Baseboard Basics

[Pacific231G]

I've seen a couple of articles recently on project layouts for beginners and they both advised the "traditional" construction of a plywood board supported on 3x1 (70x20) or 2x1 (50x25mm) planed softwood frames. I know this method is supposed to be simple (I've used it myself more than once) but I thought general opinion was that it is rather prone to warping and heavy for its strength and had been largely replaced by all plywood or thin MDF box or box girder approaches. My current layouts are both quite small table sitters and used quite a lot of foamcore in their construction which is great for small and microlayouts but I'm thinking of a rather larger portable multiboard layout so what types of baseboard construction do most of you favour?

 

David

[Guest jim s-w]

Hi David

 

If I might offer 2 pieces of advise based on experience.

 

1 - Always buy the best quality materials you can. It might cost a lot more but think how much time and effort you devote to a layout, without a solid foundation you will have problems. Find a proper timber merchant, dont use places like B&Q as their stuff is total garbage.

 

 

2 - Never sacrifice stability for a weight saving. If your baseboards end up heavy so be it.

 

Cheers

 

Jim

[bike2steam]

Agree with above.

All exterior or marine ply (9mm), 4" (100mm) deep to accommodate the Tortoise point motors.

But use diagonal bracing as well as cross bracing, will give it extra rigidity.

[Kenton]

Another vote here for all plywood construction - best "marine" quality if possible usually 12 or even 18mm thick - depending on length of board - Quintland 10ft long (if it ever gets built) will be 18mm. 1ft box frame construction with diagonals in alternate boxes. It will be heavy by my normal standards (6sq ft or less) but it will not warp like Longthinney did.

 

The other two current layouts Sychpwll and Noquay are open frame (only the track bed on a base board) as they are not "flat" layouts. Sychpwll is only 3" deep and the Tortoise will need to be accommodated on their sides (more fuss and bother) unless I can get the raw mini servos to work correctly. Sychpwll also uses MDF - which I will avoid in future. All previous layouts have been ply with the exception of a number of really early layouts on various grades of Sundeala - never to be repeated.

 

Chipboard is far too heavy for a portable layout and do not use it unless you have some that fell off the back of a lorry and you are really being miserly - or it is a permanent layout. It still requires supporting and doesn't like moisture - but then nothing does.

 

I have never used foamboard - just seems more trouble than its worth on anything other than a micro layout.

[cutting42]

I've seen a couple of articles recently on project layouts for beginners and they both advised the "traditional" construction of a plywood board supported on 3x1 (70x20) or 2x1 (50x25mm) planed softwood frames. I know this method is supposed to be simple (I've used it myself more than once) but I thought general opinion was that it is rather prone to warping and heavy for its strength and had been largely replaced by all plywood or thin MDF box or box girder approaches. My current layouts are both quite small table sitters and used quite a lot of foamcore in their construction which is great for small and microlayouts but I'm thinking of a rather larger portable multiboard layout so what types of baseboard construction do most of you favour?

 

David

 

Hi David

 

I am a fan of the 9 or 12mm ply approach. B&Poo are not too bad for plywood if you get the WBP (weather and boil proof) sort, sometimes just called exterior grade. Slightly more expensive but very stable. Try and support every 12 inches or so depending on width and you will be fine. Here are some I have built before for myself and for Tim Easters Auchin thingy.

 

 

 

 

[Guest jim s-w]

 

im not sure where this idea that DIY Shed timber is always crap and the local timber merchant is great comes from I think its another Great Model Railway Myth given that there is a fair chance they both recieved supllies off the same boat....

 

 

Hi Mikey

 

Just personal experience. B&Q ply tends to come from hong kong and is mostly sawdust while proper ply comes from Scandinavia, Russia or Canada and is solid through and through. Yes Wickes ply is better but that doesn't mean its good. Its kind of like saying that a mainline castle is good without having seen the new Hornby one. They really are worlds apart. Its a shame the prices are words apart too - 60 quid for a sheet!!

 

Cheers

 

Jim

[Guest jim s-w]

Hi Mikey

 

In that case I concur.

