Hardbody painting questions

[ALEXKYRIAK 1046]

Hi all, I have a few hard bodies I need to paint. Other than a slightly awkward Mad Bull body I painted a while ago with not an optimal result, this is basically my first time. I have read the various painting and technique guides on the net, however there are two questions I can’t find the answer to:

1.  I want to paint the hardbody in multiple colours. This therefore involves masking and multiple passes. Does anyone have any advice on how to approach this? masking technique, colour order, time between paints, etc. Is it the same rule for dark to light as on a PS painted lexan shell? Or is it a different consideration? Am nervous over trying masking for three colours using TS paints. Never tried three colours, never properly tried  TS paints...  

2. I have read many times that people use automotive paints. Some say ‘best thing ever’, others say ‘Tamiya TS paints are finer particulates and therefore better when applied to a fine detail body such as a Tamiya model shell’. I am erring to using Tamiya only, however I’d like to use a proper shiny lacquer paint as the final finish coat, but Tamiya don’t seem to make one, other than a semi gloss clear TS-79. Is this a proper gloss lacquer in appearance?

(the actual question): Or do I need to go for a Halfords-alike automotive gloss lacquer? If so, will this work on a TS paint? 

Thanks all

[ThunderDragonCy 7873]

I haven't masked or striped my hardbody, but with good prep and priming I have had gojd results with single colour using automotive paint. 

This vid from AMPRO is probably what you need

I actually find painting hard bodirs much easier than lexan. Doing everything inside out does my head in 😂

[Juggular 4961]

It's an involved job.  But since you are tidy and meticulous, I would think that you are well suited.  I wonder how fine a line you'd be painting?  If they are too fine, airbrush would be better.  Above video is about the limit of can-sprays.  

I like Tamiya masking tapes.  They have rubbery tapes for curvatures too.  I've used various masking tapes from hardware stores. 3M blue tape is alright, but I'd still use Tamiya tapes, as they keep the paint from penetrating.  (It still happens once in a while. I run the back of a fingernail on edges to press down firmly)   

The order depends on what you want to do.  But largely don't matter because the paint is opaque.  If there has to be an overlap, I prefer light to dark.  

Let's look at a Jamaican flag. (I mean no disrespect to Jamaicans, with black and yellow, I think it's one of the cooler looking flags)

Now, if you paint black first, then Yellow and Green on black surface, it would look like below. 

But if you paint a big Yellow square, and put green triangles and black triangles on it, it would look like below. 

Can you see that the upper green is slightly "pea-green" instead of "forest green?"  I mixed upper green with yellow, to show how yellow could be seen in the first layer of green.  If you spray a few times, yellow won't be seen.  So, I'd recommend light to dark.  

Drying period is as short as an hour to as long as 2 days.  Depends on temperature and humidity.  I prefer to wait a day. But it's impractical. 

If the surface is completely dried after a couple days, you can paint anything over anything.  As long as you don't let the same type of paint pool.  Pooling of the same type can dissolve what's already painted.  If you do a light mist repeatedly, anything should be fine.  Except for sealant type (like gloss coats).  If the paint is not dried completely --I mean like a week or two--, sealant type can trap fumes of the paint underneath.  The fumes would want to escape, they can't penetrate the plastic, so they penetrate the sealant, cracking the surface.  Glossy paint tends to seal things too.  This is why I would prefer to dry one layer for days before I paint another layer.  (But people have paint things only a few hours later maybe in dry areas and still do fine. It's just that I'm not a risk taker)  

I have some automotive paint, but haven't used them.  My guess is that they have more primer particles inside, making them very opaque.  If nothing shows through, people would swear by them.  Thicker particulates could be explained in that context.  

I haven't tried this, but I am thinking about trying Testors.  (as he says, "high gloss" will yellow)

 

[Fabia130vRS 2098]

Automotive paint is ok. But you need to prep the surface. If a new shell... jusy use water sand paper 2000 and spray it.

[ALEXKYRIAK 1046]

Thanks a lot guys for the responses and info  

. @ThunderDragonCy awesome video (and car!), had to watch it a few times to get my head round how he did the priming, spraying, masking, priming, spraying sequence. Quite complex but the basic principle are there.

@Juggular awesome post, mate, thank you so much. Very detailed and informative. Your diagrammatic explanations are very useful. I have read in various places that different colours and  finishes have different levels of thinness or opacity. Will need to see if I can get the testor paint in the uk. 

With the above information I think I have enough to plan out the painting process and sequence for the shell and three colours I have in mind. 

Its also interesting seeing the different techniques people use, having now read a bunch of posts and videos. Some swear by wet dry sanding, then priming, then painting, then sanding, then clear coat. Other day they leave out the sanding or priming, or both.

Temperature is cited as being important. Warm space and warm paint cans. I’d like to paint now (fairly cold in UK currently) so am thinking of getting a cheap electric fan heater for the shed - is that a sensible environment to paint in? Or should I leave it a month or so?

I did the NeoFrog shell in a cold shed using my heat gun to keep the paint warm and to assist drying, and worked really well - paint can in one hand, heat gun in the other! (Although I did get an odd look from the missus...!) 

