anyone have any tips or suggestions for washes, panel lines or general weathering of bare metal foil? i am at a bit of a loss 
Do you mean large areas- say the whole model or major portions of an airframe are BMF, or merely small areas? If you covered large areas with foil, did you use small pieces shaped to panels, or are you looking for ways to create panel lines after the foil is already down?
hi, Don
about 80% is foil in smallish pieces. I have tried a bit on some scrap i foiled up but it either just ends up looking scruffy or whatever i put on just comes straight back off again. It took me ages and i dont want to spoil it now.I am hoping someone who has done this sort of thing before (i havent) can give a bit of advice,
Pic is the model in question.
IMG_1294 by omgpainful, on Flickr
Okay, now I see what you are doing. Not sure what kind of effect you want. I use an airbrush dialed way back to get a very faint cloudy effect for some stains, like exhast or such, that works on foil. If you want just to enhance the panel lines (BTW, I think what you showed looks fine) I would experiment on scrap. Put down a patch of foil on scrap plastic and try a conventional wash. See what it looks like on the foil. Sometimes you have to innovate. Someone has to be first with any trick technique 
Thanks, Don,
Ill foil up some more scrap and have another go then. All i want to do is tone down the clean shiny look and higligt the details without ruining it. The 104’s in vietnam were well scrubbed due the the awful weather.
Oh, that is just the thing for a thin airbrush coat- put on a very light overcoat of medium gray. Also, consider Alclad II instead of foil next time. They have several shades of aluminum, from polished to a “white” aluminum that represents weathered skin very well.
That’s some dang nice foiling, though. I can see why you’re hesitant to mess it up!
Gene Beaird,
Pearland, Texas
Thanks Gene
Don - i have used alclads but just wanted to try something different. on balance i agree, it would have been easier to achieve what i wanted with them. but hey ho such is life . Ill just have to do a fresher version of what i intended, no biggie.
ill probably just try to cloud it up a bit with fine sandpaper as in the photo and cut round the detail and use a dark grey acrylic wash in the panel lines and see how it turns out. the panels dont seem to have great trenches to make them stand out on the real thing anyway.
SEADaNang1 by omgpainful, on Flickr