I will be putting the 68 back on the rotisserie again in a couple weeks to put my final coating on the underbody. After 2 1/2 years, and reading countless posts on this subject, I still am unsure what to use.

1. Paint
2. Undercoating
3. Rhino-liner/Line-X type bedliner

All the pans have been replaced,epoxy primed so I'm not hiding anything,but doesn't have to be "correct", just wanting something durable,easy to clean,and will last. I'm worried about paint chipping/scratching, not sure how long undercoating lasts before it may chip/flake/or peel, and I haven't came to a conclusion on the bedliner stuff. Some have said keep it on trucks, others have liked it, are there any real drawbacks to the bedliner coatings?

I'm interested to hear what others have to say. I am thinking of spraying my frame with the bed liner.
I used it on the inside floor of my sons nova when I redid it and it turned out pretty nice.
http://www.chevelles.com/showroom/data/500/medium/000_0172.JPG

From now on I will use PPG DP90 epoxy primer. Just blast the metal ,put 2 coats on,and your done. The DP90 will keep the rust at bay,and is already a good semi flat black right out of the gun.

I'm doing a frame off on 70 BB Conv and have replaced all the floors, trunk pans and wheel housings. I will shoot PPG DP40LF and then top coat with a rubberized (rock guard type) coating (better seal and protection IMO). I too have nothing to hide but want the durability of a thick coating.... Once rust gets in your done so why not add the extra level of protection.

have you thought of por 15? i hear thats some good stuff!! i never used it personaly but iv seen it after it was done and its nice!

I have the DP90LF on there now,just deciding what to do next. I contacted a local Line-X distributor, they said 150.00 prep time plus 9.00 sq.ft. OUCH! I guess that only leaves the possibility of a do-it-yourself bedliner kit if I go that direction, but I'm not sure how well those hold up or if any special equipment is needed to spray. I was planning on using Zolatone in the trunk,I may check into using that on the underbody. I'm really leaning away from just painting it,I dont want to cringe every time I hear a rock kick up and hit the floorpan.

I will check into the rockguard as well, I hadn't thought of that stuff, and don't know much about it.

I dont think I will use the POR since there's no rust to paint over.

Thanks for the ideas,keep 'em coming

Greetings.

I wanted to add my comments to this post. I am planning on using POR-15 rust preventative paint. You can either brush this on or dilute the paint with their thinner and spray it on.

I have used this stuff on my rearend and the front portion of the frame. This stuff does a real nice job. I would, however, suggest top coating this paint with the color of your choice IF you are looking for a completely even texture across your surface. Just spraying the POR-15, gives you semi-gloss and dull spots across your painted surface. The sole purpose of this paint is to adhere to the "rust" and completely seal in the surface. It does adhere VERY well to a sandblasted metal surface. At a little over $100 a gallon, I think it is worth every penny. The company tells me that two quart can do a whole frame.
In fact, I am planning on removing my 68 body as well to sandblast and use POR-15.

By the way, how did you remove your body?

I used POR15 for my frame. It was a pain in the A** as you had to follow the instructions to a T. As with all products there are instructions to help with adhesion, curing, etc.... but I really think the basic products from PPG, 3M, Dupont etc are the same if not better than POR15.

PS. If you don't seal (not just putting the cap back on) the POR15 after you use it, it's wasted. Also, don't get it on anything, will NOT come off.....

For the $$, I'd stay with the basic brands...

Some have said keep it on trucks, others have liked it, are there any real drawbacks to the bedliner coatings?

Other than never being able to remove it.... think thats the only drawback.

I would not do Line-x or rhino....maybe an alternative that's not so thick

I have the DP90LF on there now,just deciding what to do next. I contacted a local Line-X distributor, they said 150.00 prep time plus 9.00 sq.ft. OUCH! I guess that only leaves the possibility of a do-it-yourself bedliner kit if I go that direction, but I'm not sure how well those hold up or if any special equipment is needed to spray. I was planning on using Zolatone in the trunk,I may check into using that on the underbody. I'm really leaning away from just painting it,I dont want to cringe every time I hear a rock kick up and hit the floorpan.

I will check into the rockguard as well, I hadn't thought of that stuff, and don't know much about it.

I dont think I will use the POR since there's no rust to paint over.

