What Roof Sealant to use?

[bleudanube]

All right, need some help gentlemen...

just got my DS roof back from the paint shop and it will soon be time to reinstall it. What mastic / Sikkaflex #? / silicon have you used for it? Sikkaflex 225 appears to be for windscreens and the like, but not sure it is the right material.

thanks in advance.

Sven

 

[GreenBlood]

All right, need some help gentlemen...

just got my DS roof back from the paint shop and it will soon be time to reinstall it. What mastic / Sikkaflex #? / silicon have you used for it? Sikkaflex 225 appears to be for windscreens and the like, but not sure it is the right material.

thanks in advance.

Sven

michaelr did a fair bit of research and determined Sikaflex 291 to be suitable, it is available in black and white - if there is any risk of getting any on your freshly painted roof lining the white could be a good option.

Cheers
Chris

 

[David S]

If you intend to fit the headlining to the roof while removed, you could carefully stick strips of plastic to the roof lining near the bolt points with masking tape to stop any grubby fingers inadvertently touching the trim. Test it first on an offcut in case the masking tape pulls the threads. It can be a particularly messy job with sealant oozing everywhere.

If you have fitted new mountings to the panel and not yet done a trial fit, do it before using any sealant. Especially check that the turned up edge won't be visible or push out the sealing strip when the roof is fitted. Very few of the repro parts need no adjustment.

Look at the pictures in the body manual as it tells you what the profile of the original mastic should be when fitted and also that you need to leave a gap around the edge to accept the finishing rubber strip. If you don't leave that gap in the sealant next to the edge of the rail, you will never be able to fit the side strips properly.

Have rags and a bottle of white spirit handy for cleanup of excess sealant.

 

[GreenBlood]

Further to the above, some pics that show clearly what David is describing. . .

Note this is for the later bonded roof but not dissimilar to the bolt down roof.

The original bonded roof used a heat set mastic, no longer available, it sat in the cant rail connected to 12 volts to soften whilst the roof was positioned and pulled down with straps. Hence the requirement for a slow setting polyurethane to achieve the same.

From the 814, a section drawing of the construction layers. . .

This is a nice cross section in real life, clearly showing where and how the rubber profiles attach.

The repro brackets do need a little massaging as David points out, here I have used a small vice to clamp after using an epoxy to fix to the roof edge.

If you get the bracket to sit hard up to the roof it has very little profile and the outer rubber finishing strip will sit over without bulging.

It has been suggested when fitting the outer rubber finishing strip that you cut the lower section down to about 5mm to assist with the fitting of the stainless edge trim. If you look at the section drawing above this would be what you are aiming for.

It also helps to attach this rubber with a thin double sided tape before fitting the stainless trim, makes handling easier and allows you to apply a little stretch as you run it around the front corners - this will pull the profile down against the roof which otherwise would want to buckle.

This is the rubber before trimming back, you can see that you could have a fight on your hands if the rubber is not trimmed. . .

Michael Berry supplied me with a roof rubber supplied as an incorrect part for a bolt on roof, here you can see the two different profiles - I haven't decided if I'll be using this or just seal with polyurethane, you can not use a bolt on roof profile on a bonded roof so thought it worth showing the different profiles here. The one in my hand is for the bolt on roof and has a distinct curve in profile.

Not much of this detail is of help to Sven but hopefully useful to others. . . :wink2:

 

[bleudanube]

Mine is the bolt on type. Got a new seal that looks like the left one you are holding Chris (will double check tomorrow ....).

Based on that it appears that I first need to glue the seal to the roof, then clip the stainless rail profiles back onto the outside, then put Sikkaflex into the lower groove of the rail (I vaguely remember that the old mastic was about level with the top of the groove, before I cleaned it all up... Does that sound about right ?). Then lift the roof on and push into the mastic, put all the bolts in and tighten the bugger. All without having crap go everywhere...

What can go wrong... :joker:

Sven

 

[GreenBlood]

Mine is the bolt on type. Got a new seal that looks like the left one you are holding Chris (will double check tomorrow ....).

Based on that it appears that I first need to glue the seal to the roof, then clip the stainless rail profiles back onto the outside, then put Sikkaflex into the lower groove of the rail (I vaguely remember that the old mastic was about level with the top of the groove, before I cleaned it all up... Does that sound about right ?). Then lift the roof on and push into the mastic, put all the bolts in and tighten the bugger. All without having crap go everywhere...

What can go wrong... :joker:

Sven

Sven,
You will have some help yeah, did I read that Mark is going to lend a hand?

Bolt on roof is easier as long as you are organised. . .

The seal will have a silicon release agent from manufacture - use a white spirit/Prepsol to clean it off you'll get a safer bond.

Once you have everything ready and have done your trial fit, run a bead of sika into the seal and fit to the roof, run a heavier bead in the the outer edge of the cant rail, carefully lift the roof with seal into place. Drop the front down first and push toward the front as you bring the rear down. Start bolting from the inside, front centre first and move to the rear.

Use heaps of white spirit/prepsol to clean the oozed sika around the roof edge, make sure you leave a dip between the cant rail edge and the new seal to allow for the stainless trim. Once you have cleaned, allow to set before now fitting the stainless trim. The two side pieces first, then front, then rear.

You will have established a position for the side stainless and marked, before commencing the roof fitting. Don't forget the seal that runs over the rear hoop needs to be in place before fitting the roof and the rear roof stainless is easier to fit prior to fitting the roof.

Cheers
Chris

 

[Lasya]

What can go wrong... :joker:

Sven[/QUOTE]

Bahaha!

