Sikoflex 295 UV

[RoaminRog]

Many Motorhomes have a window above the cab area. Some open and some are bonded. On our Autotrail Miami, it is bonded and I have just discovered that the bonding around 45% of the window has failed - two weeks before we are due to leave on our Italian gadabout.
It’s no secret that before we owned the bus, it spent most of its life either in Spain or travelling to and from Spain, and I am quite prepared to blame the excess of UV rays for the breakdown of adhesion.
I have ordered a tube of black Sikoflex 295 UV, intending to remove the window completely, clean up, and rebed the plastic window.
Has anybody attempted this before and got any tips to make the job straightforward please.

 

[The laird]

Roger I would go to auto windscreens or a screen specialist and get the to seal it with glass bond ? Just a thought as I done the hymer for the exact same reason
think i was about £30

 

[TJBi]

Many Motorhomes have a window above the cab area. Some open and some are bonded. On our Autotrail Miami, it is bonded and I have just discovered that the bonding around 45% of the window has failed - two weeks before we are due to leave on our Italian gadabout.
It’s no secret that before we owned the bus, it spent most of its life either in Spain or travelling to and from Spain, and I am quite prepared to blame the excess of UV rays for the breakdown of adhesion.
I have ordered a tube of black Sikoflex 295 UV, intending to remove the window completely, clean up, and rebed the plastic window.
Has anybody attempted this before and got any tips to make the job straightforward please.

Never attempted myself, but there was a recall some years ago on large numbers of Hobby motorhomes due to this issue. The action was refitting by dealers where this was possible, otherwise refitting by the coach windscreen units of National Windscreens. I managed to get the latter.

 

[r4dent]

A few years back I drove to Spain in the car. The internal rear view mirror became un boneded from the screen.

I tried many different adhesives but nothing worked.

In desperation, I contacted Nationwide Windscreens.

They came to the house; cleaned up the remnants of my failures; reattached the mirror.
Total Bill - £25, less than I'd spend trying to fix it myself.

I think this is an occasion when you get the professionals involved.
You don't want to end up with a DIY job that lets a little water in, do you!

 

[TJBi]

<snip>

I think this is an occasion when you get the professionals involved.
You don't want to end up with a DIY job that lets a little water in, do you!

Worse than a bit of water getting in is the entire rooflight flying off when you are travelling at high speed. One or two of those was the reason for the recall.

 

[RoaminRog]

Thank you all for your advice, but couldn’t resist ‘fiddling’ with it. I couldn’t get over the fact that we could have set off for three months with it virtually falling off!
This afternoon I lifted the loose section with a wallpaper scraper and the whole rear edge just popped up.
Bit more fiddling and it was free.
Spent the rest of the afternoon scraping the old adhesive out of the frame and making good for when the Sikoflex 295UV arrives, probably tomorrow.
Basically it will be the same as setting a skylight into a bed of Sika, and then leaving it a couple of weeks to cure. I have ordered a couple of suction handles, so that the screen can be gently lowered into place and left alone.
Sikoflex 295 UV is specially designed to cope with the problems caused by excessive sunlight, so hopefully will be able to ensure a bond for the rest of the vehicle lifetime.
Fingers crossed!

 

[Millie Master]

Thank you all for your advice, but couldn’t resist ‘fiddling’ with it. I couldn’t get over the fact that we could have set off for three months with it virtually falling off!
This afternoon I lifted the loose section with a wallpaper scraper and the whole rear edge just popped up.
Bit more fiddling and it was free.
Spent the rest of the afternoon scraping the old adhesive out of the frame and making good for when the Sikoflex 295UV arrives, probably tomorrow.
Basically it will be the same as setting a skylight into a bed of Sika, and then leaving it a couple of weeks to cure. I have ordered a couple of suction handles, so that the screen can be gently lowered into place and left alone.
Sikoflex 295 UV is specially designed to cope with the problems caused by excessive sunlight, so hopefully will be able to ensure a bond for the rest of the vehicle lifetime.
Fingers crossed!

Apart from scraping off all the old adhesive make absolutely certain that you the entire area is scrupulously clean as otherwise the Sika or indeed any other adhesive won't bond thoroughly.

