Dershum Posted September 26, 2012 Share Posted September 26, 2012 Lots of other folks have done it, but I decided to give dry ice a try to remove the insulation on the interior of my body shell. The media blaster couldn't touch the stuff, so I decided to take matters into my own hands. The process was fairly straightforward. Take a container (I used a bucket), fill it about half way with dry ice, and distribute liberally upon the surface of the insulation you want to remove. Wait about 20 minutes or so (you can listen to the insulation cracking lose, it's kind of cool), and then go at it with a hammer and a chisel. I used a gasket scraper...probably won't be using it for it's original purpose again, but it was all I had handy. Just a few particulars that I learned during the process that I hope can help the next person who tries it. 1) Wear gloves. I used my welding gloves. I didn't have to learn this the hard way, but I wanted to point it out. 2) Spread out the dry ice liberally, but only work on a small area at a time. I found that it chips off best if you keep the ice on it as long as possible, and only move the ice off just before you're going to chisel. I would just brush the ice aside, chisel, and keep moving along. 3) If you move fairly quickly, you can save some of the ice for later re-use. I ended up re-using about 1/3 of the ice I bought. I started with 40 pounds, but if you don't re-use, I could see it taking 60. 4) If you're going to do this, having it on a rotisserie helps IMMENSELY. I can't imagine how you'd get the sides of the trans tunnel without being able to spin it. I suppose a frame could be placed around it to hold the ice along side, but it seems like it would require a lot of extra ice. 5) Make sure you get a glass of water and put some dry ice in it. It's just fun to do when you're waiting for insulation to freeze All in all, I'm tickled pink at just how well this method worked. 3-4 hours of labor, and the insulation is all out. Now on to rust repair. Quote Link to comment Share on other sites More sharing options...
Leon Posted September 26, 2012 Share Posted September 26, 2012 That's great! I'll be doing this eventually when I get back to work on my 240Z shell (whenever that will be ). Good write-up! Quote Link to comment Share on other sites More sharing options...
m1ghtymaxXx Posted October 1, 2012 Share Posted October 1, 2012 I did this last spring and was astounded at how easy it is. At first I spent an hour or so chiseling away and maybe scraped a square foot off and it still left quite a mess. Then I went back at it and maybe used a pound a dry ice total (muuuuuuuch less than you have in your pics) and it took a couple good smacks of a hammer and it all lifted in dinner plate size pieces. There really is no other way. Quote Link to comment Share on other sites More sharing options...
v8dats Posted October 1, 2012 Share Posted October 1, 2012 Very cool. Thanks for sharing! Quote Link to comment Share on other sites More sharing options...
Dershum Posted October 2, 2012 Author Share Posted October 2, 2012 I did this last spring and was astounded at how easy it is. At first I spent an hour or so chiseling away and maybe scraped a square foot off and it still left quite a mess. Then I went back at it and maybe used a pound a dry ice total (muuuuuuuch less than you have in your pics) and it took a couple good smacks of a hammer and it all lifted in dinner plate size pieces. There really is no other way. Did you just use it on one small area, or did you do the whole interior? I probably could have gotten away with 30lb or so, but I can't imagine having done the whole interior with any less than that, especially without reusing it a few times on different areas. I particularly had problems in the front inside corners of the footwells next to the trans tunnel. The characteristics of the "rubber" had changed quite a bit in those areas. It was a lot harder and had a lot of bubbles in it. Even with the freezing, I had to do a lot of chiseling to get the pieces off...it didn't want to stay together in one piece. Quote Link to comment Share on other sites More sharing options...
zero Posted October 2, 2012 Share Posted October 2, 2012 I used a slightly different technique because I was lazy and didn't have dry ice handy. I did have canned air lying around, so I held the can upside down, and sprayed the insulation with the cold propellant. I only did a small area at a time, but it did a very good job of making it brittle enough to come up with some light persuasion. Quote Link to comment Share on other sites More sharing options...
Dershum Posted October 3, 2012 Author Share Posted October 3, 2012 I used a slightly different technique because I was lazy and didn't have dry ice handy. I did have canned air lying around, so I held the can upside down, and sprayed the insulation with the cold propellant. I only did a small area at a time, but it did a very good job of making it brittle enough to come up with some light persuasion. A guy at work that I showed the pics to said that I should have just used freon. I think he was kidding...at least I hope he was. Quote Link to comment Share on other sites More sharing options...
luseboy Posted October 3, 2012 Share Posted October 3, 2012 I wish I had seen this trick before I went at my insulation. I used a heat gun and a chisel. It all came off but not very cleanly, and I spent a lot more time on it than I would have. That was a year ago now, still working on rust repairs Quote Link to comment Share on other sites More sharing options...
TRD_240Z Posted October 11, 2012 Share Posted October 11, 2012 I was even lazier and just chiseled that thing apart bare hand. It wasn't as bad as I thought once I got a rhythm going, although it is messy. My question is: what about underneath? I don't have anything handy to flip the shell over. Quote Link to comment Share on other sites More sharing options...
Dershum Posted October 11, 2012 Author Share Posted October 11, 2012 I was even lazier and just chiseled that thing apart bare hand. It wasn't as bad as I thought once I got a rhythm going, although it is messy. My question is: what about underneath? I don't have anything handy to flip the shell over. I didn't have any on the underside. The only thing under there was crud, gunk, grease, mud, rust, and more crud. Media blaster took care of those for me. Quote Link to comment Share on other sites More sharing options...
miky360 Posted October 11, 2012 Share Posted October 11, 2012 (edited) I've seen alot of threads about using dry ice and personally i skipped that stepped and just used the old chisel&hammer technique lol Edited October 11, 2012 by miky360 Quote Link to comment Share on other sites More sharing options...
Dershum Posted October 12, 2012 Author Share Posted October 12, 2012 I've seen alot of threads about using dry ice and personally i skipped that stepped and just used the old chisel&hammer technique lol I started that way, but it left way too much residue that would have to be ground off after chiseling. Even with the dry ice, there were areas that just didn't want to come off that I really had to fight with. I also tried wire wheels on an angle grinder...giant mess. and for about 1/2 a sq foot of insulation removal, I tore through about half of the wire wheel. And it was one of those "heavy duty" ones with the strands woven together into about a dozen thicker "ropes" around the circumference of the wire wheel. I considered a propane torch and a paint scraper, but 2nd degree burns from melted rubber didn't particularly appeal to me. At the end of the day, it came down to 2 factors. 1. I'm fat and lazy...the less manual labor involved in an effort, the happier I am 2. I don't get nearly enough time to work on the car as I wish, and doing it this way let me get all the insulation off in 3 hours. I'd imagine that might be possible with a chisel and hammer, but damn...I think my arms would fall off before I got 3 hours into it at that pace As Scrooge McDuck would say...work smarter, not harder! Quote Link to comment Share on other sites More sharing options...
EF Ian Posted October 12, 2012 Share Posted October 12, 2012 I normally just wait until we get a really cold day in winter (around o'c or colder) and then chip it all off then, usually comes off really easily. Quote Link to comment Share on other sites More sharing options...
TRD_240Z Posted October 12, 2012 Share Posted October 12, 2012 I didn't have any on the underside. The only thing under there was crud, gunk, grease, mud, rust, and more crud. Media blaster took care of those for me. What a relief, I was worried the blasting would not take that crap off once it's time. Nonetheless, awesome job and keep us updated. Quote Link to comment Share on other sites More sharing options...
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