Airbrush technique troubleshooting

[A_S]

Hi

 

ive has a fox hunter airbrush sitting unused for a few years. This is the model

 

https://www.rmweb.co.uk/community/index.php?/topic/107480-so-i-bought-a-cheap-airbrush-kit/
 

In the meantime my dad has used it to paint a 5” gauge railway loco but after having recently got back into modelling myself I decided to use it to paint my current projects rather than Tamiya sprays.

 

to put it mildly im stumped.

 

every video I watch on YouTube seems to build up coats gradually and ends up with a nice glossy finish.

 

we primed with zero paints filler primer and I ended up with a very corse texture. Sanded down, tried to reprime and still ended the same. Sanded again and it turned out ok with a nice finish so primer done.

 

anyway after lots of attempts laying coats on top of the zero primer, and on a smoother automotive primer (2 separate car bodies) I’m of the opinion we should be following YouTube and layering light coats but my dad is of the opinion we need to lay it on thick and shiny on in first attempt - “if it doesn’t shine it’s too thin”, and therefore we will end up with a graney or sandy texture as in the couple of attempts we have had so far.

 

we have been using Tamiya lacquer paint thinned with tamiya lacquer thinners at about 1:1 ratio. For an attempted clear coat we did try 70:30  thinners to taimiya gloss clear lacquer (lp-9 I think) but not to put a finer point on it it wee weed out quickly and ran lots! Spraying at around 30 PSI.
 

Next on my to do list is to paint my Mitsubishi Lancer wrc white... I cant see the lay it on thick first time out is the way to go, especially with white, but it seems the only way not to get a course texture.... personally I’d rather go 5 or 6 thin layers if possible to build up the colour and kept a fine level of detail if possible but stumped as to how to do this

 

all the videos I’ve watched on YouTube are great generic videos but don’t go into specifics on technique, type of finish and don’t troubleshoot - ‘if x happens, try Y as a fix etc. so after spending a day watching them I’m non the wiser. Hence this post!

 

any tips?

 

Thanks

Andy

 

 

[Troy Smith]

7 minutes ago, A_S said:

 

we primed with zero paints filler primer and I ended up with a very corse texture. Sanded down, tried to reprime and still ended the same. Sanded again and it turned out ok with a nice finish so primer done.

 

anyway after lots of attempts laying coats on top of the zero primer, and on a smoother automotive primer (2 separate car bodies) I’m of the opinion we should be following YouTube and layering light coats but my dad is of the opinion we need to lay it on thick and shiny on in first attempt - “if it doesn’t shine it’s too thin”, and therefore we will end up with a graney or sandy texture as in the couple of attempts we have had so far.

 

we have been using Tamiya lacquer paint thinned with tamiya lacquer thinners at about 1:1 ratio. For an attempted clear coat we did try 70:30  thinners to taimiya gloss clear lacquer (lp-9 I think) but not to put a finer point on it it wee weed out quickly and ran lots! Spraying at around 30 PSI.
 

Next on my to do list is to paint my Mitsubishi Lancer wrc white... I cant see the lay it on thick first time out is the way to go, especially with white, but it seems the only way not to get a course texture.... personally I’d rather go 5 or 6 thin layers if possible to build up the colour and kept a fine level of detail if possible but stumped as to how to do this

 

 

Painting cars?

try this  I'll put a @cmatthewbacon  as well.   May not be the answer, but well worth a read anyway.

 

 

[Greg B]

Grainy or sandy texture is too much air and the paint drying before it hits the model

[Jamie @ Sovereign Hobbies]

Sounds like your dad is trying to use it like a spray gun for full-sized cars rather than an airbrush.

 

I'm not sure what size of needle and nozzle your airbrush has, but you mentioned 30psi which is what many paint and airbrush manufacturers recommend but is double what the majority of most skilled and experienced airbrush users use - although I am not qualified to comment on using Zero paints in particular as I never have.

 

30psi will give a high flow rate on the paint, and to avoid flooding you're probably airbrushing from relatively far away like a spray gun user would. Spraying from afar tends to give paints time to dry out in flight and often gives a coarse or grainy finish.

[bmwh548]

The air pressure is about double than what you should be using. Also, what distance are you spraying from? You mentioned the ratios for the clearcoat, but not the paint, how did you thin that?

Even in the automotive repair shops you'll see that they don't lay the paint thick. The first coat is misty, building up the color. The last one (or last ones) are wet-ish. 

Grab some scrap pieces of plastic and practice on them with different pressures, thinning ratios and distances. There's no universal advice so you'll need to play with it until you find the sweet spot for you.