 

Cheers

 

Jim

[Pacific231G]

Hi David

 

If I might offer 2 pieces of advise based on experience.

 

1 - Always buy the best quality materials you can. It might cost a lot more but think how much time and effort you devote to a layout, without a solid foundation you will have problems. Find a proper timber merchant, dont use places like B&Q as their stuff is total garbage.

 

 

2 - Never sacrifice stability for a weight saving. If your baseboards end up heavy so be it.

 

Cheers

 

Jim

 

I agree with point 1 assuming that the local timber merchant really is a lot better than B&Q etc. Point 2 makes sense if that's what is actually achieved but basic engineering principles (bending moments and suchlike) suggest that a lot of very heavy baseboard construction isn't adding stability and the baseboard may even end up struggling to support its own weight. It seems a bit like trying to build a bridge using a solid slab of steel rather than a box girder. In theory and I suspect in practice a 75 x12mm member should give the same rigidity as a 50x25 but at 3/4 the weight yet I still see articles recommending 50x25 (2x1) or even 25x25) for baseboard framing.

Is it general experience that plywood is more rigid than PSE of the same dimensions ?

 

Has anyone used B&Qs (or anyone else's) timber cutting service with ply? It strikes me that it should be possible to get effectively the kit of parts for a baseboard cut pretty accurately but I've not used it for a long time and then it was just to cut some harboard backscenes (I wouldn't use harboard as a baseboard material)

[cutting42]

ahhh Id agree with you on ply there.. I was talking about real tree wood in its PSE or rough sawn form..

 

I know that a certain Builders Merchant and a Proper Timber Merchant get their real tree wood from the same place and one charges several limbs more than the other for the same stuff..

 

No names obviously but its true.....

 

Sourcing from the same place and selling the same quality wood are two very different things. Wood is graded like most things and the timber yard will probably be picking firsts and seconds where as the builders yard will have at best unsorted but probably 4ths and 5ths, you will not know necessarily. If the builders yard is friendly you may be able to pick out specific lengths of nicer timber. A good timber yard will always allow you to pick and choose the best stuff and may be able to plane and cut to size as well for you. There can be a factor of 4 or 5 in the price difference especially with hardwoods between firsts and 5ths.

 

 

Just personal experience. B&Q ply tends to come from hong kong and is mostly sawdust while proper ply comes from Scandinavia, Russia or Canada and is solid through and through. Yes Wickes ply is better but that doesn't mean its good. Its kind of like saying that a mainline castle is good without having seen the new Hornby one. They really are worlds apart. Its a shame the prices are words apart too - 60 quid for a sheet!!

 

Cheers

 

Jim

 

However for ply I disagree to a point with your comments (in the politest way possible of course ) that it is just sawdust. I agree that for quality ply you should go Baltic or similar but for baseboards I think it is an unnecessary expense. Top quality ply is mostly about good quality face sheets and minimising voids in the ply laminations. The cheaper plywoods can have knots on the face sheets and faults with voids filled with bonding agent in the inner laminations but for construction this has a minimal impact on structural strength. By purchasing the slightly better WBP grade you get good strength, stability with a degree of waterproofing as well. It has served me well and as a hobbyist woodworker as well I am quite fussy about wood quality.

[Gilbert]

I've settled on 9mm Birch ply from my local speciallist supplier and its way better than the chains. I do use B&Q board for the end transport boards for moving the layout. I think the baseboard sheet spec is B/BB birch ply and its not cheap. I also use 25mm square planed redwood from the same guy for bracing and jonts. The great thing is I take in a cutting plan for an 8 x 4 sheet and a few days later I can pick up a "kit" almost ready for assembly. With back scenes and bracing you soon eat up the available sheet. A few basic tools and the "measure at least twice/cut once" approach then produce a good solid foundation. I did wonder if I'd get away with 6mm - any suggestions? Can I just add a plug for self counter sinking drill bits too. Brilliant.

Chris

[AlanR]

I used the B&Q cutting service to cut a 8X4 down to a 7x4 and then cut that to a 7 x 2 to make a two part 7x 4 board for the sons Thomas the Tank Engine set last Christmas.