[ThunderDragonCy 7873]

I painted at this time of year, and if you limit yourself to lots of quick thin coats then I would say you don't need heat. I kept the body and paint indoors to keep them warm, had a paint box setup in the garage, I would shake the paint for about 30 seconds, put the can upside down (with cap on!) in my back pocket to keep it warm, pop out to the garage, hang up the shell, quick shake of the can, test spray on the cardboard, quick coat, carry everything back in (I have a bent coat hanger to hang my bodies from so just used that to carry and avoid touching the paint) hung the body up in my office with the door closed and window open a crack to let fumes out. I could easily do a coat every 30-45 minutes of an evening. I tried the sanding paint thing to flat it down but I found I just went through the paint way too easily and ruined what to me was a perfectly good finish. Maybe I am ham fisted, but the only 1200 grit sanding that got done was on the fresh shell before it got washed in hot soapy water. That bit does seem to help. My guess is that your aesthetic might be of a higher standard than mine though, so give things a try. I know mine are all runners so the odd spec of dust in the paint really doesn't bother me. 

[max69vk 708]

I go slightly overkill with my hard bodies, but i guess that's down to having been a sprayer in my past! As a guide though...

Step 1. Light grey scotch pad all over + sand/file any major 'nubs/nicks' etc on the body.

Step 2. Plastic Primer. 3 coats, at least 5 minutes between each coat - Always spray all of the body edges first, & then the larger flat panels afterwards.

Step 3. High Build primer, leave at least 10 minutes between each coat.

Step 4. Dust coat with satin black (hold can at arms length and give a couple of quick squirts - The primer should end up with black speckles all over - only ever do very light short spray bursts, you aren't trying to cover the primer. Leave to harden for at least 12 hours.

Step 5. Rub down the body with 1500-2000 grit wet & dry till the black speckles (from the step above) disappear.

Step 6. If you've got any plastic showing through after step 5, re-prime with plastic primer .

Step 7. Prime over the high build with suitably coloured primer (high build is usually yellow out of a can so it can cause top coat colour issues).

Step 8. Once dry lightly sand over with 2000-2500 wet and dry.

Step 9. Wipe shell with a tack cloth to remove any fibres/dust etc ready for the top coat.

Step 10. Place the top coat spray can into a plastic bag (without any holes) and then sit in a warm bucket of water for at least 5 minutes. after which remove the bag from the bucket & then remove the can from the bag. Shake the can for at least 1 minute.

Step 11. Start spraying the shell with a light coat - Always spray all of the body edges first, & then the larger flat panels afterwards. For the first 2 coats you aren't looking to get total coverage, at this point leave at least 5 minutes between each coat.

Step 12. Wet coat - On this coat you are looking to achieve total coverage across the shell, again start edges first - Don't worry if don't get a complete coat though, leave it for at least 10 minutes for the paint solvents to 'flash off' & then spray a 2nd wet coat if required.

Step 13. Only applicable if spraying a metallic - After achieving total coverage & allowing to sit for at least 10 minutes & apply a light dust/drop coat all over. Spray from at least 1m away from the shell and haze all over. At this point you are not looking to make the paint wet again, the dust coat will help fill any patchiness in the metallic flake within the coat giving it a nice even finish that really helps the metal flake 'pop'.

Step 14. After painting leave for at least 24hrs-48hrs so the colour/metallic base coat can harden, and then apply lacquer if required (definately required on metallics). Spray using the same 'edges first then main panels' method allowing enough time between coats in exactly the same way as when applying the colour/base coats.

Step 15.  Leave for another 24-48 hrs to harden. If required once your colour/lacquer coats have dried, you can then use 2000-2500  to lightly flatten the top coat and polish up using a suitable product.

Now if you wanted to go total overkill you could lightly wet & dry sand in between paint coats, however this is majorly extreme for an RC & will at least triple if not quadruple your turnaround times. 

If you think all of the above sounds like a lot of work, it really isn't when you get going - Below is an example of a shell that followed all of the above steps, but was totally painted in less than 3hrs! (The final coat hasn't even been flattened & polished at this point).

I really don't recommend doing this yourself in such a tiny time-frame, but it was a scorching hot day & it needed to be on the car mega rapido. This does give a good idea of how the metal flake can be made to stand out though.

Before:

 

After:

[jonboy1 2943]

what he said above 

I'd use Tamiya paints wherever possible, and they do make a gloss clear - TS-13. Same with masking tape - Tamiya. Personally I find a lot of the automotive paint cans have far too much propellant in them and therefore make the paint go on far too heavy. Definitely warm the cans as advised.

A little fan heater is essential in this climate - the solvent just won't evaporate off in the cold and you'll end up with a crummy finish. 

@Juggular made a very good point if you are looking to do pinstripes - if they are very fine and you are going to do a clear coat over the top they may well bleed. Therefore, go over them with an acrylic clear X-22 first, to provide a barrier then go over the whole thing with TS-13. Again, as he quite rightly said, you may have to do them with an airbrush as you might not be able to get the paint light enough not to swamp the masking tape.