Getting ready to paint the underneath of my '68 tomorrow but I have one decision to make. Should I just go ahead and use the standard POR-15 or the POR Blackcote? I have approx 75% factory paint left underneath and the rest is bare metal (which I have treated with POR metal ready today). Blackcote is better for painted and standard for bare metal... I want the best adhesion possible. It took me almost 2 weeks to get the bottom ready for this and I don't want to screw it up! Thanks for all the help!
MStarmer

I've used most of their products with good results. You should treat the bare metal with POR15 and then topcoat everything with the Blackcoat. Stir well and occasionally during use.

BLACKCOTE is NOT necessary for the underneath of you car. The MAIN reason you would use blackcote is because it is UV light INSENSITIVE. You would put BLACKCOTE over POR15 on anything that might see sunlight because POR15 will be discolored when exposed to UV rays.

POR15 reccomends a THREE step process for underneath you car. First Step is MARINE CLEAN. This cleans and degreases (17.50 a gallon). SECOND step is METAL-READY. This is a self etching and is also a rust neutralizer. This promotes good adhesion of the POR15 to the metal surfaces (28.75 a gallon). NOW you are ready for STEP THREE (POR15) (95.00/gallon). I would use SEMI-Gloss black.

By the way POR15 is vastly superior to BLACKCOTE because POR15 CHEMICALLY bonds to the surface. NOTE: POR15 does NOT like smooth surfaces so if you have a very smooth surface you may want to "rough" it up a little.

Their number is 1-877-321-2629. WEBSITE is http://www.POR-GUYS.com


OK???

[This message has been edited by sr71bb (edited 04-17-2001).]

Believe me I know the process! I have gone through about 3qts of POR and plenty of Marine Clean and Metal ready...My question was on the BONDING, I understand about the UV but Blackcote bonds better to paint and I still had a considerable amount of paint left. I did hit everything with 100 grit on my palm sander the best I could, washed it with Acetone about 3 times and treated it with metal ready. I went ahead and POR-15'd it yesterday. Looks pretty good, not show quality under there or anything but way better than greasy undercoating and probably better protection as well. Here's a look before I started: http://albums.photopoint.com/j/ViewPhoto?u=1536360&a=12511695&p=46129726&f=0
After painting: http://albums.photopoint.com/j/ViewPhoto?u=1536360&a=12511695&p=46751883&f=0
Thanks for the input. MStarmer

Didn't mean to preach to the choir!!!! Looks GREAT. How much POR15 did it take (2 quarts???). If you were going to do it over again from scratch would you do anything different??? It looks like you used GLOSS BLACK NO????

I asked the POR15 guy about bonding to a painted surface and I think you have covered your bases there with your sanding process. When I did the floor pans in the interior of the car I did notice that the POR15 had a tendancy to puddle in the low spots. Of course that would not be an issue UNDERNEATH the car.

[This message has been edited by sr71bb (edited 04-17-2001).]

[This message has been edited by sr71bb (edited 04-17-2001).]

Sorry to jump in on someone elses post, but I'm painting the subframe to my 69 camaro with POR15. Should I use the blackote? I don't want my frame to discolor. is Blackote made by the POR15 people?-JOE-

I painted mine with POR15 and then chassis coat - all POR15 products. I also did my new gas tank with their clearcoat - Glisten PC. Awesome stuff. Prep is very important as already stated. I have another subframe that is perfect and I'm detailing it with the same stuff.

Maybe I should clarify, I have used 3 quarts but that was the interior, subframe inside and out (2coats) and the most of the underside (2coats). I probably used 1qt alone on the subframe. I really layed it on thick inside, turned out well though. Check out the pic, a little dusty after some sanding. http://albums.photopoint.com/j/ViewPhoto?u=1536360&a=12394856&p=46822690&f=0

POR goes on very thin and a quart goes a LONG ways. Do not buy more than you can use quickly as once you open the can it starts going bad. I don't even open the cans anymore I punch a hole in the lid and one in the side at the top and use a sheetmetal screw in each hole to close it off. I only take the screws out to mix (with a shish ka bob skewer) and pour then the are immediately screwed back in. I wasted almost all of my first can before the blasting place that I purchase from gave me that tip!
Thanks for all the comments. Feel free to e-mail me with questions.
MStarmer