Vacuum forming clear Styrene?

[craigolio1]

Any idea how plastic pop bottles take to things like CA, MEK, or other adhesives/solvents?

Craig

[wazzou]

MEK should work just as well as it would on styrene in my experience.

[peteski]

Tamiya makes transparent smoke color which is transparent gray.

I have used methylene chloride (Like Tenax 7)  to glue PETG.  I don;'t know how it would work on PET or PETE  (material the plastic bottles are made from)

[craigolio1]

Thanks I'll experiment with those solvents and see what happens.

Do you think the Tamiya smoke would do a good job of this or am I better off tinting clear coat?

[Angus Shops]

Wow, that's a tough one Craig. One of those photos pretty clearly shows the interior detail, and there's a lot of interior detail. I suspect your idea of using a wrapper of .005 styrene (maybe cut on a Silhouette cutter) over a formed clear plastic 'window layer', on a good solid base such as a resin casting to keep the car body stiff. Getting the paint on without messing up those vast windows will be fun as well.

I've never tried forming plastic, but I wonder about that plastic protective layer that comes in MT car packaging. It's crystal clear and seems to have the right stiffness for a project like this.

Tinting it will also be fun. I've been messing around trying to tint window material for my Budd cars. I've tried Tamiya's green; too green. I tried various alcohol based 'art markers'; lots of colours available and good initial results but over time the tint on the windows was softened by off-gassing from either the resin itself or the paints on the body and the tint slowly 'melted' and ran. No good.

Finally my wife let me try one of her craft products; Adirondack Alcohol Ink. She had a green tone that is about right to my eye. The bottle says there are 12 colours available and that the colours can be mixed to get the right tone so I'm betting you can get a good grey tone. I thin it with alcohol and spray it on clear styrene with an airbrush. It's still hard to get a completely even tone, but my windows are small compared to the huge ones on these cars. I'd be willing to bet that better airbrush technique than I can muster would solve this problem. Also, the tint can be scratched off the window material so I'm careful to put the tinted surface on the inside of the car to avoid damage.

This is very much learning curve project for me; eventually I'm going to have to tackle the tinting of the dome car's domes.

Geoff

[Angus Shops]

Oh lord, I started that long post above so I could ask about the idea of 'tinted clear coating', then never got around to asking!

So, um, how does tinted clear coating work, it sounds promising.

Geoff

[peteski]

Craig,
I had success using automotive window tint to tint the original Bachmann Amfleets. I put the tint on the outside of the clear window material. The tint is very shiny so it looks like glass. And you can get tints with various degrees of light transmissions.  You could probably even get away to just use the tint (with its protective film still on it)  It is thin so it should easily conform to the curvature of the car body.

It might be difficult to get a uniform coat of Tamiya clear smoke over the entire length of the car windows.   The shade can be controlled by the thickness of the coat or by multiple applications.

[Angus Shops]

Good idea Peteski, never thought of that.

Does anyone know of an appropriately Budd shade of green tinted plastic sheet, preferably .010 think? Pikestuff used to make some sort plastic material, but it was too thick IIRC. I thought about movie industry 'gels', but my guess is probably too thin and poor likely hood of finding the correct colour.

As for Craig's grey tinted material, I recall seeing some grey tinted acrylic sheet around my Dad's house back in the day; I wonder if it's still available, if the colour would be close enough, and how difficult it would be to form it into the proper shape? It would make a nice solid core to wrap a .005 'wrapper' over.

Geoff

[Lemosteam]

Every Christmas I make a habit of saving all of the clear packaging from my kids new toys, especially if it is flat or a folded box.  I use it for model window material,  I would not be fooled though, using a bottle to form the windows for the coach in the picture would provide a fairly strong structure, particularly if the ends were done.  That car is so smooth, you might not even have to put sides on it or a wrap.  Just tape the formed part and paint it.

Or you could have a 0.010" thick wrap cut using a craft cutter, paint that in the flat and wrap it over your clear shell.

[Sokramiketes]

I like all the ideas for vacuum forming plastic.  But, I'm not sure its the best way to go to model the car in question.  You're going to need a thin but sturdy framework up there on the dome, so what I would do is photo-etch a wrapper, roof and sides in one, and form it over a shaped wood block.  Then, I'd use Peteski's idea of automotive window tint, throw some glue on the photo etched wrapper, then sandwich the window tint film between the wrapper and the wood block again to get it formed to the right shape.  Let the glue dry and you're golden.

