Fixing Stuff To The Roof with Sikaflex

[cunning]

cunning

See my Post in thread 'Large solar panel mounting'

https://www.motorhomefun.co.uk/forum/threads/large-solar-panel-mounting.238904/post-4451102

Thanks for highlighting this thread....
Sikaflex 552 is now 554. I haven't been able to find a UK retailer for it :-(
My skylight will, to a large extent, act as a spoiler.

 

[cunning]

Sikaflex is merely a collective brand nme so the actual type varies, other makes also exist. Hand operated skeleton gun type application is very hard work on the hands as extrusion from the tube is slow and tough.

On a PVC roof isn't much more than a 1mm profiled sheet of standard steel paint sprayed. Pilot hole of very small drill will make any self tapper much much easier to fit with precision, in turn needing a centre punch start.

Thanks for this.... useful information.

 

[Soots]

Thanks for highlighting this thread....
Sikaflex 552 is now 554. I haven't been able to find a UK retailer for it :-(
My skylight will, to a large extent, act as a spoiler.

Sika flex-554 Versatile, Weather-Resistant, Primerless Mounting Adhesive (New Version of Sikaflex-552 and Sikaflex 252i) 300 ml White https://amzn.eu/d/fh6F8vF

 

[cunning]

Sika flex-554 Versatile, Weather-Resistant, Primerless Mounting Adhesive (New Version of Sikaflex-552 and Sikaflex 252i) 300 ml White https://amzn.eu/d/fh6F8vF

This is a German retailer charging £20 for delivery.

I am now considering 252 (as used by the Op). It is being sold by UK retailers as "the recommended choice for installing solar panels to the roof of a caravan or motorhome." Having looked at the data sheets of 522, 554 and 252, I can see that 252 is very similar to 554. Main difference being application temperature and tensile strength compared as 3MPa (252) and 3.5MPa (554). 252 has a longer skin time which should make it easier to apply.

 

[cunning]

I took one look at supplied screws with brackets, and went to Screw fix for alternatives.

4 Z brackets may be OK but fixing area onto the van roof is small and given vehicle speed isn't enough? Dunno.

Yes it was Scanstrut cable entry. Note any connectors on cables won't pass through the glands and have to be cut off. But it's a neat bit of kit designed for marine environments so motorhome should be easy for them.

I have been mulling over the small footprint of the Z brackets but I can't find another bracket that works for me. My plan is to use 8 x Z brackets (as per Renogy advice on a 200 watt panel) and then add some extra bracing (against upward movement) using 4 x angle brackets with a larger footprint. I'll glue to roof and probably use pop rivets into panel (I can drill them out if I need to remove the panel). The forward sky light mitigates risk of airflow lifting the panel from front! In fact I suspect the airflow will hold the panel in place at high speed!

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[Sandancers]

This is a German retailer charging £20 for delivery.

I am now considering 252 (as used by the Op). It is being sold by UK retailers as "the recommended choice for installing solar panels to the roof of a caravan or motorhome." Having looked at the data sheets of 522, 554 and 252, I can see that 252 is very similar to 554. Main difference being application temperature and tensile strength compared as 3MPa (252) and 3.5MPa (554). 252 has a longer skin time which should make it easier to apply.

Has sikaflex not got a technical department you could talk to?

 

[cunning]

Has sikaflex not got a technical department you could talk to?

There is a Sika web page to ask support questions but no response so far. Can't find a phone contact. I have purchased 252 and just waiting for the extra 4x Z brackets (Renogen recommend 8 brackets for a 200 watt panel). I am a bit worried about the Ops comment on difficulty with skeleton gun. I do have a heavy duty gun so hope that helps!

 

[cunning]

I took one look at supplied screws with brackets, and went to Screw fix for alternatives.

4 Z brackets may be OK but fixing area onto the van roof is small and given vehicle speed isn't enough? Dunno.

Yes it was Scanstrut cable entry. Note any connectors on cables won't pass through the glands and have to be cut off. But it's a neat bit of kit designed for marine environments so motorhome should be easy for them.

