Weathering sealers

Drew, you might try Dullcoat’s opposite, Glosscoat (also made by Testor’s). Actually, I glosscoat most models to apply decals, then seal them with Dullcoat.

Mission Models Paint has acrylic clear coats in matte, semigloss, and gloss if you want to airbrush.  I have used the matte and semigloss but it's tricky because if you spray too much it will look one grade shinier.  But that's about true with any clear coat.   Also you could try very light dusting with Pledge floor care (they bought the Future floor finish brand).

Thanks for the advice guys!  I’ll do some experimenting on some test pieces and see what results I get.

If you want it to stay chrome, then do the weathering with something that requires no sealer, such as paint.  If you chalk it, you’re other going to have to seal it, which will change the finish no matter what, or live with the fact that over time, the chalk work could come off with handling (or just don’t handle it). If you gloss cote weathering, it’s going to look like it just got rained on… probably not the effect you’re after. You can mix chalk into the paint so that the paint has some texture to it, and obviously it’ll dry in place with the paint.