Solar Panel Blown off Roof

[Louis]

Confusing

This thread is getting more confusing by the day
If stainless steel screws shouldn'd be used near Ali then what can be used ?
Or just adhesive ?

Confusing? Just wait for someone to wake up and mention that your rear suspension will also need uprating - then you’d be

 

[Figaro]

What's up with my rear suspension ?

 

[Louis]

What's up with my rear suspension ?

Nothing yet, be patient

 

[thebriars]

Just for info..

when I purchased my Alden AS 4 Auto Sat dish it was supplied with

Sika 252 + Sika Akitvator

There is no mechanical fixings or screws to hold it to the roof.. it has been on for over 3 years ..

this is the procedure, instructions by Alden


Sika 252 for fixing sat dish or solar panels.

1. Use a pencil to mark the place of the unit on the roof.
   
2. Sand the roof surface with sandpaper.
   
3. Clean each surface with a thinner.
   
4. Spread Sika-Aktivator on the sanded surface.
   Leave to dry for 15 to 20 minutes.
5. Glue generously the base of the unit with SikaFlex 252 then press slightly on the unit. Layer of glue: ± 3 mm.

1. To accelerate the polymerisation, spray a little water on the visible parts of the glue.

Leave to dry for 24 hours.

Can someone explain to me how you apply a layer of glue -3mm thick?

 

[Two on Tour]

This thread is getting more confusing by the day
If stainless steel screws shouldn'd be used near Ali then what can be used ?
Or just adhesive ?

Carbon Steel Screws

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[Louis]

Can someone explain to me how you apply a layer of glue -3mm thick?

Two pieces of 3mm ply each side of where you want the sikaflex, build up to their height then use straight edge from one piece of ply to other, and level it

 

[thebriars]

Two pieces of 3mm ply each side of where you want the sikaflex, build up to their height then use straight edge from one piece of ply to other, and level it

You've completely missed the point.

 

[tonyidle]

Carbon Steel Screws

Which will rust very rapidly. I understand the theory about stainless but galvanic activity will happen to any useful metal in contact with aluminium. I've had no problem with SS self-tapping screws or nuts & bolts in aluminium. I use chain lubricant spray on all my fasteners and they've removed cleanly after four or five years on the van with no visible corrosion.

 

[Two on Tour]

I understand the theory about stainless but galvanic activity will happen to any useful metal in contact with aluminium.

Black oxide treated screw have a good rust resistance which is why they are use to screw back plaster board where the gypsum will readerly corrode unprotected steel.

Galvanic corrosion can only occur if there is a conductive liquid between the two metals i.e. water. If the meeting of the metals remain dry then galvanic corrosion can not occur, so by using the chain lubricant spray you have formed a barrier to water ingress between the ally and stainless, so maybe thats the easy way forward for Funster now in crisis with their stainless fixings.

 

[Louis]

You've completely missed the point.

You asked a question and I answered with a simple solution? I’m sorry if it’s not upto your expectations- please disregard forthwith

Ahhh just read it again, can see now where you got the glue from? Still don’t see your point as it mentions sikaflex thereafter. Anyhow never mind I’ve had a hard day today

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[Lenny HB]

Having seen what happens on boats where ss fittings are used on aluminium without protection, no way would I use ss self tappers.
I do use ss nuts and bolts but I coat them with silicon grease before assembly.
An old yatchmans trick is a coating of Evostick.

 

[thebriars]

Point I asked was how do you put a layer of MINUS 3cm of Sikaflex? The instructions posted by Scotjimland said:

Glue generously the base of the unit with SikaFlex 252 then press slightly on the unit. Layer of glue: ± 3 mm.

 

[Louis]

Point I asked was how do you put a layer of MINUS 3cm of Sikaflex? The instructions posted by Scotjimland said:

Glue generously the base of the unit with SikaFlex 252 then press slightly on the unit. Layer of glue: ± 3 mm.

Ohhhh missed that point, thought you meant in the instructions mate

 

[thebriars]

Ohhhh missed that point, thought you meant in the instructions mate

I'll forgive you!

 

[Louis]

I'll forgive you!

Thankyou Thankyou Thankyou

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[thebriars]

Hey! Don't get too effusive, I'm likely to lose my Grumpy Old Git status.

 

[Revolvor]

I first posted this earlier this year ........

Just to add to the confusion, I contacted someone at the Technical Department at Sika, last week, as I am about to fit a second Solar Panel.

I fitted the first one two years ago, using Sika 512, following the recommendations for abrading, cleaning, applying Activator 205, and ensuring at least 3mm of adhesive.

After questioning whether my MH roof was "plastic", saying he had only come across metal ones, (!) he recommended Sika 552, which I had not come across.

His reasoning was that it had a better Tensile Strength - 3 N/mm² compared with 1.8 M/mm² for 512, but also that the surfaces to be bonded did not need to be as stringently cleaned/primed.

Also - Sikaflex®-552 is suitable for structural joints that will be subjected to dynamic stresses.

However, he confused me even more by finishing the conversation saying that despite what he had said, if I had used Sika 512 before, and the panel was still on, then if was probably fine to use it again!!!!

I still have an unopened tube of the 512 left over from the last install, but the expiry date is 12/2016, so I will have to keep that for non-critcal jobs at home, and fork out for some new adhesive .......... but 512 or 552 ??!!

UPDATE - I Bonded the Solar panel as recommended (Sika 552) and so far - so good!!

 

[stewartwebr]

I first posted this earlier this year ........

