Undercoating and sandblasting

[Quentin Hall]

Hi Paul, Happy new year. I’ve been down this road many times and years of success and failure has made me use several techniques in tandem or unison or altogether....
On body panels putting heat via a torch could destroy or warp a panel pretty fast. The tar is best softened with a thinners , kero, or turpentine. Sometimes you have to trial each to determine the best . Manually scape it .
For external panels I recommend using a caustic solution to remove paint and for rust I use a phosphoric solution. I have a rainwater tank that I can immerse whole doors and fenders and hoods in to gently lift and remove rust with out aggressive blasting.
I always try to do as much preliminary rust and paint removal as possible BEFORE using any abrasive blasting. Abrasive blasting is non discriminatory ie it takes away both debris and substrate so it should be used more to give a key to the metal.