Layout Progress (IV)
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With a long holiday over the Easter weekend, the opportunity was taken to start work on the baseboards. Most of the work had to be done outside, and I had hoped to get the two main baseboards constructed, but the weather was not too sympathetic to my needs and I was only able to get work done on one.

The baseboards are being constructed using methods developed by Dick Ganderton of the ScaleSeven Group. The main advantages of this method are reasonable cost, and good stability and rigidity combined with light weight. The main materials used are 4mm and 6mm plywood and glass fibre tape and resin to re-enforce all the joints.

Once again, the site will take a wee while to load, probably about a minute at 28.8, since it contains even more largish .JPG files.

Scale7 Trackwork A start is made by cutting out the top of the baseboard from the 4mm sheet. This proved to be a wee bit difficult since I had to use an 8' x 4' sheet (2400mm x 1200mm) and cutting with a hand saw on the small workbench was a bit precarious. Using a power saw at ground level would have been much easier.
Scale7 Trackwork The two baseboard tops cut out.

I took the opportunity of marking out and cutting the second main board top from the first one. I wanted them to be exact mirror images of each other since I intend to store them face to face (with spacers) for storage. This is also the reason for looking for light weight. Two board of this size built to more traditional methods would be quite a considerable weight.

Scale7 Trackwork The 6mm plywood sides are glued to the baseboard top.

The 6mm plywood was supplied from the timber yard already cut into strips 100mm wide. It is worth getting this done by your supplier since they should be able to cut the strips accurately and straight on their sawbench. Straightness is the most important factor and it can be difficult doing that at home with large sheets.

It was intended to glue the sides to the top with a hot glue gun but I did not have much luck with that method since the setting time of the glue seemed to be too fast when dealing with the longer strips. I finished up using white woodworking fast-setting PVA glue which added a bit of time to the operation - but worked.
Scale7 Trackwork The one deviation from Dick Ganderton's method is to use 11mm hardwood ends on the baseboards. I have done this to provide a more substantial end to attach fittings for rail ends where they cross the baseboard join.

This is maybe being a bit conservative, but it hasn't added too much weight to the structure and will probably require no more re-enforcing when clamping devices are used to hold the baseboards together.

Scale7 Trackwork The longitudinal and lateral lengths for the sub-base have been cut out using the 6mm plywood strips.

The lateral ones have been placed in position and one of the longitudinal ones is being placed to mark out the positions of the half joints required.

Scale7 Trackwork All the half joints have been cut and the sub-base members have been placed in position before gluing.

Note the inclusion of some diagonal struts which are necessary to give further protection against twisting.

Scale7 Trackwork Once everything has been tried out for size, the sub-base struts are removed and lightened by drilling large diameter holes - quite easily done using a large diameter cutter in a power drill.

Apart from lightening the structure, the holes also provide for wiring runs, etc., under the baseboard.

Scale7 Trackwork Number One grand-daughter with the almost completed board.

The sub-base members have been glued in place using PVA glue, and left on the kitchen floor overnight to set flat. In this state, the board is quite rigid and definitely useable but the addition of the fibre glass tape and resin to re-enforce the joints would be advisable since it relies on the success of gluing 6mm section on end - which may not survive the rough and tumble of being carted around exhibitions, etc.

In this state the board weighs 13lbs (6kgs) and the addition of the fibre glass tape and resin will probably add another 2lbs (1kg). It is 5'6" x 3'2" (1684mm x 960mm)

The positioning of the sub frame members and the diagonals are not quite as random as they seem. They have all been positioned to avoid sub base point operating units.

And I keep telling my wife that the grass needs to be cut :-).

Scale7 Trackwork The work on the second baseboard continues the following weekend.

The plywood was cut and placed as before, but this time I was determined to use the hot glue gun since I had bought it for this purpose :-). I had been advised by Dick Ganderton to ignore the instructions and use it like a soldering bolt - which I tried, and it worked very well.

The baseboard is being constructed on top of the first baseboard to get a good flat surface.

Scale7 Trackwork A close shot of how the glue was applied.

I tacked the items together with short beads of glue - about 3" - 4" long (75 - 100mm). On longer pieces of wood, I placed the tacks approximately 1 foot (300mm) apart.

The glue sets work hard in a few seconds after application and I found the tacking to be more than adequate to hold the assembly together prior to applying the glass fibre tape.

Note the low quality plywood being used - again, more than adequate for the job in hand.

Scale7 Trackwork And now a start is made on applying the glass fibre tape.

The tape is 1 inch (25mm) wide. The resin, mixed with hardener, is applied first by brush, then the tape is placed on the resin and persuaded into place with the brush, then more hardener is applied on top of the tape.

As you can see, this can be a bit messy since the resin is only workable for 20 minutes therefore you have to work fairly quickly. My first resin mix was 200cc but I had to throw half of it away since it had started to go off. In future I shall mix 100cc which will just about cover what I can place in 20 minutes.

I bought my glass fibre materials from a local supplier who also manufactured glass fibre products. So I was able to get reliable information on how to work with the materials which was extremely useful. Take care, as some of the chemicals can be hazardous and should be treated with respect, and protective gloves should be worn.

Scale7 Trackwork Another view of the board, with the glass fibre application on the right hand side.

I took the opportunity to experiment with reducing the number of longitudinal members to see if the rigidity was as good as in the first board. The diagonal members are still present since they prevent twisting.

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