I was headed a similar direction in Z scale before AZL announced Superliners in plastic:

[ Guests cannot view attachments ]

[narrowminded]

The idea of reusing blister pack material sounds great and should not have a problem as it's a thermoplastic, therefore can be reheated and reformed multiple times.  Then there's the action demonstrated in the canopy forming video posted above where the residual tension from the initial blow molding process was used to advantage in forming the part. 

Well, I was curious about what seemed like a good idea so cut out a piece from a plastic bottle and several blister packs and fired up the vacuum former.  Started the heat cycle and before long the material started to soften and THEN, shrunk and pulled itself right out of the former frame.  The residual tension won as the material started to soften.  So I'm going to say it's a no go in a vacuum form unless it's as the canopy was and the desired part can be made taking advantage of that residual tension.  In that case it's a total win!

If there was a desire to start with a very new and fresh form reusing material MAYBE some preheating in an oven to relax the tension before to cut to the forming blank size would work, an annealing of sorts, but it was a pretty powerful shrinking force and a pretty dramatic dimension change.  Still good for cutting out some windows when needed but begging for trouble on a reheat.  At least when done as simply as cutting a blank from a previously heat formed piece.  Hope that helps. 

[svedblen]

Don't you think the success with the bottle in the video was due to the cylindrical form. All forces then acted towards the middle, going inward. So if you place your car body form inside a bottle in the same way, you will also suceed  In contrast to heating a "flat" piece that cannot do anything else than contract onto itself.

Hope you manage to follow my reasoning   

[dougnelson]

If all else fails, I had this as a kid. Like all of our past treasures, still available on EBay.

[craigolio1]

Kids toys were the best, or dare I say it, boys toys. Based on the art I'd say it was from the 60's?  I was born in 77 but my friend Kevin still had a chemistry set. Steve had a wood burning kit! As Eddie Murphy joked, with a 2 ft cord plugged in right by the drapes. Those were the days. The first time I noticed it really going down hill was in grade 7 when I won a dart board in a raffle at school or some such contest. They were safety darts!  Can you believe it?  The board was made of plastic knobs and the dart wedges it self in between them. Lame. But there is hope. My 10 year old daughter just came in and asked what I was doing on my phone. I described our thread. She said whoa that's cool, can I help?  Yes you can my dear. Yes you can.

But anyway. I digress.

Tinting windows with window tint. What a novel idea. But seriously, super clever. Every colour and totally uniform. My windows have no compound curves so it should lay right on the windows.

Have a look at my plan I've developed using your input and please critique as you see fit.

1. make a plaster master using one of my Shapeways models as a mold . It's the right size and shape and I can sand it smooth once I remove it.

2. use the bottle trick as portrayed in the video.

3. Strengthen the glass.  I feel like the "glass" will have decent strength at the ends but the middle of the sides will be flexible. I'll make a styrene form that slides in and is stuck with either glue or a little two sided tape. This will also provide something for the bottom to attach to. I'll use the bottom from Shapeways. It's already prepped to satisfaction, has trucks and couplers and is ready for paint.

4. Make sides.  Actually a one piece sides and roof.  Likely out of .005 styrene as the protype windows are flush and the .005 will bend very easily. A friend gave me her Silhouette cutter. I have never used it before so this seems like the perfect chance. Hopefully it works with .005" styrene

5. Paint the inside of the styrene black and the out side white. (I'm modding an earlier paint scheme, not the one in the photos. It's hideous.). Temporality assemble the model, holding the sides on with a bit of tape, so I can mark where I need to mask.

6. Paint the sides and roof on the flat.

7. Window tint

8. Attach sides with two sided tape.

9.  A bunch of other stuff I havn't thought of or have missed.


What do you think? 

Thanks.

Craig.

Edit.

It needs an interrior if I'm doing windows. I have some Palace Car Co interiors which should do just fine. I also have a Kato Superliner that is the sad result of an earlier failed attempt at a kitbash of this car. I'll make up something to hold the car bodies shape and support the two levels of interrior, perhaps using parts from the Superliner.

[narrowminded]

Don't you think the success with the bottle in the video was due to the cylindrical form. All forces then acted towards the middle, going inward. So if you place your car body form inside a bottle in the same way, you will also suceed  In contrast to heating a "flat" piece that cannot do anything else than contract onto itself.

Hope you manage to follow my reasoning   

Yes.  The form from the bottle is in the same general direction of the canopy and the residual tension exceeds the necessary dimension change to make the canopy, so it works and works beautifully.  But if that canopy had, for example, a recess in the shape, it would just span it, never forming into the depression.