u/gsuhrie

I've got some pretty bad rust on my undercarriage (13' Tacoma, 6cyl) from years on the east coast. From what I understand, I should scour and grind away as much rust as possible, do the POR-15 clean/degrease, then P15 metal prep. It's here I'm confused, I see a lot of back and forth on whether to use the POR-15 preventative coating next, or skip that and just hose the whole thing down with Woolwax? I called Woolwax and they said don't do the POR-15 preventative coating under it, but found a lot of internet sources saying to do both. Anybody here have a more definitive answer on my best approach? Thank you in advance!