Fiat Ducato Posted March 31, 2015 Share Posted March 31, 2015 I am in the process of rebuilding my roof and side panel following leaks in the roof and water ingress as well and truly got in, soaking wet rotted timber and hardboard, even wet polysterene. Where the timbers got so wet they have corroded the aluminium with the chemical reaction from the rotted timbers. It looks like Auto Roller when constructing this motorhome didn't use treated timber which I find very strange, the hardboard is standard hardboard not oil tempered hardboard. And the aluminium skin was just floating on top of the pre-fabriacted sandwiched panels. I was wondering if motorhome manufacturers know that wet timber as this chemical reaction when against aluminium, why they don't apply some kind of membrane or special coating to prevent this. As it;s inevitable that during a motorhomes lifespan there will be leaks from rooflights, vents, windows etc. I am considering painting the entired inside aluminium skin with a rubberized waterproof and anti corrosive paint before installing the treated timbers and insulation, either that or a foil membrane. Also is it possible to fill a larger hole the size of a fist in the aluminium with fibreglass resin?? I have been researching this matter and even been trying to find contact details of motorhome manufactures to seek some advice on this matter. Any comments especially from coach builders or experienced Motorhome DIYers who can offer some guidance and advice would be extremely appreciated. Regards Paul http://www.amazon.co.uk/gp/product/B00AC2155A/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1BNN3MEJ8N81X Link to comment Share on other sites More sharing options...
Rayjsj Posted March 31, 2015 Share Posted March 31, 2015 Interesting that this is a Continental Constructed Motorhome ! some who frequent this forum think the problem only applies to UK constructed vans.......it doesn't. I know that there was a bad batch of 'CI' Vans for Water Ingress, indeed their name got so 'tarnished' that they ceased using the 'CI' label,(in the UK) and now ONLY sell 'Rollerteam' or 'Autoroller' although they are presumably still made in the same factory using the same methods of construction ? At least the UK industry has finally addressed their weaknesses with differant Constuction methods and Improved Warranties up to 10 years, for water ingress, THIS should be standard IMHO. Good luck with your rebuild, sounds like you are doing a good job. Dave Newell, a once regular poster on here, did a similar rebuild on his previous van, including complete new alluminium sheet side panels, quite a feat for one bloke on his own, but he did a great job, there is a article somewhere ? I will try to find it. Unfortunately he stopped posting due to all the 'catty bickering' that seemed to prevail for a while. Lets hope it's stopped ? Ray Link to comment Share on other sites More sharing options...
Steve928 Posted March 31, 2015 Share Posted March 31, 2015 Rayjsj - 2015-03-31 11:06 AM [snip]'Rollerteam' or 'Autoroller' although they are presumably still made in the same factory using the same methods of construction ? Ray Wow, that's quite some presumption. Current Rollerteams use plastic extrusions in place of timber, feature GRP external panels and plastic internal panels, use styrofoam insulation and come with a 10 year water ingress warranty. Rayjsj - 2015-03-31 11:06 AM At least the UK industry has finally addressed their weaknesses with differant Constuction methods Ray There are plenty of 'stick-built' alu-skinned polystyrene-insulated vans still rolling off a production line in Durham. Link to comment Share on other sites More sharing options...
globebuster Posted March 31, 2015 Share Posted March 31, 2015 I've PM'ed you...... Link to comment Share on other sites More sharing options...
Keithl Posted March 31, 2015 Share Posted March 31, 2015 Fiat Ducato - 2015-03-31 10:50 AM Also is it possible to fill a larger hole the size of a fist in the aluminium with fibreglass resin?? Regards Paul Paul, For a hole the size you have described I would be looking at 'Welding' in a repair using the LUMIWELD process. This is basically a soldering type process specifically for aluminium with minimal heat damage around the area of the repair. I have used it very successfully on cast aluminium and die cast parts in the past and seen it demonstrated on aluminium sheet with brilliant results. Have a look at the info on LB Restoration Services website... Link. Keith. Link to comment Share on other sites More sharing options...
