Gluing in Acetate Windows

[DoctorLarry]

In working with resin bodies, you generally don't have the luxury of molded plastic windows. Some providers can provide vacuum formed windows but often I am left with creating them out of acetate sheet.  Gluing them in without making a total mess is often the hardest part of a build.  Anybody with any great suggestions?

[peteski]

Acetate?  Kind of like calling all water-based paints "acrylics" is a misnomer, acetate is inaccurate. I don't think anybody has actually used clear acetate for model windows for many decades.  I don't even know where one would get a sheet of real acetate.  Sorry, had to get this off my chest.

Clear plastic we use for models is usually polystyrene, PET, PETG (like Vivak), acrylic, polycarbonate, polyester, or vinyl.

For glue you can use canopy cement, epoxy, odorless CA glue (it doesn't fog the plastic).  I often use standard CA glue with BSI brand accelerator.  The glue sets before it has a chance to fog, and that accelerator brand does no harm plastic in general.

[Ace-Garageguy]

1 hour ago, peteski said:

Acetate?  Kind of like calling all water-based paints "acrylics" is a misnomer, acetate is inaccurate. I don't think anybody has actually used clear acetate for model windows for many decades.  I don't even know where one would get a sheet of real acetate.  Sorry, had to get this off my chest.

Clear plastic we use for models is usually polystyrene, PET, PETG (like Vivak), acrylic, polycarbonate, polyester, or vinyl.

For glue you can use canopy cement, epoxy, odorless CA glue (it doesn't fog the plastic).  I often use standard CA glue with BSI brand accelerator.  The glue sets before it has a chance to fog, and that accelerator brand does no harm plastic in general.

Sorry to be pedantic, but while it's entirely true that many things are called by the wrong names, real clear cellulose acetate sheet is still widely available, as a google search of the term "clear acetate sheet" will show (clear sheet made from PETG, styrene, acrylic plastic, etc. is usually correctly labeled and marketed under the correct name of the material it actually is as well).

Genuine cellulose acetate clear sheet is even marketed for specific aircraft uses, and in aviation, you can't call stuff by the wrong name.

https://www.aircraftspruce.com/catalog/mepages/acetatesheet.php

Here's just one of at least hundreds of commercial sources.

https://www.jacksonsart.com/en-us/grafix-clear-acetate-pad-11x14in-003in-25-sheets

Edited April 25 by Ace-Garageguy

[DoctorLarry]

Is there a faster setting method that will grab and hold quicker?

[Ace-Garageguy]

19 minutes ago, DoctorLarry said:

Is there a faster setting method that will grab and hold quicker?

For best results, it's often wise to not be in a hurry.

I tape or otherwise fixture window-size clear parts when using any of the PVA (white) "canopy" glues that dry clear.

Using a quick-set epoxy is another option. Let it tack, then mount your "glass".

But the best way, in my opinion, is to make up retainers from strip styrene that will allow carefully-fitted windows made from clear sheet material to snap in place, often eliminating the need for adhesive altogether.

Edited April 25 by Ace-Garageguy

[stitchdup]

you could try the double sided tape they use to fit new phone screens. you can get it down to 0.5mm wide in clear and black. Its not cheap (around $20 for a 10 metre roll) but its plenty strong. one of my friends uses it to hold the headlights on his rc hotrod and he beats on that thing hard.

[NOBLNG]

4 hours ago, DoctorLarry said:

Is there a faster setting method that will grab and hold quicker?

There is this…but you have to be quick to get it mixed, applied and your part properly in place before it sets beyond the useable point.

[DoctorLarry]

Does it dry clear?

[DoctorLarry]

Peteski, thanks for the info on plastic types. What type of adhesive WILL stick to polypropolene plastics? I have found no consumer products that will adhere to that stuff. Thanks!

[peteski]

6 hours ago, Ace-Garageguy said:

Sorry to be pedantic, but while it's entirely true that many things are called by the wrong names, real clear cellulose acetate sheet is still widely available, as a google search of the term "clear acetate sheet" will show (clear sheet made from PETG, styrene, acrylic plastic, etc. is usually correctly labeled and marketed under the correct name of the material it actually is as well).

