M D F any one??

[gandy dancer#1]

HI: I put my set on 1/2 inch nice finished plywood . it consists of 2 pieces 6' x 21/2 foot with snug fit between center lines. but have noticed over last few days a little curling at corners. was considering going to 3/4 mdf. was told by lowes it wont warp like plywood? any body out there have any experience with mdf??

[poliss]

What I would recommend is to brace your baseboard with 1"x2" pieces of softwood as shown on Brian Lamberts website here. http://www.brian-lambert.co.uk/Hints%20&%20Tips.htm
Seal the board with a water based varnish. The same rules apply with MDF.

[gandy dancer#1]

i have the boards on 2 large steel leg folding tables which measure 6' x 21/2 ' with heavy grade plastic tops. the kind you see at banquets and such. so pretty stable as far as can tell. set up in one corner of my den for the little one. the finished pieceof plywood not warping as bad, but the rough plain piece really starting to turn up at corners. so thinking go to 3/4 mdf and try your idea put a sealer onit. thanks.

[poliss]

The bracing is still a good idea as it gives the ideal space for wiring. You need to make cut-outs about half the width of the bracing for the wires to go through.

[OldTimer]

You need to build a framed base for the plywood.  I use 1X4's from Lowes....inexpensive and pretty straight.  I put the crossmembers on 16" centers and assemble the whole shabang with utility screws. 
Hope this helps.
OldTimer

[jward]

framiing your plywood with 1x3 or preferrably 1x4 lumber will allow you to securely fasten it to a frame that will straighten out the warps. screw the plywood down about every foot or so, more where it warps.....mdf appears to be compressed sawdust. it may not warp, but you may have problems with it crumbling. i wouldn't use it......

[poliss]

Medium Density Fifreboard (MDF) is very stable and  does not crumble over time or when sawn. My MDF baseboard is over eight years old and is still good as new.
Particle board,  known as chipboard here in the UK, is prone to crumbling and warping when damp.
1x2 inch framing is perfectly adequate and is the size modellers have been using for 50 years or more.

[gandy dancer#1]

HEY: The reason i have it set up on 2 tables is i can get under it very easy at my age, and can seperate or slide the 2 apart down the middle if need be, just break the track at each end. my wiring what little i will need to do for any add ons at this time will be under the matt. the electrical will run off a seperate power supply 12 volt at 5 amps max, and go into a seperate very small swith box,thins such as lighting ,motion objects will  be controlled at this point. the locos at this time all are dc, and will run off the standar power pack by bachman. we are nt ready for the  dcc stuff yet, as my little engineer is 2&1/2 and our financial officer says our train co is on a limited budget,she did say maybe warren buffet might loan us some of his train money>(B N S F) Since my last name starts with a B and I am real partial to the katy line (family connection) I am going to name mine the (B K P B ) line( Burns Katy Po Boy) line

[NarrowMinded]

I think The recommendation to seal both sides is a good one for your set up, if your gonna stick with no framing its a must.

NM

[Doneldon]

gd1-

I'm not one to pile on but I have to agree with several other posters who urged you to frame your layout sections and seal the MDF. You may be fine with your current set-up on those tables but you'll want to move it someday and the unframed surface can easily flex just enough to throw track out of gauge, interrupt electrical connections and so forth, not to mention the cracking you'll experience in any plaster ground contours you might add. Last, all wood products expand and contract at least a little with weather and seasonal changes. These, too, will disrupt your railroad and mean you should seal the material as well as possible.

I notice that other posters have suggested everything from 1x2 to 1x4 material for your frames. I'll shoot right up the middle and suggest 1x3 boards. Get good enough quality boards that they have no twists and are clear enough that they'll look okay when painted. (You don't want raw wood in your study!) These should be sturdy enough for your MDF while providing adequate space underneath for your wiring. Too, you can screw handles to the frame to make it easier to transport your modules when you need to. I also urge you to consider using a piece of rigid foam insulation on top of the MDF. This will allow you to add some contours to your layout and scenic "below" the track.

Good luck with your layout!
                                                                          -- D

[jward]

if you are building a sectional layout, that makes the framing all the more important. you will need to have some way of joining the two sheets of plywood you have together. that's very hard to do without having something to clamp to. having the two halves framed, you can line them up perfectly, then use carriage bolts or loose pin door hinges to hold everything in alignment. my own layout is built on two tables, and i use carriage bolts to hold things together, with a pair of wood dowels as locating pins to line everything up.

[gandy dancer#1]

HI: the suggestio of using dowels to line up edges and carriage bolts, thanks i hadnt thought of that!! using a coating or sealer on board another thanks, the foam under the matt, i will try later, as of now not looking at contouring but will later and sure i will have to ask many questions on that one as i am a newbie!! basically right now what i have is  a6'x5' board with oval lay out for the little guy. this week will be in okc, and theres a hobby shop there, says he has just about everything in stock, so will get the grass matt, some 22 dgree curves, a couple of flat cars, and then working on an inner oval for my train to run with the litle guys seperately. i just purchase a complete set 5 units (Crown royal colors and logos) ya know paw has to have his own train And as always I want to thank every one who responds to my sometimes strange questions, its nice on my end

[NarrowMinded]

Theres no strange questions here, we all had them once and sometimes still do that's why this hobby is so fun, theres always something new.

Base on all the replies I see most of us likely had that beginner experience where we made some beautiful scenery on our first layout then had the plywood curl or flex and ruin all the hard work that was put into it.

a minute of preperation prevents an hour of regret. or somthing like that.

NM

[mabloodhound]

As a contractor by trade, what poliss says is accurate.   Although MDF is stable, it is very heavy and it may not be within your budget.
1/2" plywood is too light for a table without a frame.   I suggest the frame may well give you the support you need.
But I would not use boards.   The stuff you get today is crap and prone to twisting, etc.   Use a sheet of 3/4" AC plywood (about $25) and cut it into 1x4 strips.   Using the plywood strips to build the frame will give it the strength and will not twist or warp.   In my 1:1 jobs I do not build any frames out of boards anymore; too many callbacks to fix it.

[gandy dancer#1]

To mabloddhound: That was what i was looking for , someone that could tell me whether or not mdf is stabe.My local lowes sells it  in 3/4 only for 34.95 4x8 sheet. They have agreed to cut to my dimensions 2 pieces 6' x 21/2' at considerably less than cost of full sheet.they take the leftover or waste pieces and have a rack for those wanting the smaller pieces. i just wanted something that was more stable than conventional plywood. As i have learned in a matter of couple of weeks, 1x2" plywood isnt cutting it.I had the plywood on hand so no great loss. but it is starting to curl up at the corners. it is on 2 banquet tables in my den in a temp controlled environment , admittedly the air is very dry here this time of the yr in southwest oklahoma.so figured go to mdf put a seale on it put matt on top and go from there and should be good to go?