[Steve Noble]

Zero primer I can never get on with. It always goes on dry and grainy, so much so that I gave up on it and in fact all airbrushable primers in general. I use Tamiya Fine surface primer, or Mr Surfacer, both from an aerosol can and they spray beautifully, smooth and even coats. You shouldn't have any problems with the Tamiya LP paints. Thin them with levelling thinner, I usually do 40:60 paint to thinner. Apply the coats wet but not heavy. Dry coats will make the surface rough and it will have no shine. You don't want heavy, thick coats, just wet enough to be smooth. Get some plastic spoons and practice laying on smooth, wet coats to get the hang of it. If you need any more help, please ask away. I could talk paint for hours and hours 😀

[Rick Brown]

Hi Andy.

Practice, practice and practice some more!

Thin paint, thin coats, low pressure and close up work well.

You will get the hang of it eventually, but it can take years. But don't get put off!

Shiny coats on vehicles are by far the worse to get the hang of, except possible metal coats.

Maybe try a cheap Tamiya tank and matt coats etc, first. Then build up to shiny things.

As for Zero Primer, I had to bin mine. It just never stuck to anything! I think they may have changed their mix by now, I hope.

I just either use Tamiya Fine primers for shiny things, or Halfords cheap primers for everything else.

To be fair, the Halfords stuff is nearly as good, and a heck of a lot cheaper, than Tamiya stuff. It just needs a little polishing to get a truly smooth finish.

Keep at it though! you won't regret it in the end.

HTH,

Rick.

[A_S]

@Troy Smith - thanks - I'll have a read after work

 

@Jamie @ Sovereign Hobbies and @Greg B Thanks - we have tried at around 20 PSI as well but get a similar effect. The Airbrush nozzel is aprox 0.2mm I beleive, maybe 1.5mm. but the kit also comes with a bottom feed airbrush that has a 0.35mm nozzle. I've not used that yet.

 

@bmwh548 - sorry maybe my sintax was confusing, tamiya paint has been thinned 1:1 with Lacquer thinners. All LP line paints, and the Clear coat was 3:1 thinners to paint. spraying was about 3cm to 6cm broadly

 

@Steve Noble - great idea - I'll see if we have any spoons - what is concidered "wet" a shiny coat tends be quite thick in my experience (so far)

 

@Rick Brown - thanks so basically in summary we are going for thin coats close up with a shiny/wet finish each time?

 

In terms of the videos i've seen on youtube they pass over the model very quickly left to right, unless I do it slower I seem to get that matt finish, I am guessing they are spraying more paint but less coverage due to the speed of their pass?

 

Thanks for all your help, its much appreciated.

[Jamie @ Sovereign Hobbies]

From what I've heard of Zero paints, you will not get a glossy coat. It goes on, like a car paint, at best satin and does not shine until clear-coated at the end.

[Steve Noble]

1 minute ago, Jamie @ Sovereign Hobbies said:

From what I've heard of Zero paints, you will not get a glossy coat. It goes on, like a car paint, at best satin and does not shine until clear-coated at the end.

If I've read correctly he's only using Zero primer and using Tamiya LP for the top coats? 

[Rick Brown]

4 minutes ago, Jamie @ Sovereign Hobbies said:

From what I've heard of Zero paints, you will not get a glossy coat. It goes on, like a car paint, at best satin and does not shine until clear-coated at the end.

Most Zero paints are indeed matt. You will need a good lacquer based clear coat to add the shine. They do a Two Pack that's meant to be very good. They also do a premixed clear coat, but I don't like it at all.

I still have a good stock of the original Klear 😉 .

Andy, thin coats, not wet coats. Just lots of them. Let them dry between coats, which is only a few seconds with thTamiya LP range, which are fab!

Rick.

 

 

I have the Tamiya LP clear, but not tried it yet.

[Steve Noble]

The thin coats are fine to start with if you are building up the colour. But you will not get a shine with gloss lacquer paints by applying non wet coats. You must apply them wet for the final finish coats or they will have a dry/orange peel finish. It's the same with clear coat. As I said earlier, it doesn't have to be heavy to be wet, there is a difference.

[Rick Brown]

11 minutes ago, Steve Noble said:

The thin coats are fine to start with if you are building up the colour. But you will not get a shine with gloss lacquer paints by applying non wet coats. You must apply them wet for the final finish coats or they will have a dry/orange peel finish. It's the same with clear coat. As I said earlier, it doesn't have to be heavy to be wet, there is a difference.

What Steve said!

I forgot to mention the top wet coats.

Oops....

Rick.

[A_S]

Thanks all

 

sorry for the delay, I've been quite busy testing things.

Yes - I am using the zero primer but the tamiya LP main coat. 

 

I'll try the clear with a 50:50 ratio to see if it goes on a bit better.

 

Just out of interest how do you do a non heavy wet coat?

 

Managed to break my cheap airbrush so i've got an Iwata on order! I've ordered another cheap one on Ebay and thats arived today so I can get back to it while I await the Iwata.

[Steve Noble]

35 minutes ago, A_S said:

Just out of interest how do you do a non heavy wet coat?

