Corrugated iron
I use aluminium sheet, cut from Fosters Lager, or cider cans, that our local youths having drunk the contents then discard. Therefore they are the best price possible – nothing!
Some cans are made from Steel - when starting to cut the top[ & Bottom off if the can sparks it is steel, discard that can into the bin.
To release the sheet from the can, and using a slitting saw in a Dremel or such, and with some protective glasses being worn, having washed the can out thoroughly, I cut off the top & bottom of it leaving you with a tube: slit that with a pair of scissors (get your own they are now very cheap) the resultant sheet can be straightened out by pulling it against a right angled edge (I use the steel tube that is under my workbench, that was an old desk).
With the now flat sheet having worked out the size of the sheets needed use your scissors to cut up the sheet: I find I can normally get 4 pieces out of each sheet, an average size for my sheets is 90mm x 60mm. Always do some extra, they will generally be needed if you are anything like me.
The sheets now need annealing, to soften them: we have a gas cooking stove on which I use one of the rings, I think that a gas cylindered blowlamp could also do the job with care – fix the blowlamp and it is then like a gas cooker ring.
Hold the sheet in a pair of long nose pliers and continuously pass one half of it over the flame keeping it moving all the time, if you don’t it will melt; generally the corner goes silver and turns up slightly. What you want is the sheet to go brown, as evenly as possible, it can be turned via a twist of the wrist, I prefer to have to unprinted side uppermost as I can then see what is happening more easily. Remove the sheet and turn the sheet round and repeat the above, Let it cool off, and the continue with the rest doing the same.
When all is complete open the kitchen window to get rid of the smell – I think it’s the coating that the cans have as it burns off. The sheets are now ready for the crimper – mine came from Fred Aldous in Manchester but Hobbycraft also sell them I believe. Since this was written the crimper does not appear of Aldous's or Hobbycraft website. However it is on the following weblink
to Cheddar Crafts
http://www.cheddarstamper.co.uk/P/Paper ... 6075).aspx
it is the Light Blue ones, with a handle at both ends which is important and are needed.
The crimper needs to have a handle at each end, otherwise the sheet being crimped will not run straight; and it is much more likely that the upper roller will lift resulting in no courugations in the centre iof the sheet – not the intention! Here is a photo of mine in a ‘Stanly right angled vice, which is fixed to a Workmate to keep both still; note how far into the vice it is fitted, that is to keep it quite still, leave a space at the ends so you can add pressure when turning the handles..
Take a sheet and feed it into the join between the rollers, and gently turn them slightly to grab it, using both handles, check it is straight, and again using both handles feed the sheet in for about three corrugations, it will be hard to turn – do it gently, feed it back on itself but not enough to let it fall out, then do another 3 corrugations again reversing it – this reversing will enhance the corrugations, continue to the end of the sheet, watching to make sure the rollers do not rise in the middle, if so you need to add pressure when re rolling (no hands available otherwise!), it really boils down to practice and watching what the sheet is up to it is much easier once started. Just ‘bear in mind’ that it can & will try to twist off line so producing corrugations that are not at right angles to the length of the sheet, with care you can go over the bad one to get it straight.
I fix them to a plasticard ‘under roof, that has been braced if required (the sheet is 1.5 or 2mm thick), but first the edges of the roof around chimney stacks or such like has some aluminium foil ‘flashing added – I use the foil from food trays here as it is more flexible: fix it with Evo-stik.
The corrugated sheets are fixed with ‘window frame sealant’ - mark out the roof with a line to work to starting from the lower edge, put a thin layer on the roof top and bottom, (and possibly the end edges, and some more on the corrugated sheet, the intention is to fill the corrugations on the lower edge. To join each sheet to its neighbour I use a corrugation full of Evo-stik. The first layer is obviously on the lower edge of the roof, the next layer is offset slightly, and the join between the sheets is about 10mm or so, again sealed with Evo-stik. Rub off any excess Evo-stik before it sets hard: I find that Wilkinson’s Stores have the cheapest price for tubes if there is one near you.
The roof ridge is normally a piece of the same flat aluminum sheet, the fold being added with the reverse of a knife blade, use window frame sealer (to fill the corrugations), and any other edges (round chimney stacks at the back of a false front etc ) has another layer of foils (as above) to finish off, and let it dry.
When complete, I paint my roof as the paint will add another layer of weather protection – I use the ‘tester pots’ of light grey, or brick red (red oxide) masonry paint from the likes of B&Q paying particular attention to the edges of the corrugations and around the edges & chimney stacks. If you also fit bargeboards these are also checked, to see there are not gaps between them and the edge of the corrugated sheet. Give the roof a couple of colours, which will give a weathered galvanized iron finish, and then weather it with whatever colours you use on your railway: I use acrylic paints here and finish off with a layer of varnish.
Finally, here are some photos of some of my corrugated iron rooves.
http://www.cheddarstamper.co.uk/P/Paper ... 6075).aspx
This is my crimper in a vice - that leaves both hands free to turn the rollers.
This is the roof of part of a large produce building (built for refrigerated vans to unload at), it is the colour of the asheets aftyer annealing, and they are fixed onto a plasticard under roof with Evo-stik.
Here are a couple of rooves for the rr staff in location, and painted and weathered - it looks like some more is going to be needed. The rooves are painted with <asonry paint and varnished then you can have 'fun' with any old dirty/rusty/messy colour you want, and cap it off with some more varnish(Johnson's Klear)
A final photo (those have saved me a lot of words and will give a far far better result!) of the roof of the Assay Office.
One tyhing not mentioned is that the sheet for crimping & after annealing is about 3" x 2.5(ish)". Any larger and you will be asking too much of the crimper, which will inevitably break - NOT the idea!
Feed the sheet in - it will be a firts a bit difficult: I normally make a couple of crimps, feed it back to enhance them, and then do another couple or so, and watch that it runs straight., You can with care go over the twisted corrugation, to rectify it.
As usual practice is essential, and go slowly, the tool is meant for papaer, and has aluminium rollers which can and do bend(upwards for the top one - keep them topgether with a 'spare hand (Ha they are both in use!) when reversing the direction it can be done then by pressing down on them.
Seal the vertical join with Evo-stik, I now generally use window frame sealant in strips along the roof to lay the sheets down onto, I use the brown shade, and get it at £1.50 per cartridge.
Finally add a roof/ridge cap again with Evo-stik, from your scrap. Use the masonry paint thickly to seal the inevitable gaps at the end of the corrugations.
Now have a rest an admire your newly corrugated roof!
)
how did you get it corrugated? Was it some kind of press you made... I was thinking of doing the same as it's a a never ending source... 
