the parting line of the finished silicone mold.



Step 5:

Once your last layer of thickened silicone has cured past the point of being tacky, you will want to flip the whole thing upside down. The silicone needs to be cured enough not to get damaged at this step. Now, mix up some un-thickened silicone and pour it around the base. Use a brush to get all the silicone to collect around the helmet filling any areas you may have missed during the previous steps. Let this cure up and cut any dangling pieces of cured silicone off the mold. Flip back over once this has cured up firmly enough not to flow and the silicone portion of the mold should be complete.



Quality assurance test. Give the mold a look over and see if there are any issues or thin areas, you may not need to do anything, but it’s a good Idea to check and see if you have any additional thin spots that may need to be thickened up. If not, proceed to the next step. If you do, then tend to those areas at this point and then proceed to the next step once the additional silicone has fully cured.

Mother mold/Jacket shell portion of mold

Step 1:

Create a Mohawk down the center of the silicone mold. I use the keys to hold the card stock in place. Make a slice down the center parts of the large keys (be careful not to penetrate too far into the silicone and hit the original model); this will hold the card stock in place. If the keys are having trouble holding up the Mohawk, then use scrap card board on the opposite side of where you will start the first half of the two part mother mold. When I molded the pilot, I had to do this because the keys were not tall enough for me to cut into and place the card stock. After you have you dividing line you are going to want to wrap the cardboard/cardstock Mohawk with aluminum foil. It helps later on when you go to pull the Mohawk dividing piece out.







Step 2:

Lay the model on its side on the 5 gallon bucket (5 Gallon bucket – open side up). Now take the petroleum jelly and cover the model & Mohawk thoroughly with it. This will prevent the resin from sticking to the Mohawk dividing line and it will act to fill any holes that resin may get trapped in on the silicone. If you don’t put the petroleum down on the silicone, you could run into problems later when the mold is finished (could cause seating problems later on).



Step 3:

Once the dividing line (Mohawk) and silicone has adequately been covered (no holes through to the other side) then it is time to move onto laying down your first half of the jacket. You can use different materials for this. I chose to use shell shock fast backed with fiberglass cloth for my mother mold. You can however use fiberglass cloth and polyester resin. Both will work and the fiberglass tends to not be as brittle, but the cure times are longer. I had to do it quick, so I stayed with shell shock.

Shell Shock



FiberGlass



First half:

You will want to put down a nice thick layer of fiberglass or shell shock to create a solid firm jacket. I used approximately 3 to 4 layers of shell shock on the first side, followed up with another layer around the Mohawk. I wanted it to be stronger in the area that will receive the most stress (when de-molding for the first time). In addition I also applied fiber glass cloth on the shell shock in between the 2nd & 3rd layers. Really just one layer of glass over the whole thing. The shell shock is real strong, so I did not overlap the fiberglass cloth like you do when actually using fiberglass plus polyester resin. If you decide to skip the shell shock and go the fiber glass & resin route, you will want to have at least 3 complete overlapping layers of the fiberglass cloth over each side of the jacket. Now wait for the first side to cure up.

Remove Mohawk

Flip the whole thing over and place it with the cured shell side down exposing the side without a shell. Remove the dividing line and prep for the second half of the outer jacket. Make sure the aluminum foil is still on it. I like to keep the aluminum foil on, but I’ve seen people remove it. To me it’s an added form of security against the two sides sticking together. Flip the excess aluminum down and around so it’s under the already cured 1st shell. You should now have complete access to the side that’s about to get its shell added. Take petroleum jelly and cover the entire thing like you did before. Make sure all exposed area of the first shell receive an adequate amount of petroleum jelly. I can’t explain how important it is to not have the two sides cure to each other. When in doubt, use more petroleum jelly.



Should look like this once the dividing line has been removed



Second half

Make the second half exactly how you did the first.

Step 4:

Drill holes and trim the Mohawk down so you don’t go cutting your fingers off accidently.





Step 5:

De-molding:

Use a strong bladed knife to start the spreading of the two sides. BE CAREFUL! This is dangerous and it’s important to use care when de-molding. There is basically a vacuum holding everything together. Get the knife in between the two halves and try and go around the entire Mohawk area release each side from each other. You may need to use a flat head screw driver. Be careful not to manhandle this open as you could cause the jackets to crack. Basically, use common sense…lol



Finished!!!



Run a cast and rejoice!



Now paint and wear to work…lol





Hopefully this was informative. Ask questions and I’ll try and update the tut. Happy Molding!!

