Then 'First4Magnets' knocked on my blog door showing their vast range of neodymium magnets, many targeted at model making. Neodymium is a very powerful magnet material so we need to be careful that in delicate situations it is not overly 'sticky'.
I selected First4Magnets F321 for this application.
At only 2mm diameter by 1mm thick it is strong but at this small size is manageable and also not too conspicuous (once it is painted to blend in).
Of course, it needs either another magnet or metal to create the adhesion so, what to do about the coach plastic roof? One solution is to fix the magnet to the board and remove the roof to fix a magnet or metal strip underneath it. But I could not see how to remove the roof and did not want to mess about finding out in case I caused damage.
What I opted for was some metallised paint. Out to the garage with a file and sheet of steel to create some metal filings. These were mixed into a blob of Humbrol enamel paint same colour as the roof and a small area, about the size of a magnet, covered between the dummy board brackets. It is hardly noticeable.
Once dry a magnet was offered up and it stuck with just the right amount of adhesion.
But this revealed a problem. The angle of the roof differs to that of the board brackets and since magnets tend to lie flat to a surface the board followed the angle of the roof and not the bracket! (Bear this in mind if you choose to fix a magnet under the roof and make the board in metal to totally hide the fixing method). What is needed is either a magnet shaped to the same angle as the roof bracket or some packing between it and the board. The packing was achieved with a blob of epoxy resin glue placed between the roof board and magnet whilst in situ taking great care that it did not run onto the coach roof.
Finally, a test drive on the layout proved the method works and it looks great too. Off to paint the magnets now.
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