I'm building a 1/48th scale baremetal B-17 and I need to know how to weather it

Duck, you could go with the standard weathering.

Oil streaks from the engine,

Exhaust stains from the exhaust pipes,

maybe dull the paint a little so it isn't to shiny where the men would walk on the wings.

Just the basics, or you could have it newly arrived at base.

~Chip :-)

Hi Duckfan

Added to Chip's post...

Quite often you see Olive Drab anti-glare paint in front of the cockpit that's faded away to almost "yellow zinc chromate" in places...

Have fun and show us the results :-)

Rowan

:-) On a bare metal finish I would use a wash from artists oil colours; warm grey, which has a brownish tint, darkend with black with a touch of burnt umber. After washing the panel lines and letting the wash dry for a couple of hours (the time depends on how much the wash has been thinned). It is the correct time when you wipe it off, in the direction of the air flow, and it leaves the panel lines darkened and leaves a film over the surface. This film dirties the finish. You can add minute ammounts of warm grey to selected areas and drag back, using a finger, cotton bud or cloth. This will give oil and /or dirt streaks. This is a good technique for simulating the oil streaks from radial engines (Look out for my Corsair, on here soon, I used this technique on that).
Something that many modellers forget to do is to weather the decals. Apply them before the wash and seal with Klear (Future). You could fade them, for this you would have to mask them and spray a heavily thinned medium grey (I use British medium sea grey. See my Helldiver article). If you are going to chip any colour on the plane (anti glear panels, unit IDs, etc) then I would suggest chipping the decals a little. (Do this after the fading, using a silver pencil, or paint. Don't go mad )
Having just re-read your question I'm assuming you are talking about the Monogram B-17? For the technique I described to work properly you would need to re-scribe the beast. This is why I re-scribe (article on the way, soon, I hope). If you don't want to re-scribe then you might be able to run the wash along the raised panels?
Looking for to seeing the completed model :-)
Mal

You could also paint a single stabilizer flar or the rudder flap OD to imply a repalced part from a hangar queen. If you have any markings in red, you could fade the sections that face the sun (red bleaches out pretty fast).

Hi

I did the Monogram B-17 a while back, whilst not being my best effort ever I was fairly happy with the exhaust streaks and panel lines - whilst I can't really be of help to you with the bare metal finish, this might help you with the rest of the weathering.

the b17 was used alot during world war 2 so any ideas u had on weathering it they are problary right becuz of use

Duck, I did mine in OD . I tried to so weathering for 74 missions and many repairs. Also the evidence of engine fires at one time or another on all four engines. The markings some what clear as to show touching up for the trip home. You know, the returning hero . Mav

Does it have resests panel lines if so ues a very very very very watered down black for some weathering. mabe when the olive drab is dryed take tape put it on and pull it off it will give chiped paint and mebe you can use some pasteles in this model some where.