I have a section of my new layout which I want to put a yard. I was in Lowes this morning and was wondering about using 3/4" MDF as opposed to plywood. Before you ask I do have a clean dry as a bone basement with no moisture problems what so ever so that is not an issue.I was wondering how do it take track nails etc. you know all the mrr questions we ask.
Has anyone used it before and what are your thoughts both pro & con.
Thanks
H.E.A.V.Y.! H.E.A.V.Y.! H.E.A.V.Y.!
As long as you have a
clean dry as a bone basement with no moisture problems what so ever
Almost all of my experience with this stuff involves merchandise--generally furniture--made from it. Doesn't it come in thicknesses less than the 3/4" specified in your posting? Three quarters of an inch seems just a little like overkill to me! I, for instance, use plywood only half that thickness for virtually all of my benchwork and roadbed construction; even at that I am giving serious consideration of closing up the distance between joists and using 1/4" ply on my next layout.
From the far, far reaches of the wild, wild west I am: rtpoteet
I wouldn't use it. Though there may be ways around my objections.
I have never liked trying to put a nail in the stuff. Even when it is dry, I have found that MDF shelves, even without really long spans, warp under their own weight.
And a lot of our scenicing methods introduce a lot of water. I don't know if that ends up being a problem, but it doesn't make me comfortable.
Jeff But it's a dry heat!
I've used 1/2" and 3/8" MDF for slot car tracks, using classic flat-top and classic L-girder. The flat-top is probably closer to what you would use for a railroad yard. In that case, I reinforced 1/2" MDF with 1x3 and 1x4 joists or stiffeners underneath, screwed down through the top surface. Spacing was about on 24" centers. Legs were cross braced and mounted to the joists. Only the top surface was painted (with two coats of water based acrylic interior wall paint). No warpage even when installed in a VERY damp garage/basement in New England, for a few years.
The 3/8" MDF layout on L-girder, with risers, was analogous to model railroad subroadbed, with numerous elevation changes. About 16" centers between risers, mostly, but often more. Again, no sagging or warping, painted on the top surface only (in a dry basement with no more than 50% humidity, and a de-humidifier):Of course, as mentioned, MDF is very hard and resists nailing. The dust from sawing is irritating and is best done outdoors. For my model railroad, I used 1/2" medium-quality plywood, with an average 9" wide subroadbed, and have had some problems with curling at the ends of pieces, due to less than optimum quality plywood. My yard is going to include a 4x8 flat top sheet of plywood, carried on risers over L-girder, but it will be covered with another 1/2" sheet of homosote, which takes spikes like a breeze. I've used Homabed on the main lines (on the 9" wide subroadbed) and it is going well. Still under construction.
4x8 sheets of 3/8" MDF are heavy, and 1/2" is even heavier. 3/4" would be good for battleship armor, or maybe light cruisers, but I would hate to wrestle that stuff off the truck and into the shop.
The recommendation from me is that you do not use MDF unless you deck it with homosote, and stay away from 3/4" because of weight. 1/2" MDF is better, but 1/2" plywood of good quality would be best.
And further, my experience with track spikes, nails, and screws into plywood is that the glue between the laminations is so hard it resists penetration. I ended up drilling for the nails, on my lower-level staging. Thus, the use of homosote for the roadbed.
Allegheny2-6-6-6 I have a section of my new layout which I want to put a yard. I was in Lowes this morning and was wondering about using 3/4" MDF as opposed to plywood. Before you ask I do have a clean dry as a bone basement with no moisture problems what so ever so that is not an issue.I was wondering how do it take track nails etc. you know all the mrr questions we ask. Has anyone used it before and what are your thoughts both pro & con. Thanks
Yup.
I have it on my present layout, 2 foot by 8 foot sections supported by 21 inch by eight foot 2x4 box (leaving a three inch overhang), all supported by 2x4 legs. The secional tables double as household storage for some heavy items underneath the layout so had to make the whole thing stout.
After three years, no warping or sagging. Primed the surface before laying track and scenery so water wasn't a real issue. However, its a complete pain to nail into. Attached the 3/4 MDF to the box with glue and long finish nails. Kept bending the nails and had to drill pilot holes. Drywall screws don't recess into the surface like they do in plywood and will strip and spin when the head meets the surface. Same with nails that have a head, unlike skinny finishing nails that can be punched to recess. My basement is dry so moisture and expansion/contraction don't seem to be an issue. Latex caulk holds the cork roadbed and track and works just fine on the MDF. MDF won't accept nails driven into the 3/4 inch side without splitting, if you try to attach fascia to it.
