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Made in ca
Perturbed Blood Angel Tactical Marine



Toronto

Hello, long time lurker, first time poster here. After searching through pages of the forum I was unable to determine the cause or solution for my problem and was hoping someone with more experience than myself may be able to help.

I recently started painting a few razorbacks. I primed them black with the citadel spray and the surfaces of the model remained smooth. I then began airbrushing them red using my iwata HP-CS. I used a coat of Vallejo Red-Black then highlighted with blood red, both of which were thinned down to the appropriate consistency using Tamiya X-20 thinner. The problem I am running into is that some of the surfaces, most notably the very top of the tank has lost it's smooth finish.

I then used a thinned down coat of Vallejo gloss varnish over the entire model before I start to weather them but the rough surface on the top persisted through the gloss varnish.

My concern is for powders and decals on any of the rough surfaces. Can anyone suggest what caused this? How to fix it? Or a better gloss varnish (was thinking of using Testors since I like their matte varnish)?

Thanks for any help!
   
Made in us
Stealthy Warhound Titan Princeps






hmm... my only theory would be that the GW spray was rough, and other coats on top of it just made the roughness more noticable.
   
Made in ca
Perturbed Blood Angel Tactical Marine



Toronto

I considered that too, but I sprayed a rhino and two other razorbacks as well. Both of them without anything but primer on them, and all three are nice and smooth.
   
Made in us
Stealthy Warhound Titan Princeps






Then the only problem I could see might be the tamiya thinner.... I use Vallejo paints with an HP-CS, and never have any problems... I use Vallejo Thinner Medium to thin the paints though.
   
Made in us
Longtime Dakkanaut





USA

What your describing sounds like what is called "Orange Peel" in the automotive painting industry....This is caused when the paint to thinner ratio is incorrect causing the paint to dry incorrectly resulting in a textured surface and look to the paint. Though we aren't dealing with auto paints here some of the basic principles apply.

1. Range--how close are you when you paint? If you are too far away from your surface, the paint will actually begin to dry while passing through the air, thus when it hits the surface it does not flatten out, but stays in it's little "bubble" form, leaving behind a texture.

2. Flow--Closely related to range, and by flow I mean, how far you are pulling back the trigger on your brush, remember, that pushing the trigger down engages the air, and pulling back increases the flow of paint. Generally speaking the further you are from your surface, the thinner the paint needs to be, and the more flow will be needed.

3. Thinning Medium-- I am not a big fan of the Tamyia Thinners, I live in a very dry environment, and I find that they dry the paint out too fast, now everyone is going to tell you there own personal preference from air brush medium, windex, alcohol, ect...They all have there pros and cons, for me, depending on the paint I am using I am do 1 of 2 things, 25% Windex to 75% water, or 25% Alcohol to 75% water. This is based on the effect I am looking for, the paint I am using, and the temperature at the time.

Good luck and post if you have more problems.

Ashton

   
Made in ca
Perturbed Blood Angel Tactical Marine



Toronto

Ok, well that sounds logical. It's causing me problems when I'm trying to weather now, the rough surface is creating a capillary type action if the paint on my brush is too thin.

My range is generally around 15-20cm, and the flow of paint is what I would describe as moderate. The trigger is being pulled back to about the middle, if not a little less.

I'll try the Windex to water ratio for a thinner and see how that works on my next tank. What sort of effect does each concoction achieve? I've just been adding the thinner to the paint until I get the "milky" consistency that is generally suggested.

I'll be picking up some Testor's gloss varnish once stores open back up after the holidays to see if that helps with future ones and also to see if it will help correct the one I've already done.

I do all of my painting in the third floor/loft. It's probably the warmest place in the house (though not too warm) and has the least amount of air flow. I made the assumption that the lack of air flow would help.

Thanks for the help so far.

Wes
   
Made in gb
Fresh-Faced New User





Hi Ulterior, welcome to the board.

What kind of PSI are you using? I suffered a similar effect when painting a Dark Angels Rhino recently, and it was mentioned to me that it could be because I was spraying with the pressure too high.

I ajusted it, as well as doing some of the things @redfinger has already pointed out at the same time and I have nothing but lovely smooth tanks now. Best of luck mate.
   
Made in ca
Perturbed Blood Angel Tactical Marine



Toronto

Thanks for the welcome Kev!

Hmm, that may be something I need to consider as well. I have a TC-20 Compressor from TCP Global

http://www.tcpglobal.com/airbrushdepot/abdkitG22.aspx#TC20

I was having an issue determining what the spray pressure was and was playing around with it. Quite frankly I'm not even sure what it's set at now as I'm not sure how to read it. Any suggestions on that front?

   
Made in us
Rampaging Furioso Blood Angel Dreadnought





Boston, MA

Sounds like Redfinger is on to something...

I wonder also, are you perchance airbrushing in a 'cardboard' spraybooth?

When I first started airbrushing I was overly concerned with over-spray so I made a cardboard spraybooth... but the cardboard shed rough little hairs/fibers all over my models and I eventually stopped using it.

Please check out my photo blog: http://atticwars40k.blogspot.com/ 
   
Made in ca
Perturbed Blood Angel Tactical Marine



Toronto

Yes, I am using a ghetto spraybooth made out of an old cardboard box... though at this point it's pretty much covered with paint on nearly all the surfaces. Not to mention I haven't noticed this issue on any of my actual figures, only the tanks so far.

For working PSI for the brush, it should be around 15-20 psi right?
   
Made in us
Stealthy Warhound Titan Princeps






Ulterior wrote:Yes, I am using a ghetto spraybooth made out of an old cardboard box... though at this point it's pretty much covered with paint on nearly all the surfaces. Not to mention I haven't noticed this issue on any of my actual figures, only the tanks so far.

For working PSI for the brush, it should be around 15-20 psi right?


I usually work at around 30 PSI for basecoating...

Spray lightly at a distance of maybe 6-8".
   
Made in si
Fresh-Faced New User




Hi guys, I see that I'm not the only one with such problem.

I get realy rough surface after AB, first layer (the foggy one) was ok, then it was one month break (no time), the model was covered with cloth, and few days back I got it going again. I've blown of some small things that were on the surface but didn't wipe or blow it completly. Now after the 2nd and 3rd layer, the surface is so rough, I'd say about 400 gritt paper or even less. I'm reemoving the paint as we speak, to get it back to basic material.

What could be the reason? Pressure was around 4bar, distance about 15cm. If I had the pressure lower the paint came out in a very thin line or didn't come at all. It didn't seem thick (about milky).

The surface was the whole body of Revell Antonov An 124.

And how should I paint the hard to access areas like inbetween the flaps, the body-wing contact, I can't come cloer than 10cm...

Thank you for reply.
   
Made in gb
[DCM]
Et In Arcadia Ego





Canterbury


Thread is being locked due to thread necromancy.




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