P.S. Please let me know if I have missed anything or if I need clear anything up, I threw this up rather quickly because I have a few people that were waiting on this information.

BLACKULA, this tut looks amazing! Before reading this I knew very little about what actually went in to making a mold. Now, after completely reading through it I feel like I could confidently complete a mold of a helmet. Thank you for making this and sharing it with everyone!!!

Thanks for the insight into this type of mold making. The only type of mold making I'm familiar with is the VARTM process, which has similar procedures, but the materials used are completely different. To be honest, this still looks like an intimidating and time-consuming process. Maybe some day I'll try it just to learn how to do it, but I will need to do a lot more research on it.

Actually, I do have a few questions that may help me comprehend the process better:

What is the point of the cardboard "mohawk"? Basically, I don't understand how you cover the piece completely in layers of silicon in the beginning, then lay up the glass to make the mold, and then split it in the end. When does the silicon layer get split? It seems that you're building a 2 piece shell over a 1 piece silicon wrap of the part.

What is the point of the registration keys around the entire piece? I can understand having keys to line up the edges of the split pieces, but I don't see the purpose the keys all around the sides of the mold. Forgive my ignorance!

No problem, I intend to go through it later today and fix any issues, but I'm glad its coherent enough to make sense.


Lol, yes Spitfire it most definitely is time consuming. And yes it is a one piece "Glove Mold" with a two part shell. I like doing the glove molds because its a bit faster in producing a mold. Draw back is you tend to use more material. The keys are important, especially the way I put them in their, because they help hold the soft silicone correctly against the hard outer shell. When doing a mold, you really need to think about how gravity is going to pull the silicone away from the shell. I used the keys all over like that, because in this case, the helmet was basically a dome and would have the tendancy to fall in on itself without keys when casting. I hope that makes sense.

Thanks guys for checking the tut out!

-Tony

So when you take apart/split the mold in the end, you just cut the glove mold in half and it stays attached to the 2 part shell? Thanks for the explanation regarding the keys, makes much more sense now, but I'll admit the reason is not something I would have really thought of myself!

I'm sure that if I watched someone doing it in person, I would completely understand it! lol On that note, I think I'll look up some YouTube tuts to supplement your tutorial here. Thanks for the continued hard work to share your knowledge with us!

Edit: Nevermind, after watching a Youtube video of the process, I think I understand it. So the silicon glove mold (the actual mold that captured the parts detail) is in fact separate from the hard outer shell. When you want to cast a piece, you use the shell to support the glove mold, and that's why you need keys between the silicon glove mold and the shell: so that the glove mold does not move inside the shell while casting a part. Did I get that right?

My mistake was thinking that the silicon mold and the outer shell were supposed to be adhered to each other to create one piece.

thanks for posting this, Adam had a pod-cast of molding a hyabusa and he never continued it.

Yes, you are correct and honestly, I need to explain the de-mold process a little better. You brought up some decent points earlier that could have been cleared up had I explained that part better. Look for an update tonight. I hhave a meeting here in the next few mins that I need to attend.

Thanks again for your comments.

Yeah, I saw that. I believe it was Ithica's Busa. Glad you like the tut. I will update some unclear items later today.

be good guys!

-Tony

Great stuff Tony. I appreciate you taking the time out to document this buddy. It will be a big help when I get into molding the CQB.

Thanks shore, I hope you do. Thats a beautiful Helmet you have...lol <--Seriously Though, you should.

Favorited this, thanks Toni, amazing tut, and sweet new avatar lol

Thanks my man, I'll try and get around to updating it with some additional pictures. I've been busy lately with work and stuff and now its month end (Busy for us bean counters).

Be good,

-Tony

this is a really great tutorial, I had no clue as to what to do when I first looked into molded armor!

I do have a few questions though

I know one would have to start off with a base model (that's obvious) but that can the base model be made of? I am currently in process of designing Mass Effect 3 armor and would like to make molded armor and had the thought: "There is no way on earth that I am going to be able to successfully be able to learn how to mold anything out of clay for a base model... what the heck can I do?" After some hemming and hawing (I looked hemming and hawing up, that is actually how one would write it! I just learned that, random fact of the day) i thought "Could I make a pepakura mold of resin and fiberglass, bondo and sand it "all pretty like" and use that for a base model?" It seemed like a good idea (to me anyways :P ) but I haven't been able to find any conclusive answers as to if that would work.

in short: would a pepakura/resin/fiberglass base model work for this (or any) mold process?

and as it goes: for the life of me, I can't remember my second question :P (lol)

again, fantastic tutorial