Clear Coat and Pin Wash

[andyretro]

Hi All,

 

Where am I going wrong with my technique?

 

After 2/3 airbrushed coats of Tamiya X-22 Clear, I apply decals, the put on another coat of X-22.

 

I then leave it to dry for at least one week.

 

I then apply Tamiya Panel Line Accent Color, leave for around 5 mins, an then use a cotton bud to wipe if gently off.

 

I have dipped the cotton bud in Tamiya X-20A thinner, and this has caused the clear coat to wash off with it, making the model sticky. It appears to be dissolving the clear coat, even getting down to the decal layer and stripping them at times!

 

I have also tried dipping the cotton bud in Mr. Color Levelling Thinner, and this is less extreme but still has some dissolving effect.

 

Any advice welcomed! I've been modelling for several years now, but have never really taken to pin washes due to these poor results  I'm trying to get my models to "pop" a bit more and look more real

 

Cheers,

 

Andy

[Ngantek]

Nonono, the reason for using tamiya accent is because it's enamel, the acrylic clear underneath isn't attacked by its solvent. By wiping with tamiya's solvent, you are not only not dissolving the excess wash, you're re dissolving the clear cote.

 

X20a is surprisingly hot but MLT even more so, be very careful going near paint with the stuff. 

 

Use turps, artists enamel thinners, white spirit, but I'd suggest a dry bud to start with and only go just damp with thinners if needed.

[5huggy]

 All your "coats" of whatever - appear to be acrylic's and as such X20A will without doubt "melt" the last layer of clear!

 

Try using enamel or oil based for your pin washes - - they need to be of different constituent - they can then be wiped with "white spirit" which effects the acrylic clear coat absolutely minimally

I'm a fan of enamels and after sufficient drying time I always coat with "ACRYLIC" clear coat  followed by oil pin wash  and finally finished with an acrylic based matt coat !

[5huggy]

4 minutes ago, Ngantek said:

Nonono, the reason for using tamiya accent is because it's enamel, the acrylic clear underneath isn't attacked by its solvent. By wiping with tamiya's solvent, you are not only not dissolving the excess wash, you're re dissolving the clear cote.

 

X20a is surprisingly hot but MLT even more so, be very careful going near paint with the stuff. 

 

Use turps, artists enamel thinners, white spirit, but I'd suggest a dry bud to start with and only go just damp with thinners if needed.

Ha - looks like you beat me to it - but more or less same conclusion! @Ngantek

[Troy Smith]

2 minutes ago, andyretro said:

I then apply Tamiya Panel Line Accent Color, leave for around 5 mins, an then use a cotton bud to wipe if gently off.

 

I have dipped the cotton bud in Tamiya X-20A thinner, and this has caused the clear coat to wash off with it, making the model sticky. It appears to be dissolving the clear coat, even getting down to the decal layer and stripping them at times!

 

I have also tried dipping the cotton bud in Mr. Color Levelling Thinner, and this is less extreme but still has some dissolving effect.

I don't know what the thinner with Tamiya Panel Line Accent Color is,  but the other are the paint thinners, and will just attack the paint.

 

You really need a solvent that will not attack the base coat. 

 

My tip for washes over acrylic is artist oil paint,  dissolved in lighter fuel, the stuff for Zippos.    

Makes the thinnest wash you can make, the solvent flashes off in seconds,   I have used this over unvarnished Vallejo Model Color with no problem.

 

 For paints I use Burnt Umber, adding a touch of black, or with some white for dirty grey.

 

 

 

Black is too dark, dirty grey gives a shadow without making it look like a diecast

 

from

https://www.britmodeller.com/forums/index.php?/topic/235052380-hurricane-airfix-72nd-fabric-wing-mki-oob/#elControls_3296243_menu

 

@Casey  is the person to ask on paint. 

2 minutes ago, Ngantek said:

Use turps, artists enamel thinners, white spirit, but I'd suggest a dry bud to start with and only go just damp with thinners if needed.

all thicker and heavier than lighter fuel,  which will do the job of all the above.  

Actual Turps, as in Turpentine is something else,  it's not just another saturated hydrocarbon.   Enamel thinners is a cleaner version of white spirit, and white sprit is basically paraffin.

 

Lighter fuel is basically Hexane,  a 6 carbon molecule, or if you wish, light petrol.   Anything lighter is a gas a room temperature.

 

HTH

 

 

 

 

[5huggy]

I'm fortunate , in that I have a quantity of "Naptha" that is also good, for this role! 

