Sounds like you are refering to products like “primeguard” exterior trim boards?
They can be bought in this region, but are less and less popular because this climate is not kind to “farm grown” lumber for outdoor applications. More and more we are using Azek type products for exterior trim, so the box stores here do not stock much in the way of fingerjoint primed trim lumber.
If you want wood to hold up around here, it needs to be Spanish Cedar, or treated, or some other old growth or rot resistant species.
The only thing I use MDF for is HiFi speaker cabinets…
I just picked up some of the 5x5 sheets of Baltic birch from a local independent hardwoods dealer. Personally, I think the 5x5 results in less waste when cutting chunks of subroadbed for 30" radius or larger curves. But I’m early into this build, time may prove me wrong.
Im also using Kreg joining jigs and pocket screws this time around. Allows you to screw everything from the bottom at an ideal angle (never directly into a grain) without a ton of extra horizontal 1x2s or whatever. Anybody else used these?
Thanks for pointing out the regional differences Sheldon. Most of my work has been in California where humidity isn’t a problem although I fixed up a place in Tennessee for my sister-in-law about five years ago and learned a lot about humidity and bugs while i was there. I remember how difficult it was to paint the outside of the house to avoid the dew on the siding in the morning and getting the paint on before the wall got too hot (it was summer). I will pay closer attention to the responses here so I can learn from others.
Tim
CapnCrunch
Hi Randy,
I use MDF sparingly in my carpentry (just finishing a major kitchen and bath remodel). As others have said, MDF doesn’t hold screws, but in your case, if the MDF layer is thin enough so the screw can get a bite into the wood core, you should be okay. I would add extra blocks for support if using it for an elevated roadbed. I haven’t built my layout yet but have done a lot of woodwork over the years and I’ve become a big fan of finger-joint paint grade pine available at HD and Lowes. Very stable since there’s no grain. I plan to use it for all my benchwork.
Tim
Sounds like you are refering to products like “primeguard” exterior trim boards?
They can be bought in this region, but are less and less popular because this climate is not kind to “farm grown” lumber for outdoor applications. More and more we are using Azek type products for exterior trim, so the box stores here do not stock much in the way of fingerjoint primed trim lumber.
If you want wood to hold up around here, it needs to be Spanish Cedar, or treated, or s
Well, I know I must have been the lucky exception to using 3/4"MDF for that post-hurricane layout. I used 1/4" pine supporting material on 14" centers and it never sagged or varied in any way. It was glued as well as screwed and I painted it with Minwax clear polyu I had sitting around. That layout was built in a garage in Scum City where it’s very humid all the time.
Yes, it was extremely heavy and made lots of dust when drilling, cutting, etc. I had a fairly good experience but wouldn’t do it again if possible to find plywood.
My current layout is constructed using 1x2 and 1x3 strips ripped from 3/4" birch plywood. So far no problems after 1 year. The lousy 1"x boards at Lowes and HD made me try the plywood sticks. Very true and straight and cheaper. Just a lot more work on the tablesaw.
So many ways to build a railroad so don’t overlook or condemn any method people use. Keep an open mind and be kind.
Some varieties are less expensive than many natural woods
Consistent in strength and size
Shapes well
Stable dimensions (less expansion and contraction than natural wood)
Takes paint well
Takes woodglue well
High screw pull-out strength in the face grain of the material
Drawbacks- Denser than plywood or chipboard (the resins are heavy)
Low grade MDF may swell and break when saturated with water
May warp or expand in humid environments if not sealed
May release formaldehyde, which is a known human carcinogen and may cause allergy, eye and lung irritation when cutting and sanding
Dulls blades more quickly than many woods. Use of tungsten carbide edged cutting tools is almost mandatory, as high speed steel dulls too quickly
Though it does not have a grain in the plane of the board, it does have one into the board. Screwing into the edge of a board will generally cause it to split in a fashion similar to delaminating
I’ve used Kreg jigs and pocket screws with Baltic Birch, and it works well. It’ll work with regular plywood, unless you hit a void.
I built a 5’ by 30" frame using 19mm Baltic Birch, and it is strong. I piled a lot of (calibrated) weight onto it for a test and it only had about 1/16" of deflection.
Best feature is that if a crossmember interferes with a switch machine location, you can always remove the crossmember and relocate it.
I can get it at two specialty wood dealers in the area, one stocks 5X5 and 60X30". They can get 4x8’ sheets as well, for some sizes. The 60X30" sheets fit nicely in my vehicle and the 19mm ones are heavy enough as is.
I used a sheet of it too. I never had sagging issues, and wouldn’t think it would sag if properly supported.
Its hard, and the flathead screws I used would not naturally countersink like with plywood. Once the head got so far into the surface, the threads would strip the fiberous MDF before it would sink the screw in. Needed to drill a small countersink before screweing.
