Best way to paint a frame?

[Chevy Truck Guy 86]

On my 86 K10, I'm stripping it down to the frame and building it back up. But I'm stuck on what I'm going to do on painting the frame. I've read about POR 15 but I would like to sandblast the frame and I guess POR 15 isn't best on bare metal. I just need a long term frame paint. I probably won't drive the truck on any precipitating days, just drive it one a while with collector plates. Anyways I would like to know what you suggest to this or what has worked best for you. Thank you.

[VileZambonie]

I've used POR15 for years an never had an issue with it adhering to the frame. I tried Chassis Saver by the recommendation of Blazin here and all I can assess is that it's less expensive but works the same. Don't go crazy just shoot it on there. If you truly want a better finished result get it powder coated.

[Chevy Truck Guy 86]

I've used POR15 for years an never had an issue with it adhering to the frame. I tried Chassis Saver by the recommendation of Blazin here and all I can assess is that it's less expensive but works the same. Don't go crazy just shoot it on there. If you truly want a better finished result get it powder coated.

Do you just spray it on bare metal or just as is?

[bake74]

     Por-15 and Chassis saver both can be sprayed and "hand painted" per instructions.  I would recommend using the spray method.  I have done both with both products and I believe spraying gives better results and will adhere better.
     Both products have instructions on how to thin it and what to use before running it through a spray gun.  As far as bare metal is concerned, sand blasting will make it coarse and will allow either to adhere better, but if you are worried, after sand blasting the frame, hit it with water, wait for a couple of days and then paint it.  Both Por-15 and Chassis saver are products that take rust (oxidation) and chemically converts it to bond the "paint" to the metal.  Either way will work, just as Vile said, it still works on bare metal if prepared properly. 

[Blazin]

Chassis Saver or POR 15 will stick to sand blasted bare metal, but not virgin, ground, or sanded bare metal. It says right on the cans that it is to be applied over tightly adhered rust ( no scale ) or sand blasted metal.
I can't recall the name of the thinner that's supposed to be used with it but there is a special type. Lacquer thinner is good for clean up, but does something to it to make it less affective so its not for reducing it.
Neither of them stick to old paint even if its been sanded.
They don't have any UV protection. They will chalk up if left exposed to sunlight.
I also top coat them most times with an inexspensive activated acrylic enamel.
Wear gloves! If you get it on your skin, and leave it there, it will be there for the better part of a month!
Brake clean, or lacquer thinner on a rag will clean it off, as long as it isn't left for more than ten or so minutes.

[Chevy Truck Guy 86]

Thanks guys. I will probably use POR 15 on bare metal then put some regular paint on top.

[zieg85]

Those type primers are moisture cure urethanes.  In 2K polyurethanes the catalyst or activator causes the paint to harden, the moisture in the air causes the POR15 type products to cure.  If reduction is required to apply it by spray follow the directions on the can.  It will call out for a urethane grade reducer.  Most solvents will accept water but fresh urethane grade goes the extra process to make that percentage very low.

FWIW keep the lid clean and the ring around the can.  If you have access to nitrogen or argon from say a torch set up hiss some on top of the paint before you seal the can.  Both nitrogen and argon is heavier than air and will displace it so the paint is preserved, other than that any leftovers will cure in the can pretty quickly.

[Blazin]

I meant to mention the lid thing, but forgot. Clean the lid and top of the can to better than new, I also put a piece of 1 mil plastic over the can before the lid goes on. If you don't clean the top YOU WILL DESTROY the can the next time you TRY to take it off.
never heard of the nitrogen, or argon trick. Sounds right though. I will have to try that out.

[zieg85]

never heard of the nitrogen, or argon trick. Sounds right though. I will have to try that out.

We do it all the time in the lab.  I work with a lot of CARC materials which most are Moisture Cure. 

[Engineer]

I took time to think my project through, and considering the sad state my truck was in to start with, only one option existed for me.......

Full disassembly, sandblast, etch primer, paint:

[VileZambonie]

On my 74 I stripped the frame to bare metal, sprayed it with Chassis Saver and top coated it with Body Schutz. I powder coated the cross member and control arms. The axle, links etc all chassis saver with no top coat.

http://forum.73-87chevytrucks.com/smforum/index.php/topic,7175.315.html