I am preparing to install new hood insulation on my 87 951 by removing the adhesive left behind when a PO ripped out the original insulation. Much to my surprise, underneath all the adhesive was RUST!

Now I'm not concerned with the aesthetic issue here, since it will be covered up, but what should I cover it with before applying my new adhesive? i have some rust bullet from a previous restoration, but was hoping i could get away with a simple rattle can job to stop the rust. Thoughts?

Thanks,
Ross

 

eww, thats nasty. lol
theres a chemical called....POR-15??? i think, either way the stuff i have is green, and it kills the rust and turns it a light grey color which you can the spray over with a coat of primer or paint.

 

POR-15 would work, but you should really consider pulling the hood and having it professionally repainted top and bottom. It looks like you have rust issues in between the two pad areas as well. Rust never sleeps, and if you plan on keeping the car, it is worth the investment to do the job right the first time.

 

You have achieved the impossible! This is the last place that you would expect to see rust, the heat in the engine bay would quickly evaporate any hint of moisture.

My guess, someone replaced the liner in the past and used an adhesive that reacted with the paint/zinc coating.

I would strip to bare metal where there is rust, lightly sand the good paint on the rest of the panel and repaint. If the outside is good just do the inside area, then put your new insulation on.

 

The outside of the hood is okay, except for one spot where there is spider-webbing....I was putting on insulation because I assumed it was the heat causing it. Nonetheless the liner/adhesive was definitely not OEM based on the brace in the middle of the hood also having the adhesive (I didn't remove it, but I guess I should since the adhesive likely reacted there too).

 

There you go, apparently there are adhesives that "etch" into a surface to grip and others that "attach" themselves to the surface coating. I'm no expert but I would not want anything etching into my paint and zinc coating.

There is another thread running about hood liners. Check that one out, the recomended product looks better than oem and I am sure the manufacturer of that lining will give you good advise about the correct adhesive to use.