Jerry 87 928S4

dr bob, I just pulled my wheel well panels and put the brown bread on the back. Then I saw those large cavities - what kind of foam and where can I get it?

I am sure that if the foam is sound deadening it would make a major difference.

Any one else done this?

Max

Jerry, The stuff that you can buy at the hardware store is not the same as what is called out for in the shop manual.

I'v sleep a few nights sense doing this research and I can't name names or places. Just try a Google search of Molding Foames. If I remember right it's a A/B mix.

HTH

Max

P.S. It's the same stuff we used to fill the stiffners in with on the Thrust Barrel Assy's. on the Atlas II and Titan rockets (Modified from the old ICBM days).

Jerry 87 928S4

Tried google, just too many wrong sites.

Anyone used a product that worked?

Jerry 87 928S4

Okay, here is what I did. I attached the brown paper to each wheel liner. Then bought some insulation stuff at home depot. I only sprayed it on the passenger side rear wheel - there is a huge void space here. It was a mess to work with.

On the rear passenger side there is not much of a void and the lines to the gas tank were there so I didnt spray it.

Same with the front, insulation but no spray. I shall find out tomorrow if this was worth the effort. I will keep you posted.

dr bob

For the insulating foam in the closed cavities I made the mistake of using the non-expanding stuff from Home Depot. Keep in mind that this was done to the Explorer; the 928 is next. In the Explorer, the rocker sills, B and C pillars, and the cavity between the inner and outer rear wheel liners are accessible. I made this big mistake of using the spray stuff in there, not realizing that this foam uses moisture from the air to cure. (Read The Label, Stupid...) To get it where I wanted it, I added a few feet of vinyl hose to the nozzle fitting on the can, and poked the hose in through plugged openings reserved for undercoating.

For the next two years, the car would weep baseball-sized blobs of sticky yellow foam whenever it was parked in a place where it was hot. We had smears of yellow goo hardened on the inner rockers, the rear suspension, etc, as the stuff slowly cured and expanded out of every orifice it could find on the way.

Moral: Stay out of the enclosed places like the pillars and rocker sill unless you have the real two-part mixes-in-the-gun foam generator.


So--- If you decide to do an open cavity, add the foam into a plastic bag that you've taped into the cavity. Avoid getting this stuff directly onto anything or into any place where you don't want it to be permanent. Using the bag trick means you can change your mind, do repairs later, etc, and manage the mess. This also means you can do a little creative sculpture to get plastic panels and the like back into place too, without damaging any original metal bits. Just make sure the blobs you make are cured before you close the bags.

Except for what appears to be the high cost per cubic foot, I wouldn't hesitate to use the metal-faced stuff that Jerry recommends, inside the wheelhouses. I might be shopping with Mark or Jim at 928 International for the later-model (90+) factory rear wheelhouse liners at the same time, to add a little more sound protection as well as protect the foil-faced stuff installed there. Each time I visit Jim, I think about what the dealer would charge for the panel, and end up paying about that to him for what I need. It's really a discounted price well below what the dealer actually wants, but I'm not keyed in to the dealer charges well enough yet. When I get seriously into this project, I'll post a video and a companion picture album showing the process. It will be a springtime project earliest, more probably into the summer though, after the wedding and after the move into the new house are complete. And if I'm allowed any free time to do car projects...