Now then. You wise old elfs will no doubt enlighten my darkened mind. But, nothwithstanding the latest Baileys and Elddises which as you know, are of different construction methods. the rest of us if not the caravan manufactureres, tend to pack the awning rail and other aluminium sealing strips (which exist to disguise the joint between sections, or roof and sides/ back/front in an acceptable way) with various sealants so it oozes out the sides and prevents water ingress. Indeed, some of you old hands may do this every 5 years or so, I don`t know because I`m new to the game.
So here I am, wi Daisy. No moisture in the van or even a whiff of damp. But there`s plenty up front, in what remains of the timber frame lol! I dunno what holds the elderly lasy together, but thought I`d better do something, so I replaced the timbers in the front RH side, which was easy enough. And I`ll hopefully get the LH ones done in the coming week.
But I have to ask the question - WHERE does the water get in? Not through the overlapping joints. It can only be through the screw holes in the wood, and those in the caravan sides. So, if you inject some sealant just into the hole, then that should theoretically suffice!! Nothing more required.
Now I know my logic is suspect at times, `cos SHE tells me so. But in the event of having to remove the aluminium strips, I really don`t want to deal with clods of sticky stuff that looks like it comes out of noses . ..
Comments please! (I`ve got sloping shoulders and a feeling I might need `em)
------------- Peripheral people don`t have as much excitement but they sure live longer
Whilst I agree that along the joining strips theoretically placing mastic over just the screw holes should suffice. The join (on my van atleast) appears to be well bonded and the joining strip isn't actually placed directly over the join but more above it.
How ever though by placing mastic just by the screw holes would mean the joining rails wouldn't go back flush to the caravan and if you were just to place it in the screw hole you would never be 100% sure you are preventing water from getting in as the screw could push the sealant in further than you intended.
With the awning rails you have no choice but to get as much sealant in as you can because the side and roof panels overlap leaving a lovely area for water to get.
As for removing and replacing mastic in the future, its not really an issue if the correct materials are used to begin with. Mastic (i.e IDL99) is pretty is to remove and clean up, the issues are when some people go and slap some silicone sealant in there for extra measure making the job 10 times harder.
Water will get in anywhere it finds a hole that it can go through, especially by capillary action, it doesn't have to be a hole as such, even a crack in a sealer seam will be enough.
Bodywork isn't fixed, it is on the move all the time, daily heat/cold cycles will flex the panels, as will using the van generally.
Thats a good point, having just stripped our down I was amazed to find water sitting inside the mastic and silicone joints of the awning rail I stripped down a few days ago and the caravan has actually been stored inside for the last 3 weeks.
"Thats a good point, having just stripped our down I was amazed to find water sitting inside the mastic and silicone joints of the awning rail I stripped down a few days ago and the caravan has actually been stored inside for the last 3 weeks."
There`s no water, and STILL it gets in?? Ha ha, time to send for the Nauti Squad and effect a marine solution . . One floating caravan COMING UP!
------------- Peripheral people don`t have as much excitement but they sure live longer
I put some PVC masking tape around the area where the alu strip was whilst I cleaned it up. Since then, it`s rained heavily which is good really. Because I learned that water gets underneath (or through) the tape. And goes on into the places where its never gone before!
Honestly wouldn`t believe it! Gets into the big rubber seals, top of the front openers and takes the scenic route down the sides! The rubber seals here have very generous overlaps form the perspex windows.
It`s time for the Big Guns! I have bought a product called Geocol "The Works" and I`ve tested it as an adhesive on aluminium extrusion and oily plastic. It works! Suitable in wet conditions, it dries like a good Silicon sealant. At the moment, it`s drying on a wet test piece.
This is serious fun for an ole fella. We`re off in it in a fortnight. Without masking tape SHE hopes!
------------- Peripheral people don`t have as much excitement but they sure live longer
People only think of rain water slowly seeping in to joints but it's far more destructive than just that when you think about it really. Even with light rain travelling at 60 mph. the force of wind is much more like a pressure washer and we all know how to avoid those when cleaning the caravan. Wind will force rain water into any crevice so by sealing behind the strip itself is forcing the pressure of rain water directly over the surface of the seal which is exactly is what is required. Cutting corners by only covering the screw holes won't prevent excessive wind pressure from forcing rain water into the smallest cavities.
having been working on the side trims today I can't actually see any need to screw them to begin with. They don't do anything from what I can see other than cover the join so why couldn't they have been VHB taped on from the beginning, it would have been 1 less area where water get in.
The aluminum shell is bonded to the insulation which is then bonded to the wall boards so the side trims from what I can see offer no structural integrity (unless i'm missing something)
Quote: Originally posted by tango55 on 25/8/2012
People only think of rain water slowly seeping in to joints but it's far more destructive than just that when you think about it really. Even with light rain travelling at 60 mph. the force of wind is much more like a pressure washer and we all know how to avoid those when cleaning the caravan. Wind will force rain water into any crevice so by sealing behind the strip itself is forcing the pressure of rain water directly over the surface of the seal which is exactly is what is required. Cutting corners by only covering the screw holes won't prevent excessive wind pressure from forcing rain water into the smallest cavities.
I agree with your driving rain idea .My supposedly leak proof freedom Microlite sprung a leak every time I towed in the rain .I couldnt find the leak whilst it was stationary in the rain so decided to remove some of the lining at the front of the van, and then jet wash the van and got my Lady to look inside as I was doing it ,she noticed the water was coming from the 4mm hole where the front marker light wire passed though the hole
a good dosing of silicone in the hole and around the marker light solved the problem
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Topic: Is Sealant Really Needed??
