Preparing for my first build I have trawled the internet and note that you have to wash the plastic parts in warm soapy water to remove the grease. Next do you examine the parts and remove any excess plastic where it was attached to the sprue and if you find any surface defects I assume you either fill or lightly sand the surface. If correct do you dry sand or wet sand? I imagine this surface prep will leave a few minute scratchers which would be covered by the first primer coat. Am I on the right track?

Most model primers and paints are self-leveling - especially if you airbrush. Short of brushing on dabs of Acryl, most paints will act poorly to cover up dings and scratches - building up wet paint is a good way to develop a glob or an area that doesn't cure properly. If scratch is minor - don't sweat it; if it's deep - then putty and sand over.

Products like Mr.Surfacer are intended to cover imperfections in the surface

Have a fine ivory board (I use big nail salon ones with flexible backing) or sanding sticks to smooth out areas made rough by lower grit files. It's most common to dry sand and you don't need to ever go too coarse to remove large volume quickly - styrene is not very dense or challenge to sand.

Have a very fine abrasive paper, like 600 grit and above - if specs or globs appear in places, wait for the coat to dry and swipe away imperfections with leaving most of the paint on the surface. This will also improve adhesion of the following coat of paint.

I have never done this. I do "wash" my assembled model with a piece of kitchen paper and a drop of isopropanol to degrease it before painting or priming; Doing this earlier does not make much sense to me because your fingers will make it all greasy again during assembly.




I do this during assembly. Parts are only removed from the sprue when I want to assemble them, othrwise they fall prey to the big carpet monster.

Sanding is mostly done after assembly




I dry sand but go up to 3500 grid (Tamiya sanding tissue). Usually you start with a 800 grid, reducing gradually to 2400 or 3500 grid depending on the surface. For transparent parts i use tamiya polishing powder.





Not if i can avoid it. I strive towards perfection every step of the build. Leaving errors visible counting on the next stages of the build is not giving good results for me

Laurie,
1st off, congrats on getting ready to start your 1st build. What model & scale? Also, did you get a airbrush & compressor yet?

As far as prep work goes, I haven't washed any parts prior to painting in years. Makes no real sense simply because you're trying to wash off mold grease, which there is almost none of these days, and your going to be getting your oily finger prints, and sanding dust on just about everything during the building process. Removing parts from the sprue trees before assembly really increases the percentage of missing/lost parts when you need them. I never remove any parts till I'm actually working on that sub assembly, and then I keep them in small metal paint cups or in clear plastic boxes with tops that paper clips come in.

When removing parts from sprue trees, I generally use a pair of Xuron clippers. I don't try to make my cut right up to the part, but rather leave a small nib that I sand off with #320 then #600 emery cloth. The reason is that many times the plastic will splinter, or you'll gouge a small piece out of the part that then has to be repaired.

I test fit every piece to the sub assembly I'm working on. Any issues are dealt with then. The goal is to get the parts to mate as perfectly as possible where you don't have to force them to fit. Taking it in small steps is better then sanding, filing, cutting too much at once,only to find that you took off too much.

As for surface defects such as scratches, cuts, etc, I deal with them as I'm working on those parts. As an example Fuselage halves. I check for ejector pin holes on surfaces that will be seen. Fill with putty, or Super Glue. When dry sand with #320, 600, 4,000, & 6,000. The plastic should feel smooth as silk. No need to go with finer grades. Many times I don't even bother with 6k. If you used Green Stuff or another modeling putty, there is an additional step after sanding to 600: I seal the putty with super glue, then re-sand and polish. You can also seal with Mr Surfacer 1,000 or 1,200. I just prefer thin super glue.

When the model sub assemblies, or the whole model is ready for painting, I carefully clean them with 70% Iso Alcohol. From that point on, I wear a latex or cotton glove to handle the model. Oils from your fingers will prevent acrylic paints from sticking including on top of primer. If you're painting with enamels or lacquer based paints, they eat right through the oil so it's a non-issue.

Joel