Matford 'New'
We've taken the decision to take Matford off the exhibition circuit for the time being and to 'do an Eridge' and rebuild it. It has been suffering from several problems in the baseboard department. Firstly we used the dreaded MDF which has swollen to at least +1mm and in some places more. This is due to our proximity to a salt water atmosphere. In hindsight, perhaps these problems could've been avoided with the MDF had we sealed it all, after cutting, with varnish at least.
When this problem was discovered we had already half built our replacement DRAG test track for which we were using MDF. So all the boards were thoroughly treated with GRP resin and painted with marine quality paint. These are problem free with good track alignment and work perfectly well considering that they are erected and dismantled twice a month. The original suffered from poor quality deal softwood framework, which ended up looking like the waves of the ocean. So the lesson was learnt that always use the best materiel that can be afforded.
The second serious problem was that the side/box frames were made from a synthetic materiel (flooring laminate) which not only warped, it took on a banana shape. It was assumed that such a materiel would be stable, but no so. Avoid it like the plague! We rebuilt the board 'undercariages' with marine ply framework. This improved matters somewhat but the constant expansion on the MDF baseboard top still caused alignment problems. Each board top has subsequently taken on a saucer shape.
We are rebuilding the baseboards with the 'new' polyfoam principle, as used by Gordon Gravett on Pempoul. It consists of 1200mm x 500mm x 50mm thick pink polyfoam insulation.(I gather that it's also available in blue, but I've never seen it!). The framework is made from 4mm thick x 100mm deep quality ply glued on with solvent-free grab adhesive. (No More Nails type) To avoid having to hold it altogether whilst the glue goes off with clamps, we have used 3-4 inch long wood screws No 14/16 size which have a large coarse thread, screwed in along the ply sides at 100mm spaces directly into the foam. It's dense enough to allow a very strong grip and bite for the screws to allow the go off. After this has happened the screws are removed for re-use.
These show the style of construction. They are to be used on the Balcombe Viaduct project. The ply top strip is for the 2 track plain line. They have been made now for over a year and kept in a relatively damp garage without any sign of movement. In fact it is almost impossible to put in any torsional twist.
Another problem that has come to light is that not all code 82 flat bottom rail is exactly the same. We found that we had used Exactoscale track bases and used C&L rail which is 0.2mm thicker at the rail head, thus making the track 0.4mm tight to gauge. Not acceptable when working in P4! So this also made it easier to decide that a complete track rebuild was also neccessary.
All the buildings and as much of the scenery as possible will be salvaged and re-used. We want to preserve the essential 'look' of the layout.
That having been decided we sought advice from CK of this parish for his expertise in assessing what 'might have happened' had BR remodelled it all in the early 90s. This was bearing in mind the cost cutting and removal of expensive to maintain S & C work that 'would have happened'! To this end the complex pointwork at the fiddle yard end of the layout will be removed (three-way point and other under used pointwork) and will be replaced with a simple crossover on a new extension board between the FY and the current first scenic board and a new pointwork to the up and down sidings in flat bottom leading to 'older' bullhead trackwork.
This is the pointwork that is being replaced. You can see the track alignment problems from this snap. (ctsy David Brandreth)
This is the first bit of new pointwork (new crossover) made in copperclad FB. It is a BV 10 (1 in 10 angle). Next all the cosmetic bits and pieces will be added. Colin Craig cast 'Pandrol' fittings with clamplocks, and backdrives using Brassmasters cranks all non working! Once all this is done the whole thing will be mounted on 4mm ply and the Tortoise (or the new Cobalt) motors added and fully tested before fitting and gluing to the polyfoam baseboards. Thanks to my old friend Brian Harrap (ZOB and Quai87) for his invaluable advice in F/B point construction.
Exactoscale instruction sheet
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