[Troy Smith]

37 minutes ago, 5huggy said:

in that I have a quantity of "Naptha"

Naptha covers a lot of ground....

 

https://en.wikipedia.org/wiki/Petroleum_naphtha

 

"a virgin light naphtha with an IBP of about 30 °C and a FBP of about 145 °C containing most (but not all) of the hydrocarbons with six or fewer carbon atoms"

 

"Some petroleum refineries also produce small amounts of specialty naphthas for use as solvents, cleaning fluids and dry-cleaning agents, paint and varnish diluents, asphalt diluents, rubber industry solvents, recycling products, and cigarette-lighter, portable-camping-stove and lantern fuels. Those specialty naphthas are subjected to various purification processes which adjusts chemical characteristics to suit specific needs.

Specialty naphtha comes in many varieties and each are referred to by separate names such as petroleum ether, petroleum spirits, mineral spirits, paraffin, benzine, hexane, ligroin, white oil or white gas, painters naphtha, refined solvent naphtha and Varnish makers' & painters' naphtha (VM&P)."

 

6 carbon hydrocarbon = hexane = light petrol = light naptha.   

It will thin enamel paint,  I used it with some Humbrol gloss red to repaint lettering on a sign,  which was on a wall.  Flowed beautifully,  and the solvent flashed off as being brushed so it didn't run down.  

 

Petrol/gasoline is mostly 8 carbon,  paraffin/kerosene/white spirit is 12-15 carbon,  diesel is 25-30.  road tar is 45-50.

 

crude oil is a mix.   Bigger molecules get more complex as they have different shapes,  or isomers. 

 

Turpentine is a terpene, 

https://en.wikipedia.org/wiki/Terpene

 

These are not saturated hydrocarbons.

 

HTH

[andyretro]

Thanks for all the advice!

 

I thought Tamiya Panel Line was oil based 😬🫠

 

I was under the impression that X-20A was the appropriate thinner for X-22... what should I be using to thin Tamiya Xs and XFs? I expect this is also causing me problems.

 

I generally use Vallejo Model Air, but have started venturing into the world of Tamiya and Mr. Color (mostly by accident 😅) 

 

Moving forward, I will try Humbrol enamel thinners or some white spirit

[5huggy]

2 minutes ago, Troy Smith said:

It will thin enamel paint,  I used it with some Humbrol gloss red to repaint lettering on a sign,  which was on a wall.  Flowed beautifully,  and the solvent flashed off as being brushed so it didn't run down.

excellent info there @Troy Smith -- - -  > > that is exactly what I use it for 3:1 ratio with cheap white spirit works the best for me.

 

So hopefully @andyretro you have enough info from the above posts to help you out! Oh and by the way - - -10 years ago I had exactly the same problem - -until I worked out the "chemicals " at play! in each layer

[5huggy]

2 minutes ago, andyretro said:

Moving forward, I will try Humbrol enamel thinners or some white spirit

just remember buddy to "ONLY MOISTEN" the cotton buds

 

Patience will get you there 😉

[5huggy]

Im guessing your trying to achieve this kind of look - - >

 

 

It took me ages , and a whole load of different practice mules to start to get to this  - obviously not quite finished yet .

 

The peeps and help here on BM will get you there  - just ask!! 😉

[Troy Smith]

4 minutes ago, 5huggy said:

that is exactly what I use it for 3:1 ratio with cheap white spirit works the best for me.

and varying ratios will adjust viscosity and drying times. 

White spirit really is not great for thinning model paint,  keep if for clean up,  unless it's a highly cleaned version, which costs more but will last for ages.

16 minutes ago, andyretro said:

Moving forward, I will try Humbrol enamel thinners or some white spirit

Honestly.    Lighter fuel.  You can find it pound shops, it will mix with the others, to vary viscosity, and it's really handy for all sorts of uses. It also makes the thinnest most seeking wash.

I also use it for applying chalk pastel.

use very fine abrasive to make chalk dust,  put in palette, add a dash of LF, dab on slurry with old brush

Great for exhaust deposits and also for dust. 

 

 

add dirty grey oil wash,  and adjust with clean LF damped brush, streak with direction of airflow, it will remove nearly all the wash from the main airframe, leaving just a small amount to modulate the tone.   It's a subtle effect,

 

matt coated.

 

10 minutes ago, 5huggy said:

Im guessing your trying to achieve this kind of look

IMO, too dark a wash. Look just black.

 

why I use oil paint, I can easily mix a colour,  start with burnt umber, a little black, go easy black is a strong pigment, white to lighten as needed. = dirty grey.   Have a look at the Hurricane pics above.

