Autosleeper Pop-top Roof Bonding Fail. Why?

[bmouthboyo]

So 3 years ago just before I moved abroad for work I hastily bonded my Autosleeper Poptop Roof back down to my van using Sikaflex.

I cleaned up the areas it would adhere to and decided to bond not only the sides but the rear and front instead if using the new rubber seals I sourced as I was told the bonding chemicals now are much stronger and I did not want a repeat of the water ingress and damage going the original method Autosleeper took of screwing the pop top and covering with a rubber seal. I applied the Sikaflex liberally to the areas I marked around where the roof would be touching the van and then ratchet strapped the roof down to apply some pressure, leaving it like this for a year.

This was only really a temporary measure as I am looking to fully prep the pop top for respraying in 2017 when I return to the UK.

The van has been covered for 3 years with a breathable cover, however upon checking the van this July when I visited the UK I noticed the bonding does not look strong and is showing cracks and movement.

Video of the movement in the bonding:
https://www.youtube.com/watch?v=1FXpJ6zrhsg" onclick="window.open(this.href);return false;





I am now thinking it might be best to fully remove the pop top again for ease of prep and respray, but am now worried what went wrong originally and how I can best secure it down next time with no possibility of leaks or movement.

I vaguely remember when I originally removed the poptop years ago that it had a kind of plastic right angled strip running the length of the gutter, but cannot work out A) What was the purpose of it, and B) How I could secure the poptop to both this angled plastic and to the van.

This is what it originally had:







Can anyone offer any advice? Did I use the wrong bonding agent (Sikaflex)? Did I not apply even pressure? Did I not key / clean the surface appropriately? Can I just add more sikaflex after to patch the holes/gaps that might appear? Should I not bond the front and rear and go with the rubber seal / screw to roof method again?

Cheers in advance for any help

[Oldiebut goodie]

I clean up areas like that with acetone before using the adhesive - what did you use? (white spirit is no good as it leaves the surface slightly greasy)

[bmouthboyo]

I clean up areas like that with acetone before using the adhesive - what did you use? (white spirit is no good as it leaves the surface slightly greasy)

As I was rushing I think just a panel cleaner but I imagine I did not do a thorough job. Is it OK to paint the binding area? Must it be keyed? Sizable the best stuff?

How did you clamp it down?

[Oldiebut goodie]

Mine was on a high top but just used its own weight. I would have thought that if you clamp it down too much you would squeeze all of it out! I wouldn't paint just before applying though.

[nicq]

Mine was on a high top but just used its own weight. I would have thought that if you clamp it down too much you would squeeze all of it out! I wouldn't paint just before applying though.

Doing it under its own weight fills the natural gaps. If you clamp the sealant is under tension when released the clamp.

[bmouthboyo]

With its own weight it didn't seem to fit quite right at the rear if I remember. I guess it's going to have to be a take it back off job? No way to rectify?

[bmouthboyo]

OK back to this in a few weeks when I return to the UK.

Question is should I remove whole roof and start again or can you apply sealant over old sealant?

[Cableguy]

I spoke to a chap at Sika about this and he told me that I must use the Sika cleaner and primer to guarantee a proper bond.
Syncropatrick followed these guidelines and successfully attached his Dehler roof.

[Mocki]

You applied too much pressure I would say , ending up with too thin an layer
When I put a autosleeper hitop roof on my OHs camper I didn't strap it down , and it's all good some 4 years later
I only cleaned the surfaces with thinners and any sikaflex that did squeeze out I cut off with a knife after it had cured

[bmouthboyo]

Sorry to drag this back up but it is now getting to the weather I can finally see to this.

2 questions:

1) Can you create a goot seal / bong if you remove a small section of existing sikaflex and apply new? i.e. does sikaflex adhere to an existing application?

2) I have sourced some autosleeper poptop rubber seal for the front above the windscreen to add. Is there a product you can use to both help seal the join to the roof and the rubber? (Originally Autosleeper screw through it!)