How To: Use Dry Ice to Remove Tar Insulation

[SuperDave]

There is no paint under the tar mat. The paint was applied after the mat was laid down.

Yes, you'll need to give it some sort of coating once you remove the tar.

[dogma420]

EScanlon wrote:

but sometimes it hides rust in the seam between floorpan and firewall

If there is one place in the interior a 'rust free' rig is going to have a problem, it is this place on the passenger side. I would say that conservitively 50% of all floor pan replacements on the passenger side are this spot. I know mine is in this group! Even a stored Z in a thermostaticly controlled environment that has never seen daylight is going to have some surface rust, if not inside the frame rails in the front....There is no such thing as an original 'rust free' Z...

I think someone that has completely gone through and restored a Zed unibody could possibly boast 'rust free' but if it's original, without restore, there is going to be some rust...that is the nature of the Zed.

You can go do laps at PIR, you just have to be at the very least, invited by a group....I have a friend that has a Porsche 944 (and belongs to the local Porsche group) and he will invite me to go out if I want...just don't know if it interests me, along the lines EScanlon was saying....

[NCLarry]

How about a group buy on dry ice???

This is my first post back to the board in FOREVER... and many may have

forgotten all about me. Since I left, I've moved homes again, which of course, involved reassembling the project, packing it up and transporting to the new garage (much BIGGER).

I'll start a new thread and post some pics soon with latest updates...

Back again,

Northern NJ Larry

[Brad-Man]

I originally answered a post on Hybrid Z saying to use dry ice along with a needle scaler attachment on an air chisel (available from Harbor Freight. or Northern Tool)

This was over two years ago.

I just wanted to let ya'll know that a needle scaler in conjunction w/dry ice makes it a very easy job....

[AChev]

sorry for my hardware ignorance, but what exactly is a needle scaler? Once I had applied the dry ice I could peel the mat back with my finger, I just needed a screw driver. I would be afraid an air chisel would dent the metal. I remember reading in a thread a while ago, Escanlon said about using an air chisel for tar paper "is like killing a fly with a machine gun" or something like that

[somecreep]

In the 2 photos posted above it looks like beige paint under the remenants of the tar. (?) Was is painted before removal?

[Bambikiller240]

In the 2 photos posted above it looks like beige paint under the remenants of the tar. (?) Was is painted before removal?

There is NO paint under the tar mat, just bare metal. You are seing a stain on the metal from the tar mat. It wipes off with Mineral Spirits or Lacquer Thinner.

[AChev]

Carl, many times have I heard you say that there is no paint under the tar paper, although after removal somethings have seemed to beg to differ. I have been wondering about this for a while. After I got rid of the tar paper, there was still a creme colored coating over the metal. At first it just appeared to be the top of the metal, although one can take a screwdriver or something similar and scratch it reveling a silver beneath it. I noticed this when I was doing the drivers side floor and the transmission tunnel. If this is not paint, is it just a coating over the metal or what?

[Bambikiller240]

What it looked like on my car was a very thin ( I could see the metal through this stuff) stain from the tar mat itself or whatever adhesive they used to stick the mat to the metal. It didn't look like paint to me and didn't act like paint, since I was able wipe it off very quickly and easily with Mineral Spirits.

NOTE: My experience is with floor pans only, it's possible that there is something under the mat elsewhere in the car that I haven't seen.

[Tony D]

Matting was applied to a "body in white", that is, without any primer, straight off the spotwelding line.

There was no electrostatic procedures used on the Zed bodies then, and using the "hot attachment" method in a factory works best on bare metal.

If they applied it to paint, it would simply separate and lift the paint.

Tar Mats were not applied over painting until electrostatic coatings were used extensively. Spending time on US production lines will show you the USA Manufacturers did the same thing. After they were on the bare metal, they were primed and painted over, effectively sealing the edges from any water in the INTERIOR of the vehicle getting under the mats near seams, and causing major problems.

As for "rust free original Z" not being in existence, I know of at least one. It was ordered by a US Serviceman stationed on Okinawa in 1972. When accepting delivery from the Naha Prince Dealership, they had already applied the "tropical goop" in the panels that local market units received. Thye rotated soon afterward to the Desert Southwest, and have owned the vehicle ever since. This started to ooze out when they moved to SoCal when the high desert heat makes it runny. I have the same stuff in my 73...alas it was not put in originally, but in 81 when it was on the Island, making for some interesting things that should be rusty that aren't, and other places that shouldn't be rusty (factory tar) that are. When you see the yellow goop OVER rust, you know it was there when the car was only 7 years old.... Sad!

Anyway, this yellowish thick bodied grease was not like Ziebart used here, and had some odd creeping characteristics. This guy still owns his Z, and short of pulling up the tar mats to check, I would have to say at least one "Rust Free Z" does actually exist! The stuff gets everywhere, and you can see they went in through the holes in the floor support rails and really layed the stuff in there. Apparently in a Salt Water Surrounded Tropical Island, even in 1972, they had a real good idea that there were problems with the "rustproofing" done by the factory...

BTW, you guys did know that if you buy OEM panels, and have them finished with a certified topcoating system, they are warranted for life, just like a new vehicle replacement panel?

[280z1975]

I know this is an old thread, but thought I would add a little information.

So the two photos are of the two types of removal, Heat Gun and Dry Ice.

The heat gun worked and was a bit messy but at 15-20 bucks it's cheaper. The dry ice worked better on flat areas where it was in direct contact (and helped on the bottom side undercoating removal) but it cost me about 30 bucks.

Still, I will go with the dry ice as it was a lot easier to work with and made things easier.

The photos will show you the two type of techniques.

[NVZEE]