Plugging Sunroofs

Ok so i will be removing the sunroof assembly from my e30 and plan on welding a piece of metal into its place.

Couple of questions about the best way to get this done...

First off, what is the best thickness of metal to weld in?

Also, should any extra support structure or bracing be added to the roof while this is being done?

Any other tips are welcome as well, this will be my first time attempting this!

Thanks, Josh

Head to the junkyard and cut a chunk of roof panel out of a non sunroof car- doesn't really matter what model. A flat panel is a pain to try to fit, and most roof panels have roughly the same sort of curve to them.

I have usually riveted them in place, after some careful trimming. Trying to weld a big flat panel into a bigger flat panel is a recipe for warpage. It can be done, but it takes patience and skill.

There is usually enough built in bracing around the sunroof opening that extra isn't really needed.

Race car, I presume?

A lot of E30 guys (myself included) use the factory sunroof panel. It's already made to fit, and it's the right color. You'll want to "skin" it down to just it's outer, top layer. If you don't see already, the sunroof panel is two layers attached around the edges. Some cutting and peeling will separate them, now it's thinner and lighter. Then align it where you want it in the roof, and weld it in place with some small tabs or something. Get creative. There will be a small gap where the sunroof seal goes, you'll need to seal that with something, I used silicone. It will need to be a good seal, there's no more sunroof drains to keep you dry.

I'm assuming you're cutting out all the sunroof carrier part of the roof too. That's the main reason for doing this. Be careful when removing all that, it's very easy to damage the roof skin by pulling/etc. on the sunroof stuff you're cutting and removing. There is a crossbrace that runs across the roof behind the sunroof. Don't cut all the way through this when you're cutting out the sunroof carrier, it helps give the roof some structure. The roof skin is pretty flimsy, but not a problem.

I hope this helps. I'll be happy to answer any more questions.

Sunroof panel plus window gasket equals hole filled.

I attempted this ion my old 87 CRX Si. I made a wood buck and fit the new sheetmetal sunroof perfectly, layed it in place and then Tig welded it. I took my time, cooled the welds, did tiny, low heat tacks. I am a professional welder by trade.

It promptly warped like a mofo and ruined the roof.

My pro. advice, don't weld it. Do the orig. panel, and some window gasket and bolt it or silicone it into place.

Go to junkyard with cordless sawzall

Remove panel from same car sans sun-roof.

Cut new tin to fit with small overlap.

Buy flange tool and use.

Buy a tube of panel adhesive and glue new panel in place. Paint to taste.

No way in hell you will ever weld a fill piece in unless you develop mad metal finishing skills; low crown panels suck.

weld it, warp it, fill it w/ a gallon of putty

JK

I did this on my race car ans I used a piece of flat sheet metal of similar thickness. I cut it to fit with a zero gap between the opening and the panel. It takes time and alot of fitting and trimming to get this type of fit. Now you can start tack welding into place. I used a MIG. I have a TIG but a MIG is easier and quicker for this. I made only small tacks, using the minimum heat to get the tacks I wanted.

Move around the edges to place more tacks and then wait for the panel to cool. If done slowly you can start placing more tacks between the first set. Keep going until you have overlapped the tacks. This can take many hours or you can spread it over a few days. You can also grind down the tacks if they get lumpy, but be careful as the heat generated from grinding can warp a panel worse then welding.

Many attempts fail because the person tries to go to fast.

In the end you will still need to use some bondo to get the roof smooth. The only way to get a all steel repair is as someone has already mentioned, get a a roof panel off of a non-sumroo car. IMO that can end up being more work in the end.

On my race car I got a piece of metal that was about 1 inch bigger all the way around and attached it to the roof with seam sealer and rivets. It looks hardcore and works fine.

Lots of great information, definitely happy that I asked for some tips on this. You guys said a few things I hadn't thought of.

This will be on my e30, which is mostly getting built as a track day car/occasional uncomfortable street car. I really appreciate all the e30 specific tips, and hadn't thought of just seperating the sunroof panel and using it. I have been doing a ton of things on the car and haven't even gotten around to removing the sunroof yet, so I was unaware the sunroof panel was two pieces and could be seperated.

Getting a whole roof panel is out of the question, I am pretty sure that hardtop e30s are really difficult to come by. Thats a ton of work as well, definitely more than I am really wanting to do.

Luckily I have some amazing metal fab guys at my disposal, so I will hand over the actual metal/body work over to them. I am not the best with a welder and I am pretty sure I'd berkeley up a large piece of thin metal.

Having to repaint is not a big deal because I am going to wrap the car in vinyl when I get everything done with the body anyways. Luckily I can easily get that done myself, just need around $300 and 8 hours...

Thanks again for the tips, definitely very helpful!

Josh

On our SpecE30 went with a piece of 20 gauge galvanized steel riveted in place--it helped that our local paint supply store sells a piece of metal that was the exact size—we just had to drill the holes and seal it with seam sealer.

pimpm3 wrote: On my race car I got a piece of metal that was about 1 inch bigger all the way around and attached it to the roof with seam sealer and rivets. It looks hardcore and works fine.

What diameter rivets did you use? 3/16"? 1/8"? I gathered from somewhere else on the intrawebs that some used 3/16" but seeing if there's a consensus.

Any particular flavor of sealant? I picked up some silicone for metal bonding but curious if there's a clear winner. Some other forums said 3M windo-weld but who knows what is acceptable or best.

Window weld seems to hold damn near anything . You may even be able to skip the rivets. I just put a spoiler in my wife's Fiat and it comes with two little clips and the instructions call for a healthy bead of it to hold it in place.

if you use rivets.. get the aircraft type that are "sealed". Regular pop rivets will let water in around the shaft that deforms and breaks away to give the rivet it's "pop" name