Ughh...,just do it once all the welding is done

Just my .0000000005 cents worth....

Depends on what the final job is - what you're trying to build... a real nice driver - a show car - a riddler contender...

If you're trying to do most of the work yourself - in stages etc.... then degreasing the frame INSIDE and OUT -- maybe a couple of times -- Back in the day I even hooked up the garden hose to the drain hose bib on the hot water heater for a good blast of hot water cleaning with a suitable degreaser. You can also get long WIRE handled brushes - getting a large diameter - and run that in and out of the interior of the frame.

A nice coat or two of SELF ETCHING primer once the steel is all bare....

Or take it to a blaster.... then bring it home and put Self etching primer on it to protect it while you're still mocking up etc. Then paint it once you're happy with everything. It really all depends on your budget and what the end result is planned on. There's about a zillion hot rods out there that have their frames painted with POR 15 and they look great if done right...

Greg, or anyone else. What is a suitable top coat for POR-15 or DP 90??

POR 15 has their own top coat -- but it's only needed if the base coated parts are exposed to sun...

DP 90 is an epoxy primer... so it would need to be cleared... if you left it DP90 it would be a big b to clean...

so once the frame is cleaned and down to bare metal, you can apply por-15 onto the frame without having to apply a clear coat or anything else correct? Just spray the por-15 and if its done nicely it should look decent enough for a street car?
Im just trying to avoid spending the money to have it sandblasted and powdercoated, yet still want it to look decent

I have used POR 15 on everything from my boat keel (fresh water) to an outdoor railing. When you follow the directions and do as Greg says, use an etching primer/liquid, you will have great results. On the outdoor railing I just wire brushed and painted right over the rust (near plants) and (knowingly) did NOT top coat. Even then, exposed to Canadian winters and UV rays, it took ten years for the rust to BEGIN to come through again.

For a topcoat, FOLLOW INSTRUCTIONS to the letter and you will get great results.

cheezer

Bone --

No need to "spray" POR-15 -- a good brush will flow out like it was powder coated.... DO NOT USE FOAM BRUSH.... buy a decent enamel brush and throw it away when finished. WEAR Gloves! Don't spill - don't slop! This stuff is impossible to get off once it's dried... a good thing on the part you're coating - not so good on other stuff.

If the part is not "exposed" to UV light (sun) then there's no need to top coat. Read the directions on the can - or on their website...

CLEAN CLEAN CLEAN -- it can't be too grease free! No point in painting over flaky paint either... if it's suspect - get it to bare metal...

The stuff takes awhile to flow out and kick -- so dust can be an issue.... do it in an area that is dust free -

What he said ..... X2

cheezer

good question to ask, Chris. You beat me to it. after making my parts list for my subframe, i was curious how to finish it off. i think i might go Greg's route with the por-15. seems to make the most sense. no muss no fuss. dont want things chipping away from driving the piss outta my car:thumbsup:

Most of the Por 15 I have seen is just too thick looking. The oil on the frame I would remove with lacquer thinner and then paint.