My floor pan and torque boxes are not rusted through but do have surface rust, so I wanna sand and shoot undercoating. I have a compressor and a spray gun but it wont straight up (like if I'm laying on my back). Whats my best bet? Is there a cheap gun not gravity driven? Do I just go with aerosol cans?

 

check out the Krylon truck bed liner kit, one of there kits come with a siphon type gun (i think you can get it separate from the kit) or harbor freight for a one time use gun.

 

Thanks Ill have to go check that out, come to think of It I may have even seen the truck liner kit in pep boys

 

You could also use POR-15 and simply brush it on. It'll also spray nicely without adding any of the reducer as I found out a few weeks ago. Last month I sprayed 3 coats on the inside floors and firewall with it. If brushing 2 coats would have worked. I'm returning to the car (1000 miles away from me and in another country) end of this month and will be spraying the entire under chassis & inner/outer engine bay with it as well.

POR-15 is MUCH harder then any of the bedliners and will protect the underside of the car better. It'll also encapsulate the rust thats there and keep it from rusting any further. Bedliner will not stop the rust from spreading regardless of sanding.. it will continue and come through later.

If you have any questions on it let me know as I've talked to the guys about it quite a bit last month.

 

Thanks adrenolin, planning on doing the undercoating next week or the week after so I'm sure Ill have some questions, thanks for the tip off on POR-15. I might just have to go with brush on as I'm still having trouble finding a gun that can spray upside down.