Just way too heavy to manipulate too.
Once built, it was fine. Nice and smooth. No problems with anything. It was just less convenient to wo
Not yet. I went to Lowes today and got a 2x4 piece of birch plywood, which while 11 ply, has a thicker outer layer than their 4x8 sheets. Since most of my stuff is well packed away, I had them cut it up into 3" wide boards. I also got some of the angles and screws, so tomorrow I hope to put together a mockup of my uprights. Then I can figure out what will be the best height for each deck.
SO here’s the results of my first test, which was to drive in a few different types of screws and see how hard it would be to pull them out with a pry bar (just a short one, used it to pull up all the carpet). I had #6-3/4" wood scres, #8-3/4" wood screws, a coard thread deck screw, a coarse thread drywall screw, and a gine thread drywall screw. I Had both the sample piece of a mende-board and I also used a piece of a 3/4" 11 ply birch I picked up at Lowes yesterday.
Driving the screws in (I did not drive the drywall screws all the way through), no issue with the MDF faced stuff, even with no pilot holes. Pretty clean.
Driving them in the birch plywood - the wood screws and the fine thread drywall screw was fine, but the two course thread ones tore up the birch veneer. Would need pilot holes for those.
Pulling them out - the mdf face stuff was pretty much a complete fail. All 5 screws easily pulled out, though the fien thread drywall screw took more that a little effort to finally make it pull out. The wood screws, I may not have driven in far enough. I was simulatoing using them to attach the metal angles I got. The problem is, a 1" screw will penetrate even accounting for the thickness of the bracket, and a 3/4" I don’t think is long enough, not when subject to a force trying to pull it straight out.
For the birch plywood, they all pulled out except the fine thread drywall screw. I probably could eventually pull that one out as well if I really tried, but I didn’t feel like flipping to the floor when it finally let go if I put my full effort into it. But all of them required more force to pull out, and the #8 wood screw actually took a few tries.
So - the plywood place has their 5x5 panels of 3/4 all birch, which are actually CHEAPER than Lowes charged me for the 2x4 piece I got. I will use that for the uprights and laterals, for sure.
I didn’t get to build one like I wanted to, it’s pretty much impossible to g
3/4" wood screws would work better with those, as they have chamfered holes. The brackets I got are more intended for framing, where they would be nailed instead of screwed. What’s odd though is compared to some others, they are thicker, more like yours than the many other types of framing angles.
The only problem with that is I want to put a bracket on both sides - so the screws from one side would interfere with the bracket on the other. ANd trying to position everythign precisely so that the holes line up from oen bracket, through the wood, and into the other bracket, with the bracket sitting perfectly at the end - yeah, that’s too much work. ANd to use them to attach to the verticals - then I have to space them out from teh wall with enough space to clear the nut and washer or the screw head and washer, dependin on which way I ran them in.
Why? The wood would break way before the bracket. Brackets on both sides will actually be weaker because you’re putting twice as many holes in the wood which is already the weakest link.
With a bracket on both sides, the screws for one bracket will interfere with the screws for the other bracket.
I use 1" wood screws when attaching a bracket to a piece on the wall. I don’t care if the screw puts a dent in the drywall. I attach the grid to the wall (at studs) - no need for verticals. Almost all of my cross members attached to the edge board on the wall are done with pocket hole screws.
I only use the brackets to attach edge boards to other edge boards - where the grid turns a corner.
For your situation where you can’t put a screw in the end grain, I’d just use 2x2 glue blocks on both sides with screws in from the front and a pair of 3" screws through one block, through the cross member and into the other block. Cheaper, easier, faster and stronger.
I understand you can’t find good dimensional lumber, but it doesn’t have to be real straight if you cut into 3" blocks.
There’s no need to go into the end grain - I was putting the bracket on the side, so screwing in to the face of the vertical, as well was the face of the rib.
Definitely the screw would pull out of the vertical long before it sheared off the rib, doing it that way.
I was pretty much planning to do just that - use a 1" screw and the heck if it poked a little hole in the drywall. I can certainly do it with one bracket, if it seems like it needs more, then it will already line up with a second bracket on the other side.
In my case, this is the ONLY thing holding the layout up, I wasn’t going to put any legs under it. Max 24" depth, and that only by the yard, most of it will be 18" and under. I CAN’T put legs under the second deck, and it does need to come out as far or almost as far as the bottom deck for the lighting to work right. But there will be a lot less track on the upper level.
Not in the bracket scenario, but if you could screw into the end grain, you wouldn’t need the brackets.
The front of my ribs (good term) are attached by running 2" screws through the front edge board into the end of the rib. The good lumber I can get here in Richmond (sorry for gloating) will countersink the head of my Spax screw before spinning the threads in the end grain of the rib.