Make sure the paint is thin enough and apply it wet, but not flooding the surface with paint. If you flood the surface it's too heavy and you risk runs/sags. The magic 'wet coat' is when you hit the point where it's just before it runs/sags, where it's at it's wettest without actually running. If you make it run you're heavy. Anything under heavy without running is wet. If it's dry, rough, not shining go wetter. You should be able to practice on the spoons until you can hit the surface wet enough to have a mirror like shine straight from the airbrush, especially with lacquer paint..

[dnl42]

On 4/20/2020 at 8:31 AM, A_S said:

@bmwh548 - sorry maybe my sintax was confusing, tamiya paint has been thinned 1:1 with Lacquer thinners. All LP line paints, and the Clear coat was 3:1 thinners to paint. spraying was about 3cm to 6cm broadly

This was Tamiya's thinner, right? Not something from a hardware store...

[A_S]

Thanks all

 

I had a go at the tamiya lacquer white with a cheap airbrush this morning, generally worked ok, several thin coats and then a heavier shiny coat. However getting into the corners was a problem and at the extremities of the spray pattern (I was spraying about 3cm from my "target area") which was further away than the target area I got a lot of sort of rough blotching (see photo). Originally I thought it was a bad primer coat.

 

As i tried to apply more "wet" coat over the rough areas it worked well and covered the blotchness but it was creating more blotchness on other area's I'd alreay fixed? Anyone have any idea why? admittedly i did it over a 2/3 hour period without cleaning the airbrush nossle. When we took the airbrush nossle off it had quite a similar texture to it - could that be why?

 

 

 

Edited May 8, 2020 by A_S

[Steve Noble]

The problem you're having where the paint is bobbling in the corners is because it's quite a complicated part with many corners etc. When you paint it the paint hits the part and the over spray collects in the corners causing that dusty effect. Try more thinner it might help or reducing the air pressure a touch. I get this same problem when I try to airbrush primer, but never with actual paint..

[bmwh548]

Lower the air pressure and/or add more thinner, preferably Leveling thinner. Also you can add some retarder in the mix (look for Mr. Color T-105), that will further reduce drying time and it will help paint "eat into itself".

[A_S]

Thanks - I am using Tamiya lacquer thinner retarder type which should do the job?
 

i tried to prime a body shell yesterday and the bonnet, roof and top of the boot ended up very sandy - not quite as bad as the above but still the same effect. - I think it might be overspray?
 

ive been doing some research as I’ve recently painted th body of another car and  I can also see the orange peal effect in the same areas of the body - possibly the same issue?

Perhaps if it pull the trigger back to about 50-75% rather than 100% I’ll get a better finish on the detailed parts and bonnet/roof/boot?

[CharlieNZ]

Lower the air pressure, get closer. Paint is drying before it hits the surface. Rough paint in recesses is because your pressure is too high and the air is swirling around in the recesses leaving dry paint particles as it does.

[colin]

The only airbrush I can use to get a decent gloss finish is my Iwata HP-TH.

It's a .5 needle, this allows me to get wet coats on the model from further away thus avoiding flooding the area and runs.

Even with a.35 needle I struggle to get a decent finish, too close and you flood the area, too far away and the overspray collects like your pictures and you get rough spots, especially with all those uneven edges.

It's far easier to get a good finish on a flat surface, when you start having edges you get bounce back, the overspray which has bounced back off settles back down as dry paint.

You don't say what you use to thin your paint, Mr Levelling thinner is by far the best as it's not as hot as the general High gloss/low bloom ones from the body shop suppliers, it still drys quick but allows the paint more time to level out.

[A_S]

I think I mentioned it - it’s tamiya lacquer thinner retarder type - specifically for the LP paints. Usually in a 50:50 ratio spraying at between 15 and 20 PSI.

 

i have an Iwata eclipse on the way. That has a 0.35 needle with the option to buy and fit a 0.5 so hopefully will see the benefits over this Chinese one!

 

Edited May 10, 2020 by A_S

[Steve Noble]

1 hour ago, A_S said:

I have an Iwata eclipse on the way. That has a 0.35 needle with the option to buy and fit a 0.5 so hopefully will see the benefits over this Chinese one!

 

The smallest needle/nozzle I use is 0.4mm in my Mr Hobby Procon Boy brush. The Tamiya HG wide and the Iwata Revolution I use are both 0.5mm, the Sparmax GP-70  is 0.7mm. The nozzle size makes a massive difference. I use the Sparmax for clear coating on larger parts and it really can lay a lot of clear down in one pass with ease. Too much sometimes which makes runs very easy to get. The 0.5mm brushes are perfect for most applications..

[A_S]

Hi all.

 

i tried painting the body of the above car this morning using my new iwata eclipse with a 0.35 needle. The Tamiya LP paint was thinner roughly 1:1 with their lacquer thinner - retarder type. Around the wheel arches and some areas in the top of the bonnet and top of the boot went on dusty again.

 

i was spraying at about 12-14 psi. Still no closer to understanding what I am doing wrong!