How to weld sunroof shut

[Ho Hum 74]

Folks,

I did a little search on this but still have a question.

Once I remove the inner sunroof workings and the false roof, how does one weld in the original sunroof panel? The gap seems too large. Any ideas?

I understand that there are fiberglass options but I don' think they're allowed in clubracing. I guess I could just epoxy the original in and back silicone the edges.

Thanks for the help

Tristan

[Craig 930 RS]

Dane would know...Dane???

[Ho Hum 74]

I'm thinking that black silicone would be an easy/cheap fix right now.

[LakeCleElum]

Dane's at Alex's place right now.........ALEX, GET DANE!!!!!!!!!

[Dennis Kalma]

I am interested in this as well. I am also worried about the warping of the roof if you mig weld the thing.....could be minimized by welding in short segments with cooling in between, but I would REALLY hate to end up with a wave in my roof.

Or do you just lead load the thing? Isn't there an inner panel that needs to be removed, and if so, how much of a hassle is that?

[rdane]

I am having mine welded. But this is what I understand of the process. Two ways I am told:

Gut the roof and tack weld the slider in place from below. Seal it with black caulk on the outside. No paint needed if you are really careful with the tacks. Looks like a sunroof from the outside but you now have headroom inside. Drops a little weight.

Second is weld in inside and out, skim coat and repaint. Same weight drop but more way more time and labor involved. But aso almost as strong as original non sunroof . I have heard the warping is a problem also. I just pay the bills and ask lots of questions so am little help.

[Ho Hum 74]

Apparently the inner panel is just a few rotations of a dremel away. The hard part is welding the sunroof closed.

[Vapors]

I used 3M Automotive Panel adhesive one time to attach a complete roof on my 911 and it worked great. The adhesive is super strong. I would think you could use it to glue the sunroof also it is just another panel. I did follow the directions for preperation of the metal to the letter.

[rdane]

This makes more sense to me than welding.

Originally posted by peter wilmes
I used 3M Automotive Panel adhesive one time to attach a complete roof on my 911 and it worked great. The adhesive is super strong. I would think you could use it to glue the sunroof also it is just another panel. I did follow the directions for preperation of the metal to the letter.

[kmhemi]

The 3m Panel Bonding adhesive is some amazing stuff. My buddy has a bodyshop and we use it alot. Definately the way to go...just make sure it is where you want it to be forever !!! There are no second chances without alot of work.

[klaucke]

The panel could be braised in to keep the heat low and help prevent warping. I think someone who was well versed in welding panels with a MIG or TIG could also do it without warping, just don't take it to your local trade school. I think welding is the best alternative because then you have a non-sunroof coupe, so it's minimal weight, and it adds to the stiffness of the roof/body.

[Dennis Kalma]

Further reflection on the bonding idea. I would suppose that the panel being replaced is relatively small and obviously non-structural. When I checked the 3M fact sheet, it seems to be ideally suited to this kind of panel....low stress, high risk of warpage, non-structural etc.

Probably only concerns I have at the moment with bonding would be threefold, namely I would like to lead load the seam, not sure if the 3M panel adhesive likes heat, I would like to at least tack weld/spot weld it in a few spots - again the heat worry and lastly I would want to take the sunroof inner roof panel out, does it actually provide strength to compensate for the cutout or is it just there to hang the sunroof hardware?

The frozen (up here) world wonders...

Dennis

[widebody911]

I think the 3M epoxy would be your best bet. The spot welds on one of my VW bus's safari windows broke. I glued it with the 3M stuff, and it's holding great. You need a special gun to apply the stuff; the guy at the autobody place lent me one for free, but I've been a customer there for a long time.

[robfike]

To get rid of my sun roof, I cut out everything inside the main framework of the roof. I then cut the top skin at the inner edge of the framework. Then welded on a non-sun roof skin from a donor car that was cut around the outer edge of the roof. This gives about a 2" overlap of roof skin. The reduction in weight was 18lbs as I recall.

[Joe Bob]

Kind of the same thing.....cut a sheet metal piece slighly larger and bond it to the edges....skim coat, paint....

[rdane]

Total weight loss with the flag mirrors was -16.5# on a postal scale.



Mine is welded up and filled ready for some primer.




The underside of the now welded up sun roof. It isn't going anywhere!

[Vonzipper]

Anyone have a picture of a non-sunroof car with the headlinner out??

[Ho Hum 74]

Look up. That's what it looks like.

[Vonzipper]

I was thinking that there would be a support in the middle of the roof, long span of just sheet metal

[rdane]

nope..4 wires to support the headliner though