Hi KF, I received the Scanstrut today. Will be a few days before I fit. Need to get the panel installed first and waiting on the extra Z brackets.

Did you screw down the Scanstrut or use Sikaflex and discard the sticky pad?

TIA, James.

 

[Kannon Fodda]

Scanstrut fitted exactly as their instructions. Used their pad.

Extrusion of Sikaflex was achieved with Skeleton gun, just very tough to do by hand.

 

[Northernraider]

Everything on my van is fixed with locking nuts and bolts. Several on each panel. I don't want to be the cause of something like this.

Caravan Solar Panel Tragedy: Coroner Delivers Findings

Findings of a coronial inquest in Tasmania serve as a reminder to owners of caravans with solar panels to ensure they are properly secured.

www.solarquotes.com.au

Unless you plan to tow a trailer with solar panels lying in the back of it unsecured then its unlikely this Australian story that's always rolled out will happen . These panels were never fitted to a vehicle they were lying in an open trailer.

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[cunning]

Unless you plan to tow a trailer with solar panels lying in the back of it unsecured then its unlikely this Australian story that's always rolled out will happen . These panels were never fitted to a vehicle they were lying in an open trailer. View attachment 655715

That is reassuring!

 

[cunning]

Scanstrut fitted exactly as their instructions. Used their pad.

Extrusion of Sikaflex was achieved with Skeleton gun, just very tough to do by hand.

Instructions say to use a bolt on steel... just saying assume you used the screws?

 

[Kannon Fodda]

Yep used the screws, with tiny pilot hole drilled. Scanstrut itself has no load so bolting is OTT

 

[cunning]

Yep used the screws, with tiny pilot hole drilled. Scanstrut itself has no load so bolting is OTT

I'll do the same which means I can fix the Scanstrut and run cable, while waiting for the extra brackets! Measure twice, cut once!

 

[Revolvor]

I am a bit worried about the Ops comment on difficulty with skeleton gun. I do have a heavy duty gun so hope that helps!

I put the tube of SIKA in a bucket of warm water for a while before I used it. I had no problem with a normal sealant gun.
Make sure that you use spacers to maintain the minimum sealant thickness.

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[dhall26]

I keep seeing this reference to Fiat paint problems. I am now on my 3rd Ducato over 16 years and have had no problems.
BUT what we should remember is that these are not Fiat vehicles they are Sevel built and come off the same production line as the Boxers and Relays.
I don't know but it could be that it's just a couple of Fiat colour choices that Sevel have had paint problems with.

 

[Garry - June]

Having come from a boating background and the harsh environment at sea i stopped using Sikaflex when i was having to constantly re-bond items after a few years..., i was put on to a product "Tec7" adhesive sealant by a boat yard and have used that ever since to bond items to the roof of my van... excellent stuff....and for my panels i use the Aero mounts...gives a much larger footprint to securely bond to the roof..

 

[cunning]

Having come from a boating background and the harsh environment at sea i stopped using Sikaflex when i was having to constantly re-bond items after a few years..., i was put on to a product "Tec7" adhesive sealant by a boat yard and have used that ever since to bond items to the roof of my van... excellent stuff....and for my panels i use the Aero mounts...gives a much larger footprint to securely bond to the roof..

The Op used Aero mounts. I did consider them but they don't suit my panel and orientation (1500 x 700 with the 700 crossing ribs). I will use 8 x Renogy Z brackets (bonded and screwed) and re-inforce with some 2"x3" angle.

 

[Phoenix2023]

So far it seems there is no consistency as to what version of Sikaflex to be used, I'm not even sure whether they are long term external stable. I suspect I'm going to be poring over a lot of data sheets in the next couple of days.

Seems there is widespread paranoia that the Fiat paint won't be a good bond. Interesting the factory fitted 100W panel seems only to be stuck down without further mechanical fixings. I was hoping to avoid self tapping screws and stuff so as to minimise physical penetrations through the metal roof. Issue will then be if the Sikaflex I use is truly waterproof to create that long term seal, or if it is really just an adhesive.

