[cdrookie]

The rear window channel/filler panel area on my 75 Lemans has rust holes on the corners and a few along the channel. It’s been like that since I got it almost 20 years ago. I’ve sand blasted the area and it’s pretty solid amazingly. I know the correct way to fix it is to cut it out and weld in a new panel, but nobody makes them for my model. Would using something like Lab Metal be a long term fix? The car is garage kept and if it ever does actually get painted, I might hit a local show or 2 but it would mainly be a driver. It won’t let me post a pic to this thread, at the moment.

[PontiacJim1959]

Why not just go with fiberglass cloth/mat?

It is not a stress area. It is sand blasted, so the fiberglass cloth/resin will bond real well. Cut to fit, then mix your resin/hardner, dip/saturate your cloth, then apply. It'll most likely sink a bit in the holed area, but once cured, you can rough up the fiberglass by sanding, then apply a light layer of something like "Kitty Hair" which is a bondo with fiberglass strands, or use your typical bondo. Sand smooth.

You can "feather" the edges of the fiberglass/bondo on the edges by sanding with a block sander to create a smooth taper & transition from the repair to the good surrounding metal if it is on the top/body. Prime. Then squeegie a thin layer of glazing putty (used to be in a small squeeze tube like toothpaste - and it was red in color) and let it dry. Then wet sand that smooth. Then prime to finish.

I am sure you can find a You Tube video on how to do all this.

[400 4spd.]

If you have access to a mig welder I strongly advise that you make some simple
patches from sheet metal. A window channel is the easiest part to hand form a patch for. If you can post pictures I can make the parts for you.

[dataway]

Hard to answer without knowing what tools/skills you have at your disposal.

If you can get to the back of the panel, the method I typically use is to use a die grinder or similar to open the hole up to good metal edges. Hold some card stock on the back side of the hole and trace the hole on the card stock, use that to make a perfectly fitting patch. Then I use a magnet to hold the metal patch in place for tacking. Remove the magnet, finish welding.

If you can't get to the back of the panel I'll use masking tape ... cover the hole, rub a pencil along the edge of the hole to leave a mark on the tape. Carefully remove the tape, apply it to your patch metal and cut/grind to the lines you made. Produces a patch that perfectly matches the hole.

Method works great on flat panels, or single curve panels ... will get you in the ball park on compound curve panels. Not very useful for tight radius curved sections.

[Greg Reid]

I had to replace a few areas of my back glass and as stated, you can make those pretty easily. Even the corners are doable by using card stock for the patterns. I made those corner pieces out of two or more pieces tacked together.
You can do all the patterns with a manilla folder and some tape. Take the cardstock pieces back apart once you've duplicated the shape, cut metal using different patterns of the card stock pieces and tack them together just like you taped the paper together.
Even easier, take 400 4spd up on his offer!

[Stuart]

Welding in new metal is always going to be the best solution, if you can do it or have it done. Here is a series of photos showing how a rust hole in the rear window channel of my off topic car was fixed - putting a screw into the patch piece makes it easy to do without having to access the patch from behind, you can hold it in place while tacking it.

[cdrookie]

Thanks for the suggestions everyone. I have made and welded in some basic patch panels on a few other areas, and I can access it from inside the trunk. It's in a high visibility area though, and while I could make something good enough, it'd take me 50x longer to do than pro's like 400 4sp. Hope the pic shows up.

[cdrookie]

It worked! I put a light in the trunk to make it easier to see the holes and the other side is about the same.

[dataway]

That's exactly the method I use for checking my patches for pin holes.

[3 Chiefs]

Check this site out. http://www.beldenspeed.com/rust-patch-panels They specialize in rust around windows. I would call them as they may have pre-made panels for your car even though they don't list them. Also there is a lot of great info on the subject here on their site. Good luck. Rust never sleeps so get rid of it all.

[Greg Reid]

I'd be taking that glass out and looking at the entire area as a whole. Then you can decide on a plan. That might be the worst spot and that would be a good thing. If you've got more rot, now is the time to find it.
That is, if I'm seeing that photo right. Is that dark part at the top the trunk lid or the trunk opening?

[cdrookie]

It's the trunk lid Greg. I was standing behind the drivers door looking down at the area.

[lfdsteve]

If there pin holes cant you just drill them to clean metal use a copper backer and fill them with mig weld like you would for trim moulding holes?

[Greg Reid]

I'm no expert by long shot but my opinion is, that would be quite a bit of filling with weld. l think you would wind up doing a lot more welding and grinding in the end than you would using a patch.
My first choice would be to find someone who could cut that piece from a parts car... But then again, it's kind of hard to tell if that is a relatively flat area or not. If it's flat I would just cut it from a piece of scrap metal. I'm not that familiar with that body style and how it's formed back there.

Sent from my moto g(6) play using Tapatalk

[cdrookie]

It's not flat Greg. Finding that area, that's not rusted out, on a parts car, is extremely rare. I will see about getting the back glass out and then reevaluate the situation. Thanks everyone.

[PontiacJim1959]

Originally Posted by cdrookie

It's not flat Greg. Finding that area, that's not rusted out, on a parts car, is extremely rare. I will see about getting the back glass out and then reevaluate the situation. Thanks everyone.

Funny how a simple and quick fix has now evolved into a bigger project and once that glass comes out, there may be even more work, and then when fixed, well, the spot painting just doesn't match, so now it needs to go to the body shop to get that area blended in, and since I gotta take it to a shop, heck, I think I'll do a frame off like I have always planned on doing anyway. LOL

Does the wife know about your plan?

[400 4spd.]

Most guys don't have to get the wife's permission to fix their car. At least that's been my experience. YMMV

[cdrookie]

Ha! The back glass is the only thing that hasn't been off the car. I remember when I was first told about this car... It took me 3-4 attempts to find the thing. Once I got there, I wondered if I should even get out of my truck. The type of place that, for the right price, you could hide a body somewhere. All was cool though, and for a paltry $300, I made the biggest mistake of my life. I asked my buddy if I could put it under his carport and that I'd have it running in a couple months. Fast forward 20 years(or so) and it has more miles on a trailer than under it's own power, and is in more pieces than it has been since 1974. Luckily(or not) for me, my wife doesn't care.

[dhutton]

If you are not comfortable welding in a patch then you could blast it and fill the area with 3M panel adhesive. Not as good as welding in new metal but the repair will likely outlast you. Apply a good quality epoxy on both sides after the panel adhesive.

Don