I went by the shop today to check on the Z and the painter had just finished applying this undercoating that looks alot like a rhino liner type of product.

The new floors from Zedd's were put in a few weeks ago and were covered with por 15, and the outside received this. I'm happy with it because I am going to be driving the car and it needed to be protected, but would this be considered appropriate to a purist?

What is the acceptable method for undercoating? A little late now, but was curious to what others thought.

Thanks,

One of my 914 friends just took his car down to bare metal on a rotissorie and he used Rhino Liner for undercoating. Porsches of that era rust worse than Datsuns. This guy is a bodyman too... Not an opinion just an "if A then B" example...

Doing frame rails and floors this weekend and watching this post for ideas.

I did my frame rails and floors, then prepped them and applied por-15 as well. And I used a spray on undercoating (paintable) on the por-15 in the wheel wells... then that got painted at the bodyshop. Underneath I'm going to use the undercoating when I get all the suspension off. I wont use it on the suspension, just the bare underside. Suspension components I think I'll clean up and paint.

Lizard Skin works well too.

Whatever the Datsun dealer applied back in the late Summer of '71...

Glad to see this topic come up. I am beginning the welding/ paint process on my 72 240. Do you guys recommend removing the old undercoating from the car--if it still looks sound?

I have some minor rocker (dog-leg rust)--but can see no rust underneath--or should I suspect its just hiding beneath the undercoating??

...should I suspect its just hiding beneath the undercoating??

On my 79 I saw that some of my undercoating was torn/wearing so I removed it to see how bad the rust was. While I expected there to be some rust there, what I didn't expect was for the undercoating in a 6 in radius to just come off with just the slightest persuasion, especially since what came off appeared to be fine.

There was more surface rust under that area than where the coating had worn.

Point being- just because it looks good doesn't mean that it is.

Many will say "if you are going to do it, you might as well do it right the first time"

The original stuff is holding up good - accidently removed some (1 foot squared) last fall with a pressure washer - the steel under it looked like stainless (perfect condition). I have a spray on lubricant on it for now til I get around to it.

I went by the shop today to check on the Z and the painter had just finished applying this undercoating that looks alot like a rhino liner type of product.

The new floors from Zedd's were put in a few weeks ago and were covered with por 15, and the outside received this. I'm happy with it because I am going to be driving the car and it needed to be protected, but would this be considered appropriate to a purist?

What is the acceptable method for undercoating? A little late now, but was curious to what others thought.

Thanks,

A true purist would not find it appropriate as it didn't come from the factory with undercoating.

Rich1, I rolled under mine and thought all was fine, undercoating looked solid, beat on it by hand and felt no soft spots. Then I read somewhere here a poster that suggested using a pick or such to really poke around. Doing this, I found that under the undercoating was a lot of rust. Floor supports, part of the floor and the rail leading up to the TC rod mounting point were rusted.

I am going the POR 15 and undercoating method myself, the first to protect the metal and the second to make it match underneath if I ever want to sell and womeone looks.

The rebuild of my 240z saw the entire underside of the car stripped by using a torch and scrapper. Then sand blasted, rustphos, etch primer, stone chip protective paint (leaves a texture), primer and body colour. Wheel wells got the same treatment but double the stone chip paint as did the petrol tank.