I have fairly good carpentry skills, but one thing I never learned was the differences in grades of lumber. This never became an issue until I bought some sheets of plywood for the expansion of my layout. I use the “cookie” cutter method for laying my subroadbed.
After cutting the necessary strips, I couldn’t figure out why the ends wouldn’t line up. It wasn’t until I looked at the ends of the strips; one side of the strip had 4 plies, and the opposite side had 5! Well, no wonder.
My question is, is there a convenient link that shows the differences in lumber grades?
Regardless of the grade of the plywood, your sheet is clearly defective. I would take a piece from each end back to the supplier and ask for your money back or at least a partial credit.
Also, I wouldn’t use the four ply sections. They will be less stable than the five ply areas.
I don’t know that the old scheme for grading lumber still works. For benchwork I always buy White Pine Select lumber, which is supposed to by the best quality pine you can buy. Yet I spend inordinant amounts of time checking individual boards for straightness and warpage. Normally I go through 30 pieces or better before I find something reasonably straight and not warped. The quality is just not there anymore in the lumber industry, especially anything you look at, at Home Depot or Lowes. And you can’t hardly find an independent lumber yard anymore as the big boxes have put them out of business.
I recently purchased some excellent Select Pine at Menards imported from New Zealand. In fact even had a post composed asked JaBear is any of this fine stuff is still hauled by rail when the computer ate it last weekend and it was way late. May still do that. Here’s a pic of what I did with it, making T-girders for a catwalk and bookshelf system for my wife.
Kinda fancy for benchwork, but it’s sweet stuff. Even with Select, you do need to check boards for exact width, square ends, etc, but overall this NZ stuff is marvelous if that’s what you’re looking for.
The problem is that you can’t get 1/2" plywood these days. It’s been shaved down like most everything else (try to get a 1/2 gallon of ice cream or a 5 lb. bag of sugar). It’s more like 15/32" or 23/32", unless you buy the really good stuff like birch or maple.
There is a trick to attaching two different thickness plywoods together without sanding or anything complicated. Take a strip of the new stuff and screw it to the bottom of the old stuff. Then take a strip of the old stuff and screw it to the bottom of the new stuff. Butt the joint togther, then put a splice plate under both added strips. By adding a piece of each kind of material to the underside of the opposite part, it will level the whole thing when you screw the splice plate on.
Good of you to put in a plug for our NZ timber. I would be interested to know what price you pay because often our products are more expensive here than in the export market.
Timber is hauled by rail in the North Island near where Bear lives.
There was a propsal to haul timber by rail on a tourist line in my part of the country but it didn’t work out financially.
I am fortunate to live close to a large lumber mill that specializes in moulding, chiefly for the housing industry (Royal Wood Working in Aurora, Ontario).
One of the products they stock is poplar. When you think of poplar you usually associate it with a tree that grows like a weed, won’t burn worth heck, and is way too soft for any sort of carpentry. However, the poplar they stock is nothing short of amazing. It is straight, knot free, fine grained and stable, and it takes a beautiful finish. It has some green colouring in it so if you want to use it for cabinet work it is best stained dark, but for benchwork the colour doesn’t matter. Best of all, it is much cheaper than pine and they sell it in a variety of board sizes, and if you want a 12’ piece of 1" x 4" you can get it.
I have no idea how universal the availability of this sort of poplar is, but if you can find it, it’s worth a look.
I haven’t priced it for a while so whether or not the price would compare to 5/8" birch plywood ripped to size I don’t know, but when I get to the point of starting my benchwork I’m definitely going to compare the two.
We paid $33 for a 1"x12"x8’ board, plus 9.5% sales tax. Mighty fine pieces of wood. The T-section walkways are a 1x6 walk with a 1x4 web. Not a knot in it, mostly straight as you could ask, a couple of the picked over boards had a slight bow I wouldn’t have thought twice about, except they had all I needed in plain ol’ straight.
Excellent!. I’ll have to start that thread for sure. Thanks for the video.
Dave,
I’m a big fan of poplar, too. It would make mighty tough L-girders if you need some bigguns.
