Sunroof removal, Bonding in panel

[vlocci]

I'm seriously considering removing the sunroof mechanism from my SC in order to gain some additional headroom.

The though was to carefully cut out the "coffin" housing all of the sunroof components, ditch the gearbox, etc. Finally, I planned on going to a simple perlon headliner that is glued in place.

The problem is I don't want to weld in the original sunroof panel, then have to deal with bodywork and paint.

Has anyone ditched the sunroof mechanism, then used 2 part structural autobody adhesive to "glue" the existing sunroof panel in place to the surrounding roof? Am I an idiot for contemplating this?

Thanks

Vin

[dad911]

Not an idiot, I'm contemplating same for a racecar.......

Anxious to hear answers, but reading some posts about bonding flares, it seems like a viable alternative.

[Bill Verburg]

That should work fine, there is a fellow in England that makes reasonably priced panals w/ appropriate flanges. I'll have look up his name and get back here w/ it

[Tom '74 911]

Here's another thread that should help. . .

Sunroof Delete on my 3.8 Widebody Projekt Part 1

Tom

[Bill Verburg]

Originally Posted by Tom '74 911

Here's another thread that should help. . .

Sunroof Delete on my 3.8 Widebody Projekt Part 1

Tom

Tom's link has the contact for the flanged panel,

Contact user name chris_seven at Fenn Lane.

[NY65912]

If I had to do it again, I'd bond the panel in instead of welding it in, as suggested by GaryR.

Sunroof Delete on my 3.8 Widebody Projekt Part 2

[GaryR]

Originally Posted by Bill Verburg

Tom's link has the contact for the flanged panel,

Contact user name chris_seven at Fenn Lane.

Finally got around to contacting Chris, hopefully he gets the email and PM I sent from here.

Thanks!

[GaryR]

Panel arrived today, now that I saw how it fits I had to remove a bit more metal. The flange he rolls into it is just the thickness of the single sheet of steel itself so you have to remove everything down to the flat steel of the roof to get it in there flush. I'm not decided on how to mount it yet, bond it using 3M Panel Bond or to plug weld it then tack/seam weld it before the lightweight filler. I'm leaning toward welding right now..

[Bill Verburg]

Originally Posted by GaryR

Panel arrived today, now that I saw how it fits I had to remove a bit more metal. The flange he rolls into it is just the thickness of the single sheet of steel itself so you have to remove everything down to the flat steel of the roof to get it in there flush. I'm not decided on how to mount it yet, bond it using 3M Panel Bond or to plug weld it then tack/seam weld it before the lightweight filler. I'm leaning toward welding right now..

Pics??

[GaryR]

This is it fresh out of the box, i'll take pics of all the steel I removed and when I can I will weigh all the crap. I weighed the panel on my bathroom scale and it's 4.5LB (according to it).. It has the same compound curves of the original though it looks kind of flat in the pic.. it's not. Very well done IMO.

[NY65912]

Gary,

Bond it. You have a high risk of warpage.

[GaryR]

You anywhere near Bay 8th St?

[haycait911]

use 3M panel bond. industry standard and the best I've used.

http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UuZjcFSLXTtMxMVLxTtEV76E bHSHVs6EVs6E666666--

welding, even plug welding, will give you a warpy roof.

[GaryR]

OK, bonding it is!

[NY65912]

Gary,
I'm not too far from Bay 8th. A few exits on the Belt eastbound.

You coming by?

[sc_rufctr]

I know Gary has already bought a panel but has anybody bonded in a fiberglass panel instead?
This isn't on my project list yet but it's something I've been thinking about for a while.

From GT Racing: 145 911 SUNROOF, Avg. wt 2 lbs, orig. 11 lbs. FG (Fits 911-993)

Has anybody used this one? Is this a replacement for the stock one or is it a bond in version?

http://www.gt-racing.com/pdfs/GTR911.pdf

[chris_seven]

We designed the panel to be spot welded in place.

I think punching holes and plug welding could be tricky.

We have a 3-Phase unit with extended arms and we normally begin by completely cutting out the roof



We then hold it into postion by support from below using plastic water pipe and then spot weld starting in the centre and working outwards



We fill the edge with a metal loaded filler such as U-Pol D



Before priming and painting



I am sorry these photographs are small - I messed up the file in Photoshop.

Next time we fit a panel - within 3-4 weeks - I will produce some better pictures and produce a more detailed set of instructions with larger photos.

[GaryR]

I would have have used a glass panel but between the fact that it's illegal in my race class and any weight savings would be negated by the bar I feel I would have to add to my cage, steel is the only option. Either one will require filler unless you just bond in the FG panel and use seam sealer to fill in the gap (if the FG panel is an exact copy of the original).. It is a lot of work to do a complete removal and correctly prep for the steel panel..

Hi Chris, as you see it arrived in perfect shape and (will) fit great, THANKS!

[chris_seven]

Gary, Thanks for your comments.

We initially produced this panel to remove the sunroof for Gravel Rally Cars which are driven at speed on really poor surfaces in English and Welsh Forests and to avoid the cost/complexity of complete roof replacement.

Our experience of bond-in glassfibre panels was quite poor and they tended to show cracks and witness marks after only a couple of events.

We also didn't want a panel that could be pentrated when 'shown the trees'

We have fitted the spot weld in panels to a number of cars now and so far none have shown any cracking of filler or witness marks.

When spot welded correctly the 'tension' of the roof panel is virtually indistinguishable from a non-sun roof panel.

[vlocci]

I'll contribute my small data point after staring this thread way back when.

I eventually gutted my original sunroof, did some hammer and dolly work to the roof side flanges, and bonded the original sunroof panel in place.

My reasoning was pretty simple: I was afraid of warping the roof or sunroof panel with too much heat.

The bonded in panel worked perfectly, with very little bodywork required, and almost no filler. I'm very happy with the results, especially the increased headroom. I've only put a few hundred miles on the car before winter set in, but I have no reason to believe any cracking of the filler or witness marks will come back to haunt me.

With the pre-formed panel that you have, I would not hesitate to bond it in place. I expect this to be even easier than my re-use of the sunroof center panel and the end result should require very minimal filler.

Vin