The hold off bracket for the aerial is metal. Instructions show that being bedded to the roof with the adhesive and four small cross headed self tapping screws to each corner. Separately I'll need a cable entry housing. Will try and fit all of these on the top, rather than bottom ribs so they have less risk of sitting in any pooling water.

Cable routing in the van will be a separate issue. I'm aiming the aerial will be over the microwave housing (rarely used) for least disturbance to visible areas in the van. If I do change the solar, that will use existing cable routes which are over the shower room area. Even so I've somehow got to get other 12V power round to the microwave area to do the WiFi router. Nothing is simple and given I once vowed not to do anything to my van so it would remain pristine, free of DIY ....

Im sure I read somewhere that Sika are very helpful, if you tell them the materials you want to bond and where, they will advise which sika to use and whether they recommend additional fixing, worth a try for peace of mind….

 

[cunning]

Im sure I read somewhere that Sika are very helpful, if you tell them the materials you want to bond and where, they will advise which sika to use and whether they recommend additional fixing, worth a try for peace of mind….

I raised a case, no response so far. Unless I here soon, my decision is made,

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[G14HOM]

So, I'm about to embark on some modifications, initially adding a WiFi aerial on a hold off bracket, but also contemplating a bit more solar.

I have a Ducato based PVC. So it's a ribbed type painted metal roof no doubt with some form of insulation under the metalwork and then the internal ceiling linings. I don't want to be pulling the ceilings apart to try and find methods of mechanical fixings through the metalwork. It's going to be challenging enough just to find a suitable small route for any cables above perimeter cupboard areas.

Plenty of posts suggest I should be using Sikaflex 552, being some a structural adhesive. Is this also waterproof to seal around fittings where the cable then passes through, preventing corrosion on the edges of the hole cut?

How do I ensure an adequate bond? Is it sufficient to clean and degrease the paintwork, and with what, some sort of alcohol cleaner? Will the paint be adequately bonded to the metalwork, or do I have to somehow abrade the paint back to bare metal (with the inevitable risk of corrosion)?

It does appear the existing, manufacturer fitted, 100W solar panel on aluminium bracket rails, and other fittings are simply bonded to the roof without mechanical fixings, so hoping I can repeat that process.

Thanks

I have used Stix All from Toolstation to fix my brackets for my solar pannel to the roof of my MH ...I have also use stix all to reseal around the windows..you need a standard silicone gun to apply it ..I think its the best flexible water proof adhesive on the market.

 

[cunning]

Hi All,

My solar panel is sitting on the roof of my MH (relying on gravity only) and electrically connected and working. I am still waiting for the second set of Renogy brackets (probably due to industrial action at Royal Mail). Clearly I won't be driving my MH until panel is securely fixed!

In the meantime, I have been researching optimum fixing method for the Z brackets. Renogy recommend using M5 (imperial equivalent) well rivets as per images but with no adhesive. Well rivets will add protection against water ingress. My plan is to add a 1mm spacing washer between the well rivet collar and the bracket which will be 2.3mm on a bed of high tensile Sikaflex 252. (optimum Sikaflex depth is 2mm). I will use A4 stainless steel (marine grade) bolts and washers. I will also add some silicon grease between the rivet collar and van roof.

Inviting comments on this plan,

TIA James.

 

[cunning]

Update: the extra 4 Renogy brackets have still not arrived. Fun and games with their support! I ordered via their UK website and order in "awaiting shipment!" for ever! The only method to raise an issue is via a web form case which is directed to US support (who can't help). I traced their distribution centre to Leicester but, when I called, I had no joy. I have my money back by making a Paypal claim. Moral of story, if you order Renogy, their UK web support is non existent so go via Amazon or eBay instead. I actually had a support conversation with Renogy-UK through eBay (they are probably in China).

I reordered brackets via Amazon and expect in next day or (parcel tracking is active)....... I already used the well rivets (purchased from Spalding Fasteners) on 4 brackets and they are a nice tight fit (supplemented with silicon grease I am sure they are water tight). I have decided NOT to use Sikaflex for the solar panels. This will simplify a future panel swap and I can renew the well rivets over time.

I used the canister of Sikaflex that I purchased to fit an awning rail (supplemented with screws)!

The solar is working well....