I have been using the Alclad Klear Gloss, which is an acrylic clear. It works great for coating things before using oil washes. I used it to coat the cockpit of a 1/32 Bf-109G-6 and will be using it as a sealer on the exterior before weathering.
***Update*** After some thinking that I referenced the wrong Alclad product, I went home last night and checked the bottle to make sure I was talking about the right product. I was mistaken, the product I was referring to is the Alclad Aqua Gloss, this is the acrylic clear that I use before weathering. Sorry for any confusion.