One of the ugliest jobs I've done while stripping down an old 240Z has been removing the tar-like insulation that covers much of the interior floorboards and transmission tunnel. I have done it by using aircraft paint stripper, but this was a big mess. It softened up the tar, but made it flow into low spots. Once I had most of it removed with a paint scraper, I had to use a wire wheel and more paint stripper to get the last of it off. Some have suggested using heat, but I'd think this would also be a mess. There must be a better way.

Actually, I found that with no chemicals at all, some of the insulation will come off quite easily. Just get the corner of a paint scraper under it and it flakes right up and breaks off. That's the good news. The bad news is that, unfortunately, these pieces come off easily because of what's underneath--rust! The insulation that covers clean metal doesn't want to budge.

A few years ago, a fellow racer had said that dry ice was the best way to clean off this insulation. I saw it mentioned a couple of other places on the internet, but I couldn't find any articles about it. Armed with just a few instructions of how to do it, I decided to give it a try. I would try to use dry ice to remove the insulation tar in the rear hatch/ trunk area of the old 240Z.

Getting the dry ice was easier than I thought. My local Kroger stocks it for 99-cents a pound. They broke open a ten pound bag to sell me 5 pounds. I brought it home and tried to break it up into as small chunks as I could. Then I simply spread it on top of the insulation tar. All the areas I treated were level. I don't know what is the best way to apply the dry ice to vertical areas like a transmission tunnel.

I got a really good feeling about this process when, before I was finished spreading the dry ice, I could hear cracking sounds where the dry ice had been sitting for a few minutes. Due to the cold, the tar must have been shrinking faster than the metal and finally becoming separated from it! Once I had spread out the dry ice as best I could and broken it into as small chunks as seemed reasonable, I went inside to watch the finish of the Daytona 500 and to eat supper.

I came out about two hours later. All the dry ice had melted (had become CO2 gas and sunk invisibly to the floor and out of the garage). I started attacking with my paint scraper.

Now, with minimal effort, chucks of the insulation as big as 3-by-9-inchs broke right off. In just a couple of minutes I had removed almost all of the insulation tar.

The bad news is that I found some really nasty rusty areas that I wasn't aware of. But they will be fairly easily repaired. I'm glad I know about them.

I did not try one technique that I had read about elsewhere--to use a hammer to strike the insulation. It is supposed to just shatter like glass. I was afraid this would leave dents in the underlying metal. And, if I remember it correctly, you're supposed to strike it when it's still cold (and mine wasn't really dry-ice-cold when I tried to remove it).

I didn't get every bit of the insulation. I think there were some spots where I didn't spread the dry ice thoroughly enough, so I guess the insulation didn't get cold enough. So it looks like I'll go back in a few days and repeat the process on those spots.

This was an incredibly effective and simple process and I will highly recommend it to anyone who wants to remove this material from any type of vehicle. It didn't involve any nasty chemicals, and didn't leave anything to clean up. Obviously there are precautions to take--I used leather gloves to handle the ice. It gives off CO2 gas, so make sure you have some fresh air to breathe. Other precautions will usually be listed on the package of your dry ice.

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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-

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

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-

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.

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.

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.

...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

heres pictures of one section of the dry ice "technique

*sorry about the bad photos

I'm going to start a new thread to continue this discussion about thrill seeking...

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?

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

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.