What should I paint underside of truck with?

Search POR 15 here, plenty of threads and guys have tested rusty vs clean metal. It's no good on clean metal.

 

just finished spaying my 70 AMX floorpan with 2 part catalized truck bed liner. got it off e bay for @ $200.00 for 3.5 sprayable gallons with a shutz gun included. looks super clean and seems tough. will have to see how it holds up when I finally get it on the road.

 

On almost ALL of my builds.....I spray on 2 coats of POR-15, one day apart. When the second coat is just "tacky" I spray on bedliner. Double coat inside the wheel wells. I usually do it on sandblasted metal, though it might not be 100% "white metal".
I live in NJ. Lots of snow, salt, and rust.
Even if the bedliner gets chipped the POR keeps it from spreading.

 

If youre spraying it I'd say quick coat of etching primer, then truck bed liner. plan out where youll be mounting stuff, hit those area with some semi flat black, mask those areas off for solid mounting surfaces, do the rest with bed liner.
http://www.tcpglobal.com/detailsupplydepot/dsd18.aspx

semi gloss tractor enamel would be cheaper and easy to touch up and would work better if your brushing it on. Need to be careful you keep your enamel away from the rest of you painted areas.

Depends on the level of detail you want. If its a show truck or high level build do it in body color, it will get chipped and need maintenance touchups - get single stage mixed to the same color if doing base clear on the rest of the truck, you can do the bottom of the truck, firewall inner fender in single stage to save some $.

 

Everything is flammable, if you get it hot enough.

 

just finished spraying the floorpan of my AMX with catalized (2 part)truck bed coating. looks great and feels tough. got 3.5 sprayable gallons off e bay (liner xtreem is the brand name) for @ $200.00 with shipping including a shutz gun. still have about 2.5 gal. left. will use the rest for inside the trunk and the inside floor pan.

 

Here is a pic of the underside my F100 cab...sprayed the bare metal with 2-part (2pak) epoxy primer and then sprayed about three coats of rattlecan DupliColor bedliner over it. This may be the perfect solution for you...durable and it will match your paint scheme.

 

Chuck how long did this take you to do. Can you pm me the brand name of the epoxy primer? I appreciate it. Donald

 

Any PPG retailer can get you PITT-GUARD Rapid Coat in black. This a 2 part Direct to Rust Epoxy Primer. It can be applied to clean or clean rusted metal. Very thick and very tough. It can be sprayed if you have a big enough spray gun (1.8 tip) or rolled/brushed. Has a nice semi gloss sheen which is easy to clean. This stuff cannot be sanded with any thing less than 80 grit. We spray every car we strip with this and you can block out small door dings with 2 coats. $85 gets parts A & B which mixes 1:1 so it makes 2 gallons. I did the whole bottom of my 61 cadillac with about a quart.
Hope this helps. You will not be diappointed.

 

Thank you for the tip my friend

 

Thanks for the info. What kind of rust removal do you need to do to lay this stuff down. Got a ton of surface rust in the trunk of my caddy.

 

Just knock off the loose scaley rust with a wire wheel and spray/roll. This stuff is DTR (direct to rust). It likes rust. We spray old rusted drill pipe that we make cab/ body dollies with and the rust does not come back. It does not like uv rays, it turns chaulky if exposed to direct sunlite. This stuff gets so hard it's almost impossible to "key it" down to the metal with just 2 coats.