1960 VBB 150
Stripping and paint:
I had heard of a process that would remove all grease, paint, and rust by immersing the frame and other parts in a tank of acid and looked through the phone book until I found Norcal Metal Stripping (707) 838-9470 and gave them a call. They can strip any steel part but all cast or aluminum parts must be removed as the acid will "melt them". The tank is big enough for a full car so a scooter is no problem. Below are the before and after (after a quick wet dry sanding) pictures of the frame.
Although the frame is clean it needs a good sand with fine grit wet/dry paper. I poured thinned out primer down the cable tunnel to coat any internal parts I could not reach with a gun. The frame also needed to be thoroughly cleaned before spraying the primer.
I sprayed a 2 part epoxy primer from PPG on the bike in a few hours. I honestly can't remember what the product was as it was so long ago but it was evil and required a serious respirator to apply. The result was decent but I would recommend a sandable primer as the frame had small stretch marks from the original pressings which should have been filled. PS - all good scooters live inside at this point in their life!