I had Lowes cut the lengths at the store before I loaded them. You won't be able to load, or unload, a 3/4 inch 4x8 yourself.
Wouldn't use 3/4 inch again, but I think you'll have many of the same issues with 3/4 inch plywood as well. The 3/4 inch stuff, either MDF or ply, is really stout stuff and won't sag unless its poorly supported.
On the newer sections, I used 1/2 inch MDF. Much easier to work with all the way around.
You could use MDF in your yard application ok, but there are probably better options. Maybe use MDF as a constant support surface, with homosote on top, rather than as a surface to put the track directly on. I think it would work the same as plywood in that application.
- Douglas
I posed this question a long time ago here. The answers were amazing. So many authorities!
I chose to use 3/4" MDF in spite of the authorities and have no regrets. At the time here in Scumcity plywood was extrememly scarce, of poor quality and expensive. I found all the MDF I needed for the cost of 1 & 1/2 sheets of plywood.
YES................it's very heavy!
YES.................it cuts easily.
YES...............it makes a LOT of dust!
NO................it doesn't sag, warp or come apart if properly supported.
I live in a very humid city and it has performed admirably for me. I built the layout about 5 or 6 years ago. It's screwed to 1X4s spaced approx 18-22" and I glued cork roadbed to it with Elmers wood cement (water based). Scenery is plaster cloth and plaster over foam, cardboard forms and some wire. So far, no problems. I can't say if I was the exception and God was just smiling on me and my railroad or what others have experienced is the norm or what but I would and probably will use it on my next railroad if the situation is the same with plywood.
My train room is airconditioned, however from the remnants of the MDF sheets I purchased for the railroad I also built cabinets and shelves for my garage and it isn't airconditioned. So far they are doing well too.
Good luck with your layout and decision.
My 2ยข
Roger Huber
MDF doesn't warp, cup, or crown such as dimentional lumber does, but is subject to sag if not sufficiently supported and will swell if subjected to water for a period of time. I have used MDF for many different applications, including a small layout, and have not had any problems whatsoever. It takes wood-glue well, is easy to machine cut, doesn't splinter, and the sawdust can be mixed with acrylics and a glue/water mix and used for ground shrubs. I have also used 3/4" MDF ripped to 1/4" strips and used it for spline roadbed. After it was glued, clamped and dried, it was quite stiff and retains curves well. It is easily sanded for super-elevations, can be bent to tight diameters, and automatically puts in easements. Since MDF is a lot more stable than dimensional lumber and moderately more stable than plywood (MDF does not expand/contract as much as plywood) , I would never have a problem using it for splines or benchtop. Now the downside.... MDF is not so great for spans of any length, and the length decreases with any increase of weight. Just about everyone has at least one MDF shelf that sags in the middle. In other words, I really wouldn't recommend it in leu of benchwork. I prefer plywood I-beams for that. MDF should not be subjected to continuous moisture, such as a damp basement or contact with concrete or masonary. MDF is also fairly heavy due to the binders and density. It doesn't hold screws well and is prone to splitting if you don't pre-drill holes close to the edges.
MDF is fine if used within it's strengths, and a bitter subject when one asks too much of it. I think any moderately sized layout should actually use ALL the different materials; dimensional lumber, plywood, MDF, and foam, as each has its strengths and weaknesses.
Despite all of the negative feedback you get regarding MDF in layout construction, I have actually seen it used quite successfully in a handful of layouts. Here is an example (lots of construction photos):
http://www.owensvalleysub.com/
Jamie
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It's the 21st century. Try foam.
NO................it's very heavy!
NO...............it makes a LOT of dust!
YES................it doesn't sag, warp or come apart if properly supported.
Foam solves most of the negatives of MDF. No, you can't nail or screw into it, but you can use a variety of glues very effectively. Need to run a wire through it? No problem - just punch a small hole with an awl, or even a larger one with a dull pencil. Need to plant a tree? Stick the trunk in the foam. Cut a big notch for a river, or a small one for a drainage ditch, after the track is down? Get a steak knife and do it in minutes.