 

I thought that this would be the easiest way to make the cut the boards and get the sheet home more easily.

 

Unfortuately none of the cuts were at right angles and are cut to the nearest centimeter where as being an engineer and a modeller I would measure to the mm and allow for the width of cut.

 

The operator did his best but the vertical cutter was only calibtrated in centimeters and relies on gravity to keep the board still - the smaller the boards get the more likely they are to move and give a non square or wavy cut especially if you cut a sheet horizontally near the middle and the weight of the top part tends to flap and spoil the end of the cut.

 

It certainly wasn't accurrate enough to provide a cutting list and expect a set of parts that will fit together but ok if you only need a small strip taken off.

 

I managed to build the two part boards after, but instead of cutting the frame to suit the board I made the frame square and then trimmed the sheet to fit - resulting in boards a bit smaller than planned and taking lot longer than expected.

 

The quality of the board seemed ok to me for what I paid for it but I did look through the pile and chose the best I could find.

[57xx]

The best quality ply is Birch Ply, it's way better than WBP, but you pay the premium. The WBP I've got from timber merchants appears no different from Wickes/B&Q stuff, the only up side is they may store it better than the DIY outlets who's stuff is 90% warped. I once sorted through 20 sheets of Wickes 4'x2' 12mm ply to get 3 "flat" sheets and only one of those was truly flat!! Luckily I then realised they would be under sized (and over priced) anyhow and put them back. I used my local timber merchant and they cut exactly to the size I requested, nice straight square cuts, and were good enough to remind me I'd loose a little on each rip.

 

From my recent experience, I would say 9mm is the absolute minimum thickness to use as a single skin and that would require lots of bracing inc diagonals as has already been mentioned. 12mm may be better for stability I think. 6mm would only be any good when used in a sandwich construction, an example shown here or a box girder approach.

[nswgr1855]

The best quality ply is Birch Ply, it's way better than WBP, but you pay the premium. The WBP I've got from timber merchants appears no different from Wickes/B&Q stuff, the only up side is they may store it better than the DIY outlets who's stuff is 90% warped. I once sorted through 20 sheets of Wickes 4'x2' 12mm ply to get 3 "flat" sheets and only one of those was truly flat!! Luckily I then realised they would be under sized (and over priced) anyhow and put them back. I used my local timber merchant and they cut exactly to the size I requested, nice straight square cuts, and were good enough to remind me I'd loose a little on each rip.

 

From my recent experience, I would say 9mm is the absolute minimum thickness to use as a single skin and that would require lots of bracing inc diagonals as has already been mentioned. 12mm may be better for stability I think. 6mm would only be any good when used in a sandwich construction, an example shown here or a box girder approach.

 

From my experience and observations I agree with the above statements for the plywood used as a track base. I would suggest for plywood track base, as used in open grid or L girder type constructions, that the plywood support distance be calculated using the formula plywood thickness squared times 3.5. For frame timber I would suggest the following formula for the leg support distance, the beam height squared timed the width divided by 100. Both formulas require all dimensions to be in mm.

 

Terry Flynn

[bike2steam]

I know some will be a little shocked, but a little warping of plywood sheet doesn't worry me. The framework, all 9mm thick x 100mm wide, is assembled in a jig so all is straight, and square, all pinned, and glued, the top is added, warped or not, it ends up flat. Finished off with 2 liberal coatings of sanding sealer - no problem.

[Etched Pixels]

Another reason to check your local timber merchant and also local furniture makers and the like is you can often get offcuts of really nice wood that are too short for their intended use. Some of my boards have oak cross braces because that was what was going cheap in the offcuts department. I imagine the layout will disintegrate well before the ply base, and the frames have brass screws so ought to be good for a century !

[Andy L]

Hi guys

 

With regard to baseboard construction, i'm a massive fan of Bob Harpers (of Teign House sidings fame) design.

 

He recomends 9mm Ext grade ply with 100mm x 12mm (4" x 1/2") cross braces.

 

We've just finished building my boards (12' x 2' in 3 boards of 4 x 2), i'll take some photos tomorrow and post them.

