This is Accurate Miniatures' (ex-Eduard) P-39Q Airacobra in 1/48. For a kit this grand, I thought it'll be a walk in the park especially for a returning aircraft modeler. It seemed to have some fit problems.




I've applied some putty, but before I sand it, are there other alternatives so I could preserve most of the detail?

Personally, I only use CA glue for stuff like this. It works much better for me than putty, but putty is OK also (its just not my first choice). Anyway, it seems to me you're gonna have to rescribe the panel lines after the sanding process to preserve the details.

If its Tamiya putty or Mr Surfacer you may be able to use 100% Isopropyl Alcohol with a FEW cotton buds.

My suggestion for the future is you may find you can get a better fit if you attach the upper wings to the fuselage first and then attach the lower wing sections but dry fitting is the key.

Cheers
Wiz

If you're asking about methods to preserve the details before applying putty, I would use masking tape to protect the seam's surroundings. Other way would be using q-tips and thinner to remove excess freshly applied putty without the need for sanding.

On this case however (what a coincidence. it's kinda my will-be case too, as I'm currently building Eduard's P-39Q), I would combine careful sanding and re-scribing detail beforehand so you don't have to do it from scratch if so much sanding is needed that they would disappear.
From the pics it seems that most of the details endangered are mostly straight panel lines and some rivet detail, so this shouldn't be too hard.
I would first scribe out the obscured details, then begin careful sanding (with rolled-up sand paper, suitable files, etc), constantly checking your progress so that you don't lose the scribed detail on the puttied areas, re-scribing details and applying more putty when needed. Continue until the seams are fixed, then finish by scribing the details to the same depth as the rest.

Using tape even in this instance would still preserve the areas near the filler. several layers will be your best bet.

No matter what kind of filler you use you're probably going to have to do some re-scribing. Like Goran I use CA glue- it dries rock hard, can be polished like the surrounding plastic and isn't porous like some fillers. Whatever you decide to go with, try and avoid rescribing along the filled lines, I always rescribe a fraction of a mm. to either side of the filled line so I'm working into the actual plastic.

Finally! I found gold.





Note the seams now, and minimum detail is lost. I first started using this metal file, then do it with a grit 400 sandpaper. Yes, some details were lost, but they were rescribed and it's new again.

Thanks for all the tip guys!

Nice job, mind telling me how you got the rescribing done with the nice straight lines? Freehand?

You did a great job. Do take note of the method lampie discusses here
https://aeroscale.kitmaker.net/forums/98974&page=1