How would you fix this panel hole without welding?

My E28, being a grey market import, naturally has holes drilled in the rear valence for gross federal marker lights. The marker lights are long gone but the holes persist. Now that the car is mechanically sorted these bug me more and more every day. One big hole approx. 30mm in diameter and two smaller 7.5mm holes.

I’m trying to figure out how I want to fill/fix these. Bodywork has never been my strong suit; I can see a few different ways to tackle this. Welding is not an option for right now so I’m thinking:

• use the smaller holes to pop rivet a piece of sheet metal to the backside of the panel, fill surface, sand, etc
• pound a freeze plug or similar into the big hole, skim the whole thing and just fill the smaller holes with putty
• use a substantial compound or putty to just fill the whole thing
• ???

Proper way would be cut a piece of metal and weld it into the big hole and then fill the smaller holes with weld, then grind down, bondo and repaint.

or just throw a fiberglass patch kit at it.

You sure you don't want to put the light back 'til you can weld it up? Try to find a tidier light to fix those holes?

I just hate the idea of doing anything that'll make it harder to fix later, and which may trap water and start rust.

You're planning to repaint the area, yes? 

Absent welding skill/capability I'd cut a patch large enough to cover the holes and use panel adhesive to glue it to the back, then fill will body filler. 

Just make sure the panel is dead "flat" and the patch matches the panel perfectly. Bodged up screw holes aside, most panels are distorted slightly around punched holes (Even new) and you won't be able to fix it after the patch is bonded to the back. 

You have the gravel guard going for you here which will cover some imperfections. Since welding isn't an option gluing a patch from behind (rivets will show on the outside) or fiber glassing on the back might be your best option (I've done the welding thing personally so I'm sure someone else can make a better recommendation). Once that has set hit it with the body filler and start sanding, for best results you will need to take all of that texture down (probably the whole valance realistically) and redo it so you can start with some pretty aggressive methods. Apply an even coat of some sort of gravel guard (I used dominion sure seal gravel guard on my rockers up here put I'm sure you can get something decent where you are, I don't think the rubberized ones are the way to go though). Then paint it, color match spray cans should be fine and since that beautiful euro bumper is there you won't need to worry about a 100% match. 

Adam

Have someone else weld it

Patrick said:

Have someone else weld it

When you say smart stuff, it’s like we share a brain.

You could fill the holes with side marker lights...

Slap a GRM sticker over them

Welding is probably the best option, but Eastwood does offer this. 

Make a block off plate out of carbon fiber and rivet it into place. Makes it look more race car.

AngryCorvair said:

Patrick said:

Have someone else weld it

When you say smart stuff, it’s like we share a brain.

FYI - the main reason I don't want to weld is because right behind this hole is the fuel tank, fuel filler neck, 3 vent hoses, pressure and return line, etc...the amount of disassembly I would have to do to be able to safely complete the repair without blowing the car up will basically take it out of commission until the middle of summer. And that's presuming I don't break anything NLA in the process.

Why not just remove the rear valance and then weld?

1x10mm bolt behind each rear wheel arch and 4x13mm nuts in the boot below the rear lamps.

FuzzWuzzy said:

Why not just remove the rear valance and then weld?

1x10mm bolt behind each rear wheel arch and 4x13mm nuts in the boot below the rear lamps.

Rear valance is not removable on the E28. It is welded to the body; you are describing how to remove the bumper. (not my car but an example)

If you don't have any fuel leaks where vapor is a concern, is it possible to get some metal placed behind the hole to shield heat and sparks from hitting any of the sensitive bits? 

rslifkin said:

If you don't have any fuel leaks where vapor is a concern, is it possible to get some metal placed behind the hole to shield heat and sparks from hitting any of the sensitive bits? 

The 1985-spec evap system on this thing is...get this...a hose that vents fumes directly to atmosphere about 16" away from the area that needs repairing 

Can you temporarily plug or extend the hose while you're working?

STM317 said:

Slap a GRM sticker over them

I don't know how this correct solution hasn't gotten more attention. Otherwise I'm all for fiberglassing the back side, filling the front with bondo. 

pointofdeparture said:

The 1985-spec evap system on this thing is...get this...a hose that vents fumes directly to atmosphere about 16" away from the area that needs repairing 

I was working on one a few months ago and was trying to figure out if that was correct!  It worked so I left it alone but I was confounded by it not going to a cannister or anything.

I'm another vote for GRM sticker, put it on some magnet paper and just stick the magnet over the hole.

I am firmly on the panel bond adhesive and a scrap of metal side of this fence.

The adhesive when cured is a great body filler on its own, but it isn't inexpensive.

Wire brush the inside of the valence down to bare metal. Hammer and dolly the area flat. Cut metal to shape. Apply a layer of the goo to it and stick it in place on the back side. After it cures sand it smooth and then apply the desired surface finish.

Acquire a federal marker. Reinstall, even if not wired to light and revel in the car's gray market origin. 

I'm a little confused as to where this light/hole is and what is the purpose of a federal marker. 

John Welsh said:

Acquire a federal marker. Reinstall, even if not wired to light and revel in the car's gray market origin. 

I'm a little confused as to where this light/hole is and what is the purpose of a federal marker. 

Euro-spec German imports of the 80's didn't fully comply with federal DOT/NHTSA regulations on marker lights & turn signals.

In order to be "federalized" for use in the USA, importers typically blasted holes in whatever panel was convenient, slapped some trailer marker lights in place and wired them up.

I don't want E36 M3ty trailer marker lights on my car when they were never supposed to be there in the first place.

You can weld near the fuel stuff, just shove a few damp towels behind the panel have a buddy zap er in

I am liking the panel bond adhesive idea. This car will probably never be worth anything so I plan to keep it forever - it has had a million owners, over 300k miles, and is already in "scruffy driver but generally solid" territory - so I just need a fix that won't cause MORE problems in the long run.

I am open to having someone else weld - but the close proximity of many fuel system components is my big worry. Since I can't/don't weld I am not sure if this is a legitimate concern.

Here is a pic of the car from three previous owners ago with the marker lights installed. Just below the rear bumper. They are long lost at this point.