 

When it comes to sourcing the timber, i have a major advantage over most people, i work for and indie diy store, so i can order exactly what i need straight from our suppliers.

 

plus i dont have to pay anyone to cut or deliver it (not that my work actually charges for either of those)

 

If there is anyone in the south manchester area that needs sorting out with supplies for baseboards then by all means get in touch with me. please do so via email and i'll give the the name and address of my work.

 

to do otherwise i think would be breaking the rules (and i'm a good boy (or so my misses tells me!! ))

 

 

 

 

[woodbine]

Here are some I have built before for myself and for Tim Easters Auchin thingy.

 

I see that Cutting42 used pattern makers dowels set into the end ply. How do you allow for the depth of the PMD into the ply? Surely there would be nothing left to fix to?

Is it a skin of thin ply with the PMDs fixed somehow to a thicker piece of something behind it, or since it has to take the strain of the bolts too, is it just a really thick piece of ply to start with? What do other people do?

[cutting42]

I see that Cutting42 used pattern makers dowels set into the end ply. How do you allow for the depth of the PMD into the ply? Surely there would be nothing left to fix to?

Is it a skin of thin ply with the PMDs fixed somehow to a thicker piece of something behind it, or since it has to take the strain of the bolts too, is it just a really thick piece of ply to start with? What do other people do?

 

Hi Woodbine

 

For that board with the PMD I screwed and glued a second skin of ply on the inside to give more depth. On my board I used 12mm ply and a centering pin from Osborns models which were only 10mm deep so no extra depth required.

 

HTH

[scott_efc]

Regarding actually joining the board together how do people go about it? Obviously if you are attempting to join a board to an edge only say 8mm thick for example, how do you go about it? Ive seen some incredibly neat examples on her ethat show little sign of screwing etc is it a job for PVA or something more substantial?

 

On a side not also but not wishing to clog up the forum with a new thread... How do modellers models right to the edge without going over so you get a cean front? i.e you are building a bank up to the front of your layout obviouly either in papier mache or modroc etc. How do you go to the edge so it seems a seemless transition from layout to front of the display? (Sory if that makes no sense at all!!

 

Any replies would be great as im about to start building and spening alot of time pondering! Cheers, Scott.

[Donw]

I find 6mm wbp ply ok for baseboards. I findit easier to use and fix it to 40x18mm pse sides. Brace underneath with 25mm sq in an x shape halved at the join. This produces a light rigid board I then fix 6mm ply shaped pieces to the sides. If you assemble of a flat surface it seems ok. My experience with thicker ply is that it will pull the board into the shape it wants thinner ply will stay where you put it. If you can bother with the extra cutting. Two pieces of 4mm ply with 18-25mm spacers makes a good side member. (Barry Norman's frames but thinner) I made one curved for the baseboard front on and exhibition layout.

For the ends if you are using dowel for alignment. I cut two 4mm ( for C+L ) pieces and drill through both for the dowels. These are then backed with pse or 9mm ply. This sorts the alignment out.

 

I like a baseboard to be light enough to hold in one hand whilst you open the door with the other.

 

DonW

 

 

[Russ (mines a pint)]

I know some will be a little shocked, but a little warping of plywood sheet doesn't worry me. The framework, all 9mm thick x 100mm wide, is assembled in a jig so all is straight, and square, all pinned, and glued, the top is added, warped or not, it ends up flat. Finished off with 2 liberal coatings of sanding sealer - no problem.

I was a little alarmed at some of the ply that I have bought being already curved- but I think bracing is the key and sealing- I used oil based paint but anything that keeps moisture out has to be a good thing, I have my boards in a celler which is damp and adverse so try to get stuff sealed pretty much as the boards finished before doing anything else.

I dont think chain ply is all that bad- especially the exterior grade but the plain softwood I have bought for bracing on occassion has been too bad to use- it still comes in as scenery supports though

 

I like a baseboard to be light enough to hold in one hand whilst you open the door with the other.

- and carry up the cellar steps!

Another reason to check your local timber merchant and also local furniture makers and the like is you can often get offcuts of really nice wood that are too short for their intended use.

