Inner fender rock proctection?

[Threebrand]

Jay, Dynamat in an exposed area. Interesting. Would you then seal it off with the brush on rhino lining or some other similar product to keep it intact and attached?

[JCoop]

After I got a star crack in one fender on my previous SPF, I immediately lined the fenders on the new BB SPF and my GT40 as well. I used the Dynamat because I had left over material after lining everything in the GT40 as a sound-deadening project. The material has a peel off liner and a good adhesive. Surface has to be really clean, though. I didn't seal on top of it, just around the edges; with rubberized undercoating spray. I think it actually deadens road noise.

[double ugly]

I didn't think Dynamat was rigid enough to withstand road debris. It's great for a heat reflector but rocks? I still think a rubberized coating would be more efficient for the intended purpose.
John

[JCoop]

Originally Posted by double ugly

I didn't think Dynamat was rigid enough to withstand road debris. It's great for a heat reflector but rocks? I still think a rubberized coating would be more efficient for the intended purpose.
John

Actually, you do need a rigid material, almost like a second skin. Dynamat also has the tar-like material between the aluminum sheet and the fender, absorbing any impact. FWIW A rubberized coating will NOT prevent star cracks. The fender that got the crack on my previous SB had rubberized undercoating almost 3/8" thick before the injury.

When I run my set of sticky GY slicks, I can hear the debris and pebbles being kicked up the fender, and TG, not a crack yet.

[RedBarchetta]

Originally Posted by JCoop

FWIW A rubberized coating will NOT prevent star cracks.

I would agree that a rubberized coating ALONE will not prevent star cracks. It will arguably eliminate many opportunities for them, but the occasional rogue rock (i.e. large) will give you pain. Adding another layer (neoprene, Dynamat, etc.) along with a couple coats of rubberized coating is about the most care you can apply to the inner fenders to hopefully prevent a problem. No system is a sure guarantee. For me $50 in materials and killing a Saturday was a lot easier than dealing with a potential a star crack. And (God forbid) if I still get one, well then shame on me for putting such a sticky tire on a fiberglass-bodied car.

-Dean #747