I have heard the same thing as Brian. I was also told that some shops will put the parts in a oven at I think around 140 deg. for 24 hours to eliminate this problem. I have had many flat panel parts dipped and found it to do a wonderful job. The trick is to have it phosphate dipped after stipping and then primmed as soon as possible. The problem is with leaving the phosphate to long is it is like it crysalizes and makes the metal rough. I have taken some of my panels to be dipped the other day and have started to sand the cab and doors down to bare metal (boy do I hate sanding) I have been lucky to know the owners of the shop and will be scuffing the parts with 120 grit and painting the panels with epoxy primer as soon as it comes out of the tanks eliminating the cost of the phosphate prosses. Hope this helps you in your decission