Tracker Posted March 31, 2015 Share Posted March 31, 2015 The last time I repaired an aluminium skin on a van I pop riveted an aluminium patch to cover the hold then tapped the area down and filled it with flexible polyester car body filler before painting it with etch primer, grey primer then cellulose. CI vans of that era were 'budget' models and sold at a very competitive price. That meant a low cost price too and now we know where the savings were made! I sincerely hope that production methods have improved but I would not bet on it! Rightly or wrongly I attached the new timbers (treated!) to the aluminium skin by double sided tape in the hope that it would provide a mebrane between the two but if nothing else it did at least hold it all in place whilst I secured it! I then fixed the polystyrene insuation in place with contact adhesive in the (vain?) hope that it would give the body a bit more rigidity? Other than where repaired or pitted I don't know if I would paint all the inside of the aluminium as with my limited knowledge I don't really see any advantage in so doing? But I could be wrong! Mind you this was all some 30 years ago on a tight budget and methods may have improved since as well as much more info being available on the internet. Link to comment Share on other sites More sharing options...
Will86 Posted March 31, 2015 Share Posted March 31, 2015 I favour riveting a skin to cover the area mentioned, very simple and very effective as Tracker says. The Lumiweld process is good on castings and lumpy objects whereas the skin of a van is totally different. The biggest problem would be expansion during the Lumiweld application. You cannot simply lay a skin over the hole and join it by a welding process. If a Lumiweld decision is to be attempted the applied skin should be riveted first. On a van roof the patch area could expand some 4 ins in height with never any guarantee that it will settle again. It will also become distorted as heat is applied unevenly around the patch. Riveting with an added sealant is the only cure. PS ... I challenge Keith's suggestion that its 'basically a soldering type process'. Soldering is carried out with a heated copper work-piece, the Lumiweld process is mostly applied using an open flame. either Oxy Acetylene, Propane or another gas and air mixture. With a small solid object preheating could be carried out in an oven with the Lumiweld material added as its melting point is reached. A van roof repair could only be attempted with an open flame. Will Link to comment Share on other sites More sharing options...
Keithl Posted March 31, 2015 Share Posted March 31, 2015 Will85 - 2015-03-31 2:28 PM PS ... I challenge Keith's suggestion that its 'basically a soldering type process'. Soldering is carried out with a heated copper work-piece, the Lumiweld process is mostly applied using an open flame. either Oxy Acetylene, Propane or another gas and air mixture. With a small solid object preheating could be carried out in an oven with the Lumiweld material added as its melting point is reached. Will Hi Will, I referred to it as a 'Soldering type process' as the only material that is actually melted is the additional material, the base metal is nowhere near its melting point. I do agree however that the process of applying the heat is entirely different! In a true 'Welding' processes the filler metal is melted into the base metal. Perhaps I should have referred to it as a 'Brazing' type process? Keith. Link to comment Share on other sites More sharing options...
Guest Peter James Posted March 31, 2015 Share Posted March 31, 2015 Fiat Ducato - 2015-03-31 10:50 AM Auto Roller when constructing this motorhome didn't use treated timber which I find very strange, the hardboard is standard hardboard not oil tempered hardboard. Well the structural timbers in a house are not normally treated. As long as they are kept dry they don't need to be treated because the organisms that rot timber can't live without water. With some of the later vans they seem to have accepted the inevitability of water getting in so have made the frame out of waterproof plastic instead of wood. As to covering the hole I imagine welding such thin aluminium sheet in situ to be so difficult as practically impossible, so would stick a plate over it with adhesive sealant and pop rivet for good measure - covering the pop rivets with sealant. You can get small pieces of aluminium plate from places like B&Q. Link to comment Share on other sites More sharing options...
Muswell Posted March 31, 2015 Share Posted March 31, 2015 I should think that if you use a van in the winter months you are bound to get condensation on the inside of the aluminium unless you have a vapour barrier on the warm side of the insulation to stop warm moist air from inside the van migrating through the lining and gaps in the insulation. That's what happens in your house if it's not built properly....and it leads to rot if the roof space is not ventilated. Link to comment Share on other sites More sharing options...
