Fixing the rust holes 94 wagon

I can't post  links.
I showed how I have fixed the rear wheel well rust.

On buickforums.com/forums/threads/45069-94-wagon-rust-repairs-to-rear-wheel-wells

You did not leave a drain hole for the spare well.

I did drill a small hole which drained out about 3 gallons after I did some more rust flushing back behind the rear pillar, but the pics don't show it. I put on more PL-sawdust mix which sealed it up again, will drill the hole bigger perhaps 3/8 inch.

When it rains, the inside of the rear pillar gets wet, so I think it is leaking from up above the roof area.

I have read about the roof rack torx bolts, are they the only thing holding on the roof rack and black moldings, are they all on the outside, no need to drop headliner if those rivet nuts do not spin in the car body?
I took out some fine using too small a torx driver, I seem to have lost track of all my torx tools, since they were loose, the smaller one worked, had to order some torx drivers since some were tight.

What exactly happens with the roof rack leaks, do the rivet nuts themselves leak?

I also used marine waterproof-resistant  grease to seal the 3 roof rack bolts I took out. Most greases mix with water, so use a grease that does not.

The roof rack bolts do not usually leak. The main leaks come from the side glass, and the channel under the edge of the roof rack.

The rivnuts will often rotate in the roof. You will probably have to remove the headliner to get to them. Once you have the screw out, you can tighten them with a long bolt, nut and washer. Put the nut on the bolt, next the washer, then screw the bolt into the rivnut. Once you have it partially screwed in, hold the bolt still while turning the nut against the washer, and hence the rivnut. It will pull the rivnut tighter against the roof, and you should be able to reattach the roofrack.

Once you have removed the roofrack, scrape all of the flaky sealant out of the channel, and fill it to the same level with fresh sealant. If you make it too full, the roof rack will not go into the channel as designed. I used regular roof cement.

If either the top channels, or the windows are leaking, the water runs down the channel in the headliner, and to the back of the car. Often it will drain out of the grab handles, and into the trays on the tire cover or the storage compartment. From there it ends up in the spare well, or the bottom of the driver's side quarter panel.

There are other possible leak sites, but those are the most common.

The only water I saw was on the inside of the rearmost pillar. Water was trickling down there and then spilling onto the ledge hidden behind the metal. You know where the pull plastic handle sits to remove the spare tire, the area behind that pull handle, flowing on the inside of the space.

So are you talking channels as in a metal body weld seam under those black plastic covers?
And that sealant cracks? If so, my plan would be use Loctite S30 roof and flashing polyurethane sealant.
I have used a lot of it and it is durable rubbery sealant. Similar to 3M 5200 but softer. and a lot cheaper cost.

at loctiteproducts.com/p/pl_seal_rf/overview/Loctite-PL-S30-Polyurethane-Roof-&-Flashing-Sealant.htm

Right now have 6 inches of snow on the car, but later this week will be in the 60's here in Newport News, VA.
So will post back pic updates thru the other forum.

Yes the seams under the edge of the plastic trim on the very outside of the roof rack sides.

The water must run down from somewhere to get to the D pillars. If you look at the shape of the car, it can run there from a number of places. There is sealant under the corners of the gate glass as well, and rubber grommets on the studs for the rearmost trim that the wiper motor shaft goes through. These are all places where leaks will occur. There may be a rust hole under the sides of the roof rack, but I have not had that happen to my cars. The others have.

I even had rust holes in the support for the rear of the vista glass. Both sides had holes big enough to stick your finger through. The back side of the support looked like it was shot with rusty birdshot as well.

Removed all bolts, but had 1 spinner at front on the center piece.
So also found out there are a bunch of inside screws that hold down the black plastic molding edges at the very front of the rack.
Reading the threads, I saw no mention of those when removing the rack.
Since I dont wish to make this job 5 times harder, I noticed I could pop the plastic molding right out from those screws, and some were not holding anyway.

One side held tough, so I put a paint brush handle under for a fulcrum and popped it out easy.

That one roof rack bolt that is a spinner, I am going to grind the top with a cutting disc using my dremel.
Then I can deal with the remaining stud.

These rivet nuts seem awful cheap solution for GM to use, they are easy to fail, but they worked and they were cheap so GM used them.

I wonder, does the rear black plastic molding where the window motor mounts also have pass thru hidden screws on the inside?

Yes, there are three. You must remove the rear headliner trim to get to them. The "screws" that look like they are holding the trim are just locks for the actual clips. Once you get the locks out, you must slide a blade under the trim to disengage the clips from the body. If you just pull on the trim, you will put stress bends in it before the clips will let go. There are 3 nuts holding the rear trim from the inside. They are accessible with the interior trim removed.

The front cover over the vista window brace has three nuts holding it on. You may be able to get to them by removing the vista window trim. It is a reach, but possible. You need a ratcheting box end. Getting them back in place is a lot harder than getting them off. You may be able to get the side nuts from the side of the rear door opening by reaching under the headliner after removing the upper B pillar trim,, grab handle, and the courtesy lights.

I count 5 across the top front
I simply popped them off without unscrewing.

An inner screw is shown to extreme right, and the spinner to extreme left.
I ground  off the top and removed the rack front section

The spinner rivet is so badly rusted, now to get it out i have to drop headliner.
Since I have to drop headliner any tips?

I know people dont like rubber well nuts to hold the rack, BUT, we had a 1975 Chevy Impala wagon, and the OEM attachment method for the rack used rubber well nuts.
Each chromed zinc corner was held with two or three 1/2" rubber well nuts. Two corners in back, two corners in front and a fifth at the very front middle. So 12 to  15 rubber well nuts that I recall were used.

The five across the top are on the outside, there are three nuts on the inside as well.

