Sub assemblies painted, best glue to put them together

Got a question about techniques, materials or other aspects of physically building a model? This is the place to ask.

Moderators: DasPhule, Moderators

Post Reply
ulvdemon
Posts: 527
Joined: Thu Sep 09, 2010 9:10 am
Location: Alpharetta, GA

Sub assemblies painted, best glue to put them together

Post by ulvdemon »

I have to admit, I've been looking into this but I think I am just missing this most basic concept.
I understand the need to build and paint in subassmeblies, but to minimize on sanding the joins, what is the best type of glue to use? Epoxy or superglue
I'm aware that good ol' styrene glue is pain to bond on painted surfaces, but if you have to build, paint and decal in subassemblies, what is the ebstw ay to glue everything together to minimize any gaps that can occur?
Current build: 1/32 Hasegawa F6F-5 Hellcat

Completed: 1/48 Hasegawa F-16CM<,1/48 Revell Mig-21PFM, 1/48 Revell/Monogram AH-64A, Revell/Monogram 1/48 F-14D, AMT 1/420 USS Defiant, AMT 1/650(?) USS Enterprise, 1/72 Bandai VF-1J, AMT 1/537 USS Reliant, Academy 1/35 M1-A1 Abrams, Academy 1/48 F-86F30, Linbergh's USS Gato
User avatar
Dieghigno
Posts: 68
Joined: Sun Aug 22, 2010 2:06 am

Post by Dieghigno »

This one: http://www.anticsonline.co.uk/l.aspx?k=13754

Try to make the thinnest layer you can...
It melts paint and plastic and made a very strong bond
ulvdemon
Posts: 527
Joined: Thu Sep 09, 2010 9:10 am
Location: Alpharetta, GA

Post by ulvdemon »

Thank you. Will look into it.
Current build: 1/32 Hasegawa F6F-5 Hellcat

Completed: 1/48 Hasegawa F-16CM<,1/48 Revell Mig-21PFM, 1/48 Revell/Monogram AH-64A, Revell/Monogram 1/48 F-14D, AMT 1/420 USS Defiant, AMT 1/650(?) USS Enterprise, 1/72 Bandai VF-1J, AMT 1/537 USS Reliant, Academy 1/35 M1-A1 Abrams, Academy 1/48 F-86F30, Linbergh's USS Gato
User avatar
Kylwell
Moderator
Posts: 29643
Joined: Sun Nov 02, 2003 9:25 pm
Location: Lakewood, CO
Contact:

Post by Kylwell »

Any glue has issues with paint largely because the glue attaches to the paint which then attaches to the plastic. With acrylics this leads to an exceptionally weak joint. I tend to clear the joint areas carefully and bond with my usual Tenax 7R.
Abolish Alliteration
User avatar
dizzyfugu
Posts: 640
Joined: Fri Oct 23, 2009 7:14 am
Location: Right behind you!
Contact:

Post by dizzyfugu »

Kylwell wrote:Any glue has issues with paint largely because the glue attaches to the paint which then attaches to the plastic.
That's the main point. Whatever you glue together, make sure you have clean surfaces - not only without paint, but also without grease from your fingers, etc. Scratching away paint will suffice (and also prevent potential ugly reactions of the paint with glue!), and if you want a really clean basis use some Windex or iso alcohol, e. g. with a brush.

For the glue itself, use whatever is appropriate for the materials. I found that a clean surface on polysytrol kits is "enough" when you use normal plastic glue, so that it can meld and bond the material as it is supposed to. One (or even two) layers of paint considerably weaken this bond, so that IMHO no extra glue is necessary. But on other materials, where you do not change the material properties and just make the surfaces adhere, some super glue or even 2C glue might be the best option.
DizzyFugu - Reporting from Germany
http://www.flickr.com/dizzyfugu
Tankmodeler
Posts: 949
Joined: Fri Jul 30, 2010 12:04 am
Location: Ontario

Re: Sub assemblies painted, best glue to put them together

Post by Tankmodeler »

[quote="ulvdemon"]I understand the need to build and paint in subassmebliesquote]
Actually, I'm not sure I agree that there is a need to build and paint in subassemblies.

I only build and paint in subassemblies if I can do so and not create a joint whith a seam or where the adhesive will be seen later. If it leaves a seam, it all gets built together so I can fill the seam before I paint.

Now a separate part, like a suspended weapon on a pod or a dropable fuel tank or the like, I'll build and paint separately because I can make sure there is no gap and the seam is actually supposed to be there.

I only have to controll the gloss from any small amount of glue visible and I do that by hitting the joint with my last flat or gloss coat before weathering and then weathiering the entire model as one. I almost never weather seperate assemblies, so the final weathering give a last chance to hide any gloss from the adhesives andbelnd it all together.

That said, if you are bound and determined to bond a painted part to another, make sure you remove the paint from the joints. For most small aprts yuo really only need to remove a vers small amount of paint to get a good solit styrene to styrene join. If the glue is something else, like epoxy or CA, then you'll need a somewhat larger area.

In bonding, cleanliness of the bond line is the golden rule!

Paul
The future is in your hands. Build it!
Tankmodeler
Posts: 949
Joined: Fri Jul 30, 2010 12:04 am
Location: Ontario

Re: Sub assemblies painted, best glue to put them together

Post by Tankmodeler »

[quote="ulvdemon"]I understand the need to build and paint in subassmebliesquote]
Actually, I'm not sure I agree that there is a need to build and paint in subassemblies.

I only build and paint in subassemblies if I can do so and not create a joint whith a seam or where the adhesive will be seen later. If it leaves a seam, it all gets built together so I can fill the seam before I paint.

Now a separate part, like a suspended weapon on a pod or a dropable fuel tank or the like, I'll build and paint separately because I can make sure there is no gap and the seam is actually supposed to be there.

I only have to controll the gloss from any small amount of glue visible and I do that by hitting the joint with my last flat or gloss coat before weathering and then weathiering the entire model as one. I almost never weather seperate assemblies, so the final weathering give a last chance to hide any gloss from the adhesives andbelnd it all together.

That said, if you are bound and determined to bond a painted part to another, make sure you remove the paint from the joints. For most small aprts yuo really only need to remove a vers small amount of paint to get a good solit styrene to styrene join. If the glue is something else, like epoxy or CA, then you'll need a somewhat larger area.

In bonding, cleanliness of the bond line is the golden rule!

Paul
The future is in your hands. Build it!
ulvdemon
Posts: 527
Joined: Thu Sep 09, 2010 9:10 am
Location: Alpharetta, GA

Post by ulvdemon »

Thank you everyone.
Current build: 1/32 Hasegawa F6F-5 Hellcat

Completed: 1/48 Hasegawa F-16CM<,1/48 Revell Mig-21PFM, 1/48 Revell/Monogram AH-64A, Revell/Monogram 1/48 F-14D, AMT 1/420 USS Defiant, AMT 1/650(?) USS Enterprise, 1/72 Bandai VF-1J, AMT 1/537 USS Reliant, Academy 1/35 M1-A1 Abrams, Academy 1/48 F-86F30, Linbergh's USS Gato
Post Reply