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How best to cure oil painted wooden effect on plastic

stimpy
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stimpy
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Joined: July 17th, 2012, 1:12 pm

August 6th, 2018, 1:46 am #1

I've been building some WWI kits this summer, using the oil paint technique to stain a previously varnished base layer. I read somewhere, that if thin enough else having worked your magic on the stain that the layer of oil should have dried and/or cured? typically within 48 to 72hrs. Then you lay down a protective varnish coat and continue building or decaling etc.

Now it's really humid and warm at the moment, and I did my oil streaking and work 4 days ago and still the oil is not dry, so I can't touch it without smearing the surface. 

How best to proceed? How do I speed up the drying process before I loose interest in the project !
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Petri
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Joined: October 3rd, 2010, 6:28 am

August 6th, 2018, 11:45 am #2

Well, living in Finland I’d use (electrically heated) sauna: put the heater on low, and leave the parts there overnight. You have to be very careful with the heat though :)

Why don’t you start form scratch and use acrylics? First airbrush a suitable base layer, and once this is dry take two (or more) different wood tones and using a wide flat brush paint and mix these while both are still somewhat wet. Afterwards you can tone down the contrast using a suitable clear color like orange. Vallejo even has a transparent wood color. Quick and easy, and at least to my eye works well, at least in smaller scales.
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stimpy
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stimpy
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Joined: July 17th, 2012, 1:12 pm

August 6th, 2018, 12:47 pm #3

Petri wrote:
Why don’t you start form scratch and use acrylics? First airbrush a suitable base layer, and once this is dry take two (or more) different wood tones and using a wide flat brush paint and mix these while both are still somewhat wet. Afterwards you can tone down the contrast using a suitable clear color like orange. Vallejo even has a transparent wood color. Quick and easy, and at least to my eye works well, at least in smaller scales.
A fine point, it just shows when you look online, the majority use oils, so I figured that was the way.  As it happens I have done what you suggested on a test piece with acrylics, thinned and brushed over a layer of enamel varnish.  I did this to see if I could attain enough transparency.  Unfortunately I have already used oils on my two current builds, so must continue with that.  For future models, I want to stay away from oils.
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jvenables
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Joined: June 18th, 2012, 2:48 am

August 6th, 2018, 1:35 pm #4

I have never quite understood the wisdom/attraction of using oils on scale models, especially for things like wood grain and panel line washes. I must admit that I have very limited experience with both (don't build aircraft with timber props and generally feel panel line washes are too much in this scale) but I have always thought water soluble products are a more sensible way to go. My only "routine" use of a wash is for interior detail shading, highlighting and grubby-ing; for this I use diluted water soluble ink and/or watercolour paints. At times, I have even used kids' poster paints. This approach makes it very easy to clean up any bloopers or even wash it all off and start again if I'm not happy with the colour/effect.
James from Brisbane, Australia
Now living in Laos

Nil illegitimi carborundum
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Chuck1945
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Joined: May 25th, 2011, 7:05 pm

August 6th, 2018, 2:55 pm #5

Years ago when Xtracolor was new I used them thinning with Testors enamel thinner. This thinner was too hot for the paint and I ended up having to force dry using a relatively low wattage bulb (60W?) in a desk lamp left on over night with the bulb perhaps 18” above the model. I do remember worrying about potentially over heating the model and probably tested the technique on a junker first.

Switched to Humbrol thinners to solve the problem and then a few years latter switched to acrylics and quit using enamels. The light bulb technique may work on your oil paints too
Chuck
Eastern WA, USA
Finished 2018:
Eduard Spitfire IXc, VIII, Monogram/Starfighter BFC-2
On the active bench:
Eduard Bf 110C, Hasegawa B-24D, SH P-40E
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Mark Schynert
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Joined: September 27th, 2010, 4:42 am

August 7th, 2018, 8:47 pm #6

If i can't do it with lacquers or acrylics these days, I mostly don't bother. That said, the only wood I've tried to simulate lately was the bed of a Queen Mary trailer. Not exactly a shiny varnished prop--dull and flat-toned instead. For that, an acrylic base coat and selective streaking with a lighter color worked fine. I'd probably try a lacquer base coat with a lighter tone, then dry-brush with a darker acrylic, then finish with Varathane water-soluble polyurethane for the gloss. 
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walrus
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walrus
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Joined: March 30th, 2012, 12:57 am

August 8th, 2018, 12:48 am #7

It's a case of waiting 
Oils don't dry by evaporation, but cure by a process of oxidisation of the binding medium (usually linseed oil) 

For future reference, you can add siccatives or thin with turpentine which makes for quicker drying.  