Just to add to the confusion, I contacted someone at the Technical Department at Sika, last week, as I am about to fit a second Solar Panel.

I fitted the first one two years ago, using Sika 512, following the recommendations for abrading, cleaning, applying Activator 205, and ensuring at least 3mm of adhesive.

After questioning whether my MH roof was "plastic", saying he had only come across metal ones, (!) he recommended Sika 552, which I had not come across.

His reasoning was that it had a better Tensile Strength - 3 N/mm² compared with 1.8 M/mm² for 512, but also that the surfaces to be bonded did not need to be as stringently cleaned/primed.

Also - Sikaflex®-552 is suitable for structural joints that will be subjected to dynamic stresses.

However, he confused me even more by finishing the conversation saying that despite what he had said, if I had used Sika 512 before, and the panel was still on, then if was probably fine to use it again!!!!

I still have an unopened tube of the 512 left over from the last install, but the expiry date is 12/2016, so I will have to keep that for non-critcal jobs at home, and fork out for some new adhesive .......... but 512 or 552 ??!!

UPDATE - I Bonded the Solar panel as recommended (Sika 552) and so far - so good!!

Now I am really confused, not hard!

I have received an e-mail back from Sikaflex instructing me to use Sika 252 but should also use Sika Primer and Activator as part of the process. I should also ensure that the application is between 4 and 5mm thick. I have 2 panels in the post so not sure which Sikaflex to use now???

 

[Lenny HB]

Now I am really confused, not hard!

I have received an e-mail back from Sikaflex instructing me to use Sika 252 but should also use Sika Primer and Activator as part of the process. I should also ensure that the application is between 4 and 5mm thick. I have 2 panels in the post so not sure which Sikaflex to use now???

If you really want to make sure use 292i, it's a marine grade adhesive, I used it on my sat dish. For my panels I used 291i which is a marine grade sealant adhesive. I must admit I didn't use their activator I just abraded the surfaces then cleaned with meths followed by alcohol.

 

[Steve and Denise]

If you really want to make sure use 292i, it's a marine grade adhesive, I used it on my sat dish. For my panels I used 291i which is a marine grade sealant adhesive. I must admit I didn't use their activator I just abraded the surfaces then cleaned with meths followed by alcohol.

How many glasses did you need @Lenny HB

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[scotjimland]

Can someone explain to me how you apply a layer of glue -3mm thick?

if you read the Sika instructions.... it is

± 3 mm. NOT -3mm

Plus-minus sign

• In the sign indicates the , which is the range of values that are considered to be acceptable, safe, or which comply with some standard, or with a contract.[2]

 

[Two on Tour]

If you really want to make sure use 292i, it's a marine grade adhesive, I used it on my sat dish. For my panels I used 291i which is a marine grade sealant adhesive. I must admit I didn't use their activator I just abraded the surfaces then cleaned with meths followed by alcohol.

Yup, same as per Lenny, I used 292i on both the our satillite dish and solar panel mounts. I scuffed the surface to be bonded on the mounts with 60 grit sand paper and the roof with 120 grit to give the Sikaflex more surface to bite. The 292i does take a fair while to cure, but does give you more clean up time.

 

[Larrynwin]

If you really want to make sure use 292i, it's a marine grade adhesive, I used it on my sat dish. For my panels I used 291i which is a marine grade sealant adhesive. I must admit I didn't use their activator I just abraded the surfaces then cleaned with meths followed by alcohol.

Which alcohol how much and were you happy in the end

 

[Lenny HB]

Which alcohol how much and were you happy in the end

Only the weak stuff didn't want to over do it.

 

[thebriars]

if you read the Sika instructions.... it is

± 3 mm. NOT -3mm

Plus-minus sign

• 
  
  
  • In the sign indicates the , which is the range of values that are considered to be acceptable, safe, or which comply with some standard, or with a contract.[2]

Oh dear! Big letters, he he. I did read Sika instructions: "Layer of glue ± 3 mm"

I'm well aware what the ± sign means, but without defining the actual glue thickness first, it reads you could have a layer -3mm thick.

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[fullfat]

All this effing about!! just nail em down, wimps

 

[scotjimland]

I'm well aware what the ± sign means,

 

[gus-lopez]

I'm well aware what the ± sign means, but without defining the actual glue thickness first, it reads you could have a layer -3mm thick.

What he said ^^^^^ without an actual measurement it means nothing & is ambiguous.
It should just read 3mm.
as it is written it means 3mm is allowed either side of the measurement that is not given.

 

[scotjimland]

Oh dear! Big letters, he he. I did read Sika instructions: "Layer of glue ± 3 mm"

I'm well aware what the ± sign means, but without defining the actual glue thickness first, it reads you could have a layer -3mm thick.

What he said ^^^^^ without an actual measurement it means nothing & is ambiguous.
It should just read 3mm.
as it is written it means 3mm is allowed either side of the measurement that is not given.

ever wish you never bothered posting ..

instead of saying thanks or that was useful information.. .. ohh no, lets nit-pick the post

and then wonder why people stop posting ..

 

[gus-lopez]

It isn't nit picking @thebriars pointed it out originally as a 'funny' .
I'd already seen it but hadn't bothered commenting.
I'm merely pointing out that as an Engineer it is not a way that any sensible person would write it.Yes I understood that they wanted 3mm but you do not write +/-in front of it unless there is another measurement.Otherwise it reads as though it has an allowance of 3 mm either side of the measurement that isn't shown. I'm sorry if you consider it is nit picking but it isn't meant like that just informative for people that don't understand how it should be correctly written & hope it doesn't stop you from posting.

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