Are you referring to the TORX screw in the middle, left of the picture? If so, you are probably right about dropping the headliner. You can try removing the courtesy light, grab handle, and vista trim. Then you may be able reach under the headliner to get a channel lock pliers or vice grips on the rivnut to extract the screw.

The remaining stud and rivet nut are completely falling in. I loosened the pillar speaker plastic, I can try taking off the handle and reaching in there.
It is attached tight,to roof is it velcro on?

I used well nuts to replace the rivnuts on my 91 OCC rack, but I would not trust it to hold anything of substance or size. The well nuts can and will pull out. I have removed the center slider rails, that are held on by well nuts, with a door panel tool and a screw driver. I never took the screws out.

Once you get the screw out of the rivnut, you can tighten it in the hole with the tool I mentioned above. Just use some rust remover, and paint first. Then you can re-install the rack.

#2 If the rivnut is completely falling in, you should be able to pull the rack panel off. If you can not, it is just loose. I would not suggest yanking on it, you will damage the roof. There are some of Velcro fasteners on the headliner. The 92 OCC manual shows three evenly spaced down the middle, behind the vista window, and one on each side at middle of the front door.

The difficult part is that the C pillar can not be removed without damaging the attachment to the bottom half in the door jam area. They are heat welded together at the seam. Detaching the C pillar at the top will not give you any more room to work, and probably damage the headliner in the process, because there are hooks to hold the headliner on the pillar trim.

more pics. I cleaned the roof with a scrunge and pressure washer. I have only one totally failed rivet nut due to rust.

metal body roof seams, caulk looks good.

I got the failed rivet nut out. Took off moon roof molding and light and handle and could reach it.

Some of the blue paint is failing, so to prevent rust will spray some grey primer.

Since the surface of these rivet nuts is rusting on some, I am thinking, let it dry.
Clean up with alcohol or acetone.
let it dry, use a heat gun to dry it good and warm.

Take some instant glue and saturate the rivet nut top and seam. That can work into where the nut meets sheet metal and secure it better.
Then put a little epoxy on top, then a little primer.
Some areas under the black plastic are getting rusty.

I wonder if the forward failed rivet nut was the cause of my rack leak.
Plan to repair with a rubber well nut from HDepot etc.... or maybe I have something, somewhere I have these stamped steel nuts that expand in a hole. They draw up like a moly bolt in principle. They are called JACK nuts.

Nice work,good pics showing the details. This is a project I will probably need to do.

I decided to use what I have to fix the missing rivet nut. I took a washer and copper brazed it to the remains of the rivet nut, then primered backside. I then roughed up the inside paint of the roof which was not rusty, and JB Welded the washer - rivet nut to the inside of the roof.

Then I block open the headliner so I could get my hand in there, and put some grease on the bolt and tightened it onto the roof sheetmetal. So all I need is a bolt.

And I was looking and it could be the seam caulk has a crack, so plan is to use rubber Loctite S30 roof polyurethane and put some on there with my finger. It is good stuff and can be spread thin.

I also cleaned rust off remaining rivet nuts, 3 are rusty. Wiped with acetone, then sealed with some instant glue. Will over top with a little epoxy also later.

I have mostly done with sealing everything.
Just need to wait till it cures, the Loctite S30 roof polyurethane can take a few days to fully cure. And it is paintable, permanently flexible and waterproof.
I dug anywhere the rust was showing back to no rust.
One good tool is a snapped drill bit in a drill, that will eat out rust pits.

It is amazing that so much crud gets into a relatively sealed space under the front cross piece. You are doing a good job. I do not envy you at all. I have done the same thing, and I found rust holes in the back of the vista window support that were big enough to stick my fingers through. I had my headliner out at the time, so it was a little more accessible. It still was a royal PITA.

Be careful adding caulk to the seam. If you make it too high, the roof rack side pieces will not go into the seam properly.

I have the sealer about 1/16 ".  It spreads very smoothly and turns into a soft rubber with lots of give.
You can also mix milled glass fibers into the Loctite S30 Black PL which gives it more hardness, about 70-30 favoring the glue of 1/32 milled FG fibers and it creates a surface that is really tough yet pliable, like a tire. I did that on my old wood boat hull last haul out, sealed it up watertite. It was easy to spread using a 6 inch putty knife. And a wire wheel on a drill can shape the surface smooth out any rough spots.

Surprising how much crud builds up under things, AND complete leaves too. When I power wash the upper trim, I get lots of blackish debri from rotting plants washing out.

More repair pics.
Using that piece of aluminum sheet from an old screen door with the impressed design has made for real strong glue repairs.

inner fender repair, nice there was enough left to get the correct shape. The crimp between inner and outer was still intact. behind this piece, so It was easy to get the length correct.




Paper pattern to fit the hole.


Cut out pieces to glue in. Little one extends my edge, it was too short, the flow of the curve was looking wrong.
Cutting tabs allows easy curves to be made and the lip edge.




Little piece glued in. Once this glue starts to set, don't move the parts or it may fail, depends on how cured it is when you move it.


Large area filled. Most of my glue jobs I am mixing in some sawdust.
Cereal bag on top and it will not stick. Lets you smooth it. It will still require grinding down and filling.


This hammer, rebar, bord and RR tieplate hold down the patch while the glue sets.



I have never seen this glue allows metals to rust anymore, and it makes a solid repair.

I have acetylene torch, arc welder, and know how to use them. But really heating the metals and welding is just not worth the trouble.
What I am doing is easier and cheaper.
And high heats burns off all the paints and then it rusts again. This glue sticks well to everything as long as it is clean. And it forms a truly waterproof barrier. I have coated it also on metal parts just to stop rust.

To get the glue off your hands, use a scrunge pad and dish soap. I use both a SS scrunge and a nylon pad and it works better than gasoline. But clean your hands soon.