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SuperDave

How To: Use Dry Ice to Remove Tar Insulation

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sheesh,

you guys really like to bring it down on the noobee! i should have clearified, i am not saying my z doesnt have rust, it has plenty of it, just like any other. it just happens to have been kept in a garage for 10 years and has minimul rust on the interior. i had heard the problems that z have with rust before i bought my z for $500. i did a thorogh check around on the frame and looked okay, not good, but ok. i understand that they were made without very much consideration for rust prevention, but under my tar is fine. i have taken chunks out in random places on the tar and found no trace of rust.

here it is, i was looking for a reason to save some effort and leave them in. Shevets answered my question the best, and i will probably be puting new sound deadening insulation in.

EScanlon, here is an answer to your cancer question... NO, offcourse. i see your from washington!!! do you race your z? i was thinking about racing, but i dont know any tracks besides bremerton raceway, and i dont know how to get started. i dont wanna join the scca, just rather to a relaxed thing. gimme tips! thanks

again, sorry, but i am new to this car. it is my first restoration, and i wanted some reason for your rhyme, before i did it myself.

thanks again,

mark-

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Mark

As far as racing, I would say that I'm a potential race-aholic who knows NOT to see how tolerant he can be. I love racing, enjoy going to them, watching them and have often fantasized about being in the car, either driving or as a passenger (rally navigator).

Unfortunately, I know that I would be seriously, no let me rephrase... $eriou$ly addicted to the sport. If I could afford it, and had a vehicle that I wouldn't mind getting a couple of dings knocks etc into, then I'd be ears-deep into it. But, I can't afford it, and I'm a body-man and painter hobbyist and I don't relish the thought of scraping one of my paint jobs on another car or wall. So, racing is out for me.

I know that PIR (Portland International Raceway) has days available to clubs, and sometimes to certified individuals, but you have to pass a safety inspection and have the proper insurance and insurance waivers. That's about all I know.

As far as the rust / newbie issue. I don't think that anyone is coming down hard on YOU. I do think that everyone would rather you investigated and made sure, rather than suppose that it's ok. Far, far too many new guys have posted "Rust-Free Z" and have followed it up within some short period of time with "Oops...found some rust!" and sometimes gone onto "Can you believe that the floors were still holding together?". As a member of this site and others, believe me, even if some users were read about twice, there are still a vast majority of members who've found rust, rather than NOT finding rust. So, since you are at that stage of your project that a little bit more time and expense NOW will literally save you HUNDREDS down the road, you can see why we came down "hard".

Almost without exception, the tar mat may indeed be good where you've gotten it to bust off, but sometimes it hides rust in the seam between floorpan and firewall, underneath the seats, by the rocker panels and almost always by the drain holes. When you remove all the tarpaper you may be indeed shocked and pleased that you found it before it got worse, as opposed to discovering it by installing Flintstone Brakes. (Where you can put your foot through the floor.)

So, welcome to the club. Use the search function and you will literally be inundated with ideas, tips, procedures and all sorts of troubleshooting.

Enrique

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thanks for the help, i know this site is going to come in handy for my restoration. enrique, you convinced me to take the tar off, im gonna do it this weekend. hopefully it wont be too bad.

as for racing, i agree with you, i dont wanna get my 'sun all shiney and beautiful and then get a scratch or dent. i built a wooden kayak a couple of years ago and barely use it because it is too beautiful, just hang it on my wall. i also dont wanna put the $$$ into racing. i was hoping there was a vintage race group in the NW that didnt require scca regulations like a 4 pt harness and a roll bar, or a competitive license. i just wanna go on a open raceway and try drifting, or something, just relaxed. the less likely to damage the better. i just dont want to do it on the road and endanger my life and others. basically, i want to go to the raceway to get my fix fr speed so i wont tend to on the road :)

mark-

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In my microbiology lab we use ethanol and dry ice to freeze bacteria very fast to prevent the ice crystals from rupturing the cell wall, I think of it as the cheap liquid nitrogen. Maybe this would work.

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Although I did have one problem. I did not purchase enough dry ice.

I'd say that, roughly, you need a minimum of 1 lb of dry ice per square foot. That's if you're able to get the chunks broken down into as small chunks as possible.

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I was surprised, after I saw the pictures of your dry ice I expected the chunks to be large. Although when i got mine each piece was the shape of a tootsie rool, almost exactly the same.

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...i was hoping there was a vintage race group in the NW that didnt require ....

....i just wanna go on a open raceway and try drifting, or something, just relaxed. the less likely to damage the better.....

.... i just dont want to do it on the road and endanger my life and others. ....

....basically, i want to go to the raceway to get my fix fr speed so i wont tend to on the road :)

mark-

Not to sermonize, nor give you a hard time, but a friend of mine once said to me: "There are Bold Fools, and Old Fools, but you rarely see a Old Bold Fool."

What he meant is that those who take chances are more prone to accidents. Unfortunately, you sometimes find out that you took too bold of a chance....afterwards.

If you are serious about getting your fix for speed, while having a blast, and staying relatively safe...try indoor go-karting. I will guarantee you that you will have an absolute blast, feel exhilirated, and get all the fix you want. All in a relatively safe environment, with enough acceleration (which face it is what you can feel, not speed) and g-forces and skids and donut and 180° thunks into the rubber to chill you out for at least.....a few weeks. Also, TONS cheaper. If you go to a local rink, they may have cars for rent either by the lap or by time.

As far as getting on a track, I doubt any track in the U.S. would allow you to race on their track without a waiver of responsibility. What form that takes is between you and the track. However, the tracks that I've heard of, give access only to established GROUPS. Unfortunately, I don't have any knowledge of any group that races that doesn't require some form of acceptance. Again, since I've not investigated it, I can't tell you what to expect.

As far as racing on the streets, I agree with you. I'm all for you getting your thrills out of life. When you decide to involve ME, you had better have discussed it with me and I had better have agreed, or you run the risk of MY taking the thrill out of YOUR life.

Personally, activities such as sky-diving, racing, deep snorkle diving, bungee jumping are thrilling because of many reasons. Not the least of which is the risk involved. Without addressing whether they should or shouldn't be done, my thought is that all of those activities are those that, in my opinion, require proper training and supervision. To attempt any one of those without them is a very boldly foolish way to die.

So good luck in finding a venue to get a racing fix.

Enrique

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Sorry to dredge this thread back up but I just came acrossed it. I will be needing to strip off my matting soon, so this thread has been very informative. I do have one question though: In some of the photos posted here, it looks as though the dry ice has not only seperated the matting, but the paint as well, is this correct? If this is true on my floorpan, no problem as they're shot anyway. But I'm going to need to do the rear deck area and don't necessarily want to remove the paint if it's not needed. Can one of the successful experimenters please clarify on this?

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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.

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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....

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How about a group buy on dry ice??? :D

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

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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....

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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

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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.

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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?

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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.

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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?

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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.

post-10327-14150796588457_thumb.jpg

post-10327-14150796588778_thumb.jpg

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 Thanks for sharing. I've heard of this method but haven't tried it. I was very impressed when the tunnel tar came off in one piece. I'll definitely try it in the future.

 

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