I use 3M 40C-10R for just about everything but vehicle wraps and short term signage. I make quite a bit of safety floor graphics for a local factory using it with the 3645 overlaminate. Use the 8508 for generic decals, 8518 for outdoor signage, contour cut vehicle graphics, box truck and trailer wraps without rivets although I usually try to steer the customer with the 3M 180CV3 if they are trying to get the absolute best product. More often than not though they go with the 40C due to the cost savings. I've been using it for almost 2 years with no failures yet. I think it's a great all around product.
You can use 8518 on anything, as long it's cast. I use it for any outdoor translucent prints, on 180 Vinyl, Oracal cast, Arlon cast...doesn't matter. Only time it matters is with a warranty issue with 3M.I always thought the 8518-8520 was intended to be used with the 180 print films? Do you see an advantage using the 8518 over the 8508 when printing on 40C-10R?
Here's the product bulletin for 40C with the recommended overlaminates. The 8508-8510 is only rated for up to 4 years....... it doesn't actually provide much UV protection. To get the most UV protection I use the 8518-8520.
http://multimedia.3m.com/mws/media/1001244O/product-bulletin-40c.pdf
I get mine from Liz at Platinum Sign SupplyThanks! ProColorGraphics, where do you get your Hexis products from? John