Guest daven Posted March 31, 2015 Share Posted March 31, 2015 Depending on the position of the hole what about placing a grill over it & after painting the van it could look like its always been there ? it would also ventilate the cavity of the wall Link to comment Share on other sites More sharing options...
George Collings Posted March 31, 2015 Share Posted March 31, 2015 A bit more about soldering. Unlike welding where a joint is formed by melting the same metal as being joined, soldering is joining metal by using a metal with a lower melting point to make the joint. Lead- tin alloys, silver, gold and if a copper-zinc based alloy the process is known as brazing. Just to confuse the issue some very high grade soldering, using the copper based alloy bronze, is know as bronze welding. Although usually an iron( made of copper) is used to heat the joint soldering can be done with an open flame (sweating ?) and is normal for silver soldering. I have patched patched radiator header tanks this way. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 1, 2015 Share Posted April 1, 2015 George Collings - 2015-03-31 10:36 PM A bit more about soldering. Unlike welding where a joint is formed by melting the same metal as being joined, soldering is joining metal by using a metal with a lower melting point to make the joint. Lead- tin alloys, silver, gold and if a copper-zinc based alloy the process is known as brazing. Just to confuse the issue some very high grade soldering, using the copper based alloy bronze, is know as bronze welding. Although usually an iron( made of copper) is used to heat the joint soldering can be done with an open flame (sweating ?) and is normal for silver soldering. I have patched patched radiator header tanks this way. In the interests of completeness, there is also "lead burning"! :-) Link to comment Share on other sites More sharing options...
Fiat Ducato Posted April 1, 2015 Author Share Posted April 1, 2015 Thank you for all your comments, really appreciate your comments. However with all your respect I think you are all way off track and been a bit over the top with your solutions. The hole is just a size of a fist, I have ripped out all the wet rotted timber and whilst doing this, where it was bonded to the aluminium on removing the timber pulled away the aluminium as well, through the corrosion from the rotted timber, There are also a serious of small pin hole size holes again through rotted timber causing corrosion. The larger hole I am going to clean with sandpaper, treat the rust with a decent rust killer and then bond a patch of aluminium over the hole from the inside, and fibreglass the outside, this should cure the problem while reinforcing the structure, the I have ordered some Motorhome Roof repair paint -http://www.amazon.co.uk/gp/product/B00AC2155A?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00 It as very good reviews and actually works. 1) I am going to apply this on the inside over the smaller holes probably 2 coats, as well as a layer on the outside. 2) I am then going treat the hole inside of the roof the Alumiinium skin with either Bonda G4 Marine Primer or Owatrol oil, then a layer of 4mm double sided foil bubble insulation against the Aluminium (instead of standard hardboard like they originally put in, when manufactured) This should prevent any condensation from attacking the timbers causing the chemical reaction which causes the Aluminium corrosion. 3) Then construct the timber frame with 40 x 25 mm treated timber, a layer of 25 mm Kingspan Celotex and finally either white finishing wallboard or 3/4 mm exterior plywood with paper finish or lining carpet. 4) I will be upgrading the original ligting for LED chrome downlighters 6 in all operated by a single switch for on/off. 5) I will be replacing the original roof light (that was fitted with screws to all 4 sides to the timber supports (now been removed as rotted) and left with around 20 screws poking through the Aluminium skin. I am going to construct a larger timber frame then cut out all these screws (holes) and fit a larger more modern rooflight - one of a sandwich type fitting (no need to screw) less chance of a leak. The bathroom that as ceiling rot as well as wall rot on the side wall and rear wall around the window, surprised window hasn't fell out lol well this is a bit more of complex job, but will be dealt with in roughly the same way. I am a perfectionist and have to do the job right otherwise its not worth doing in my opinion for example all the rotted timber every last bit WILL BE REMOVED and cut back past the rot by at least 100 mm dried out with a dehumidifier and treated with wood preservative. