Glue on top of failed VW panel?

[charliefleet]

Is it possible to simply glue a new semi-rigid panel on top of an old failed panel, assuming they are same size.

The old panel is completely down with copious adhesive and sealed around the edges. It's going to be a complete pain to remove.... assume they would use a cheese-wire? And cut it off underneath.

The roof is completely flat with no ridges.

So how secure would a new panel glued on top be? I'm thinking it might alwo provide some degree of insulation... the old panel perhaps failed due to heat, lack of cooling?

 

[yodamota]

have any photos of the panel on the roof?

 

[charliefleet]

 

[charliefleet]

Its really thin and stuck down with Sikaflex all over.

 

[charliefleet]

And I'd remove the old junction box....

 

[yodamota]

It looks like what was there held up. I don't see an issue with installing over it. Sikaflex is a good product.

What is wrong with the panel on there?

 

[charliefleet]

The panel has just failed... no power coming from it when testing at the connections going into the charge controller. And taken the junction box apart... dug out the silicon and tested the terminals inside... no voltage.

 

[SamDeleted]

@charliefleet

I'd do it lol !

 

[charliefleet]

@charliefleet

I'd do it lol !

Seriously? It seems OK to me... but wanted second opinion! ?

 

[mikefitz]

In a few years you will have multi layered panels. Typically last for 2 years but I have seen such panels fail within months.
Take care with the PU adhesive, the surface coating of the existing panel may not bond well with the Sika PU adhesive/sealent.

Conside a rigid panel with metal mounting brakets through bolted.( Still leave the failed panel in place).

 

[SamDeleted]

Seriously? It seems OK to me... but wanted second opinion! ?

Yea , I mean, that original panel was simply just GLUED to the roof , and it's so strong you literally can't get it off


So I figure that glue is pretty damn strong ?? Use the same stuff for the Flexi panel


you could just keep glueing new panels on top of each other as they break down ?

 

[SamDeleted]

@charliefleet


What's your power usage like in the van , did that little panel cover your usage?


Now is the right time to upgrade if you need to, consider metal frame residential PV panels , they are much more reliable than those cheap rubbish flexi panels

Trina Vertex S 425W Black White Mono

High-power mono panels with half-cell technology for optimal energy production with minimal loss.

midsummerwholesale.co.uk

 

[Solar Guppy]

I wouldn't write off the panel yet, a shorted charge controller or bypass diode could be the issue as well. Since you have the junction box open, disconnect one of the feed wires ( or diodes ) and measure again, there isn't much to a panel to fail. Also where the wires enter the roof looks could another place to short out the cables.

 

[0truck0]

Sure you can glue one on. I would use way less glue, maybe just the leading edge and some spots along the edges, but not a continuous bead of glue. No need to glue anywhere but the edges.
The fail was probably because it was glued down. If you are willing to keep replacing them then keep glueing them.
Panels will get very hot. They need air circulation under them to help cool. Glueing down provides no circulation. you could put a cut-out piece of corrugated plastic (yard sale sign plastic) under the panel so air can get into the flutes.
I would suck it up, remove the old, put in a rigid panel and do it right this time.
You will probably see that your fiberglass truck topper is burnt under the panel, or discolored from the excessive heat.

 

[charliefleet]

OK I tend to agree about installing an aluminum framed panel... they're actually cheaper and will be stronger. Plus ventilation underneath...

Would these z-brackets be suitable to glue on, if I use them every 20cm or so?

 

[Supervstech]

Many on here claim it works, and holds up.
There is no way I am mounting one with only glue holding z brackets on.
No manufacturer will approve the install. You will be liable if a panel comes off on the highway.

 

[charliefleet]

Many on here claim it works, and holds up.
There is no way I am mounting one with only glue holding z brackets on.
No manufacturer will approve the install. You will be liable if a panel comes off on the highway.

That's what I was thinking... Best to use some screws into the fibreglass roof - belt and braces... As you say, driving at 70mph is a lot of wind force on a large surface area... and an 11kg panel flying off at that speed won't be pretty.

 

[mikefitz]

Through bolt the mounting brackets with load spreading large washers . There is already something fitted internally bolted to the roof.

 

[SamDeleted]

That's what I was thinking... Best to use some screws into the fibreglass roof - belt and braces... As you say, driving at 70mph is a lot of wind force on a large surface area... and an 11kg panel flying off at that speed won't be pretty.

I am always concerned about drilling holes in a van roof . alright if you live in the Nevada desert , it's a different story sat out in the british summer ...?

That's said , I would NOT glue on with just brackets, 4 tiny little contact points that's crazy .. you are asking for trouble

I would lay metal frame PV panel on van roof flat and StiXall it in place over the entire frame


One issue with glueing to a van roof (especially coach built) is delamination , if they layers of the roof start to separate them obviously your panel is only actually attached to the top layer of roofing materials

 

[SamDeleted]

Through bolt the mounting brackets with load spreading large washers . There is already something fitted internally bolted to the roof.

Yes absolutely, through bolts and plate washers is by far the best way forward. Sandwiching the roof