Hatch Hinge Pocket Rust Repair

[Roberts280Z]

After I noticed rust on the interior at the rear part of the roof at the hinge pockets, I removed the hatch hinges and saw this mess.

This doesn't look like an easy area to weld in, and the replacement pocket would not be an easy fab job.  As an alternative, I'm thinking of just cleaning it up, applying POR, and then lining the pocket with fiberglass.  The other pocket is not quite as bad, but is also rusted through.

 

Has anyone else dealt with this area?

 

Thanks in advance,

Robert

 

[calZ]

If the guy who's going to buy your car in 2, 5, 20 years could talk to you now, he'd beg you not to use fiberglass. 

[Sanchez]

As somebody who going through the process of tons of rust repair right now too, I can tell you that there is very little you want to just fiberglass over and forget. Maybe a few small pinholes or some pitting around some of the seams can be epoxied or glassed so that way weatherstripping can get a good tight seal, but for that just do metal and get a new rear hatch hinge boot from Zcardepot. Unless you are going for a completely clean and stock look with show quality welds everywhere all that stuff will be hidden and unnoticeable when done. Cut it out and repair with sheet metal it’s pretty much a slightly curved square of metal so not to difficult, if getting the welder inside there is difficult you could cut out the part of the roof rail that holds the dome light and access from the back and patch that up again too.

[Roberts280Z]

I guess I'll try to weld in some sheet metal there. I've avoided glassing this far (rusted fenders, rockers, floor panels, door bottoms, etc., etc.).  And if I could talk to myself 10 or 20 years ago, I would have told me to keep it in the garage!

 

[grannyknot]

4 hours ago, Sanchez said:

if getting the welder inside there is difficult you could cut out the part of the roof rail that holds the dome light and access from the back and patch that up again too.

This about the only way you are going to get at that pocket,  if the car was on a rotisserie it wouldn't be too bad at all but if on its wheels, well it will be a pain.  I would like to know how the water got in there?  That's not an area know for rust.

[Roberts280Z]

Yeah, well a rottisserie is next on my shopping list after a lift (I wish...).  I just love welding on my back.

 

It looks like to me that the caulking failed around the bottom of the pocket liner.  With the failure of the outer hatch weatherstrip, that allowed water to pool on the inner hatch weatherstrip rail, and then seep under the pocket liner into the pocket itself.  Also note that the spare-tire well was nearly full to the brim with rainwater, but there was absolutely no rust there!

 

[toolman]

Robert,   I think you are correct in assuming that a leaking hatch hinge liner was the main cause of the corrosion.   I inserted my borescope into

that INTERIOR  LIGHT channel that holds both Right & Left hinges.  Only the hinge boot keeps water from entering the channel.   If you didn"t have those big rust

holes there under the R/hinge,  water would mostly flow along the channel then go down the inside of the rear quarter panels.  Then the water

would exit from either the front or rear wheel well edges.   To repair it. by cutting those rust holes out and cover the area with a sheet metal  patch

welded on the botton side of the channel.   Use polyurethane seam sealer to the top side of the patch.   A new hinge boot will keep the water from

entering.  

 

 

Edited December 9, 2020 by toolman
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