Help on wing and fuselage seams

[Splatman812]

I keep running into this problem. Mostly wings. Using testors, revell, etc glue, i have problems with the glue drying a bit before joining the wing top and bottom (mostly because of trying to carefully put glue on the seam edge without getting it everywhere. I see people using Tamiya thin, so on my latest build (a AR 555), I mated the bottom and top, taped after alignment and applied Tamiya thin around the seams. Much easier.

But after a little handling, the seam opened up along the leading edge. The thin just doesn't seem to create a strong bond.

 

Any suggestions for a better way would be greatly appreciated!

[denders]

Which Tamiya thin? The one with the green lid or the yellowish-green lid?

 

The yellowish-green lid is faster evaporation and doesn't penetrate as far. The green lid takes longer (not really all that long) but should penetrate better.

 

[Splatman812]

The Tamiya was the lighter green top. I have of the darker green top, but didn't use it as it was just about empty. I guess extra-thins aren't the same? To be honest, I never noticed the two were different

[Juggernut]

If you tape the parts together before cementing, you run the risk of preventing the cement from penetrating the joint effectively or possibly at all.  
 

Try simply holding the two pieces together loosely between your fingers with a hairline gap between the parts.  Touch a full brush of the Tamiya extra thin (shouldn’t matter if it’s the regular stuff or the quick setting type) to the joint and you’ll see it run along the joint via capillary action.  It will travel an inch or so.  Wait a few seconds….  Now squeeze the glued part of the joint together and allow the melted plastic to squeeze out of the seam.  Now you can tape the joint securely together to dry.  Continue around the joint, gluing, squeezing, and taping until the entire part is glued. This works well for wing, fuselage, and stabilizer halves.
 

After the glue has fully cured, you can remove the tape.  The joint should now be strong enough that it won’t split.  Having said that, split joints do happen from time to time, usually at the most inconvenient moments.  Reapply glue as above and hope it stays glued.

[Splatman812]

Thanks Juggernut.

From your advice, I can see one thing I didn't do------allow a slight gap, apply and then mate. This kit is  a 1/72 AR-555e with a top and bottom wing (with cranked wingtips), so getting the two halves aligned was tricky (thus the tape). But I applied with a tight seam, thinking the capillary action would work anyway.

[Stevepd]

2 hours ago, Splatman812 said:

Thanks Juggernut.

From your advice, I can see one thing I didn't do------allow a slight gap, apply and then mate. This kit is  a 1/72 AR-555e with a top and bottom wing (with cranked wingtips), so getting the two halves aligned was tricky (thus the tape). But I applied with a tight seam, thinking the capillary action would work anyway.

The capilary action would have worked, but it would have run along and not in and along. As J has said above its got to get in there and the join not be "water tight" as such.

[Splatman812]

Thanks for the replies guys

Ready to change my ways on the next build

[thierry laurent]

Capillary gluing only works if the fit is excellent, if there is no tension in the plastic parts and if the parts are not too large! Otherwise you need to rely on other glues plus clamps, pegs, tape and so on. Personally, I'm generally relying on a combination of glues for the large parts. This goes from ultrathin glue to the gel type you can find in tubes sold in DIY shops! The thicker glues offer some advantages such as longer drying time as well as a filling action in the larger seams. Similarly I'm quite often combining CA spots with epoxy! CA offers a quick drying whereas epoxy offers strength. Do not hesitate to experiment using different glues and combining them. Actually I'm using at least a dozen of different ones as all of them have pros and cons!

[quang]

Why don’t you try the old school way?

Regular plastic cement in tube (Humbrol, Revell, …) works wonder for fuselage and wings.
I just don’t try to glue them in one go. I only work in sections, one after the other. I never use clamps, only masking tape and customized wooden cloth pins.

[mozart]

Wot Quang sez! He’s a very wise man…..and old. 

Edited Saturday at 06:14 PM by mozart

[thierry laurent]

If you use gel type cement (the tube one also mentioned by Quang) you can normally glue wings in a single step. The drying type is normally sufficient. For fuselages this depends on the length.