Tips of Spray Painting and Sanding?

[Didact]

Greetings everyone! I recently moved and while my wife was packing things away they stumbled upon a 1/1 Darth Vader helmet I got from TRU years ago. It's completely plastic and I completely forgot about it. When I found it, it had bits broken off and the paint has faded along with the gloss so I took it upon myself to buy some putty and fix it up. Now I've been working on it lately and I have a couple of questions I was hoping some of you painting experts can help me with.

Here's a step by step of what I did:

1) Sanded out areas I wanted to apply the putty
2) I applied the putty and worked on it, allowed it to dry and sanded it down with 1500 grit until it was super smooth.
3) I then sanded the entire Dome, stripping the paint first with a lower grit and then I sanded it down until it had a nice smooth feel.
3) Bought Tamiya Fine Surface Primer and I primed it with 2 coats.
4) I left it to dry for 24 hours and about an hour ago I spray painted it with 3 nice coats of Tamiya Black.

Now as it's drying now, it doesn't have a completely smooth surface. It almost has a grainy texture to it. The surface just looks grainy and not gloss smooth.
I bought Tamiya Semi Gloss Clear as a top coat but I was curious if you fellow members can help my make my future spray painting progress better.

Now I have a couple of questions.

1) Should I leave the paint to dry for 24 hours before applying the semi gloss? Can I spray it with coats of the gloss clear right away or is there some sanding I need to do to achieve that super smooth glossy surface? Since I'm using Semi Gloss I'm not looking for a glass effect but I would like my surface to lose the grainy texture it has so that when I handle it, it's smooth when I slide my finger. How do I go about getting that? I bought the following a couple of minutes ago in case they will help me:

3600-12000 Grit Polish Pad
Micro Mesh HSX200 Paint Polishing Soft Touch Pads 5 Grits 3600 to 12000 | eBay


Novus Plastic Polish
Novus Plastic Polish 1 2 3 2oz Bottles 1 Each Scratch Remover Cleaner Kit | eBay



2) Is there any sanding/wet sanding that I should have done in between one of my steps to make the outcome better?

3) Instead of spraying the Semi Gloss, can I use the Novus Kit to make a smooth surface or do I need to spray the semi gloss first and then use the kit to polish it?

As I said before, any suggestion will be thankful as I'll be working on the helmet itself after I'm done with the Dome.

 

[division 6]

Personally i would have gone with lacquer automotive paint (Duli-color) instead of acrylic model paint.
It would be harder and longer lasting.

 

[Sean]

Ditto on that. and did you do any fine sanding on your first coat of primer?

 

[Didact]

At this point though it's too late so I'm more than happy with just sticking with the paint I bought. If it fades or becomes absolute, I'll go down the lacquer automotive paint route but for now I need to know how to move forward. Once I see how the dome turns out, I may use automotive paint for the faceplate.

And to sean, yes I did. I had a few errors here and there so I fixed it up and then fine sanded it down again before priming that area one more time. I then left it to dry 24 hours and then spray painted it black but it has a very light grainy texture.

I found a perfect example of what the texture looks like on another forum. It's pretty much the same texture that I see on mine.



You can see in that example that it has a satin like texture, which is what I have as well.

I want to know what I have to do to get rid of that. I bought polish pads and Novus plastic polish kit, do I use those before a gloss clear coat or after?

 

[thejakemoore]

What I've done with good success is wet-sand between every coat of paint, including primer, making sure to spray VERY light coats of paint. Then don't sand on the last coat of paint, and then hit it with your clear-coat

 

[Kevin Gossett]

Lightly wet sand with a high grit before clear coating, then buff to a shine

 

[Didact]

What I've done with good success is wet-sand between every coat of paint, including primer, making sure to spray VERY light coats of paint. Then don't sand on the last coat of paint, and then hit it with your clear-coat

Lightly wet sand with a high grit before clear coating, then buff to a shine

What grit would you recommend?

Also is there a tutorial for buffing in this scale? A tutorial for a model kit would work fine too, whenever I look for tutorials on buffing I get tutorials for actual cars.

 

[ower]

the grainy texture you're seeing is probably Orange Peel, that can be caused by everything from wind, temp, distance from piece or not mixing the paint well enough ie.. not shaking the can hard or long enough. Just practice on throw away stuff. You will need to find the happy medium of distance from target vs application rate, also be considerate about temp. Too hot the paint dries too fast and you get uneven flow and Orange peel, too cold and you get kind of a weird cracking effect, You also want to avoid wind, it also causes the paint to dry faster as you're spraying causing uneven drying.

As for getting rid of it, I think a few have covered it with the wet sanding and buffing. I think it's just the nature of painting with cans, it takes practice and a little more TLC to get the look you'd get from a gun

 

[Didact]

So should I

Wet Sand -> Clear Coat -> Wet Sand -> Buff
Clear Coat -> Wet Sand -> Buff?

 

[Didact]

Bump. Anyone?

 

[Kevin Gossett]

Thought we already covered it... Wet sand, clear coat, buff.

 

[Didact]

Thought we already covered it... Wet sand, clear coat, buff.

What grit am I suppose to go from? Is 3600 - 1200 fine?