It takes an iron man to play with a toy iron horse.
I used 1" blue foam sheet as a quick, easy, sky-colored ceiling over my layout. I just nailed it to the floor joists overhead (basement RR). It was easy to notch it out here and there, with a matt knife, for the odd pipe or light fixture. It looks much better, to me, than a suspended ceiling (a matter of taste), is cheaper, and provides a good "background" for the era-correct airplane models I hung up there.
As I live in northern California and not back east where most postings come from I ask what is MDF? Maybe particle board? Homosote is another item no one at the home improvement or hardware stores seem to have knowledge of. I finally figured it may be what is called white sided building board. Brown compressed fiber like with a coating of white on one side. Does any of this make sense to any one? Ken
Ken G Price My N-Scale Layout
Digitrax Super Empire Builder Radio System. South Valley Texas Railroad. SVTRR
N-Scale out west. 1996-1998 or so! UP, SP, Missouri Pacific, C&NW.
Most MDF is manufactured in the Pacific Northwest. You are living closer to the source than most of us "back East". MDF is usually used without the extra layer you describe. Google it and you will get more info than you can use. The stuff I used is Temple brand, if that's any help. Cost is around the same per 4x8 sheet as middle-quality plywood. The sheets are actually 49" x 97", with the extra inch provided so you get a 4x8 sheet that is completely usable. The main use appears to be cabinet making.
MDF seems to be the stuff that wall molding is made from, as I found online. I used some that I had left from a floor project for a grade incline on my layout around the back side. I had to drill holes for the screws to go through into the raisers. Then glued the road bed and track down.Can not imagine using it for the bench work top though. Unless homasote (white sided building board) or foam sheets are going on top of it. On my bench work it is all deck screws, no nails. Easy to take sections apart to make changes as I found out.
Ken
Lakehomasote (white sided building board)
dante, thanks for the information.
Lake dante, thanks for the information.Ken
Ken, you're welcome!
Dante
MDF? As a watcher of This Old House I have never seen them try to pound a nail into it - they always use pneumatic guns - and Norm always says that it's the same material used for freeway signs. If it's that tough I elected not to use it and stayed with good old fashioned plywood. As far as Homasote is concerned, in my area if you ask for it the people at Lowe's, Home Depot and Menard's will give you that deer in the headlights look which says they don't have a clue.
My vote - plywood all the way!!!
There's never time to do it right, but always time to do it over.....
I have a friend that is using mdf on his very large layout and he is happy with it. I built all the benchwork for him and had to make sure it was beefy enough to support the mdf. Also had him paint both sides of the mdf to seal it. He uses a air powered pin nailer to nail down the track, as the mdf is VERY hard to pound in track spikes. Myself I would rather use homosote or plywood, even foam, which I do use all three on my layout. Lowes has a 1/2" five ply plywood for about twenty five bucks a sheet that is excellent. Home Depot has a similar product, but is not as good as quality as that from Lowes. I use it for modules and yards.
MDF is an acronym for Medium Density Fiberboard. You might be able to use this term at Lowe's or Home Depot and get better response. Here we find it sold not only as sheets but also as pre-milled shapes for baseboard, crown molding and such. Often one surface of these premilled shapes is painted white.
I looked at this material when I was planning a fairly major home remodel and decided not to use it because it is so hard to nail by hand. Nailing into the edge really causes problems.
Be aware that the binders used to manufacture this product include waxes and formaldehyde emitting products. Their presence not only makes the product heavy but also makes the dust produced during cutting hazardous. Use a respirator or, better yet, cut it outdoors. It may outgass formaldehyde for a period of time after manufacture, so consider this factor when planning for room ventilation and building practices.
Homasote is compressed paper. It is gray and has little strength of its own. It is nasty stuff to cut or work with, but many modellers swear by it. Its only redeeming quality [IMO] is the ability to accept track nails easily. It also bends nicely for easements in elevation. I used it for a layout 35 years ago and swore never to use it again. I have been using 3/8" Baltic birch plywood for my last two layouts. Once I found a 4x8 sheet of 1/2" cedar plywood that would have been an ideal material -- it was light, took nails easily, glued well, was warp resistent, and made great easements. Haven't found any more of it though.