Excellent recommendations cyclopsblown34! Epoxy first then urethane surfacer. That always works great. I came across another option I use at my shop on every project now. I strongly recommend the House of Kolor KD3000 primer. It can over nearly anything, it is a DTS (Direct To Substrate) primer. It is a "hybrid" of epoxy and acrylic polymers. It is made to go over bare metal, paint, body filler, most all plastics, fiberglass, pretty much anything you will encounter. It can also be mixed as a high build, medium build or sealer! I have used this at my restoration shop since HOK came out with it. It is amazing. It lays out extremely nice and flat (much like a straight epoxy). It builds yet doesn't dry with extensive orange peel. It sands excellent and I have never had any issue with bleed through, swelling or die back. Another advantage is it is the only primer you will need for your entire project! No need for an epoxy then high build then sealer! Not to mention, you can buy it tinted to provide an excellent base for your topcoat. It is more expensive then some other primers out there, but when you consider you only need to buy one product instead of 2 or 3, I think it pays for itself. I know I may sound like I must be a HOK rep, I am not. I just firmly believe in this product. I have used so many other primers over the last 25 years, this is by far the best! Anyway, that is just my 2 cents!