Tag Archives: 2mm MDF

Now. Where Was I?

Well, summer’s over. We’ve even seen a surprise snowstorm here in New Jersey. And my sister actually lives on Dartmoor tells me they’ve had snow there as well.

So it’s back to work on the Boltorr branch. 

I’m currently working on the road bridge which forms the scenic break at the northern end of the layout. It’s built using a structure of 2mm MDF, and stonework of chips of DAS modelling clay. 

The bridge ready for trimming
The bridge ready for trimming and rendering

All stonework is finished except for some trimming and my next stage will be representing the road, actually one of the most difficult exercises in modelling. I also have some etched drain covers and rain grills to add some detail. I just have to figure how to give the road a hint of camber.

The bridge will then be ready for painting and rendering.

Devon General 46 squeezes across
Devon General 46 squeezes across

My priority now will be to get the basic landform settled so I can actually lay some track. Initially the layout will be DC, but I’m wiring it so it will be easy to convert to DCC at some point. 

Sometimes you have to Double, Double Check

Remember that bridge I’m building?

Well, the first attempt looked pretty good, but…

When it comes to scenery and structures I’m pretty much of the school of If It Looks Right, It Probably Is Right.

So far, most of my layout building has been done by eye. No need for scales and engineering drawings.

However, I have used spirit- and laser-levels to set the bed of the permanent way, and checking for horizontal when positioning Boltorr Dam, and routing the access road. The access road does look a bit like an Ordnance Survey contour, and I’ll be relieving that a little. But that’s by-the-by.

When I made the final check of my first road bridge I found it had racked while the glue set. That is, twisted.

Unfortunately, this isn’t the age of Scotch glue – not that Scotch – animal glue – sorry vegans – or Seccotine – something for you piscatorians – so steaming or warming the modern PVA I used didn’t work.

Back to the drawing board.

All the component materials are much the same – 2mm MDF, foam-board, PVA, except that rather than gluing up the entire structure in one go and hoping for the best I’m completing one process at a time, letting it set, and then move onto the next.

Which is where I am now.

Diversion. When I was at grammar school, one of my first choices was “Latin” – sorry Fred Stacy – or “Woodwork“.

C’mon it’s difficult to be true to your roots.

Guess what I chose?

A lesson with “Woody” Worrell was a lesson in life. In the morning, come in, turn on the Scotch-glue-pot over the Bunsen Burner. In the afternoon, smell the dead animals boiling and rendering away in the glue-pot – still better than McDonald’s by a million miles. No really. But you know that, don’t you?

Anyway, we’d listen to the cricket on long-wave BBC from Droitwich. At the end of every lesson, he’d read a poem. Sorry Woody. I can’t remember any of them, but I know John Masefield and Rupert Brooks were in there, every time. Sometimes even Kipling. Thanks Woody. I mean that.

Then bus home, even if I wasn’t wearing my cap. Thanks, PGS.

Sorry. No Pictures of my abject failure. But I did win the school Woodwork Prize. Oh yes…
Just wait until my next posting…

Meanwhile in Dumnonia…

Bridge Building: I

Time to think about the road bridge over the tracks. This is going to serve as a scenic break so that the layout appears to run north-east all the way to Exeter.

I’m going back to the method I used for the tunnel portal to the south. For the basic structure I’ve used 2mm MDF. This is quite hard to source here. In the end I got mine from Am@zon, but it actually shipped from Sweden.

2mm MDF and foam-board
2mm MDF and foam-board
Aligning and levelling the bridge
Aligning and levelling the bridge

I made a template for the stonework of the bridge as described in another article and cut the front and the back of the bridge together so they would – hopefully – be identical. I used foam-board for the road plane and as internal braces to stabilise the structure. The whole lot is joined together with PVA glue.
The bridge in situ. There is space on the right for the platform to continue under the bridge
The bridge in situ. There is space on the right for the platform to continue under the bridge

I’ve applied foam-board and styrene strip to represent buttresses and some masonry embellishment. Only the layout side is going to be treated since the other side of the bridge won’t be visible.

Next step is to install the bridge liner and roof.

Build a Road-over bridge

Impermanent Ways - volume 6... Noodle Books: 978-1-906419-99-8
Impermanent Ways – volume 6… Noodle Books: 978-1-906419-99-8
I had hoped to find a laser-cut bridge kit somewhere on the interwebs, but nothing looked quite right.

My DAS chip method is tedious, but it looks so good. I think I’m committed to it now, if only to maintain a “look” across the layout.

I looked around Google images for a bridge to base Boltorr’s on, but didn’t find an example which fitted Dumnonia’s needs better than the one illustrated on the cover of “Impermanent Ways v6“. So I’m not certain the rights’ issues involved here, but buy the book! The whole series is a huge resource if you model in this area.

The real issue when building a model bridge which never actually existed, is getting the arch right.

The image is on the oblique and needs to be adjusted
The image is on the oblique and needs to be adjusted

The photo of the bridge on the cover is on the oblique, so I used an image editor to square the perspective and match an ellipse to the arch.
I adjusted the perspective then constructed an ellipse to match the arch
I adjusted the perspective then constructed an ellipse to match the arch

I then reduced the image to black & white to produce a template. I’ll jiggle with the width of the bridge and the chord of the road deck to fit my location.

In Boltorr’s case, this means spanning the branchline, a siding and possibly an extension of the platform under the bridge. I will also have to adjust to accommodate the road level above.

I reduced the image to b/w to use as a template
I reduced the image to b/w to use as a template

The northern exit starts its evolution
The northern exit starts its evolution

At this point, I’m not considering a hi-tech solution. It’ll be a combination of printer settings and a pair of scissors.

For construction I’m going back to 2mm MDF with appliqué stonework courtesy of DAS. This provides the most stable foundation.

Boltorr Dam and the rail bridge abutments were built using foam-board which tends to take a form of its own if it possibly can. This is not necessarily a bad thing, but for engineering elements it’s a problem. MDF resists the urge to distort far better.

Boltorr Road Halt – here we are again …

Well our move is over. Of course there are still one or two things which haven’t turned up yet, but there are still one or two boxes to unpack.

The Boltorr Road baseboard was spirited from its old home to the new with virtually no damage and now sits in our basement waiting for Creation to start again.

The layout showing the profile - I don't like the "nailed on a board" look
The layout showing the profile – I don’t like the “nailed on a board” look

Believe it or not, I’m still working on Boltorr Reservoir dam. Made mostly from braced foam board and DAS air curing clay with every stone carved into it by hand. I think future stone construction will revert to the method I used for the Bolt Tor tunnel entrance. That is individual DAS blocks glued on piece by piece. I think it may be a bit slower but rather more satisfying and convincing.

Bolt Tor Tunnel mouth - every stone individually applied
Bolt Tor Tunnel mouth – every stone individually applied

So the dam is just about ready for rendering and placing on the layout. This means I should be able to finalise the lie of the land around the Boltorr Brook and start work on the water course.

The next “structural” construction will be the retaining wall for the passing loop and head shunt.

Boltorr Road Halt - track plan
Boltorr Road Halt – track plan