- also this may not be a national phenomenon but found that Birch Ply in the Timber merchants is cheaper than the cheapest stuff in B&Q and thats before discounted offcuts! the trouble is they dont have the long hours of the DIY places.

[brossard]

My last layout was built using regular plywood. 1/2 thick for the tops and 1/2 x 4" for the sides. Its weight was horrendous though. I am building a new one based on MRJ's Inkerman Street (11 ft long x 28" wide) in 4mm 00. I have used 1/2" x 4" birch ply for the sides and 1/4" birch ply for the tops. I have also used C&L steel dowels between boards(my last layout used 1" wood ones which wore out and fell out over time). Fasteners are 1/4" dowels and carpenters glue (the yellow stuff), no screws. These boards seem to be quite a bit lighter than the last ones.

 

I totally wouldn't use the 1x2 pine for sides that I see recommended in benchwork books and even in certain Model Railway mags recently.

 

I would add that one should use a proper wood sealer - like Shellac. Never had a problem with warping on my old layout despite carting it to numerous shows. I have my doubts that paint actually seals wood.

 

John

[Re6/6]

Go for the best ply that you can afford. Preferably 'marine grade'. Avoid MDF like the bubonic plague. We used it four or so years ago and have bitterly regretted it since. I'm still working to rectify the expansion/swelling up problems, by replacing as much of the 'undercarriage' with quality ply. No easy task with the layout in place. I've replaced as much as I can the MDF material at the edges of the board joints with marine ply. To give you an idea of the problem, I measured the thickness of the MDF pieces that were removed and found that the 6mm thick stuff had become nearly 8mm. In other words it had taken on moisture over time, and caused all sorts of problems at the joints.

 

There certainly is a big difference in so-called quality ply. I bought some 'shop fitting quality' birch-faced ply. Had it cut to order, put into store and it's now like the waves of the ocean! On the other hand I'm using some recycled marine ply from an old (20+years) layout, and it's still straight and true.

 

If ply girder type construction method is used, don't waste time drilling holes everywhere in the framework. I did this once, so it looked like an old airframe and weighed the bag of 'holes' after cutting them out and the bag weighed virtually nothing!

 

Finally, consider the 'new' method using 50mm thick insulation boards (B&Q and elsewhere) and glued ('No More Nails' type) 4mm/6mm ply facings/bracings. This method was used very successfully used by Gordon Gravett on Pempoul (MRJ article a couple of years ago?) Has anyone on here had any experience of this method?

[Kenton]

I was a little alarmed at some of the ply that I have bought being already curved- but I think bracing is the key and sealing

No amount of bracing or sealing is going to right a bendy piece of plywood. The reason why it is bent is that the internal structure is unsound (too few ply gaps in the sheets or poor gluing) Yo will find that the warp will be transferred to the framing - especially if it is poor quality knotty pine or other softwood. It is no use sealing the dampness in. The forces twisting a flat sheet are greater than the integrity of a few lengths of skimpy bracing.

 

I never understand why (well I do because I've made the mistake myself ) folk skimp on the baseboard design and structure. You are going to put lots of hours of your time and effort into laying superb trackwork and building your layout. Maybe even transporting around the country to shows and yet we skimp and begrudge spending a few quid on quality material for the basic structure.

 

and weighed the bag of 'holes' after cutting them out and the bag weighed virtually nothing!

Was that a surprise? a bag of holes would weigh nothing - shouldn't you have been weighing the bits cut out to make the holes ? ;)

[dave_long]

 

Finally, consider the 'new' method using 50mm thick insulation boards (B&Q and elsewhere) and glued ('No More Nails' type) 4mm/6mm ply facings/bracings. This method was used very successfully used by Gordon Gravett on Pempoul (MRJ article a couple of years ago?) Has anyone on here had any experience of this method?

This seems to be a very big trend in the US if you look through most of the railroad forums about and look at the layouts I'd say over half have gone down this route, lots of pink and blue madness. I still reckon its quite an uneven and inconsistent surface even after sanding/skimming or similar, fine maybe for the coarser scales but could be quite rough on the EM and P4s of UK equipment.