Slick 60's

so I'm putting my truck back together and when I took the fenders off the truck I noticed this white goop between the fender and piece above the grill when I separated them. I was wondering what the goop was and do I need to use it when I put back together?
thanks for the help
James

mine was put together with a strip caulking tape, used in auto and trailer manufacture. it is actually light gray that scars white,it comes in a roll with a paper separating strip. I don't remember if I found it at an auto store or at a hardware store. use to be able to get it at Trailer/camper repair facilities

I expect what you're finding is "Strip Caulk", also referred to by some as DumDum (don't know where or why that started, but I've heard it since the late seventies)

It is good for sealing, doesn't get hard (anytime soon), and works good when installing fenders, you roll a little strip down to ~1/8", make a ring and place it around the bolt holes, then after you put the bolts in and are shifting the fender for alignment, the washers on the bolt heads won't scratch your fresh paint. And after you tighten the bolts, you just remove the excess that was squeezed out.

***And many Auto Body Jobbers will sell it "by the strip", as most folks will never use an entire box, and a whole box is a bit spendy.

https://www.amazon.com/3M-08578-Black-S ... C87&sr=8-1

https://www.3m.com/3M/en_US/p/d/b40068361/

https://multimedia.3m.com/mws/media/277 ... -sheet.pdf

It is (or used to be) available in Grey or Black. Seems when you search most sites, it shows you black??

**Seems the gray has been discontinued:(

thanks guys much appreciated!