How to fill small gaps?

[Safire6]

I know, it's not a car! I'm building the Revell 1:48 B-17G Flying Fortress....The first airplane I've built in over 45 years. (Thought I would try something different for a change.) Gluing the two fuselage halves together has left some small (approx. .010-.015"?) gaps between them. What is the best way to fill them and make it appear there was never a joint there? Thanks in advance!

[SfanGoch]

You can use 405nm LCD UV-Curing Photopolymer Resin, used in SLA 3d printers as a gap/ seam filler. Somebody at one of the a/c modeling sites (I forgot which one. I stupidly didn't save the page) uses this to fill gaps at the wing/fuselage joints and to fill seams along the fuselage. Since it's a liquid, just apply it with a toothpick. paintbrush or small dowel along the seam/gap. Cure it using one of those penlight UV lights (375-405 nm). Once cured, it's easily sandable and feathers nicely.

To fill ejector pin marks, apply enough so it surrounds the pin mark and slightly overfills it. When sanded, you're left with a perfectly smooth surface. It's a lot neater than using putty.

Black resin is recommended because it contrasts with the styrene. It's slightly translucent which allows you to see the seam/gap/ejector pin mark while sanding. This technique can be used to fill in sink marks on bodies and damage caused by removing unwanted custom parts on rare builtups you might pick up for restoration to stock.

Elgoo Regular or Plant-Based UV Resin, Anycubic or Voxelab are all good and inexpensive.

[Sandboarder]

I would use a Tamiya putty

[SfanGoch]

To each, his own. Unlike Tamiy putty, the resin provides structural strength when cured.

[OldNYJim]

It looks like the challenge there is also going to be fixing/replacing those raised panel lines after sanding 

That said - are they meant to be panel GAPS?  If so, I’d be inclined to scribe them now whilst they’re still there and then rescribe them when you’re done shaping that fuselage

[Sandboarder]

I wouldn’t think 2 pieces of glued plastic would require extra structural strength. 
 

When I want a stronger bond I do use the epoxy putty by Tamiya to fix my kids toys and they last 10x longer then new. 
 

Just offering suggestions, not disagreeing with Sfan. 

[Dpate]

This is really why i don't deal with aircraft kits also boat kits too.  Other than putty's or milliput or some other forms of it most people will take tamiya cement and than squeeze the two halves together and that will ooze out some plastic that helps fill in the gap.  You can than scrap off the excess , BUT there is another good alternative too that method even though it's almost the same.  You could take and make some sprue goo using the sprue parts from the kit to make the sprue goo the same color.   Make it like a medium thickness and use that and once it's dry it'll be easy to sand cause you're left with the plastic itself.  

P.S those zip ties aren't holding tight enough either.  You need clamps like your blue ones or adjustable claps to hold those halves together tight.

Edited January 20, 2022 by Dpate

[Plowboy]

I use crazy glue to fill small gaps. Get a drop on a toothpick, touch it to the gap and it will wick into the joint.

[Ace-Garageguy]

Just a thought...the alignment pins on model aircraft fuselages and wings (and model car engines, gearboxes, axles, blower halves, scoops, etc.) are very often misplaced, and can be a serious detriment to getting a precise fit.

The second, the close-up photo, appears to be a perfect illustration of the problem.

On parts that I want to mate clean with minimal (or NO gap, which is preferable), I routinely remove the pins and "machine" the mating surfaces dead flat on a piece of 180-or-so grit sandpaper on a sheet of glass, or other dead-flat backing.

I then align the parts as closely as possible to get features lined up (panel lines, turrets, etc.), often splitting the differences where tooling is less than precise, and carefully wick liquid cement into the seam...holding the alignment with my fingers as the solvent takes its initial set.

After decades of doing this stuff, I've found the additional effort involved is absolutely worth it in terms of the superior results obtained.

 

Edited January 20, 2022 by Ace-Garageguy
CLARITY and ACCURACY

[Safire6]

Thanks everyone for all your comments and suggestions. I decided to use some Perfect Plastic Putty in the seams/gaps. I'm not too concerned about fixing any raised panel lines after sanding, which should be minimal I think. Not sure how PPP compares to the Tamiya putty, but I've had good results with it in the past. I'll post picks when done. Thanks again!

[Erik Smith]

I agree with Bill’s advice above. I do the same thing with car engine blocks - the pins lead to misaligned parts. Cut pins off, sand both halves flat, hold together whilst wicking thin glue on the joint, press to get a little ridge of melted plastic, clamp if needed, let dry. A very strong joint and filled gap. 

[Rocking Rodney Rat]

x3 with Bill above.

First order of business is to get the two seams to mate together as close as possible. I fill gaps with very thin strips of plastic (cut from Evergreen sheet) and then push the into the seams and super glue them together and sand...I know KK mixes up styrene sanded dust with super glue, but I find that makes too much of a mess. Try a few things and see what works best for you. -RRR

[R. Thorne]

Perfect plastic putty is ok for very small imperfections, but I have never had much luck with it for what you are attempting. Sprue glue, 3M 2 part putty, or mr. Dissolved putty might be a better option to fill such a large gap.