Thanks for the ideas,keep 'em coming
You can use this for @ $160....comes with the gun and everything

http://www.southernpolyurethanes.com/Spray%20In%20Bedliners.htm

http://www.southernpolyurethanes.com/Photos%20-%20bedliners1.htm
You can see some shots of a Mustang they did as well. Looks pretty nice.

I just finished DL40LF epoxy and 3M Brushable Seam Sealer on undercarriage of 70 conv. It's on a rotisserie and had new floor and trunk pans, and wheel wells replaced. I'll be shooting SEM Pro-Tex bed liner on the undercarriage and wheelwells tonight. It costs $130 for a 3qt kit. You need a special gun to shoot it though.

Under what conditions are you planning to drive the car? Most of these cars only come out on nice, dry days and don't need bed liner or other thick coatings.

Personally, I also don't trust the thick coatings. They remind me too much of the old undercoatings that dealers offered when selling new cars in the past. If any part of the coating separated from the surface, rust could get between the floor or frame and the undercoating. I would be surprised if many of the worst rust buckets did not have undercoating applied when purchased new.

Thorough sandblasting and then painting with a thinner paint product makes it much easier to see what is going on in the future. Something like an epoxy primer (or POR 15) as a basecoat, followed up with Eastwood Chassis Black or another finish paint should provide a nice looking and durable job.

I agree with Northern 396. Heck, we just about broom the streets off before we drive our restored cars. Why do you think you will need all that rust protection? Undercoating does cut down on road noise but you can get that with an extra insulation under your carpet. What if the guy you bought this Chevelle from had bed liner sprayed on the bottom and you didn't like it or had to replace a floor pan?

I had the interior floors and the bottom of my 59 Elky rhinolined.
Not so much for rust, but for sound deadening. With that, dynomat, and the extra insulation---this car is almost dead quiet with the windows up.
Can't hardly tell when to shift, and still forget there is a fifth gear.

Bryan

I agree with Northern 396. Heck, we just about broom the streets off before we drive our restored cars. Why do you think you will need all that rust protection? Undercoating does cut down on road noise but you can get that with an extra insulation under your carpet. What if the guy you bought this Chevelle from had bed liner sprayed on the bottom and you didn't like it or had to replace a floor pan?


Yeah, I'm getting away from the bedliner idea, Undercoating was one idea because of the sound deadening, it's inexpensive, can be easily applied in the garage, but it does look as if you may be hiding something in my opinion. I dont think the sound deadening should be a hangup on what ever i decide since it is a vert,so I'm not even sure if I will bother with the dynomat type stuff. The guy installing my quarters has suggested using body schutz, so I am tossing that idea around now. Any thoughts on this stuff???

anyone use metal-shield by hy-tech?

I think POR 15 is garbage and if your going to do the job right spray it with epoxy primer and than top coat with your favorite black.

I would shy away from the bedliner idea for the reasons already stated by everyone about the fear of the unknown. I just had new floors put in the wagon, a few minor rust spots patched, and will be blasting the undercarraige and firewall soon. We (the fabricator and I) decided to go with a glossier black as it is a bit less expensive than flat black. I need the gloss black for some metal interior pieces and there will be enough to spray everything underneath. I'm not building a correct car as far as correct colors, so the underside will be gloss black instead of low sheen black. Good luck on your project.

Por-15 has its uses in my opinion, but if you already have the floorpans clear of rust, I wouldn't use it. It actually adhere much better to rust anyway, even if you use the metal prep. But here are some tips (from past experience)...

1. When using Por, buy it in small cans. That way if and when some of it goes bad, you didn't waste as much.

2. To open/use a new can of Por, turn it upside down, and drill two small holes at opposite ends of the bottom of the can. I usually go with 1/8 or so...Now you can pour the Por (pun intended) into a container, such as an old plastic cool whip container, and use it for brushing on. Only pour out what you think you will use, it goes a long way.

3. As soon as you have finished pouring what you need into the container, wipe any excess off the can, and use two sheet metal screws to seal it back up. I have used this procedure many times, and have yet to have any go bad on me...

4. If you want to paint over the Por, and I recommend you do, then do so when the Por is still tacky, as per the instructions. When it dries, your topcoat will be super durable, almost like a powder coat. If you wait until the Por is dry, the topcoat scratches and comes off much more easily. I personally use the semi-gloss black Por, but it still has too much shine for me, so I topcoat it with Krylon black semi, and the sheen is perfect.

Hope this helps...