removing underbody rust

Any tips on how to get the rust off the underbody and should i use the spray can bed liner or rubber spray to coat the underbody.

Yes you can use undercoat on the underbody but you should consider cleaning it and making shure the metal isnt rusting I would use elbow grease and a palm sander with 80 gritt to work the heavy stuff down then treat it with some acid and car soap to nuetralize it then rinse and dry with a air gun. Then spray the portions that you sanded with rust paint once the rust paint dries the undercoat can be applied. Dont spray the drive shaft or it will shake on the highway.

You can use a product like POR-15 to seal the rust. It can be painted directly over the rusty surface-- but wash it first to get rid of the loose pieces.

Thanks a lot guys that definently helps.