I would not soda blast anything. Several major paint companies like PPG will NOT warranty their paint once soda blasting has been involved.
The soda leaves behind a thin film on the metal that is very hard to remove. This film wont allow paint products to adhere to the metal even when sanded/grinded.
Do some research on the type of soda the blaster uses before hand.
A good dipper will do a second wash to neutralize any chemicals. This way you dont have chemicals seeping out from seems.
My current 49 will get dipped, metal worked then ecoated, will look brand spanking new...Eric