Sanding/Filling question

Tools, Techniques, and Reference Materials Techniques
1

I am working on an Academy Corsair kit. I had some fit issues and got it filled and sanded nicely. How fine of a grit sand paper do I need to use once everything is sanded level? I have only airbrushed once, so I don’t know what it will cover/ show. I don’t want small scratches from sanding showing through. If anyone has a picture that would be fantabulastic!

Thanks,

Scott

2

That depends on the type of finish:

  • Flat camouflage—800 grit final
  • Glossy—1000 grit or higher final
  • Metal, flat—1200 grit final.
  • Metal, shiny—1200 grit minimum final. 2400 is generally not too much. However, you may be better off over 1500 sanding and polishing a primer, as many paints adhere better to a polished primer than to a polished plastic surface.

However, for metallic finishes, follow the recommendations of the coating manufacturer.

Keep in mind that when sanding, glare is your friend and ally. Glare will show up imperfections and true surface conditions better than any other illumination.

3

Couple of things for you to read. Here and this one here. This should help you with your questions. Remember its better to do it “right” the first time. Paint accentuates flaws in the surfaces it is applied to. It’s all about the prep work!

4

That was a very nice article. Thanks for the link. Right now I am using the squadron white putty, and CA. CA seems to work better. The only issue I have with it is that its’ clear. Sometimes it can be hard to tell if things are filled or not. CA is much harder to sand, and with the extra sanding I have to rescribe more panel lines than when using the putty. Its’ good practice for me though. Now I’m not too fond of the putty, and I’ve read you can thin it. I also see a lot of information on Mr. Surfacer. Do you have a preference on putties, and would thinning the squadron brand help? Oh, and what would I thin it with?

Thanks again,

Scott

5

I was a Squadron Green Putty user for decades, in fact I still use it occasionally. I switched to CA but found that it can be labor intensive if you cannot work it immediately after applying. It hardens and hardens with time, making it more difficult to sand, file, grind.

As you probably noted while reading my articles, I’ve tried to improve my building skills to negate the use of any fillers when possible. However, there are times when it is required and I like the 3M Acryl-Blue glazing compound. Finer and feathers cleaner at the edges. Also the light color makes it easier to cover with paint. For the heavier filling jobs…styrene…strong like the weld line on steel. Easy to shape because it maintains the same consistancy as the material around it…because it is the same! Mr Surfacer is good to but it getting harder to source. Both the Mr Surfacer and the 3M Acryl-Blue can be thinned with thinner. I don’t use Mr Surfacer as a primer, just as a filler.

6

The best thinner I’ve found for 3M Acryl Blue is 90% isopropyl alcohol. It evaporates more slowly than lacquer thinner and is less aggressive to styrene.