Canopy glue?

[blakeh1]

How/what glue do you use to attach canopies

I have been using the Testor styrene cement or CA previously, but neither is a great solution

CA can sometimes fog it up, and the testors stuff can sometimes ruin the paint, or yellow, or even fog as well

I have seen some dedicated clear canopy glues, but was wondering what others have typically been using

 

[urumomo]

I started using this stuff : https://www.scalehobbyist.com/catag...t=2&u=0&pg=2&ppp=48&sb=stocknumber_a&so=d&e=0

Performs very well .

https://supergluemsds.com/Docs/PT56 - Formula 560 Canopy Glue, Rev 4 - 2012.pdf

 

[urumomo]

It's a PVA like Elmer's white glue so it's qualities are similar but I don't know how the tiny amount of formaldehyde affects performance .

Hmmm : " It is certainly less known that other types of adhesives, such as vinyl, may also contain formaldehyde in discrete quantities. In these cases, formaldehyde may have been added as a preservative or it may result, as a by-product, from polymerization reactions of the same resin or in consequence of the self-crosslinking mechanisms involving certain types of water-resistant adhesives. "

From : https://catas.com/en-GB/news/formaldehyde-in-vinyl-adhesives

 

[urumomo]

When I ordered this stuff from Scale Hobbyist last year I wanted to see if it was any different than regular white glue or just priced much higher for the gullible hobbyist I figured since it was only a couple of bucks I'd check it out .
Your question got me back on topic research .

So maybe this stuff is a product of one of the following :
( UF = urea-formaldehyde , MF = melamine-formaldehyde )

" Several modifications are used to enhance the resistance to moisture and to decrease creep of PVAc adhesive bonds. One such method is the addition of other types of vinyl monomer during polymerization to improve the properties. A second method is to add cross-linking agents that increase the rigidity of the polymer.

Because of the fact that PVAc is polymerized with minor amounts of vinyl alcohol, there are free hydroxyl groups on the polymer. Also, free hydroxyl groups can be formed by hydrolysis of the acetate groups. These hydroxyl groups offer sites for cross-linking. Cross-linking agents include strongly chelating metal salts such as chromium complexes. In addition, other adhesive resins such as UF, MF, and isocyanates have been used to advantage as chemical cross-linkers. Cross-linked PVAcs are more rigid, have better moisture and heat resistance, and have greater initial tack. "

From --> https://www.sciencedirect.com/topics/chemical-engineering/polyvinyl-acetate

 

[blakeh1]

I started using this stuff : https://www.scalehobbyist.com/catag...t=2&u=0&pg=2&ppp=48&sb=stocknumber_a&so=d&e=0

Performs very well .

https://supergluemsds.com/Docs/PT56 - Formula 560 Canopy Glue, Rev 4 - 2012.pdf

Before posting here, I had bookmarked that in my wish list and was reading some reviews on it, but wasn't sure if it was worth it over Elmer's

Does it dry clear, or does it dry more like Elmer's

May have to pick some up

Kudos on the MSDS link as well

 

[urumomo]

It cures out about like Elmers -- clear if thin , slightly less so if fairly thick .
I think it's aimed at the RC crowd and provides higher adhesion and shock resistance for that genre .
More economical to just use regular white glue for static models .

 

[Belugawrx]

I tried Tamiya clear gloss to glue headlights and windshields a couple times, where visible glue, even if clear, leaves a goopy line if not applied very judiciously..which I don't..
.. anyways the clear worked quite well..still holding up

 

[urumomo]

Acrylic gel medium works well too .
Static models live a pretty cushy life so you can get away with less than robust assemblies .

 

[Marktastrophe]

I've recently stumbled upon BSI Super Gold + it is a CA glue, but it does not fog plastics. I think the product page actually calls it out as Ideal for canopies, lol.
Super Gold +
It is pricey, and that price seems to vary depending on where you go. I got a 0.5 oz botte for around $10 at a locally owned place, but saw them running at $18 at Nankin Hobby, which is a very small (smaller still after a few years of COVID) chain in Michigan.
That being said it seems to be stocked at most hobby and RC shops.

I gleamed the brand off this guy's YouTube:
Jun's Mini Garage
I've used other BSI glues in the past and they work well, but I do wish I would've known this particular bottle doesn't fog plastics WAY sooner, lol.

Now for the grain of salt: I just picked this glue up last week and have not had a chance to use it on clear plastics myself.

 

[the Baron]

I usually use white glue aka PVA glue (brand is Elmer's), but I'll also use styrene glues, like Testor's styrene cement in the tube, or Tamiya liquid cement, depending on the specific application.

White glue has a couple of advantages. It doesn't react with paint or styrene, it can help fill gaps around a canopy or windshield, and it can be dissolved if necessary with warm water.

I don't use CA glue, because it's supposed to give off fumes as it cures, that etch the clear parts (aka "fogging"), but also because I prefer where possible to use styrene cement to join styrene to styrene.

