I am almost ready to paint the underside of my car with POR15. Is it advisable to put undercaoting over the POR, or leave it POR only. Perhaps just undercoating with no POR. Which way should I go. I have the rear end out and have all of the parts painted and ready to install. (axle, springs, perches, spring pockets, driveshaft etc..) They look so good I hate to install them. They have all been done in POR, and came out awesome thanks to the help of the TC folks. :)

I would POR it and thats it. As you said, the POR when done right looks really good and its basically bulletproof. I can think of no reason why you would want to coat over POR, not sure how well it would adhere anyway.

It is really a matter of personal preference. I POR'd the entire undercarriage this winter and applied undercoating to the rear wheelwells only. You shouldn't have a problem undercoating over POR either. In hindsight I wish I would have undercoated the floorpan to, but like I said its a matter of personal preference.

Craig,

Like these guys already said.... it's a matter of personal preference.
I like the way Rod did it by just undercoating the wheelwells. Nothing is gonna touch POR, so to me it basically comes down to what you want the bottom of the car to 'look' like.
I undercoated all of mine mainly for the vibration and sound deadening properties (to augment interior sound deadening material).

Craig,

Like these guys already said.... it's a matter of personal preference.
I like the way Rod did it by just undercoating the wheelwells. Nothing is gonna touch POR, so to me it basically comes down to what you want the bottom of the car to 'look' like.
I undercoated all of mine mainly for the vibration and sound deadening properties (to augment interior sound deadening material).

Sound deadening is one reason I was interested in undercoating. I was mainly concerned about whether or not the undercoating would "stick" to the POR15. I also don't want to put the POR on and cover it with undercoating unless there is some benefit to having the POR protection under there in addition to the undercoating.

Thanks guys.

Gotcha, yeah wasnt really thinking about personal preference, only the fact that POR would work great. Im not a big fan of undercoating on floorpans and such, wheelwells yes. Like you said, personal preference. Good luck

call POR and ask them if undercoating would stick to their stuff before you did it, if you chooose too. Id just leave it POR myself. That might be my next winter project, the underside, yuck :)

Undercoatings will stick to POR-15, if scuffed up a little with a 3M pad. But if your thinking of going the under coating route, skip the POR-15 just because of cost but that is up to you. I used Truck bed liner under my 69 because it is a catlized type liner, which makes a hugh differance in how long it will last. I also over reduced the liner to keep it smooth and not to rough. I also used 8300 3M seam sealer to seal all the seams before putting on the liner just to make sure it is all sealed up tight. Either way you go it sounds like your in the right direction.

So i've used a SEM rust incapulator on the surface rust under the rear end, I was going to overcoat w/ Spray Bomb and was considering undercoating as well. For protection and sound deading. But I was thinking that it would damage the car/reduce the 'value', like 'whats under the undercoating what are you trying to hide?' I guess I can't take some pictures first? Please weigh in.

Thanks for the input

Thats why I didnt undercoat over the POR 15. Undercoating can hide a whole bunch of issues and is looked upon by some with suspicion.

Por 15 can be coated over. Scuffing it up is CRITICAL to adherance! Another way to go would be to look into por's "tie coat primer", then coating over that. Por will fade if used where the sun can get to it, but under the car should not be an issue. I have used a bunch of their products and have had very little problems over the years. The putty is neat stuff to. I used it to fix a few cracks in the steering wheel. I can't even tell where they were now :thumbsup: Good luck with whatever you decide!

Dano :beers:

Undercoating was an option that a dealer could install. My 1969 SS396 Chevelle had it from the dealer. I had all the paperwork to prove it from when it was bought new. I know there was not just one dealer doing this. It looks kinda ugly form a resto standpoint but the new types are looking pretty good. Some one here posted pictures a while back of the car they have. He live in the New orleans area I think and is a body man I think? His looked great.

Joe

Some one here posted pictures a while back of the car they have. He live in the New orleans area I think and is a body man I think? His looked great.


http://hobbystage.net/camaro/shoddyfbody/1106508006-005424.jpg

3M 8111. Thanks for the compliment. :)

http://hobbystage.net/camaro/shoddyfbody/1106508006-005424.jpg

3M 8111. Thanks for the compliment. :)

That is a look I can definitely live with. I doubt mine would come out that good, but in my mind, that is what it should look like. :)

Craig,
You really can't mess up undercoating. I'm sure it'll turn out just fine. I just wanted to lay under my car and stare at it when I was done shooting the Mar-Hyde.
:thumbsup:

Craig,
You really can't mess up undercoating. I'm sure it'll turn out just fine. I just wanted to lay under my car and stare at it when I was done shooting the Mar-Hyde.
:thumbsup:

One more question. The Mar-Hyde comes in a few variations. Would you use the rubberized, or the type that dries very hard. I have some of both. At least I think that is the Mar-Hyde brand. I could be mistaken.

The pic posted is a perfect example of a job done right. To answer your question on what type rubberized or rock hard type. Well look at it this way your Muffler will get hot enough to melt the rubberized type. I used a brand by the name of Gator guard it gets hard enough to with stand the heat, but it is a wise idea to get heat sheilds for the mufflers. I also took plenty of PIC's before spraying it on just to prove nothing is hidden. From the pont of restoration ppl they tend to frown on the idea of undercoating, but if your going to use the car and not trailer it everywhere it's a good investment. I'm a painter by trade and I will say this, it only has to be done once and it stays nice a long time. Good luck hope it turns out like mine did.

69RS/SS Pro touring Camaro
X-11 540/M-21/12bolt-4.10 Major Handful.

I tried two different rattle can Mar-Hydes and another off-the-shelf brand - maybe Plasticote - and ended up going with a Mar-Hyde called Paintable, Rubberized blah blah blah. If you do a search, I mentioned the part number a few times. I can't remember off the top of my head. 4311 I think.
The reason I went with the paintable, rubberized version is because it cured hard and a little thinner than the other version. The other Mar-Hyde (and the Plasticote) went on thicker and didn't dry hard. They stayed a bit soft which I did NOT want. It turned out looking like Shoddy's.

Also, I went with the rattle-can method out of shear cheapness. 3M and others offer coatings that need to be sprayed with their special sprayer and I couldn't justify spending $60 on a sprayer for something I'd use once. Plus I got the Mar-Hyde at shop cost through a buddy in the business, and I can pop a can open and shoot some more whenever I want.

Has anyone found a undercoating that looks like orignal ,also what about a correct color for the underside . It's my understanding that the underside was originally grey not black.