Having so far re-sealed one third of an awning rail (mines are in three sections) I couldn't quite work out why caravans are made like they are...
The aluminium sheet forming the roof is basically folded over the edges of the van with a small overlap. The roof and side sheets a
re then pinned together with mini staples every so often. No wonder so many vans (including mine) get damp.
Why are the roof and side panels not welded together? I could see how water getting under the awning rail could then be sucked up between the two sheets of aluminium and into the van.
That got me thinking. When re-sealing the rest of my rails would it be worth trying to weld the roof panel to the side panels? That way the only possible way for water to get in would be via the screw holes holding the awning rail on. Even then I am certain you could do without the screws on the awning rail and use something like this...
(http://www.shop.tison.biz/product_info.php/siroflex-mighty-strength-grip-and-grab-adhesive-290ml-clear-sxmsgga290c-p-19721)
to glue the rail into place.
I was thinking about using one of the epoxy metal products or epoxy putty to cold weld the two panels together. I would then use mastic / sikaflex etc. over the top of the weld when applying the awning rail.
Replacing an aluminium panel or roof would be a huge bit of work and would cost a fortune. I don't think it would be cost effective for anything but a very new van.
I can't envisage why / when I would every have to replace a panel unless I was involved in a road crash etc?
------------- Love a lot. Trust a few. But ALWAYS paddle your own canoe!!
Minds are like parachutes:- They only function when they are open!!!
Those who talk don't know.
Those who know don't talk.
like this.
Tazhearts. fast forward the video to 5 minutes and this is how its done very crude and outdated.
Bailey has made a start in the right direction and i have read that another company has started to bond all the panels together no nails stapels or screws, i think its elddis and will be on show at the Caravan Show.
While being towed the amount of flex in a caravan is staggering. If the panels were welded then they would start to split and tear. This is why a non setting sealer is used rather than adhesive sealer.
Quote:
Originally posted by DaveCoaches on 05/9/2012While being towed the amount of flex in a caravan is staggering. If the panels were welded then they would start to split and tear. This is why a non setting sealer is used rather than adhesive sealer.
But the successful continental vans, plus the Bailey Alu-Tech and now the Elldis SoLid are indeed all bonded with "setting" though compliant polymers. As are indeed are things like mine hunters to withstand the shock of an underwater explosion; its all a case of using the flexibility to your advantage.
Welding, with aluminium, would be totally wrong and it would crack in the weld effected areas on its first trip out. Rest easy knowing that the penny has at last dropped with two British van makers, lets hope they dont screw up the details!
Sikaflex is such an excellent adhesive I wouldn't bother with the epoxy, just bond the panels with Sikaflex, then use Sikaflex as the sealant for the rails. If you degrease thoroughly with meths it won't ever leak, and you'll never need to take it apart again.
I'd go with the sikaflex. it has the best of everything. It is an adhesive but remains flexible. The only downsides are the price (around 3 times the price of mastic) and the fact that if you ever need to remove it it will be a devil of a job. It also makes a mess which is much harder to clean than mastic.
How long do you intend your caravan to stay with you? Your topic is similar to mine under the "repair"section. If caravans were screwed in and sealed correctly in the first place, they`d never leak.
I would contend a sealing run on the outside (upper) edge of the awning/alu sealing strip should suffice if you use the right stuff; you may be able to reposition the screws if they are not biting for any reason. But you`ll then need to replace the plasiticky inner extrusion to check for this.
If you stop the water getting in, any damp in there will dry out. You may not need to go to so much trouble as you first thought! Best o` luck man
------------- Peripheral people don`t have as much excitement but they sure live longer
Agree with most of you that fully welding the panels and the state of UK roads would soon cause the van to tear apart.Sikaflex is fine if you never need to take the repair apart. If you do god help you. The first time I came across the stuff was a few years ago when a neighbour, and fellow caravanner had a hole in a corrugated roof.He glued a 2p piece over the hole with sickaflex. Many years later, afler removing the roof, we tied to remove th 2p piece, hammer chisel and everything else in our arsenal, nothing would shift it.