Hi

Has anybody used Blue foam insulation sheets as sold in B&Q? and

is this suitable for use as a base board?

Thanks

Mark Griffiths

Hi Mark,
I'm currently using the white insulation foam that can be bought from building supplies merchants and I assume the stuff you are asking about is similar.
Not suitable for the base layer of a board, mine is stuck onto Plywood, which is braced underneath with softwood. The reason I'm using it is to facilitate scenic construction, particularly forming a tidal inlet below track level.

Wayne Williams is using a denser material (which happens to be blue) See it described in his layout thread here:- 

http://yourmodelrailway.net/view_topic.php?id=509&forum_id=21

or PM him for further information.

I would not use blue foam insulation board  for a baseboard.  We built a layout for our club and it shrunk!  I will use it for insulation behind vinyl siding, although on one particular job where we had to remove some siding from the insulation it had shrunk. so I now know that it is not a good material for something like a baseboard.  I still use it for forming contours for my scenery.

William

Hi

thanks for the info!

regards

Mark

Mark,
Blue foam (Styrofoam) at any thickness would not be sufficient for baseboards. HOWEVER, if you were to laminated with a contact cement, a thin wood skin like luan (5/32" thick) to both sides of say 1 1/2" foam, it would be extremely rigid, and would in my opinion work very well and be very light in weight.

Please know this, I have never tried it. Sometimes things look great but some kind of hidden issue pops up that shouldn't have.

I have built in my prior working life a 50 long mobile home with the walls and floor of a laminated construction. I had a lot of naysayers but it proved them all wrong. It worked beautifully. Granted that was a thicker laminate than you are looking for, but this just points out that the technology worked perfect.

If you chose to do something like this, PM me and I can give you more advice.

Wayne

Hi

A big thank you to all that answered my query, I found it a great help.

Regards

Mark

Hi Mark,

I wouldn't recommend it for a baseboard. It needs a support frame, it shrinks and warps, it will continue to out-gas styrene monomer for months, and it dents easily. By the time you've built a frame you might as well but a wood-based top on. Plus which putting point motors in (Cobalts, etc.) requires a wooden support anyway. Something that is never addressed is flammability. Burning polystyrene gives off some really nasty products.

Nigel

Hi Nigel,Mark is a former member and won't see your post.Nothing wrong with your post itself though as it will still help current members.

Raven here.
  I am reading a good book titled "N Scale Model Railroading" by Robert Schleicher
  In it he discusses the use of blue extruded insulation pieces to be used for the base board for a 6ft. x 6ft. N scale layout.  The board is several pieces laminated together. This is used as is and put on several legs or saw horses for support.  He feels that no plywood under layer is needed.  Only the blue foam as described.
  I just finished building the bench work for my N scale layout, but, have not yet put the base board on the framework. I have been thinking about using the insulation board. However, I can see what you mean by the objections. Question.  What would you use as a lite weight baseboard instead ?

I'm using Celotex, which is a finer grain than the white poly, and is sandwiched between two layers of foil and also has a layer of fibreglass embedded, I have it on a base of 40x19mm timber screwed and glued to 6mm fibreboard.

Celotex comes in either 25, 50, 75 or 100mm thick sheets from 1200x450 (4'x 18") to 1200x2400 (4'x8'). It cuts with very little mess, unlike the white stuff. I have left the foil on mine, I have seen reports of it warping if you remove the foil from only one side.

I then use a track bed cut from flooring tiles

http://www.wickes.co.uk/search?text=celotex%2050mm

I am familiar with celotex. However, the lumber company
that I went shopping at today had a very poor selection of lite weight products and no celotex. I found a fiber board very similar to dry wall however.
I am going to use it, after installing some support underneath the pieces. The material is like ceiling tiles only without the holes. Over large areas it needs some reinforcement underneath. No problem.
Well, now to break out the hammer, saw, and glue.
I appreciate your input. Having a layout, especially where in my case I want portability, lite weight is important.
Thanks
   Raven (Ed)

Hi Ed,

For a regular sized module (4 x 2 feet, 4 x 1.5 feet) adding a top of 6mm ply (1/4") gives a nice, non-crumbling base without adding very much in weight. I've built modules using this dimension ply (4" sides, internal bracing on 16" centers, top), I can lift a 4 x 2 one with one finger.My 5 x 1 built using 12mm ply (1/2") weighs in at 15 lbs.

Check if that material you've bought stays stable if using water-based glues and paints before you commit. may need a sealing coat of paint before you start scenicking and laying track.