Yes there are grades (Gooogle search for plywood grades). But most of what you see at the big box stores doesn’t follow a grade. For model railroading the letter graded plywood BB is usually adequate if you can find it (the letters refer to each side with A being the best and D the worst). BC can work as well, but the C side can be a little rough. Baltic Birch is the best with 1/2" having 9 plies. As with anything else the better stuff costs more. Also you may find 9 plies a bit difficult to bend. If you go with the cheap stuff, I would make sure it’s at least 4 plies - 5 is better. I don’t buy 3 ply.
For solid structure that doesn’t bend or warp, use 5 ply 1/2" plywood for building your layout support structure.
Grades range from A to D with A being virtually flawless and D being rough.
Most exterior construction uses C to D grade plywood, thus the term CDX. Incidentally, the X does not stand for exterior, per se. Instead, it refers to the bonding glue between the plies, meaning that the glue used will withstand eXposure.
AC grade means that one side is A grade for virtually flawless finish , whereas C means that the other side is C grade for rough finish. The A side would be the surface of your layout and the C side would be the underside. Same reasoning for BC grade except that the surface side is not quite flawless, usually some sanded knots.
For my layout, I use only AC grade plywood. Expensive, but worth it.
Mike, my wife would be envious of your cat jungle gym.
As for grades, I do like the OP, I go to home depot and sort through 30 pieces of wood to find a some which are reasonably straight/true and buy them to use. I don’t have one of those premium lumber stores around to brag about like some do and I don’t have the budget to get the posh stuff either. I have managed to make do just fine with what I can fish out of Home Depots lumber.
As for plywood not matching end to end, just shim one of the sides to match the surface. There are lots of ways to make thing line up and work and still be dimensionally sound and even. With a little effort, you can build very decent layout benchwork without spending a small fortune.
The only dimensional lumber I used on my current 10’ by 19’ double deck layout was several premium grade 2" by 4"s that I let sit for several months to completely dry, then carefully ripped down to an actual 3" width (from the original 3 1/2") using a long and straight rip fence. These were then used to frame a stud wall that became the central backbone for a long peninsula with two layout decks double-cantilevered off this stud wall. All remaining framing lumber was made by ripping sheets of 7-ply 1/2" birch plywood into strips of the required dimensions. A couple extra 2" by 4"s were ripped in two and then cut into short blocks for use as glue blocks used to reinforce the plywood joints. All joints used 18 gauge brads and GLUE! The layout decks were made from 3/16" plywood pinned to the open grid framing using brads and glue. The backdrops on the long peninsula were made from 1/4" drywall glued to the central stud wall to provide shear strength and structural rigidity. Except for legs supporting the two helix structures and the center frame wall of the penisula, my layout has no other legs. Everything else is cantilevered off the walls with the structural fascia pieces adding span strength. I have several lengths of 24" deep deck as much as 15’ long with no support other than the cantilever and fascia spans. These sections easily hold my 200 pound weight and I routinely grab the end of the peninsula to haul myself up when crawling out from under the one helix structure. “Big deal” you might say but keep in mind that about half of the peninsula is truly freestanding as the sectional door of my garage needs the space above one end of the peninsula to open. There was some flex in the peninsula framing prior to adding the decks and backdrops, but the added shear strength provided by these two components made the structure a rock! I built my benchwork over six years ago and hav
I gave up buying lumber at Home Depot. Lowes seems to have a better selection. There is a caveat to this. They seem to have two sections. They have the normal lumber section (typical of any big box store) and they an aisle farther down that has their “premium grade” lumber. This stuff is what used to always be available. The majority of it is straight I usually only have to check 5 or six pieces before i find what I need.
What I use for plywood is B-C 1/2" (actual is 0.47") Sanded Ply from Lowes. It is $31 for a 4x8. It is very smooth. The only issue I have had is on a rare occasion (only happened to one sheet) I had some seperation happen between the layers when I was cutting it. I glued them back together so it wasn’t really an issue.
It is flexible enough to make elevation changes but sturdy enough to hold my weight.
