Permanently Sealing the Sunroof

[max]

I've been working the past few weeks on camperizing my 89' Exceed and while I plan on posting a full writeup on the van at some point I figured I'd share a project I started on today I think could be interesting.
I plan on doing a lot of winter camping so decent insulation is key to my not freezing. Unfortunately, the huge and poorly placed sunroof, one of my favorite features of the van, takes up primo insulation/headroom real estate - a premium in my low roof model. My plan is to drop the assembly and figure out a low profile way to permanently affix the sunroof in place. So far I've pulled down the assembly, isolated the glass and it's mounting brackets and cut out a couple cardboard templates of brackets I'm going fab from sheet metal. From here, I'm going to model the brackets in Solidworks and send them off to get cut and bent while I figure out how I'm going to seal this thing.

 

[13mclean]

Oh man I'd totally buy that sunroof if you're replacing the whole thing. I have this custom tank hatch I'd throw in as a down payment! It seals well, but you can also unbolt one side and swing it open. I think it's cool, but would love a legit sunroof!

 

[Delicatessan]

Here's how one guy (GrowlerBear) put in something like [I think] you're shooting for.

 

[max]

View attachment 1613
Oh man I'd totally buy that sunroof if you're replacing the whole thing. I have this custom tank hatch I'd throw in as a down payment! It seals well, but you can also unbolt one side and swing it open. I think it's cool, but would love a legit sunroof!

I'm keeping the glass from the sunroof, but I don't have plans for the slider mechanism if anyone in South Florida wants it. You'd probably have some trouble getting it to seal properly with how the lip of the roof rolls over, but it's yours if you're close.

 

[Growlerbearnz]

While you have the sunroof off, find some rust-killing penetrating body wax and rustproof the sunroof support bows and frame, making sure you get the wax between the outer roof skin and the spotwelded frame. It's a rust trap, and by the time the rust peeks through it's all over. Here's what it looked like on my roof, and how I solved the problem.

As you'll see, I moved my sunroof forwards, but I did a whole heap more non-reversible modification. Ignoring the "cutting off the entire roof and moving the glass forwards" bit, I basically folded/hammered the edges of the sunroof aperture up to form a lip, removed the metal frame from the sunroof glass, and bonded the sunroof glass to the lip using windscreen sealant. Then filled the gap between glass and roof with more sealant.

Since you're bolting your glass in place using those nifty brackets, you could probably just remove the existing seal, put some duct tape along the underside of the gap to catch the sealant, and fill the gap with sealant from above. If you use masking tape on the glass and body to define where the edges of your sealant line will be, you can force the sealant hard into the gap and not have to worry about where the excess sealant ends up: it'll end up on the masking tape. Then peel the masking tape off while the sealant is still wet and end up with tidy, even edges. Like so:

 

[max]

While you have the sunroof off, find some rust-killing penetrating body wax and rustproof the sunroof support bows and frame, making sure you get the wax between the outer roof skin and the spotwelded frame. It's a rust trap, and by the time the rust peeks through it's all over. Here's what it looked like on my roof, and how I solved the problem.

As you'll see, I moved my sunroof forwards, but I did a whole heap more non-reversible modification. Ignoring the "cutting off the entire roof and moving the glass forwards" bit, I basically folded/hammered the edges of the sunroof aperture up to form a lip, removed the metal frame from the sunroof glass, and bonded the sunroof glass to the lip using windscreen sealant. Then filled the gap between glass and roof with more sealant (Sikaflex 295UV, a UV stable marine urethane).

Since you're bolting your glass in place using those nifty brackets, you could probably just remove the existing seal, put some duct tape along the underside of the gap to catch the sealant, and fill the gap with sealant from above. If you use masking tape on the glass and body to define where the edges of your sealant line will be, you can force the sealant hard into the gap and not have to worry about where the excess sealant ends up: it'll end up on the masking tape. Then peel the masking tape off while the sealant is still wet and end up with tidy, even edges. Like so:

View attachment 1615

Your original sunroof post still gives me rusty nightmares so I was considering a good coating of POR15, but a wax sounds much better. Lucky for me there’s no rust at all on the flange now so I worry something like POR could encapsulate any future rust between the metal and existing paint.

From what I remember, you mentioned another Sika product on the original roof replacement post. Was that just an adhesive? Should I be okay using the 295UV only? I really like the tape idea, I’ll definitely be using that.

 

[max]

Also, I’ll be posting photos of the bracket when I get back to my computer. I sent it of to be waterjet earlier today. The original design for a 1/8” piece of stainless steel with bends to match up with the existing brackets had to go out the window when I got quotes back on bending. Now it’s a less elegant hunk of 1/4”.

 

[Growlerbearnz]

POR15 is great on areas you can see, but I wouldn't trust it not to encapsulate rust either.

From what I remember, you mentioned another Sika product on the original roof replacement post. Was that just an adhesive? Should I be okay using the 295UV only? I really like the tape idea, I’ll definitely be using that.

That was Sika Tack-drive, a windscreen adhesive. It was to bond the glass to the flanges I made. I couldn't use it to fill the final cosmetic/sealing gap between the glass and the panel because it's not UV stable- It's only suitable for use where it's shaded behind the black edge ("frit"). If your brackets mount the glass solidly, the 295UV's really only there to seal the gap. 295UV cures a bit softer/rubberier than regular urethanes, so I wouldn't rely on it to support the glass all on its own.

295UV does not bond to glass. Ugh. Use black silicone sealant to make the join between glass and bodywork watertight.

 

[Nenw]

@max I am getting a bunch of leaking and was searching around for the forums for the exits of the drain tubes but haven't had luck finding them.

I can't trust to open the sunroof right now to feed wire in from the top to unclog. Everyone says this has to be done with the sunroof open.
The motor is messed and I can't risk it not shutting this time of year in the PNW. I figure I can come from below to clear the lines.
Do you know where the drains exit at the exterior?

It looks like one might come out the bottom of the B-pillar somewhere, and the rear one?

 

[Growlerbearnz]

The drains exit just behind the mud flaps, both front and rear- B-pillar and D-pillar. Little rubber hoses sticking out with their own rubber grommets. You can't miss them.

You can manually close the sunroof if it sticks open- on the sunroof switch panel, pop the black plastic trim piece off (it just unclips from the main panel). This reveals a hole in the panel, with a hex/allen socket behind. Use a hex key to turn the socket and you'll be winding the window closed. If you have the original toolkit there should be a hex key in it.

The sunroof front drains are the easiest to clean. The rear drains are way back in the mechanism, you really have to pull remove the sunroof to get to those. Check that the drains aren't rusted- that's a pain to fix.

 

[crawdaddy]

Also, I’ll be posting photos of the bracket when I get back to my computer. I sent it of to be waterjet earlier today. The original design for a 1/8” piece of stainless steel with bends to match up with the existing brackets had to go out the window when I got quotes back on bending. Now it’s a less elegant hunk of 1/4”.

Apparently I'm two years late, but I'm having the same leaking issue. Just dropped the sunroof to seal up the glass on it's own. Was this project ever finished up? Brainstorming a similar bracket