Need advice making one way mirrored visor

[SonOfTheGun]

Hey all,
I am just starting on my first build and i decided to go with Emile from Reach. I am 3d printing the entire helmet other than the visor and will probably use the 3d print to make a fiberglass mold.
My question begins with the visor. I am going to try and heat form acrylic sheeting into the shape of the visor as i want it to be rather thick because i plan on making it removeable. Is it reasonably possible to do this? and also is there a way to coat the visor with a one way gold mirror?

 

[Cadet]

Acrylic is going to be too thick and hard to heat and form. Acrylic has a tendency to crack and splinter when you try to form it. You should explore using PETG plastic. Also, you visor does not have to be thick and super rigid to make it removable. In fact, the more flexible your visor is, the easier it would to be remove it from your helmet.


The most common effort of tinting/coloring visor with a one one mirror effect these days is to form your visor with clear plastic, usually PETG. Then you submerge it in a dye bath with a fabric dye designed for synthetic fabrics. At the point the visor will take on the tint of the dye, but still be transparent. The interior of the visor is then hit with a light coat of chrome paint, either through a an airbrush or there are "rattle can" chrome spray paints that also work.

Here is an example of the technique:

TurboCharizard's Halo Reach CQB Build Log

I've been using an old Pfaff hobbylock 788. Its a super solid old machine. I'm not sure they sell it anymore but Pfaff is a reliable brand. And its not too complicated to thread or fix.. As far as sergers go. So happy to see my old thread is useful for you XD I'm so close to getting that video...

www.405th.com

 

[SonOfTheGun]

Ok i hadn't thought of using PETG. Every time I've used it it hasn't been super see through?
how would flexibility make it easier to remove? I'm planning on using magnets to retain it but idk if that will actually work

Oh thats genius! fabric dye with plastic is something I've done before in airsoft I will play around with it.
Thank you!

Acrylic is going to be too thick and hard to heat and form. Acrylic has a tendency to crack and splinter when you try to form it. You should explore using PETG plastic. Also, you visor does not have to be thick and super rigid to make it removable. In fact, the more flexible your visor is, the easier it would to be remove it from your helmet.


The most common effort of tinting/coloring visor with a one one mirror effect these days is to form your visor with clear plastic, usually PETG. Then you submerge it in a dye both with a fabric dye designed for synthetic fabrics. At the point the visor will take on the tint of the dye, but still be transparent. The interior of the visor is then hit with a light coat of chrome paint, either through a an airbrush or there are "rattle can" chrome spray paints that also work.

Here is an example of the technique:

TurboCharizard's Halo Reach CQB Build Log

I've been using an old Pfaff hobbylock 788. Its a super solid old machine. I'm not sure they sell it anymore but Pfaff is a reliable brand. And its not too complicated to thread or fix.. As far as sergers go. So happy to see my old thread is useful for you XD I'm so close to getting that video...

www.405th.com

 

[PlanetAlexander]

For Emile's helmet, you might want to explore vacuuforming. For a visor of say the Mjolnir helmet, heat forming might be fine (except for the embossed detail) as it really only curves around one axis. It would be much harder to heat form Emile's helmet, as it is cylindrical. To take a flat plane of plastic and form it into such a shape without seams or the build up of extra material would be very difficult. If I sound confusing, which I probably do, try this: take some fabric and droop it on something like a beach ball. You'll notice down the sides are folds from excess material.

Where vacuuforming is different, is that it will stretch the heated plastic to properly fit around the buck (the mold) and will give the desired shape.

 

[SonOfTheGun]

For Emile's helmet, you might want to explore vacuuforming. For a visor of say the Mjolnir helmet, heat forming might be fine (except for the embossed detail) as it really only curves around one axis. It would be much harder to heat form Emile's helmet, as it is cylindrical. To take a flat plane of plastic and form it into such a shape without seams or the build up of extra material would be very difficult. If I sound confusing, which I probably do, try this: take some fabric and droop it on something like a beach ball. You'll notice down the sides are folds from excess material.

Where vacuuforming is different, is that it will stretch the heated plastic to properly fit around the buck (the mold) and will give the desired shape.

I completely understand what you are saying and I agree, I have access to a "high tech" (as high tech as they come) vacuum molding machine at my college so I will give that a try.