There also lies the MAJOR problem that currently in the UK it is too cold for Sikaflex to be used whereas the mastic type rubberised solutions used by the likes of the windscreen fitters should be OK, so currently Sika and all similar adhesives might not be of any use at the moment!

 

[Martin P]

I did ours 3 years ago. I as surprised by how much sealant I needed. Although there is a steel box section supporting the grp moulding at the top of the aperture it still bows inward a little. When I removed it I discovered a couple of spacers embedded in the old sealant. I think these are to ensure a minimum thickness of sealant when fitting. I needed about 8mm thickness at the maximum point. Also I got it all really clean and gave it a good rub with cellulose thinners. I dry fitted it then masked around with masking tape and masked the top edge of the rooflight. When it was fitted i could tool around it.
It has held up fine so far

 

[Thistle]

@RoaminRog
As mentioned above now is not the right time for sealants to cure, I think most quote a minimum constant temp of 12c to cure correctly. I assume the windscreen companies use something that can cure in more adverse conditions so might be worth checking.

 

[TonyEmm]

Several years ago I replaced all my yachts leaking windows (which were aluminium framed, glued and screwed) with flush 8mm thick acrylic, using Sikaflex 295.
it’s not a simple job! After removing the old windows and thoroughly cleaning up, I then needed to primer both the GRP and the acrylic with different primers. Only when they have dried can you start with 295. I also needed to use thin spacers (like tile spacers) to ensure there was a continuous flexible bed between both surfaces. As the yachts hull was curved, temporary bracing was needed across all surfaces to ensure it didn’t slip and/or detach.

Well worth doing right though! It’s still good….

 

[Fisherman]

Several years ago I replaced all my yachts leaking windows (which were aluminium framed, glued and screwed) with flush 8mm thick acrylic, using Sikaflex 295.
it’s not a simple job! After removing the old windows and thoroughly cleaning up, I then needed to primer both the GRP and the acrylic with different primers. Only when they have dried can you start with 295. I also needed to use thin spacers (like tile spacers) to ensure there was a continuous flexible bed between both surfaces. As the yachts hull was curved, temporary bracing was needed across all surfaces to ensure it didn’t slip and/or detach.

Well worth doing right though! It’s still good….

Would you use the primer when fitting solar panels to motorhome roofs.

 

[Millie Master]

Several years ago I replaced all my yachts leaking windows (which were aluminium framed, glued and screwed) with flush 8mm thick acrylic, using Sikaflex 295.
it’s not a simple job! After removing the old windows and thoroughly cleaning up, I then needed to primer both the GRP and the acrylic with different primers. Only when they have dried can you start with 295. I also needed to use thin spacers (like tile spacers) to ensure there was a continuous flexible bed between both surfaces. As the yachts hull was curved, temporary bracing was needed across all surfaces to ensure it didn’t slip and/or detach.

Well worth doing right though! It’s still good….

As for the spacing for the Sika (or similar), I believe the minimum thickness is 2mm

 

[Martin P]

For the record I used Sika 522.

 

[Martin P]

Probably if you did the job first thing in the morning and then put a duvet over the top then put the van heating on temperature would not be an issue

 

[Nabsim]

Check the data sheet for the specific Sika, the stuff I used said 5 degrees C, if colder than that it was just extended time before moving/disturbing. There probably is a lower limit stated where it says don’t use but see what it says

 

[Martin P]

Then you could get the duvet back on the bed in the evening before wifey notices

 

[RoaminRog]

Sikoflex 295 UV is more resilient to UV rays than 522 and hopefully won’t breakdown chemically.
I’ve decided to copy the Burstner recall method, which involved not only adhesive but also half a dozen plastic nuts and bolts to hold everything in place. Belt and braces.
I will also use an old duvet cover and let the heating run for a day, so feeling confident about the outcome now.

 

[Martin P]

Have you fixed it yet?

 

[Pauljenny]

Where are you, BTW..?

 

[RoaminRog]

No I haven’t fixed it yet, hoping to spend today doing it.
We are still at home at the moment Paul, Chunnel booked for next Monday.
I wish the weather was warmer.