Are all car roof materials similar?
Are all car roof materials similar?
(OP)
Hello everyone!
I am developing a product which uses magnets to attach to the roof of cars. I am aware that some cars use aluminum or fiberglass in their construction - that's easy to test for. Ignoring this, the question that I have is - is there any information to help me be sure that all cars in the US (and hopefully foreign) market are sufficiently magnetic-attractive?
All the cars I've tested thus far (with a magnet attached to a scale) have shown a sufficient degree of attraction, yet some differences are noticeable. I imagine that this is mainly caused by the variations in thicknesses and types of steel used. Not surprisingly, fancier and older cars seem to do better.
What worries me is - how can I be sure that there isn't some outlier that is drastically lower in magnetic attraction (thinner/some different strange metal) than what I've seen (on about 40 different cars) thus far without testing every car out there?
Is there a typical steel that is used or is there an average gauge thickness? I imagine that in the quest to save money, there are some other limits that manufacturers must heed...but these I do not know.
Thanks a bunch!
I am developing a product which uses magnets to attach to the roof of cars. I am aware that some cars use aluminum or fiberglass in their construction - that's easy to test for. Ignoring this, the question that I have is - is there any information to help me be sure that all cars in the US (and hopefully foreign) market are sufficiently magnetic-attractive?
All the cars I've tested thus far (with a magnet attached to a scale) have shown a sufficient degree of attraction, yet some differences are noticeable. I imagine that this is mainly caused by the variations in thicknesses and types of steel used. Not surprisingly, fancier and older cars seem to do better.
What worries me is - how can I be sure that there isn't some outlier that is drastically lower in magnetic attraction (thinner/some different strange metal) than what I've seen (on about 40 different cars) thus far without testing every car out there?
Is there a typical steel that is used or is there an average gauge thickness? I imagine that in the quest to save money, there are some other limits that manufacturers must heed...but these I do not know.
Thanks a bunch!





RE: Are all car roof materials similar?
Regards
Pat
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RE: Are all car roof materials similar?
RE: Are all car roof materials similar?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Are all car roof materials similar?
What is Engineering anyway: FAQ1088-1484: In layman terms, what is "engineering"?
RE: Are all car roof materials similar?
... as will extreme curvature, e.g. associated with pressed-in ridges and bumps found on the roofs of many SUVs.
... as will presence of a glass or plastic panel/ sunroof/ moonroof.
Other issues arise:
- How do you prevent the magnet from scratching the paint?
- How do you remove the magnet without scratching the paint?
Mike Halloran
Pembroke Pines, FL, USA
RE: Are all car roof materials similar?
Thanks for the info, Greg. I guess I was just wondering if there are any specific "guidelines" or "rules of thumb" that are used for body/roof design that I'm not aware of... or any suggestions that the manufacturers have been reducing panel thicknesses as of late. If not, all of that is good to hear.
What's a "snow powered oddball," if I may ask? :)
Paint would certainly impact the results - and maybe that is already responsible for a bit of what I'm seeing - with magnetic attraction, every thou of separation from the metal matters.
Thanks, Mike. Yes, the instruction manual for this product specifically states that it is not designed for uneven surfaces/any non-metal interference. Scratches to roof are prevented by a combination of a thin (<5 thou) covering and a compressible "foam" surface surrounding the magnet(s).
Thanks everyone! If there's more info on the subject, would love to hear!
RE: Are all car roof materials similar?
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Are all car roof materials similar?
Won't work on Corvette (fiberglass), late model Audi A8 (aluminum), original Honda Insight (aluminum), some of the old 1970's and 1980's T-top cars (glass), anything with a vinyl roof, or any convertible, and it could get interesting if someone puts something on one of those newfangled folding-roof convertibles and then presses the button.
RE: Are all car roof materials similar?