Undercoating smooth paint/primer/e-coat/whatever

[bull]

My interior projects have stalled so I've decided to go ahead and get my fenders installed and start on the grill. Instead of paint I used Chassis Saver on the inner fenders and the manufacturer recommends that you scuff the stuff before top coating after it dries. I called them about it and got sort of a blanket statement confirming this in regards to undercoating when used as the top coat but I can't help but think this might be overkill. Is it common to scuff paint before shooting undercoating? I can't imagine them doing that when these cars were new. Those of you who replaced your floor pans and sprayed undercoating, did you scuff the smooth surface before shooting? I swear that stuff would stick to grease covered ice.

[elitecustombody]

Using red scuff pads prior application of undercoating will definitely improve adhesion and prevent against chipping or peeling, I would highly recommend doing that. Unless you plan on using cheap tar-like undercoating that never dries or hardens. If you feel lazy, you can shoot a coat of Bulldog adhesion promoter or any brand adhesion promoter should help.

[bull]

Using red scuff pads prior application of undercoating will definitely improve adhesion and prevent against chipping or peeling, I would highly recommend doing that. Unless you plan on using cheap tar-like undercoating that never dries or hardens. If you feel lazy, you can shoot a coat of Bulldog adhesion promoter or any brand adhesion promoter should help.

I'll be using the Resto-Rick stuff. http://www.restorick.com/proddetail.asp?prod=Undercoat

[bill440rt]

I've never scuffed the surface before shooting undercoating. Just sprayed away.
No problems with adhesion here. But if you have doubts then you can always scuff before spraying it as a precaution. What would it hurt except consume a few minutes of your time?

[Silver R/T]

In most cases when you shoot undercoating the topcoat/primer is usually still fresh so undercoating should bite into that fresh paint.

[bull]

I've never scuffed the surface before shooting undercoating. Just sprayed away.
No problems with adhesion here. But if you have doubts then you can always scuff before spraying it as a precaution. What would it hurt except consume a few minutes of your time?

It's not a time/avoid work thing, although I don't want to do more than I have to. What I'm trying to avoid is having visible areas of scuffed paint that aren't covered with undercoating. By that I mean there are spots that don't get covered with undercoating (around the UCA, frame rails, access covers, etc.) so what I will probably do is stay back from those areas with the scuff pad and overlap the scuff marks when the undercoating is applied. Basically that means not all the areas that are undercoated will have been scuffed but all the areas that have been scuffed will be covered by undercoating. Does that make sense?

In most cases when you shoot undercoating the topcoat/primer is usually still fresh so undercoating should bite into that fresh paint.

Well, perhaps that's sometimes true when doing a restoration but as per my first post you know the dealerships weren't doing fresh paint undercoating back in '68.

[Charger-Bodie]

I would just spray it without scuffing. My reasoning is that I dont want the chassis saver broken down at all. Besides Ive NEVER scuffed anything for undercoat and Ive never had a problem.

[bull]

I would just spray it without scuffing. My reasoning is that I dont want the chassis saver broken down at all. Besides Ive NEVER scuffed anything for undercoat and Ive never had a problem.

[JB400]

Being that we're on the subject, would you guys recommend a special product made for undercoating, or could you get by with something like a bedliner like Herculiner?  Just wondering if there is that much of a difference.

[bull]

Being that we're on the subject, would you guys recommend a special product made for undercoating, or could you get by with something like a bedliner like Herculiner?  Just wondering if there is that much of a difference.

It depends on the results you want. I don't think I'd go the bedliner route myself because that stuff won't ever come off, and I might want it to come off someday. I prefer the RestoRick undercoating because it's very similar to the original stuff. Since I wanted to leave as much of my factory/dealer undercoating intact as possible it was a no-brainer in my case. I'm sure the modern undercoating is superior in many ways but I went for originality.

[HeavyFuel]

It depends on the results you want. I don't think I'd go the bedliner route myself because that stuff won't ever come off, and I might want it to come off someday. I prefer the RestoRick undercoating because it's very similar to the original stuff. Since I wanted to leave as much of my factory/dealer undercoating intact as possible it was a no-brainer in my case. I'm sure the modern undercoating is superior in many ways but I went for originality.

    My approach exactly.