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 1, 2015 Share Posted April 1, 2015 Fiat Ducato - 2015-04-01 10:07 AM............................There are also a serious of small pin hole size holes again through rotted timber causing corrosion. The larger hole I am going to clean with sandpaper, treat the rust with a decent rust killer ......................... But, where is this rust (iron oxode)? The material you have described to date is aluminium, which does not rust. Any corrosion on the aluminium will be the product of attack by contaminants. Rust treatments are generally based around phosphoric acid which converts iron oxide to iron phosphate. I have no idea what effect phosphoric acid may have on aluminium, but would imagine it would be somewhere between useless and deleterious. Clean it up, wash it off, and immediately prime with zinc chromate. 2) .............................then a layer of 4mm double sided foil bubble insulation against the Aluminium (instead of standard hardboard like they originally put in, when manufactured) .............. The function of the hardboard/ply originally under the aluminium skin was to support it. The material you describe sounds unlikely to be able to provide any support at all. The insulation boarding may prove adequate, but it will add little strength to the roof. What you are trying to reconstruct is a stressed skin panel, where two rigid layers are spaced apart by, but fully bonded to, battens to form a plate beam. If the structure lacks the necessary rigidity, it is likley the aluminium will be distorted during heavy rain or snow, and will develop a sag, leading to ponding on the roof, leading to further sag, etc. etc. Ultimately, this will be liable to strain the peripheral joints between the roof sheet and the over-cab fairing, the rear wall, and the side walls, resulting in leakage. I would be inclined to use 3mm ply, with a thin polyester fleece separating layer between it and the aluminium. However, as you propose to paint the U/S of the aly, there should then be no direct contact between aluminium and ply, so why not give the aly two coats, and rely on that. Link to comment Share on other sites More sharing options...
Fiat Ducato Posted April 1, 2015 Author Share Posted April 1, 2015 Thanks Brian You surely seem to know what your talking about? What is your background? I wondered about the hardboard sandwich, where I have trimmed it right back to the timber frame on the edge of the roof, any hardboard or ply I put back, will no longer be supported by the the side panels and without bonding it to the Aluminium sheet, will always just be floating. I will be relying on the new timbers I will be bridging and framing the ceiling with, I will be attaching these to the existing dry edge/side timbers with stainless steel 90 degree angle brackets screwed with stainless steel screws also a stainless steel bracing strap for other places. I will be putting a couple of extra timber supports in as the was a huge gap in the ceiling joist from the roof light to the nest one which is the start of the cab. My theory is that the timber supports (highlighted in yellow on the pic, showing the location of the new timber supports) along with the foil barrier above the timbers will support the roof, with celotex in between these timber ceiling supports and then 3 mm exterior ply bonded to the timber for the inside face. I could apply a coat of the flexible rubber paint I was talking about and then use 3 mm oil tempered hardboard instead of the foil. I did check with the Hammerite website and they say that you can use Kurust on Aluminium and its safe to do so, the same with Hammerite rust remover. Maybe I'm in way out of my depth and need to get some professional advice and help!!! Link to comment Share on other sites More sharing options...
Will86 Posted April 1, 2015 Share Posted April 1, 2015 Hi Will, I referred to it as a 'Soldering type process' as the only material that is actually melted is the additional material, the base metal is nowhere near its melting point. I do agree however that the process of applying the heat is entirely different! In a true 'Welding' processes the filler metal is melted into the base metal. Perhaps I should have referred to it as a 'Brazing' type process? Keith. Good on you Kieth, Yes closer to brazing of which I did many years on aircraft, using a 10/12 % silicon alloy wire on pure aluminium components. The critical part there was the very close melting point between the two. To aid the repair on a casting a spatula can be used in conjunction with the metal being applied to agitate the base metal in order to increase adhesion. This modern stuff is excellent particularly on silicon castings having done quite a few. Will Link to comment Share on other sites More sharing options...
Will86 Posted April 1, 2015 Share Posted April 1, 2015 Brian doesn't tell. Link to comment Share on other sites More sharing options...
Guest Peter James Posted April 1, 2015 Share Posted April 1, 2015 Fiat Ducato - 2015-04-01 4:26 PM I wondered about the hardboard sandwich, where I have trimmed it right back to the timber frame on the edge of the roof, any hardboard or ply I put back, will no longer be supported by the the side panels and without bonding it to the Aluminium sheet, will always just be floating. I will be relying on the new timbers I will be bridging and framing the ceiling with, I will be attaching these to the existing dry edge/side timbers with stainless steel 90 degree angle brackets screwed with stainless steel screws also a stainless steel bracing strap for other places.!! I was wondering how you are going to do it without taking the roof panel off. I cannot see how screws into the end of thin timbers will replicate the strength of the panel bonded directly on top of the side walls. You have to bear in mind the roof does a lot more than support itself. Its part of the vehicle structure. The thin chassis of a motorhome has almost no torsional (twisting) strength. To demonstrate this, get an oblong biscuit tin / food container metal or plastic, see how hard it is to twist it with the lid on. Then take the lid off and see how easy it is to twist. This shows how essential the lid, like the van roof, is to the structure when its being twisted by being driven over uneven roads. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 1, 2015 Share Posted April 1, 2015 Fiat Ducato - 2015-04-01 4:26 PM Thanks Brian You surely seem to know what your talking about? What is your background? I wondered about the hardboard sandwich, where I have trimmed it right back to the timber frame on the edge of the roof, any hardboard or ply I put back, will no longer be supported by the the side panels and without bonding it to the Aluminium sheet, will always just be floating. I will be relying on the new timbers I will be bridging and framing the ceiling with, I will be attaching these to the existing dry edge/side timbers with stainless steel 90 degree angle brackets screwed with stainless steel screws also a stainless steel bracing strap for other places. I will be putting a couple of extra timber supports in as the was a huge gap in the ceiling joist from the roof light to the nest one which is the start of the cab. My theory is that the timber supports (highlighted in yellow on the pic, showing the location of the new timber supports) along with the foil barrier above the timbers will support the roof, with celotex in between these timber ceiling supports and then 3 mm exterior ply bonded to the timber for the inside face. I could apply a coat of the flexible rubber paint I was talking about and then use 3 mm oil tempered hardboard instead of the foil. I did check with the Hammerite website and they say that you can use Kurust on Aluminium and its safe to do so, the same with Hammerite rust remover. Maybe I'm in way out of my depth and need to get some professional advice and help!!! Construction industry, but design/technical, not site based. Suggestion: Could you make up panels with the top ply (which I still think preferable to hardboard) pre-fixed to the battens, but without any insulation or lining board in place? You'd have to make them in sections to get them in, but as large as can be manoeuvred into place. You may need to remove wall cupboards on one side to rotate the panels up and into place. If the panels have an edge frame, the ply would then be fully supported on all sides. Ply goes up tight against the aluminium, and the edge frames can then be screwed/glued to the existing edge framing batten at the top of the wall. Install one full length cross batten mid-way across each panel except first and last panels (see next para), with longitudinal noggins as you indicate. Make up the panels with a half panel at each end of the roof, and full length (relative to what you can manoeuvre in) panel/s in the centre. Screw and glue each panel to the next as installed (Full dry run desirable :-)). Then fit the insulation board into the voids, and finally fit (glue and staple?) inner lining boards so that they run in full widths down the length of the van. Set out the lining board joints to correspond with, and lie on, the mid point batten in each panel. That way, the lining boards would bridge the transverse joints between the panels, and should take care of any flexing stresses, and the joints between the lining boards will be fully supported across the width of the van. Then apply a plastic faced fabric lining (the sort of stuff that is used for contract quality wall linings) to the boards. It will involve a lot of "measure twice and cut once", and a lot of measuring (and no doubt swearing!), but I think it might offer a way if you have to work with the van in the open. However, I still think it would be easier if you could get the van into a shed of some sort, carefully remove the aluminium roof (which is already shaped, so should go back on relatively easily) and put the roof panel on as a single pre-fabricated element working from above outside of the van, in the way it would have been done during original assembly. Then re-fix the aluminium roofing into place, and re-bed and screw on the various joint cover strips. I don't think there is anything especially complicated about the assembly, though it will require a lot of precision. It will just take time and patience, good, methodical planning, and a certain amount of help at times to remove and re-fit the larger chunks. I assume you already have all the tools you'll need, and you have the right skills, it just needs a thorough, step by step, plan. The guys who run building sites are almost invariably chippies, or brickies, because they are the numerate, thinking, trades. You're almost home and dry - but it's going to take you a while! :-D Link to comment Share on other sites More sharing options...
