Rust Bubbles..?

[FuryInferno]

Well, I did a search on the forums but couldn't find it discussed anywhere else. Has anyone ever had rust bubbles develop under the paint of the air intake grill? I have some that seem to be small... but I'm wondering what I should do next..? Any ideas? I don't mind having to sand anything down or ruining the paint, I just don't want anymore damage to be done.

Sorry for the poor quality pics. Bad Camera & I can't seem to upload pics right on this forum.. :dead:

[hls30.com]

There are foam pads on the underside of the valence panel in approximately that location, and they are known for holding water when wet. Looks like you may have that issue.

Fortunately, removing that particular panel is relatively easy, remove the wipers, and the sheet metal screws under the edge of the hood, tilt up at the front and carefully pull the panel free. Those panels are also pretty plentiful, so finding a suitable replacement won't be difficult.

Alittle prep and paint and you should be good!

Will

[Nissanman]

When you have that grille panel off, have a good look inside the air plenum.

There may be a horror story lurking in there, depending on what environment your car has been exposed to:eek:

The plenum is large enough to get your hand into most areas: do just that and scoop out anything that shouldn't be there.

There is an especially bad area around the heater blower duct.

This is an oval shaped "chimney" that sticks up into the plenum on the passenger side of the car.

It is under a water shed that hides it from view completely.

A lot of debris can get trapped between the chimney and the firewall, causing severe rot:(

Trust me, I've been there and it wasn't pretty.

Also, you could probably do without the foam blocks that have been mentioned.

They shouldn't trap moisture (but they DO!) and are only there to dampen any flexing of the grille. You could achieve a similar result with modern technology, a lump of neutral cure silicone sealant.

Oh, and that water shed is usually spot welded in place.

I drilled the welds and re-attached the shed with stainless self tappers.

Now I can remove it and clean out the plenum a lot easier than before.

I did a LOT of resto work in this area on my '73 240, but unfortunately, it was before they discovered Digital Cameras.

I have real photos somewhere but no digi pics.:disappoin

[TomoHawk]

I have one or two bubble behind the rear wheel on the skirt.

[beandip]

tomo we are not talking about fenders ! Are you going to start asking questions about helmets next ?

[beandip]

Well, I did a search on the forums but couldn't find it discussed anywhere else. Has anyone ever had rust bubbles develop under the paint of the air intake grill? I have some that seem to be small... but I'm wondering what I should do next..? Any ideas? I don't mind having to sand anything down or ruining the paint, I just don't want anymore damage to be done.

Sorry for the poor quality pics. Bad Camera & I can't seem to upload pics right on this forum.. :dead:

Generally when when you see this on the surface the problem is that it has rusted through form the back. As hls30 said this is a simple fix because the panel can be removed . I had the same issue only not quite that bad. I was able to do he repair with POR using the mesh from the back side. Normally I don't condone using this for repairs , but this panel is not structural . Gary

[moonpup]

I have one or two bubble behind the rear wheel on the skirt.

Why, Why,Why.....do you do that! :mad:

[beandip]

thanks moon ! Gary

[FuryInferno]

Well, I pulled the air intake grill. HLS30 was right. Those foam pads were retaining moisture and it was caused rust to form exactly where the bubbles are. Gonna sand down the inside and see just how bad the damage is.

I'm gonna follow your advice as well Nissanman and pull the water shed. I don't THINK there is much debris in there, as the previous (original) owner took pretty good care of her. She's spent all her life in Southern California, with the exception of 1 year in Birmingham, AL when I moved out there. Thanks for ALL of your help! I'll post more pics once I finish.

[FuryInferno]

Oh one more thing.. What do you all recommend to use in place of those foam pads? They've pretty much had it. Just a lump of generic neutral cure silicone sealant? Any particular brand?

[280z1975]

Here is what mine looked like when done I got around to it:

http://gregggermer.com/photos/280z/album/During/slides/during_repairs_02_26_2006%20002.html

It was in bad shape ... I replaced the foam with some foam hobby pads I found at Wal-Mart. They were 88cents each and you will need 4 of them, they are a little thin compared to the original. I remember they were a pain in the arse to glue on ... I used POR-15 (por-15.com) to treat the underside so this problem should never rear it's ugly head again.

The foam deterioration was also the reason my panel didn't sit right on the car. That and my cousin use to let her friends sit on the car when she owned it. :devious:

[beandip]

After I treated the underside of the panel with POR to seal it and repair the holes . I used some 1/4'' sill seal . It is the stuff used in construction for a water barrier between the bottom of a wall where it contacts the concrete foundation. It comes in a roll and you can find it at Home Depot or most any construction supply store . It is really cheep, I have found many uses for the stuff . I used silicone to stick it in place . Gary:rambo: