Dash Crack FAQ


Many Z cars, primarily the first-generation cars, suffer from cracked dashboards. This problem is not unique to Z cars, but just about any 20ish-year-old car with a dashboard made from a similar material is likely to have this problem. The information here was gleaned from the pages of the IZCC mailing list, and is summarized from reports from members, with a bit of commentary from me.

Contents

Uncracking a cracked dash
Prevention
"What causes dashboards to crack?"
THE CONTROVERSY: PROTECTANTS
How To Apply These Protectants
Uncracking a cracked dash
You just bought a cherry [insert favorite Z-car model here], beautiful in every respect, except the dashboard has cracks in it.

YOUR OPTIONS


Prevention

Unfortunately, much of the discussion of how to prevent a dashboard from cracking has little real, scientific basis that I could find on the Z car list. There is a bit of theory, and a wealth of owner's experiences available there, but what the difinitive "right answer" is may not be possible to evaluate given the data available from the mailing list archives. Here, I will attempt to present all of the arguments and summarize the pros and cons of each solution. You will have to evaluate what you think is best on your own.

Before we get into how to prevent your uncracked dash from becoming a cracked dash, it makes sense to get into exactly what makes a dashboard crack. While I'm no expert, there are some IZCC members who either are experts or were thoughtful enough to colsult experts on our behalf, and I will use their descriptions as fact here.

"What causes dashboards to crack?"

Tom, friend of IZCC member Carl Beck, engineer/scientist in the Aerospace industry says: So we can conclude that the cause of the dashboard cracking is [drum roll please]... THE SUN! So for an uncracked dash to stay that way, it must be protected from the sun. The other method is to undo the damage that the sun does. Since there is really no way to completely protect your dash from the sun (except, maybe to keep it in the garage during the day and only drive at night :-), then this makes sense. There is also mention on the list that dashboard cracking may be related to high temperatures inside the cabin of the car, and also may be related to rapid and/or extreme changes in interior temperature.

Cover the dash when it is in the sun. This is simple and makes lots of sense. The easy and cheap way to do this is with a towel or a sheet [I use a pair of hand-towels -jk]. Custom-fit covers are available commercially if you are inclined to utilize a prettier solution, but for about the same money you can get a car cover, which is probably the best solution [plus, it will protect the paint, seats, carpets, and can discourage thieves from stealing your radio when used in conjunction with an alarm -jk]. To reduce interior temperatures, tinted windows may help but ultimately a car cover is the best bet.

THE CONTROVERSY: PROTECTANTS

"Protectants" refers to substances that you may apply to the dashboard to prevent it from cracking by undoing the effects of the sun (or, perhaps, by blocking UV, etc.). Most of these products tend to restore oils that are lost due to "outgassing" or "drying". Some of the items listed here are not commercial car-care or vinyl-care products, but have been reported to have the effect of keeping the dashboard looking good when applied in similar fashion to those designed for vinyl.

This is a controversial topic, primarily because there are a lot of options and very little objective information available.

How to apply these protectants


Dash Crack FAQ by Josh Karnes (
joshk@tanisys.com). Last updated 9/18/95. Please email me with any additional information that I should have here, or suggestions, etc.