Guest Peter James Posted April 1, 2015 Share Posted April 1, 2015 Brian Kirby - 2015-04-01 6:13 PM Construction industry, but design/technical, not site based. As in 'I just have the ideas, its your job to make them work' ;-) Seriously though, I can't think of any better suggestions than what you have made here. Unless the exterior panel can be taken off, which you have also suggested. Its going to need some high precision measuring and cutting, as you say. Very interesting thread. Link to comment Share on other sites More sharing options...
Brian Kirby Posted April 1, 2015 Share Posted April 1, 2015 Peter James - 2015-04-01 6:31 PM Brian Kirby - 2015-04-01 6:13 PM Construction industry, but design/technical, not site based. As in 'I just have the ideas, its your job to make them work' ;-) ............. Of course Peter! :-D But, if you keep serving up ideas that don't work, folk complain, and then you have to start looking for a new job! Besides, everyone needs a bit of a challenge from time to time. It's what gets them out of bed. Easy, is boring. :-) Link to comment Share on other sites More sharing options...
Guest Peter James Posted April 1, 2015 Share Posted April 1, 2015 Brian Kirby - 2015-04-01 6:42 PM Peter James - 2015-04-01 6:31 PM Brian Kirby - 2015-04-01 6:13 PM Construction industry, but design/technical, not site based. As in 'I just have the ideas, its your job to make them work' ;-) ............. Of course Peter! :-D But, if you keep serving up ideas that don't work, folk complain, and then you have to start looking for a new job! Besides, everyone needs a bit of a challenge from time to time. It's what gets them out of bed. Easy, is boring. :-) Oh I dunno, I think I have had enough challenges to last me (lol) If the roof panel is released, its possible the body could twist as easily as the food container when you take the lid off. It may be necessary to jack up one of the wheels a little to twist the body back into its original shape so the roof panel fits again. Link to comment Share on other sites More sharing options...
Fiat Ducato Posted April 1, 2015 Author Share Posted April 1, 2015 I wish I could put it under cover and take of the Aluminium roof, I would prefer to do that and do the job correctly, I totally agree with you Brian I will use 3 or 4 mm exterior ply instead of hardboard. Even if I could find somewhere to store it under cover and remove the roof, I'd be frightened of moving it now, as I've ripped out a lot of the structural timber supports, I would probably hit a pot hole and it will all buckle and twist. Maybe I could check out the weather (not that the weather forecast or ever right) and plan to do it on a nice weekend, put some kind of gazebo or marquee up over the top of it. Would you make the pre-fabricated panels in sections or try to make one complete panel?? I doubt it as this would be extremely heavy and difficult to manoeuvre into place without it buckling and snapping under the strain. Link to comment Share on other sites More sharing options...
Guest Peter James Posted April 1, 2015 Share Posted April 1, 2015 Fiat Ducato - 2015-04-01 7:13 PM Would you make the pre-fabricated panels in sections or try to make one complete panel?? I doubt it as this would be extremely heavy and difficult to manoeuvre into place without it buckling and snapping under the strain. Won't the size be restricted by what you can get through the habitation door? Link to comment Share on other sites More sharing options...
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