Best regards,
Brad

 

[urumomo]

" a 0.5 oz botte for around $10 at a locally owned place, but saw them running at $18 at Nankin Hobby, "
LOL , WTF

 

[blakeh1]

My reservation with the testors styrene cement is I tend to glue on the canopies after painting and getting even the tiniest amount ooze out ruins the paint it touches

 

[Palantirion]

I have read that you can safely use CA around clear plastics if you hit it with accelerator. It's the CA offgassing that fogs the plastic, so curing it nearly instantly prevents this. So I have read, but not yet tested to verify.

 

[urumomo]

True . And always use the smallest amount possible .
Just a note for those unfamiliar -- that off gassing is not chemical byproducts from the curing but vaporized CA monomers themselves :
https://www.resinlab.com/resources/cyanoacrylate-frosting-or-blooming/

Good video on how CA cures :

 

[golgotha]

I have read that you can safely use CA around clear plastics if you hit it with accelerator. It's the CA offgassing that fogs the plastic, so curing it nearly instantly prevents this. So I have read, but not yet tested to verify.

There are special CA Glues, Zap is the one I know, that are formulated not to fume. I don't know how, but it works.
Also if you have any contacts who can help you, Medical CA wound Glue works too.

 

[Palantirion]

True . And always use the smallest amount possible .
Just a note for those unfamiliar -- that off gassing is not chemical byproducts from the curing but vaporized CA monomers themselves :
https://www.resinlab.com/resources/cyanoacrylate-frosting-or-blooming/

Good video on how CA cures :

-Great vid, thanks for posting. Now I have more questions: Like, why should we spend money on CA accelerants when plain water will also accelerate curing?

And...I was under the impression that we should keep our accelerant and CA glue very separated (Mine are in the same bin but the accelerant is in it's own zip lock baggie), but according to the vid the fumes come from the CA glue. So, should we not keep our CA in an airtight baggie, and also add a dehumidifying packet to said bag? As it's the water in the air, not the air itself, that starts curing our CA inside the bottle.

 

[urumomo]

The humidity in the air is enough to set off the chain reaction to polymerization .
Liquid H2O would act as a bond breaker if on the parts to be connected and would cause dilution of the monomers and too rapid a reaction creating a very weak bond .

This one commenter touches on this fact discussing accelerators :
" One thing that I can think to add is that the faster CA polymerizes the weaker the overall bond is (due to overall shorter polymer lengths). A slow exhale on the surfaces to be bonded tends to work better for me than accelerants (though that is totally anecdotal evidence). "

And his response :
" Awesome! Yeah I figured chain length was the explanation for why accelerators contain such such crappy nucleophiles (tertiary conjugated amine? wow.) If accelerators had better nucelophiles, the mechanical properties of the cured glue would be even worse. "


Once you open the bottle of CA it is indeed exposed to atmospheric moisture and begins a cure .
An opened bottle will have far less shelf life than an unopened bottle .
CA has a very limited shelf life ( ~ 1 year ) which can be extended a bit by storing in the fridge , or better yet , the freezer .
But let the bottle come up to ambient temp before using it to avoid condensation of atmospheric moisture on the cold bottle dispensing tip .
keeping the lid on tightly is enough since you are going to remove the bottle from the desiccant protected bag and expose it to room humidity anyways . ... unless the bag is big enough for you to climb into - but wear a rebreather to avoid contaminating the environment with the vapor from your breath !

 

[Palantirion]

BIG WORDS! Lots of big sciency words! Makes sense though, thanks very much for explaining about the importance of chain length.

 

[urumomo]

I'm gluing pieces of scrap polystyrene on edge to the face of sheet polystyrene using that Formula 560 Canopy Glue and Elmers , and then after at least 24 hours of cure , pull them apart using a spring gauge to see if there is any difference in bond strength between the two .
Destructive test for both shear and tension on the joint .
Probably post the results Monday .
Plastic to plastic , I'm not expecting any difference but we'll see . Maybe I'll be surprised . ( probably not , lol )

 

[urumomo]

Ok ,
Pleasantly surprised .

The Contenders :




The Testing Setup :



One and two mm styrene with holes drilled to load the glue joint in either tension or shear .
42 hours cure time @ 78 F , so definitely fully set .

The Testing Apparatuses :




I clamped the sheet styrene to a workbench for the tension test and clamped it vertical in a vise for the shear test .
Unfortunately , one of the Elmers samples popped off as soon as I clamped the sheet down on both sides .
It flexed it just enough evidently .
It was the smaller disc pictured above .
So no data , but we'll give Elmers a fail anyways .

The following are the values for force in grams .
Every sample failed instantly at the noted value .
I don't note the thickness of the styrene or the joint length but each test utilizes identical joint parameters for each .

Tension Test :

1) Elmers - 950 grams , Canopy Glue - 5000 grams , Formula 560 = 5.55 times stronger
2) Elmers - 650 grams , Canopy Glue - 2000 grams , Formula 560 = 3.07 times stronger
3) Elmers - Pop loose , Canopy Glue - 1250 grams

Shear Test :

1) Elmers - 1700 grams , Canopy Glue - 2750 grams , Formula 560 = 1.62 times stronger
2) Elmers - 650 grams , Canopy Glue - 2750 grams , Formula 560 = 4.23 times stronger
3) Elmers - 800 grams , Canopy Glue - 2500 grams , Formula 560 = 3.12 times stronger