Filling tiny gaps

Extra thin CA glue. Let it cure. Scrape away excess and sand smooth. Remember CA glue is harder than styrene, so sand carefully. Works great on tiny spots like that.

BK

wpwar11

What's the best way to fill these tiny bubble like gaps in this piece?  It's two halves that make up the rear spine on a MIG-31 build.  

I use Gorilla Super Glue with the light blue cap.  Use a toothpick to dab the glue into the gap (the dabbing with the toothpick will help work it into the gap and push out any air bubbles) and then let it cure a few hours (I usually just go overnight with it while I work on something else).  Once its cured, I take a black, Ultra Fine Point Sharpie and scribble along the lines of cured glue, making sure especially to get the ink on the edges of the glue and where it and the plastic meet.  The reason for the Sharpie scribble is to give yourself a visual indicator of when you have sanded the glue flush with the rest of the part.  After that, I wet sand with progrssively finer grits of MicroMesh sanding sticks, starting with 1500 and working my way up, following the curves/contours of the piece until all of the black Sharpie is gone.  When you put primer on it, you won't be able to tell where the parts are joined.  Every once in a while, the primer will reveal a tiny void here and there.  If that happens, just repeat the process with those spots.  Most of the time though, this is going to work on the first shot.  If you're gentle and careful enough with the sanding, you shouldn't have to re-scribe the lines around the part.

I still  use Testors enamels.  They are notorious for rapidly settling out when they sit, and ordinarily have to be well stirred.  I stick a toothpick in bottom of jar without stirring, and find a big drop of what is almost a putty. Easily fills cracks that small.

Maybe even a spray of primer might suffice,hard to tell with pictures,but I have found that primer covers a multitude of small imperfections.

If you take a piece of thinly stretched kit sprue, lay it over that seam, and flow liquid styrene cement over it, it'll fill the holes and give you a weld of the same material.  When the glue has cured, you can scrape and sand the seam smooth.

I like to use the extrusion technique to head off things like this.  I'll use liquid styrene cement on that join, apply pressure while the glue is still liquid, and extrude a bead of melted plastic along the seam.  When the glue has cured, same thing, scrape and sand the seam smooth.

Mr. Dissolved Putty. Like Mr. Surfacer, only thicker. Apply it with a small brush, allow it to dry, then sand smooth.

https://www.mr-hobby.com/en/product2/category_12/263.html

Thanks for all the great responses.  When I glued the pieces together I did get a nice ooze of extra thin.  Maybe I sanded to much that revealed those tiny gaps?   I'll use some of the advice here.

If I'm trying to really tighten up a joint on assembly, I look for more than an ooze of TET.  I let it soften the plastic a bit and then give an extra squeeze.  I want to see actual melted plastic (a bit) coming out of the joint, not just clear TET.  

Hmmm;

        On gaps like that I use Mr. Color primer OR Sprue Glue.They both work well. Usually though I use Tamiya Yellow Cap(It's thicker.)Let it sit for a minute and then squish the parts together. That beautiful Ridge of melted plastic comes out and fills everything. Now, you know why I also remove All locator pins. Cause sometimes they will push parts apart because air got caught in the holes and this lets it push out when we ain't looking!

wpwar11

Thanks for all the great responses.  When I glued the pieces together I did get a nice ooze of extra thin.  Maybe I sanded to much that revealed those tiny gaps?   I'll use some of the advice here.

 

I still get the occasional, tiny voids like that too, Paul.  Don't know why it happens sometimes...just does.  I'm sure you're already doing this, but try to have a gap between the parts about half the thickness of a sheet of paper when you apply the Extra Thin.  After you do, count to 20 before pressing the parts together so it has time to get the plastic melted along the joint.  Then you'll see the bead of melted plastic that MJY mentioned when you press the parts together.

I agree with yoiu 100% That is my go to product for filling small holes.

sometimes spruegoo is pretty good in these cases .

Much better.  Used Bob Smith super thin CA.  Filled the tiny holes and light sanding.  Primed with mr surfacer mahogany to check.   Thanks for all the responses!