Guest Le Thou Posted November 24, 2007 Share Posted November 24, 2007 Bought a new Satellite system which is the Maxview crank up and bought a stud detector, point is, a quick call to Autotrail revealed that there is no pipes or cables in the roof but I do need if possible to find the studs,hence the stud detector, but the system is mounted on a flat steel plate about 12" square (that's roughly 30cm in new money) and there are screw holes around the edge of the plate at about 2" intervals. Question is , after cleaning the roof with acetone and in all probabilities won't be able to find the studs in the correct place, will the adhesive be stong enough to hold the system in place, I am using Sikaflex which is apparently 50 times better than silicone, the fixing screws are only about 15mm long so it looks like it's all down to the adhesive. Any comments? Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted November 24, 2007 Share Posted November 24, 2007 From a totally amateur perspective and an admittance that I have not as yet had or done something similar. I would think that adhesive should be enough on its own and I am sure thats what normally is done. screws just into a GRP or aluminum sandwich IMO would be pointless and a concern for water penetration. screws into frame or plated bolts through roof would be another matter (I would still be concerned with water penetration) but if this was done I would be concerned that if I drove of with dish in up position, if to well fixed it hit it may damage the roof significantly rather then just falling over.... remember to seal cables going through roof as well as plate just my thoughts..... Link to comment Share on other sites More sharing options...
derek500 Posted November 24, 2007 Share Posted November 24, 2007 I fitted a Maxview Crankup in January. In the roof space of my MH there is a plastic conduit for electric cable for lights and the cooker extractor fan. I used a tester to check that where I drilled the large hole was clear. I used Sikaflex and four of the little screws, one in each corner. I found it was the best way to hold the plate, flat on the roof, whilst the Sikaflex was drying. The screws are very short and don't penetrate the roof space enough to cause concern. I fully coated the screwheads with a liberal amount of Sikaflex Our roof is 33mm thick and the black conduit is only 12mm thick and set into the lower part of the roof space. Link to comment Share on other sites More sharing options...
davenewellhome Posted November 24, 2007 Share Posted November 24, 2007 Hi Anthony, I've fitted lots of sat systems and solar panels using just Sikaflex to bond them to the roof. As long as you thoroughly clean and abrade the surfaces to be bonded you should have no problems. D. Link to comment Share on other sites More sharing options...
Guest Le Thou Posted November 24, 2007 Share Posted November 24, 2007 just a thought derek but if the screws don't penetrate that far why you didn't put them all in? Dave....thanks for that ,what I planned to do was a final clean of the adhesive area with acetone but are you saying to sort of sand the area to increase ahesion for the plate? Thanks Link to comment Share on other sites More sharing options...
Guest JudgeMental Posted November 24, 2007 Share Posted November 24, 2007 It really is pointless using screws through thin sheet material into soft insulation check instructions on adhesive, as if its on or about freezingm and doing the job outside you may have a problem with setting..... use duct tape to secure till dry Link to comment Share on other sites More sharing options...
derek500 Posted November 24, 2007 Share Posted November 24, 2007 Le Thou - 2007-11-24 7:00 PM just a thought derek but if the screws don't penetrate that far why you didn't put them all in? I'd read on several forums that Sikaflex would be enough and the screws not necessary. However, when I was pressing down on the plate to make sure it was tight, I'd press one corner and the opposite would rise up etc. A screw in each corner solved the problem. Link to comment Share on other sites More sharing options...
Guest Le Thou Posted November 25, 2007 Share Posted November 25, 2007 Fittd the crank up sat dish today and in total took about 2 hours, all in all a nice piece of kit and it works a treat finding Astra 2 within less than a minute, don't honestly know why anyone would pay thousands fo a sel seeking system. The only thing that I was comfortable with was after applying Sikaflex to the base I put all the screws in around the perimeter of the plate. It really did pull it down onto the roof and wih the temperature only being about 4 or 5 degs I thought it best to, I didn,t want to totally rely on an adhesive, but overall very impressed. If anyone is interested I bought it from Riversway Leisure at Preston (just around the corner) and it was on offer for £347.95 collected. Link to comment Share on other sites More sharing options...
eddie123 Posted November 26, 2007 Share Posted November 26, 2007 I have fitted a Omnistat CrankUp to my MH using Sikaflex with no screws, as Judge says if your roof is a light guage alloy sheet over polystyrene you are at risk of doing more harm than good. I rang Sikaflex technical dept for some advice. They advised an application of four continuous concentric rings of adhesive and said that the bead thickness must be as far as I recall 3mm (after setting), so be careful if you load the square mounting plate with the dish before the Sikaflex has had time to cure otherwise the combined weight may flatten the adhesive bead so much that it become too thin to comply with the general movements of the roof and mounting plate resulting potentially in a ruptured bond or water ingress. Link to comment Share on other sites More sharing options...
JohnP Posted November 26, 2007 Share Posted November 26, 2007 I have fitted two crankups using only sikaflex. I put three continuous beads of the adhesive on the plate, one at the edge and the other two spaced in at about 1" intervals. It is a good idea to put a bead where the rows of screw holes are in the mounting plate. Four house bricks gave sufficient weight to close the joint to the one recommended. Sikaflex also provide a cleaner for cleaning the fixing plate and the van roof to enable the adhesive to cure on a clean surface. It is not necessary to roughten the surfaces with abrasive papers. I suggest that you drill the hole for the mechanism before you glue the mounting plate on and use the aluminium tube provided to line up the mounting plate with the hole. The Sikaflex requires a dry warm day when using it outside. Link to comment Share on other sites More sharing options...
