Get it dipped by the chromers or get it sand blasted and then go over the frame with wet and dry yourself making sure you are happy with the bare frame before letting the chrome plate be applied. A good chromer will do all the prep work but expect it to be expensive that way. Best to do most of the major work yourself and then agree with the chromer the bits you want/need him to do. The quality of the finish is dependent on the preparation and the way in which the chrome is applied. You need to make sure that a show chrome finish is applied, this will usually be a base layer of brass, then nickel and then the chrome.