I am considering putting something inside my fender wells to protect from rocks "starring" the paint from the underside.

What does everyone else use?

I am thinking of glueing neoprene sheets (like a mousepad) to the underside of the fender with contact cement.
I have 12" X12" squares instead of large sheets.
So if one ever comes loose on the track, a small piece would not be a hazard.

I think the neoprene sheets would be lighter than a thick coating of spray undercoating or bedliner.

Next - anyone who has done this, how much of the fender is at risk?

I think Mikey made some.

There was a thread on Rennlist a while back on this topic

http://rennlist.com/forums/racing-and-driv...?highlight=star

Thanks. They suggested pretty much the same: closed cell foam glued in with contact cement.

I think I'll go with two of this:


But one more in front of that.
I think I can see one chip already about 2 inches forward of the edge of the rubber.

I think the spray contact cement (headliner adhesive??) would be adequte.
I dont want it coming off on the track, but I dont want it 100% permanent either.

You must be stalking me. I just put the finishing touches on these today.
Pics will follow tonight.
Don't glue the closed sell foam in there, it will trap water, just like the mud and dirt you are trying to keep out.
I think you will like the solution I have finally got worked out.

Original thread

http://www.914world.com/bbs2/index.php?sho...p;#entry2134176

Closed cell foam does not absorb water, so it won't trap it. Depending on how you glue it, if there are voids, it could get trapped in there. If you are worried, you could use open cell foam and then it would hold water, but you would be able to squish it to get the bulk out and then it would air dry.

I really need to do this on Papa Smurf. Light weight and very wide fiberglass fenders get destroyed from the inside.I thought about spraying on that Flex seal stuff...its kinda rubberized so might help

My solution was expanding foam in a can......windows & doors (the yellow stuff). It's a messy job if done "in place" but efffective. No "stars" on my FG fenders. Didn't seem to absorb water. You do have to clean off the dirt pretty well before hand. It held up for years.

Is there any reason spray on bed liner wouldn't work? I know there is a small weight penalty but seems hard as nails and you could just spray the small area needed?

I doubt it would work. You need something that is going to absorb some of the shock.