Guest Le Thou Posted November 26, 2007 Share Posted November 26, 2007 Good comments, Can't say that I would entrust something of that size and weight to three or four rings of adhesive, I'm sure Sikaflex would be more than happy to reimburse me for the cost of repairing the damage done by a sat dish coming off the roof at 70 mph on the M6. The screws do serve a purpose and the manufacturers recommend their use, incidently the roof of the Autotrail is Upvc or plastic over ply the screws go into a depth of less than 10 mm. Point in fact: as a time served Cabinetmaker I would always trust a joint that has been glued and clamped and left to dry naturally as opposed to two surfaces having a glue coat and left to dry. I,m sorry guys but I will take my chance with water ingress because it won't happen, but I will not put my trust in an adhesive with something that weighs over 20kgs, Link to comment Share on other sites More sharing options...
Guest Syd Posted November 27, 2007 Share Posted November 27, 2007 I have had the same system fitted for three years now and have found the performance to be disapointing in Europe hence the decision to go for an automatic system for next year Link to comment Share on other sites More sharing options...
Dave Newell Posted November 27, 2007 Share Posted November 27, 2007 Sika Flex 252 comes with a small bottle of activator which speeds up the curing time and the instructions say to clean the surfaces to be bonded with a mild abrasive and then degrease with white spirit or similar before applying the activator to both surfaces, leave for 15 minutes to dry before applying a bead of adhesive which when the items to be bonded are brought into contact should be squeezed to give a 3mm average adhesive thickness. Sikaflex will cure in cold temperatures but it takes a lot longer. Sika 252 is also moisture cured so will cure faster on a warm damp day than a cold dry one. Sika 512 is the more usual adhesive/sealant used for general purpose work and doesn't require the use of the activator. D. Link to comment Share on other sites More sharing options...
derek500 Posted November 27, 2007 Share Posted November 27, 2007 Syd - 2007-11-27 10:11 AM I have had the same system fitted for three years now and have found the performance to be disapointing in Europe hence the decision to go for an automatic system for next year In what way disappointing? Perhaps a new thread to discuss? Link to comment Share on other sites More sharing options...
Guest Le Thou Posted November 27, 2007 Share Posted November 27, 2007 Spoke to Maxview to day expressing my concerns about the adhesive only aspect and the Tech guy told me that some people bond them without screws around the base plate and some use the screws, his words were "Its down to personal preference because some people are concerned about water ingress" But dont most motorhomes have Heki's, 2 or 3 or 4 roof vents, through the roof antenna ?? so if sealed properly the screws shouldn't leak, but as sure as eggs is eggs that adhesive in time WILL let go. The Tech guy even went on to say that the system that they have as a demo on a caravan roof has been glued and screwed down. Mine is screwed and glued , that's my preference purely because of safety, I will not accept that the glue will hold it forever, you won,t convince me. Link to comment Share on other sites More sharing options...
Guest Syd Posted November 27, 2007 Share Posted November 27, 2007 derek500 - 2007-11-27 11:01 AM Syd - 2007-11-27 10:11 AM I have had the same system fitted for three years now and have found the performance to be disapointing in Europe hence the decision to go for an automatic system for next year In what way disappointing? Perhaps a new thread to discuss? I found the tuning of the ariel to be too fiddling and the further away you go the more difficult it got, might just be me but, it sometimes took 30 mins to get half the channels that you thought you might get. With an automatic ariel you might still only get half the channels that you thought you might get but at least you don't have the frustration of the time consuming tuning Link to comment Share on other sites More sharing options...
Guest Le Thou Posted November 28, 2007 Share Posted November 28, 2007 Hi Syd The simple answer would have be to increase the size of dish to 80cm, the clearance of the crank upwould allow that to fit. Link to comment Share on other sites More sharing options...
derek500 Posted November 28, 2007 Share Posted November 28, 2007 Syd - 2007-11-27 10:11 AM I found the tuning of the ariel to be too fiddling and the further away you go the more difficult it got, might just be me but, it sometimes took 30 mins to get half the channels that you thought you might get. With an automatic ariel you might still only get half the channels that you thought you might get but at least you don't have the frustration of the time consuming tuning I live in Valencia and can get a signal in 30 seconds. I don't usually use my Sky Box to tune in, but the FTA Silvercrest which I got with my previous Lidl Suitcase system. This receiver includes a very precise instant sat finder which you can use whilst watching the picture. I always choose a strong channel that can easily be picked up by a smaller dish then the Crankup e.g. Sky News. If I want to watch a FTV or pay channel I swap the box for my Sky Digibox with my viewing card. Also beware of false information. There's a thread on MHF 'RoadPro, Satellite trip - Sat Map. It shows that where I live an 85cm dish will get Astra 2D. I need a 1.9m dish!! Further down the coast towards Alicante they show a need for 90cm, whereas in fact 2.4m is the minimum. Link to comment Share on other sites More sharing options...
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