Gaps!

Another method not mentioned here is to use stretched sprue.  I once saw a project where the persons goal was to build a perfect looking model minus one thing....paint.  That is right, a perfect, seamless model, no paint.  That meant no putty or filler.  The person used stretched sprue to fill the gaps and then sanded through the various grades until to a polished surface.  Looked lovely!  I tried it a few times.  Works well, though it is not as fast as putty since you are using your liquid glue, which you obviously need to wait to fully dry before sanding.  But if you plan things right and use stretched sprue to fill your gap then move on to another sub assembly while that dries then it all works out in the end.  The beauty of stretched sprue to fill gaps is you have absolutely no issues with shrinking, cracking, or any of the other minor problems putty can give you.  It sands as perfectly and as smoothly as you would expect styrene to sand.  Voila!

OMCUSNR

Cyano Acralate (AKA super glue).  Developed for use as a dental adhesive.  I remember when Eastman 910 was $90/oz (back in '74).

I remember Eastman 910 and $90/oz too. But I think it was a serendipitousl discovery by a manager of some Eastman scientists who were trying tp find an improved acrylic (plexiglass) for airplane canopies. It's many use (dentistry, surgery, etc) were much later. Anyway, that's what I remember.

Cyano Acralate (AKA super glue).  Developed for use as a dental adhesive.  I remember when Eastman 910 was $90/oz (back in '74).

Of course you  can always fill a gap with plastic.  I have cut up bits of sprue and put it into a bottle of Testors liquid cement.  Give it time to melt and it makes a good filler.

I gotta say DITTO to DOOGS ATX for his comment .

     I do this differently .I will use either green or red putty .Either one works , but I think the green is softer after drying . I do NOT use CA and ACCELERATOR . Never have ,never will . I tried it and found out , that if you,re sanding and torque the part a little it cracks and it is actually harder to fix . Stick with the red or green putty and I think you'll be happy with the results .

I use Tamiya white putty thinned with lacquer thinner.  I squeeze out a small blob on the palette add a couple drops of lacquer thinner and thin to about the consistency of paint then brush it on.  Does not shrink and the thin coats mean less sanding.  Worked well so far if you don't mind the a little bit of lacquer odor.

Superglue

Squatch88

newbie question...everyone keeps referring to "CA" what exactly is this?

super glue.

newbie question...everyone keeps referring to "CA" what exactly is this?

The best sanding sticks I have ever used are by Flory Models: www.florymodels.co.uk/skinny-sticks

I just had that moment lol. That's a "where have you been my whole life" moment. Thanks :)

Thanks for all the good advice!

I use CA almost exclusively for filling gaps.  No shrinkage and no waiting for it to dry.  I use 320 grit to sand it down, then switch to finer grades to remove the scratch marks.

I use Tamiya Putty or Mr Surfacer 500 for filling gaps,You might look online for Mr Surfacer,I know Amazon sells it.

I use sanding sticks which I got from squadron or sand paper of different grits which I got from my hobby shop

Awesome suggestions!  Thanks very much.

I also use auto glazing putty.  But if the gap is too big it needs to be supported. If  the gap is over about 1/16 inch I fill the gap with sheet styrene, then putty any remaining cracks.  If the gap is very small- just a surface scratch that does not go clear through, then I may use gelled superglue.  Styrene strips come as thin as ten mil, twenty mil is a popular size, and  one can use several of such strips in a stack.

Vallejo has a putty that I like to use. It does not shrink and sands great. I have used Squadron sanding sticks forever and never had issue with them.

Thad

Gonna have to agree with everyone here.  I HATED using any form of putty until I had that "Well DUH!" moment of using the tape.  Now whenever I have a gap, I just use the tape to mask of only the extremely narrow area where I want the putty to go.  I apply the putty (Squadron green putty in my case), smoothe it down with my finger dipped in rubbing alcohol, then remove the tape.  After the sanding is done, I only have a wee narrow area where I need to rescribe the detail rather than an area the size of a golf ball.

I loved my Mr. Surfacer 500 when I had it.  Now I can't find it locally anymore.  For those smaller seam issues, I use plain and simple White Out correction fluid.  It fills those tiny hair-like gaps and sands just great.  I think many of them have the pointed foam applicator now rather than the little brush.  The pointed foam helps me place just a thin line only where I need it.

Eric

I'm a big fan of 3M acryl glazing putty (I use red...). Thins excellently with lacquer thinner, feathers out beautifully with sanding, though it'll clog up a sanding stick like nobody's business. I "gate" my puttying with tamiya tape so I'm only applying it to the exact gap or seam or what-have-you.

For larger gaps, you can shim it with some sheet styrene, weld it in place with something like Tenax or Tamiya Extra Thin Cement, cut the plastic down and then sand it flush.

Sanding sticks - I really really like the Flex-i-file sanding sticks. Squadron's are way rougher, leave grit behind and all that.

Something I learned after years of "the hard way" is not to let CA set up too long before sanding.  Apply it (I use either a straight pin or safety pin to keep the amount small); try not to use too much; wait no longer than an hour--sometimes even 10,15 minutes is enough.  Then start sanding.  If you use smaller amounts of the CA, it sets up quickly and hardens, but not so hard that the sanding is heavy work.

This way doesn't require accelerant.

And like any other technique, trial and error, practice, practice, practice.

Good luck.