I suspect this issue was already mentioned on these foruns but a seacrh by "motor oil" brought dozens and dozens of threads, none actually related with motor oil.

So, what I would like to ear from you is how do you treat engines at scale 1/35, specially oil simulation.

if you mean oil spills and leaks around fillercps,sump plugs ect just use a black wash or for grease use a mix of black/brown it's hard to say as oil goes blacker the longer it's in use if it's freash go for a light broenish colour but around the caps ect it does acctract dirt grit ect so goes black very quickley, also if it's fuel you want to simluate try adding some satain around the fuel caps to simluate the sheen off the diesel if its just beeen filled/filling up

Well... color is not the main problem. Problem is I don't think oil effect can be achieved only with paints. I'm trying to find a technique making "oil" looks like oil. Oil is a little shiny and shows a specific consistency.

I’ve been experimenting with Floquil enamel railroad colors. Grimy Black, Rail Brown, and Oily Black, used alone or in combination, have been producing some satisfactory results. You might want to give them a try.

Mike

If you want the stain to look glossy/wet, just paint on your favorite clear gloss. But as Mike said, thick, sticky oil is a natural dirt magnet and will quickly become a mucky, bloackish sludge. Adding some black pastel shavings to your color of choice will help withthis effect.

I think Tamiya Jet Exhaust mixed with a little black or rubber might do the trick.

Mostly use the Jet Exhaust thinned for diesel stains but the bottom of the engine compartment of the M106 I was on always had a layer of oil in it so that would be a good chance to really coat something will 'oil'

Paul

I use gloss black and purhaps some brown pastels to make it look dirty

Just a thought guys, but how about using a small dab of the real deal, i.e. actual dirty motor oil? It could be applied with an old small brush around the fittings or any other desired areas-----> the only issue would be possible smearing as it would be difficult to "fix" the oil to the model. Just a thought (and maybe not such a good one lol).

Steve

Try this thread: https://armorama.kitmaker.net/forums/15640&page=1

I'm with Steve on this. When I need I go to my car and perform an oil level check then I get a drop of two of oil and then apply it very carefully with a toothpick being sure not to overdoing the effect...
Ciao

I would think twice about using real oil. It may react with your paint and/or plastic.

Iuse a thick wash of black and brown for POL spills. If I want it to appear fresher, I put the spill on after I use any pastels, or other weathering. I can then streak the "older dirt". Oil spills quickly gather dirt and loose the gloss, so unless you want to protray oil spilt just "a minute or two ago", I wouldn't worry about the shine.

Jeff

I never had problems using minimal quantities of real oil over an acryl finish... Anyway I cannot exclude that it can spoil your paintjob
Ciao

I've never tried it but it would make sense for oil puddles to mix some Testors Windshield making glue with some brown/black acrylic paint. I've used the windshield glue before to show water spills from canteens and water jugs and it works pretty good. It doesn't dry exactly flat so it would give some contour to the spill. May be worth a try.

I have never been happy with they way my painted on oil and grime came out. Lately I have been experimenting with pastel chalks. I haven't been too happy with those results either, but I think with enough practice it will come along.

Has anyone tried mixing any type of powder with the paint or chalk? Would baking soda/powder add to the fluid's thickness or simulate the dust and dirt that accumulates on old oil?

I am looking forward to trying out some of the ideas already posted and reading more on the subject. Keep the ideas coming guys.

Baking soda or baby powder wont help much as theyre from nature more solid looking when dry instead of the total wet glossy look of oil . I believe that gloss black enamel thinned and some brown shade added will do the job fine . Some black pastel with semiglosss coat over them will make a good effect od long time oil that has been spilled and dried leaving a mark

I liked this tip for... leaking oil drums.... maybe a little off topic:

Leaking Oil Drum

Jim

Oil, Oil... Humm... Well I've never tried it really but I think that you can achieve a good effect using chalk pastels... you can find it in any craft store... i don't know were you are from but here at Porto we have Araujo e Sobrinho, Papelaria Modelo, Papelaria Fernandes etc, they have it there... with real oil i believe that it can mess with the plastic and paint... The only to know is to experiment...
Here somethin' for you:
http://members.xoom.virgilio.it/msfxmini/mini68.htm (em português)
Hope it helps...

See yaaa

just an idea... thin down some white glue, get shavings from artist grade charcoal, make a mix, then wash or drybrush some brownish black color on it. if you want some shine try a big of future.. but its really not that shiny, because dirt makes it dull. its only shiny when disturbed. ex: when you are taking off a cap and run a knuckle across it. its actually about as shiny as normal black or brown paint when it has dust and dirt all in the oil... from my personal experiences. i would love to know how this works.. that is the best way i can think of to do it.. if it works let my know by private message.. i want to try it but i try to avoid building cars and i cant find a good halftrack, cargo/troop, truck or anything... and i have not started my king tiger w/ engine. good luch