 

[DoubleChevron]

Are you guys sure you want to use sikaflex ............................ What happens if you want to remove that roof in the future ...

seeya,
shane L.

 

[GreenBlood]

Are you guys sure you want to use sikaflex ............................ What happens if you want to remove that roof in the future ...

seeya,
shane L.

If the job is done properly and the roof seals - why would you want to remove it?

Many of the problems we encounter today are the result of poor preparation and products available at the time. The bonded roof can be re-painted in situ by lifting the outer rubber dress seal. . . I really can't see any reason to lift a roof once sealed, but if needed you would simply run a piano wire around the perimeter

Cheers
Chris

 

[bleudanube]

Thanks Chris (again - time for a beer at my place I think...?!)


You will have some help yeah, did I read that Mark is going to lend a hand? Yes...and he even volunteered you at the same time ������... I am sure the neighbours will be happy to assist, too...

The seal will have a silicon release agent from manufacture - use a white spirit/Prepsol to clean it off you'll get a safer bond. Will do!

allow to set before now fitting the stainless trim. The two side pieces first, then front, then rear. I read somewhere it would be better to fit the two side trim pieces before putting the roof on to ensure they fit properly..??!! It shouldn't interfere with the roof rubber / Sikka I would think?

You will have established a position for the side stainless and marked, before commencing the roof fitting. Don't forget the seal that runs over the rear hoop needs to be in place before fitting the roof. Done, already in place!

and the rear roof stainless is easier to fit prior to fitting the roof. Good idea, will do!

Cheers. Sven

 

[GreenBlood]

I read somewhere it would be better to fit the two side trim pieces before putting the roof on to ensure they fit properly..??!! It shouldn't interfere with the roof rubber / Sikka I would think?

Cheers. Sven

The only downside I can think of would be if you need to remove the two side stainless at some point? Sika 291 is not only a sealant, it is an adhesive and a bloody strong one at that. I could see someone destroying the stainless if it needed to be removed. . .

. . .and of course that approach would not be possible with a bonded roof (not that yours is).

Let me know when, if I'm available I'd be happy to shout instructions

Cheers
Chris

 

[bleudanube]

Thought it might pay to ring Sika and ask what they would recommend... And he said: 252 as it has some remaining elasticity and the 291 is too strong as a marine product... Available at Bunnings... Easy.

so I might go with their advice and have a crack this weekend... Will keep you posted...

 

[ScotFrog]

Thanks Chris (again - time for a beer at my place I think...?!)


You will have some help yeah, did I read that Mark is going to lend a hand? Yes...and he even volunteered you at the same time ... I am sure the neighbours will be happy to assist, too...

The seal will have a silicon release agent from manufacture - use a white spirit/Prepsol to clean it off you'll get a safer bond. Will do!

allow to set before now fitting the stainless trim. The two side pieces first, then front, then rear. I read somewhere it would be better to fit the two side trim pieces before putting the roof on to ensure they fit properly..??!! It shouldn't interfere with the roof rubber / Sikka I would think?

You will have established a position for the side stainless and marked, before commencing the roof fitting. Don't forget the seal that runs over the rear hoop needs to be in place before fitting the roof. Done, already in place!

and the rear roof stainless is easier to fit prior to fitting the roof. Good idea, will do!

Cheers. Sven

I'm now contemplating a move to Brisbane.

SF

 

[bleudanube]

Always welcome! I am sure I can find a second bottle of beer for you....

 

[SteveS]

Hi Guys ,

Looking at the cutaway photo posted by Greenblood it looks like 2 seals are used when fitting the 17 bolt roof, or am I wrong?
I note that the main seal is available from Franzose . I am planning to take my roof off tomorrow - Wish i could find a youTube of a roof being fitted.

Kindly advise re the rubber gents.

 

[Budge]

The cutaway photo is of a later, bonded roof. It doesn't have 17 bolts. On the later roofs, the 'main' seal is formed by a glue that bonds the roof down. So (if it's for a later type of roof), the strip that Franzose sell will only be the decorative strip. The photo shows the bed of dried black glue, plus the decorative sealing strip.

EDIT: the black rubber stuff at the bottom is the rubber seal around the window glass - nothing to do with the roof.

Earlier cars had a bolt on roof with a substantial sealing strip. The 17 bolts grip that strip down and that is what makes the seal.

 

[SteveS]

Thanks Budge - this is the seal i meant for 17 bolt roof. https://www.franzose.de/en/Citroen-DS-11CV-HY/DS/Karosserieabdichtungen/ANR35005/ - So is this all I would need mate? Im quite the noob at this haha.

 

[forumnoreason]

a mate to help you put the roof on would be a good idea mate!

 

[DoubleChevron]

If its a bolt on roof.... See if you can find a non-hardening mastic to use. I'm still wary of using sikaflex on anything .... What if the damn thing still leaks, but you can't get the roof back off to see why (just look at every caravan made in Australia if you want examples of seals failing).

I'd use mastic, but far to much of it, "everywhere". The idea is it must "squeeze" out as the roof is assembled. The hydraulic pressure created by the "squeeze out" will remove any and all air bubbles and force sealent into every crevice. It will also make one hell of a mess! This is how I assemble caravans for a leak free seal.

seeya,
Shane L.

 

[bleudanube]

It has been a while since I installed the roof on my previous DS, but with two helpers it wasn’t difficult after all. The Sikaflex 252 in white worked well and never leaked. A fair bit squeezed out and needed to be cleaned up, but gel time was longer than I thought, so I didn’t have to rush after all tightening all the bolts.

i also installed the side trim pieces before installing the roof as they clip over the rail. Not sure that’s still possible once the roof is glued in and tightened properly!

here some photos that may help





Sven