 

[Cadet]

Ok i hadn't thought of using PETG. Every time I've used it it hasn't been super see through?
how would flexibility make it easier to remove? I'm planning on using magnets to retain it but idk if that will actually work

I myself have not Vacuum Formed a clear PETG visor, however I have one that came with a Mark V helmet I purchased from another member, and I know several members here have used it for their visors. Here is a thread on the RPF from 2014 that goes into some great detail on a getting a nice clear vac pulled PETG visor. From what I remember of that thread the big issues are heat and the shape/smoothness of your buck.

Vacuum forming clear PETG problems

I'm trying to vacuum form a clear dome for the head of the Robot from Toy Story. The problem I'm having is that I get little "dots" like stars and also clouding. I've formed .08 PETG before but never had this problem. Any idea what's going on?

www.therpf.com

How to get PETG crystal clear after vac forming ?

Hi guys, long time reader on this great forum, ended up signing up a while ago to ask a question but lost interest in the project (haha). I've since purchased some clear PETG after doing countless hours of research as I read that it has the best clarity out of all the plastics (this could...

www.therpf.com

As for the flexibility, I don't mean extremely flexible, like rubber or foam, just maintaining the inherent flex of the plastic used, like PETG or HIPs. It's like motorcycle visors. They are rigid and hold their shape, and if flexed too far will snap, but they still have some level of flexibility that allows for ease of installation. I can tell you that with the visors I have put in a wide variety of helmets, having some wiggle room and flex to finesse the visor into place makes all the difference in the world. Especially with the unusual nature/shape of some Halo helmets where for example the neck opening is tighter than the helmet circumference at the visor, so you do have to squish the visor together a bit to get it into the helmet, then let is snap back out. Even with Emile where I can see you sort of loading it in from the "top," if you want ito sort of lock back under the edge around the visor, you will want to have some flex to get it into place easily.

 

[TurboCharizard]

Cadet hit the plastic properties rundown perfectly. Acrylic will be stronger overall but isn't as friendly for forming as PETG. The benefits of PETG are the lower transition temperature and the commercial availability in different thicknesses which makes our life easier.
That low transition temperature makes it so that we can heat it up using simple heating elements (I use an old dead toaster oven that'll never be used around food again) for forming and then during the dye stage plastic "pores are opened up" to accept dye at a temperature below the boiling point of water so that process can be done safely on a stovetop (also in a pot that will never see food).

 

[SonOfTheGun]

Has anyone experimented with tinting the visors the same way car windows are tinted?
I think they use mylar?

 

[FalseShepherd]

You can do that. I'm not sure how mylar works specifically, but you can always try using a tinting film applied to the plastic like a window tint. You can find them in various colors and mirrored-ness. Due to the extreme curve involved with this helmet, I think it would be extremely difficult to apply a tint after vacuforming without getting a lot of wrinkles and bubbles.

You could try to apply the tint before vacuforming, but it likely would not remain adhered to the plastic during the heating step. Feel free to try it though, nobody has posted what happens if you try it yet everyone just poops on the idea whenever it's brought up.

 

[TurboCharizard]

You could try to apply the tint before vacuforming, but it likely would not remain adhered to the plastic during the heating step. Feel free to try it though, nobody has posted what happens if you try it yet everyone just poops on the idea whenever it's brought up.

I tried playing with that on my Reach CQB because I had some spare blue tint leftover. It's... less than stellar because the two materials have different thicknesses and transition temperatures so bubbling forms. That being said I only did two pull attempts so there might be a way to make it work, I just didn't luck into finding the right mix and didn't want to waste more material fiddling with something that was unlikely to get good results.

 

[SonOfTheGun]

You can do that. I'm not sure how mylar works specifically, but you can always try using a tinting film applied to the plastic like a window tint. You can find them in various colors and mirrored-ness. Due to the extreme curve involved with this helmet, I think it would be extremely difficult to apply a tint after vacuforming without getting a lot of wrinkles and bubbles.

You could try to apply the tint before vacuforming, but it likely would not remain adhered to the plastic during the heating step. Feel free to try it though, nobody has posted what happens if you try it yet everyone just poops on the idea whenever it's brought up.

I'm thinking maybe pull the visor first then apply the mylar with a heat gun so it stretches a bit as it applies. But I'm not sure how that will work.
I'm going to talk to a window tinting company that is local to see what they have to say.

 

[FalseShepherd]

The heat gun is a decent idea. Might keep it more maliable. If you go slow enough might just make it work.