Ply top?

[whynot]

Having decided that space constraints rule out (for me) an N tail chaser in 5'x 3', found an alternative home for end-to-end, near 12' x 15". Start will be "station" in 6' x 15".

What thickness ply recommended for top, please? It will sit on an existing (sturdy) shelf same size, so I reckon cross-bracing at c.18" spacing will suffice?

All comments welcome!

[Flashbang]

Hi
I use 9mm ply in Marine or Birch quality. I support the 9mm ply on a frame work of 44mm x 21mm (2" x 1") PSE timber on a grid of no greater than 400mm (16") centres.

You can use 6mm ply, but it is rather thin and needs good bracing underneath. Here I would be looking at bracing at 300mm (12") centres.

If Marine/Birch ply isnt available, then use WBP ply (WBP = Water & Boil Proof) but do check its not warped or damaged on the surface before purchasing it.

[b308]

My baseboards are all 9mm ply for the edges and 6mm for the baseboard itself... I've used 18" bracing without any problems on four layouts so far.

[whynot]

Thanks both!

[noel]

+

My baseboards are all 9mm ply for the edges and 6mm for the baseboard itself...

I agree, and I just use a good quality glued ply, but not Finnish Birch or Marine

My table modules are 750mm x 1500, supported by 150mm (6") support and
cross-frames Because, from a 1220 x 2440 (8' x4') sheet there are enough off-cuts
for the frames.

The 150mm(6") depth allows for interesting detail below datum.

+

[chris6166]

Am I in a majority of ONE, I have used chipboard as a base, it is of no interest to bugs, needs no preparation, is cheap, track pins push into it nicely but does need good framing underneath, I have never used MDF nor has my old dad and his chipboard has been down 30 years! there is a lot of it too. I see no advantages of MDF over chipboard.

Standing by for the deluge!

[b308]

I've used chipboard in the past, nothing wrong with it... but I prefer ply 'cause its stronger and lighter, and as my layouts are for exhibition use that's important.

[whynot]

Only the weight of chipboard prompted me to think of alternatives - but maybe with only 6' x 15" that would not be a significant problem.

Thanks.

[Zunnan]

The only problem I've ever had with chipboard is when ballasting. If you get excessive glue seepage onto an unsealed bit of board, the glue can swell the chipboard. I had this happen to me at a board join under a bridge, the resultant swelling was incredibly difficult to remedy and caused the track join to push upwards into a ridge which caused no end of problems with long wheelbased locomotives (8F and 9F in particular). As long as you adequately seal the baseboard, and support it with a good sturdy framework then it is a decent baseboard material. As pointed out above though, Ply is stronger and lighter so you can get away with using a lighter framework which is perfect for portable layouts.

[Bufferstop]

The thing you need to avoid in any baseboard is flexing. It's the depth of the frame it's attached to that determines how stiff it will be. I'd go for 6mm ply on a frame of 1" x 3/4" battens continuous on the long edges, cross battens at about 18" but most importantly a backscene board at least 9" deep screwed and glued along the back. If the front edge overhangs the front of the shelf you could also add a scenic profile board which continued 3 to 4" below the baseboard at the front. That should stiffen it up a treat. There's a school of thought that goes for even lighter construction on the same principal, make the board from 2" thick solid insulation material (the stuff they build into cavity walls and make the front and rear boards of 5mm foam core display board. I did a little 4foot long tester about 7 years ago. It comes out around Christmas every year and it's still going strong!

[buz]

Hi
I normally use a 12' spacing for frame supports with a 1/2'' 13mm top of chip board even used this for "N" .
only having solid top where its needed to support track work a yard or a town
Leaving an open frame to allow scenery to go above and bellow track level I also top the chip board with a soft board
that is normally used to make pin boards it means pins don't need much force to get them in quieter running.
However you build your bench work it needs to be solid and well made and have a level from which all measurements up or down are taken.
Your entire reliability depends on a good base and good track work take time and care with both.
regards John