Another useful colour is Paynes Grey. 

You can a darker pin wash for control surfaces. 

 

HTH

 

[5huggy]

25 minutes ago, Troy Smith said:

I also use it for applying chalk pastel.

I like this idea - I hope you don't mind me plagiarising this! and use it going forward.

[Troy Smith]

2 minutes ago, 5huggy said:

I like this idea - I hope you don't mind me plagiarising this! and use it going forward.

It's all about sharing ideas, and finding what works for you,  this is why I added my SIG line about tools and techniques and it getting a result you are happy with.

Chalk dust used as described in these builds

https://www.britmodeller.com/forums/index.php?/topic/235095700-matchbox-176-morris-c8-mk-ii-17pdr-gun-willys-jeep-set/

https://www.britmodeller.com/forums/index.php?/topic/235104634-pk-78-m16-half-tracknow-with-an-added-p5002-american-infantry-figure/

as well as oil paint/lighter fuel.

 

I just got some basic chalk pastels

 

https://www.ebay.co.uk/itm/234773226916

no connection to seller,  but these seem to be the cheapest online.

 

Some colours are less useful than others,  but I tend to make a  mix. 

 

One last point, there is a tendancy to apply weathering and stains, and then a final matt coat.

I've not found the pastels to rub off easily,  if anything they stick very well, I think the fine grain and the very seeking LF means they wash into very fine surface roughness.

 

But not using a final matt coat you can show differing ranges of matt/gloss,  example, aircraft even if 'matt' tend to be smooth and are really more an eggshell finish,  but exhaust deposits are dead flat matt, sooty and sticky, and also vary in colour depending on how  the engine is run.

 

And, study photos, and how they look on different airframes,  and why....

 

High power makes black sooty deposits,  a leaned out mixture will get a light browny grey.

Famous 50 Sq Lancaster photo

Avro Lancaster     1942. by Etienne du Plessis, on Flickr

 

showing both heavy black and browny grey,  also note the way the outboard exhaust due to wing dihedral goes under the wing, not over....

 

again....

Lancasters at Swinderby, 1942. by Etienne du Plessis, on Flickr

 

the sootyness is well seen here

Lancaster service. by Etienne du Plessis, on Flickr

 

dirty black, and note the shape

Hurricane                 1944. by Etienne du Plessis, on Flickr

 

Leaned out light browny grey

Hawker  Hurricane. by Etienne du Plessis, on Flickr

 

leaned out, long flight, and exhaust deposit going horizontally down fuselage

Hawker Hurricane. by Etienne du Plessis, on Flickr

 

dead flat chalk pastel exhaust on eggshell finish airframe

 

 

HTH

 

[5huggy]

Thanks @Troy Smith this so just perfect for me - info wise, as I am slowly improving my weathering techniques 

 

so a big  

 

this will really help.

[Ngantek]

1 hour ago, andyretro said:

Thanks for all the advice!

 

I thought Tamiya Panel Line was oil based 😬🫠

It is, which is why if you want to clean off excess, you need something to thin oils. However one of the advantages of oil and enamel washes is that they take a while to cure so it's often not necessary or even better to remove excess without thinners (which will tend to squeeze out of the cotton into the panel lines and sweep the wash back out again)

 

 

1 hour ago, andyretro said:

I was under the impression that X-20A was the appropriate thinner for X-22... what should I be using to thin Tamiya Xs and XFs? I expect this is also causing me problems.

 

Yes all tamiya acrylic paints, X and xf, but not lacquers like LP. You can also use MLT, which is a bit hotter, for spraying, or indeed many use IPA. 

 

To clarify, the paint/clear coat is soluble in its thinner, so you can vary the viscosity. Once sprayed or brushed, the thinner evaporates and in the case of acrylics, allows it to cure.

 

Scrubbing the same thinner back on (in this case x20a onto cured x22) will just dissolve away the paint or coat again. You are trying to leave the protective clear coat intact by using a wash on top of it that doesn't dissolve the clear and can be cleaned away without affecting it, hence using an oil based wash and thinner.

 

 

 

 

 

1 hour ago, andyretro said:

I generally use Vallejo Model Air, but have started venturing into the world of Tamiya and Mr. Color (mostly by accident 😅) 

 

Moving forward, I will try Humbrol enamel thinners or some white spirit

Yes just to be clear, use the enamel thinners to thin and remove enamel wash (like the tamiya panel liner). Use x20a or MLT to thin your tamiya x or xf paints for spraying