Paint and Body Mastic Seal washers necessary for body kit?

[AnthonyA1234]

When I removed my spoiler and various rear body kit parts the nuts had sticky gaskets on them. I see lmr includes them in their hardware kits labeled as mastic washers. Are these necessary or can I just reinstall my old hardware without them?

 

[89ripper]

In my opinion they are necessary to provide a seal against water and also to counter against the tightening of the hardware.

 

[91AOD5.0LX]

I used “butyl tape” when I replaced my rear spoiler to form a seal.
Inexpensive, available at local home stores, and forms a nice seal without hardening.

 

[General karthief]

They help with keeping them tight and not squeaking too.

 

[Willybill32]

When I removed my spoiler and various rear body kit parts the nuts had sticky gaskets on them. I see lmr includes them in their hardware kits labeled as mastic washers. Are these necessary or can I just reinstall my old hardware without them?

I’d be really reluctant to install the spoiler without them, but the butyl rubber tape seems like a good alternative. The hatch on my ‘86 developed rust from inside, and my assumption is that water got there through the spoiler mounting holes. I looked at a lot of hatches to replace mine, and they all had the same problem.

Bill