No, that's fine Bill.  Thank you.

Good to know that acetate is still alive and well, and available, but I just haven't seen any acetate clear sheets for sale at any hobby shops I have been using in the last 30 years.  And while I agree that the materials are usually labeled correctly by the manufacturers, I still believe that majority of modelers actually use different materials, while generically calling them "acetate".  At least in my experience.

[peteski]

1 hour ago, DoctorLarry said:

Peteski, thanks for the info on plastic types. What type of adhesive WILL stick to polypropolene plastics? I have found no consumer products that will adhere to that stuff. Thanks!

I did not mention polypropylene as I have never seen it available in thin clear sheets. It is usually used to for making Tupperware or similar food containers, and it is usually not crystal clear.  As you said, adhesives do not stick well to it.  Probably best to use something else.

[peteski]

1 hour ago, DoctorLarry said:

Does it dry clear?

Most quick-set epoxies while they harden clear (or slightly amber in color), will become darker yellow with age (after several years).  But if you use epoxy in a way that it is not visible outside the model, that is not a problem.

[Ace-Garageguy]

11 minutes ago, peteski said:

Good to know that acetate is still alive and well, and available, but I just haven't seen any acetate clear sheets for sale at any hobby shops I have been using in the last 30 years.  And while I agree that the materials are usually labeled correctly by the manufacturers, I still believe that majority of modelers actually use different materials, while generically calling them "acetate".  At least in my experience.

Something else for modelers to consider...true cellulose acetate is biodegradable, and the packaging even says "compostable" sometimes.

This means it's not as stable as high-quality petroleum-derived plastics, and as most of us old fossils know from experience, "acetate" plastic promo bodies from the 1950s and early '60s are mostly either turned to dust and chunks by now, or warped beyond recognition.

I'd say that this point in time, either PETG or polycarbonate would be the best choices for model windows, as acetate will eventually self-destruct, and styrene sheet tends to be soft and scratches easily during handling.

PETG is probably the ultimate, as it can be had for free, it can be heat formed fairly easily, it's reasonably scratch-resistant, and reasonably stiff for flat windows.

[Dave G.]

Anything clear that I'm gluing on a model and I reach for Testors clear parts glue. Ya it's the white stuff that dries clear, but for me, it's held great.

[slusher]

Clear coat works great also brush it o but leave it taped until it dries..

[bobss396]

I sometimes leave material for little tabs when I am making up "glass". This gives a bond surface away from what will be visible. Some plastics bend better than others. I'm now using something from Hobby Lobby that is .015" thick and will hold a bend.

I just unwrapped a new dress shirt and of course saved the pins (great for shifters) and the little clear plastic part that supports the collar.

[NOBLNG]

On 4/25/2024 at 2:01 PM, DoctorLarry said:

Does it dry clear?

It looks pretty clear to me.

[R. Thorne]

I liked the g-s hypo needle type applicator.

[StevenGuthmiller]

The method that I've been using is probably a little unorthodox and requires some forethought, but it will give you a very clean finish on the inside instead of the obligatory globby glue mess that you generally see around the inside of the glass on a model.

 

This technique involves adding plastic stock to the inside of the A-pillars and the windshield header, creating a slight channel, so that when you clear sheet plastic is ready to be installed, it can be cut slightly larger than the opening, and "friction fit" into the opening.

With this method, you can run a small bead of clear epoxy along the windshield header, let it tack up slightly, slide the glass into the opening from the bottom, and then tape or clamp the lower cowl edge into place and glue.

The glued cowl area will be covered by the dash board, the sides of the glass require no glue due to friction, and the only exposed glued area will be along the header, the least noticeable area. and even there, you'll notice a much cleaner look.

Of course this technique is much more involved, but it will make installing the glass itself much easier, and if you want the interior windshield area to look as realistic as possible, this will do the job.

 

The green painted A-pillar pieces and header were the plastic stock that I added to the kit frame.

 

 

 

 

 

I think you'll agree that the interior windshield area looks much more realistic using this method than what you'll normally see.

 

 

 

 

 

Steve