Nigel

Nigel
  
  Checking to see if the fiber board I have is stable when using water-based glues and paints is a good idea. My plan is to paint the whole top of the layout with a coat or two of latex earth brown paint.  I will check stability to see if it's ok first.
  My layout for N is 4 x 12 ft. Built in three sections, each 4 ft. square with a 1 x 4 in. piece bracing one side of the square. Every piece is a 1" x 4" piece attached edge to edge with  glue and nails. The glue is used with a caulking gun and this saves a lot of fiddly work.
The glue is "Power Grab - Loctite." A narrow spine of wood runs lengthwise along each section to prevent the fiberboard from sagging, since it is covering a large area. Each square is attached to the other with big C clamps and the whole rests on three sawhorses. The layout can pivot or slide in a limited area. Necessary to allow a path from the garage door to the inner kitchen door with groceries in hand. My problem has been that each section is 4 ft. square and figuring a way to mount lite weight fiber board and not having it sag was a problem. The wood spines solve this. I tried 1/4 inch plywood but it sagged also.
  Portability and some  maneuverability necessitated some  "thinking out of the box" to build what I wanted.
4 ft x 12 ft. should give me plenty of space to run N scale for awhile till I decide to expand and either dig a basement or knock off the garage roof and go for two stories.
  My skill as a carpenter is limited to say the least, but, my ability to hammer nails and use a caulking gun seems to be improving.

    Ed

Hi Ed,

4-feet wide, hope you can work from both sides (or have long arms). You might want to put in a few cross braces, as you seem to have a 24" center design (correct me if I have got this wrong). Conventional wisdom in the building trade is 16" centers (hangover from the days of 8 x 4 feet boards). Each 4 x 4 module would be better with at least 2 cross braces on 16" centers (or even 12" centers). Half inch (nominal) width is OK for the bracing timber (and frame).

Loctite Powergrab, any idea how that compares to regular yellow wood glue (apart from the tack time)?

Nigel

Hi Ed,

Presumably the Powergrab is the acrylic-based one. Much less shear strength than regular yellow carpenters glue. Unless those nails are SS or galvanized, you might want to replace (or add) some SS wood screws. If you need to sand the adhesive a good mask/respirator is advisable because of the silicon dioxide content.

Nigel

Hello Nigel
  My cross bracing on the 4 x 4 sections is at 2 ft. intervals.  The fiber board is strong and should work ok as long as I don't try to put excessive weight on it.
  The Power Grab is acrylic. I used galvanized wall board nails, after drilling pilot holes. The result is solid.
  Each 4 x 4ft. section appears to be quite sturdy, yet lite weight for portability.
  The Power-Grab is reputed to be good enough to replace nails. I don't believe this. I used drywall nails also, and Tite Bond II as well in strategic spots.
  The entire layout is designed to pivot so as to allow access to all sides. Super long arms not needed.
  The idea of using a respirator when sanding is a good one.
  Thanks for the input.  I am now ready to start putting up mountains and digging valleys and doing scenic work. Personally, I enjoy this aspect of putting a layout together a lot more than the carpenter work.
  Happy railroading

    Ed

Hi Ed,

Galvanized nails plus the adhesive sounds a good mix for butt joints. 

Two foot centers might be a tad wide for dimensional stability of the module box (and support of the top).  Fingers crossed.

Nigel

Hello Nigel
  I can understand your concerns about dimensional stability using 2ft. centers. However, I ran a test putting excessive weight on the fiber board covering the frame. No problem. The combination of the thick fiber board and the wood spine underneath works well. Not as strong as plywood, but, unless I actually stood on the layout  there is no problem. Having built six layouts in 40 or so years of model railroading, a friend of mine said he thought I over engineered things. But, the secret of this current creation is the thick fiberboard and the  spines or braces.
  This business of baseboards seems to be tied closely with whether the layout is permanent or needs to be portable. In my case the problem of design hinged on the need to be portable and the ability to disconnect the sections and move them. Therefore lite weight and strength where needed, was an important consideration.
The extruded styrofoam insulation board being strong enough, if laminated, to stand on its own was duly noted.
The author of the book I had mentioned thought so. However, since I could not get the product where I live (for reasons I have yet to understand) I decided to try the fiber board approach. Lite weight, being able to pivot like a "lazy susan" and the ability to be taken apart, is I think one way to solve the challenge of construction.

    Ed

Hi Ed,

Stood the stand test, should be good for some time to come then.

Portability and light weight is the key. My next batch of modules will have to go from storage into the condo to be worked on, back again, off to a show, back again……..and I live on the 14th floor!

I'm now somewhere past 20 modules over the past 14 years, I standardized on Baltic ply* some years ago, having tried wood, regular plywood, foam, fiberboard, foam board……..I can use 12mm for the frame (1/2"), 6mm for the top (1/4"), supports at 16" centers, and still lift it with one finger bare, one hand with track and scenics.  The top is always screwed, not glued, frame is glued and screwed. the modular group I belong to has 2 x 4 foot module standards, Four of these fits in the car comfortably.

Any details on how you get them to pivot? I have visions of a very large lazy Susan.

Nigel

*Searching a couple of years ago for some Baltic ply, I went into my local Lowes hardware store. "Baltic ply"? - "Huh?". "Russian ply"? did get a reply - "Not in this store!". I finally tried "Finish ply"? - "Follow me". Whence I was shown regular ply finished on one side. "Very nice" I said. Since then I have found a local lumber yard that stocks all thicknesses, and will cut to size for free. Turns out the beech ply core is actually made in Russia using formaldehyde-free glue, the finished beech exterior ply is applied here in the USA.