Do you glue canopies onto paint?

[keiron99]

Hello. First post :) Back in the game after more than, ooh...30 years.

 

I'm building a 1/72 Airfix Harrier. I stocked up on all the tools for the job, including some special "canopy glue" (which I guess is PVA decanted into a little bottle with a large markup...)

 

But, what do I do regarding paint on the mating surface? Do I glue the canopy onto the bare plastic, or do I paint the plastic surface onto which the canopy will sit then bond it to that?

 

(Actually. I've done things a bit back to front...I have already sprayed the plane before attaching the canopy, which I think was probably a mistake? So I may now have to scrape the paint (acrylic) from the mating surface?)

 

[ckw]

The whole point of canopy glue (yes, basically PVA) is that it doesn't interact with plastic so there is no risk of damaging clear parts. The down side is that the bond is not as strong as using polystyrene cement. But because there is no interaction, it doesn't matter if the mating surface is painted or not.

 

Cheers

 

Colin

[Alex Gordon]

G'day old fruit, .I've used paint to fix canopies on before,it seems to work on sash windows.

 

Depending on whether the canopy is fixed or moveable I will use glue on plastic to plastic for a seamless joint or paint,PVA,or varnish if the joint doesn't need to be hidden.Have fun with the Harrier,there's plenty of folks around these parts would enjoy seeing it.

Edited February 22, 2021 by Alex Gordon
spelling

[keiron99]

I tried the special glue I bought, between the painted edge of the cockpit and bare plastic of the canopy. It didn't stick it

[Shin]

9 hours ago, keiron99 said:

I tried the special glue I bought, between the painted edge of the cockpit and bare plastic of the canopy. It didn't stick it

like it didn't stick at all? pva glue is fairly slow curing, I wouldn't touch or manipulate the model at all for a few hours. 

[pigsty]

These days I always use PVA and I almost always have to glue across at least one painted surface.  The reason for that is that I paint the sills the right colour to ensure there's no bare plastic showing up, and the clear parts' mating surfaces black to cut down internal reflection.  That helps mask the fact that they're horribly thick compared with the real thing.  My PVA of choice is Pacer's Formula 560, which is, as you say, the conventional stuff marked up - but it seems thicker and stronger than good old wood glue.  After a couple of days it's nearly as hard to remove as CA superglue.  The other advantage is that you buy a lot less at a time, which means I don't end up with 90% of a big bottle unusable because I build so slowly.

[Mike]

As others have alluded, the join between canopies and models can be fairly weak if you use PVA or the like, so the presence of paint doesn't really matter. 

 

The question is, should you add the canopy after you paint the model?  My own personal answer would be generally no.  I tend to fair in my canopies if appropriate, and like to have as little difference betwen the paint on the model and the canopy, so I usually add the canopy before paint, rendering your question moot.  GS-Hypo cement is my glue of choice, but if it needs fairing in I then fill the outer seam with small quantities of black CA and sand back to flush once the GS is cured.  If you don't have black CA, just mix in some black pigment to clear CA - trust me, it works I've been working on the new Kinetic Pucara lately, and that doesn't need fairing, as they've sensibly moulded it along a panel line, which saves me some time.  Other models may vary, so check your references to see if you have any work ahead of you.

[fishplanebeer]

Another vote for GS-Hypo cement which is for watch glasses, jewellery work etc.. but works a treat and gives a strong bond. It can be a bit stringy so some care is needed but the tubes have a very fine applicator which makes it very precise. I also fix the canopy before painting/spraying as this way you can fill in any gaps between the fuselage to get a nice fit although I tend to use pva as the filler or liquid putty.

 

Regards

Colin.