  
Paul from Birmingham, UK
Now living in Barnsley.
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walrus
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walrus
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Joined: March 30th, 2012, 12:57 am

August 8th, 2018, 12:52 am #8

If you want to use acrylics I would recommend a glazing medium and maybe some form of retardant if you wish to blend colours.  
Paul from Birmingham, UK
Now living in Barnsley.
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dknights
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Joined: September 30th, 2010, 7:07 pm

August 8th, 2018, 1:19 am #9

If you want to use tube oils, you can leech out some linseed oil by putting it on a piece of cardboard first.  That should speed drying.
David M. Knights
Fortes fortuna adiuvat

14 Finished: Special Armor V-2, Airfix P-51
15 Finished: SBS Gladiator engine
16 Finished: Brengun C2 Wasserfall, Merit SS-N-2 Styx, World's smallest diorama, Airfix Hurricane.
17 Finished: Japanese Carrier Deck, Belcher SS-4, Italeri AB41, PLAN Type 039A (not 72nd scale)
18 Finished: Tamiya A6M2
The bench:Platz T-33, Trump. T-34/85, Meng F-106, Airfix P-51 #2, Airfix P-40
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Aaron_w
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Joined: March 17th, 2011, 5:53 am

August 8th, 2018, 2:24 am #10

I've become quite a fan of oil paints for weathering and wood graining. The long dry time is an advantage. More time to play with them to get the effect you want and you can mix different colors at various states of drying to blend them together and create a more realistic look. 

However with wood graining I find the payoff really comes into effect at larger scales. I've done this on 1/24 scale "woody" wagons and achieved a very nice effect. In 1/72 however the level of detail for realistic wood graining is very subtle. I do still like to use oils because of the longer working time and ease of redoing (wipe off and start over), but acrylics do work quite well.

I've not run into issues with extended drying times, 18-24 hours being typical with the light streaking I use on 1/72 aircraft. I use the Winton brand oils which are common in the US at craft stores like Micheals. Different brands may have longer drying times I expect.

There are additives you can mix into the oil paint to speed the drying process.


The Tamiya transparent colors also work nicely for certain types of wood grain. The orange in particular looks good streaked over some of the light / medium browns and being acrylic lacquer has a quick drying time. This is one of the few uses I have for Tamiya paints. With the right combination of base colors the yellow and orange transparent paints as a top coat can give a nice appearance of varnish.
   
Aaron Woods
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stimpy
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stimpy
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Joined: July 17th, 2012, 1:12 pm

August 8th, 2018, 3:21 am #11

Thanks for all the tips.  Playing around with ideas.....
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stimpy
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stimpy
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Joined: July 17th, 2012, 1:12 pm

August 8th, 2018, 12:00 pm #12

So what I can surmise is though thinning the oil with turpentine, it was still too thick/neat and I've applied far more than I should have. Add that to my ignorance of how oil paints dry/cure, I've gone treated the medium like an enamel.  I've even made the mistake now of giving the surface a coat of varnish (oil paint specific from the art store). 
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Aaron_w
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Joined: March 17th, 2011, 5:53 am

August 8th, 2018, 4:13 pm #13

What are you using as a brush? I have a couple sizes of fan brushes like these

http://www.michaelsweddings.com/soft-gr ... t+Supplies

I just lightly dab the tips which gives a very light application. You can wobble the brush a bit do give a wavy grain effect, or just drag it for a straight grain..
Aaron Woods
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Petri
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Joined: October 3rd, 2010, 6:28 am

August 8th, 2018, 6:55 pm #14

Stimpy, going off on tangent here -  apologies in advance - but if it is not too late for your Hannover build, have you considered wood grain decals like these:

https://www.uschivdr.com/products-in-de ... in-wgc-72/

This is my plan A when having to simulate large wood/veneer surfaces next time :)
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stimpy
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stimpy
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Joined: July 17th, 2012, 1:12 pm

August 8th, 2018, 8:59 pm #15

Petri wrote: Stimpy, going off on tangent here -  apologies in advance - but if it is not too late for your Hannover build, have you considered wood grain decals like these:

https://www.uschivdr.com/products-in-de ... in-wgc-72/

This is my plan A when having to simulate large wood/veneer surfaces next time :)
Yes I had looked at them.... next time, they are expensive. I do have hesitation using decals over large areas, the Techmod lozenge and rib tapes on my Albatros were a nightmare to deal with. However the Hannovers wings have just been completed using Aviattic 5 lozenge decals and they were pretty darn good at conforming.  So, yes, next time I would consider investing on the Uschi decals.

Funny I've been doing a lot of work, but can't transfer my photos to this MaC at the moment; both the USB ports have died!
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Chuck1945
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Joined: May 25th, 2011, 7:05 pm

August 9th, 2018, 1:06 am #16

While on the subject of oil paints ... I have seen and purchased Winsor-Newton's new version, oil paints that are water soluble http://www.winsornewton.com/na/shop/oil ... oil-colour. No clue regarding the chemistry, but I have used them on control surface hinge lines. They do thin and flow nicely using just water although the capillary action doesn't appear to as good as traditional oils thinned with mineral spirits. (This observation is based on a one aircraft sample size though, so not statistically significant)
Chuck
Eastern WA, USA
Finished 2018:
Eduard Spitfire IXc, VIII, Monogram/Starfighter BFC-2
On the active bench:
Eduard Bf 110C, Hasegawa B-24D, SH P-40E
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