So the last three days I’ve spent some time building some benchwork for my first layout. I was using the NTrak standard as a base to build off of, as I don’t plan on these being modules, just how I wanted to do my benchwork.
However it’s been almost 20 years since I did any real wood work. I built some things in 4-H when I was a kid, I know the basics of measuring, using a square to draw the cutline, and have a small mitre power saw I got from Sears for $69 to make the cuts. I remembered to cut to the correct waste side of the pencil line to account for the width of the saw, all the little tips. However after assembly is complete, its a bit wonky
I’m gluing, clamping, and then gluing & screwing the outline together. After discovering that the so-called 2’ x 4’ piece of plywood I bought was really 23 3/4" by 47 3/4" and shortening the 1x4s accordingly when I get it into the rectangle I want the four pieces of wood bow so that one edge is off the ground.
after brad nailing the 3/4" plywood to the top, it rocks on the floor of my garage. If I stand on it, it’ll flatten out.
So I’m wondering, did I do something wrong putting it together? Or is the wood just warped a bit causing the wobbling. It’s not a tiny wobble either. one edge is about 1/2 - 1" above the ground when its sitting flat on my garage floor.
I think I can make it work, but I’ve followed the same procedure on three 2’ x 4’ sections now and all of them do this, so I’m wondering if I"m doing something wrong. In the past, I could call Dad for help but now he’s 1800 miles away and I don’t have his expertise as handy as I’d like.
You should accept that there are probably numerous and cumulative errors that you didn’t know enough to anticipate simply because you don’t do this often enough to be competent. Had you worked at this for a living, your post would be about something else entirely. So, ease up on yourself, find one or two legs that are clearly too short and replace them, or use cedar door jam shims under the high leg(s), or get some leveling screw jacks suitable for your purposes and bolt them to the bottoms of your legs so that you can adjust to account for the garage pad.
I suspect that most of us are a bit dismayed with the disparity between what we imagine our bench will look like and what becomes the reality. I know I was with my first bench nearly three years ago now. Didn’t stop me from figuring out fixes, and then enjoying my layout immensely.
[#ditto] Sounds like an uneven floor and some warped wood. Don’t screw your legs in till you get the table in place. Hold them in place with some clamps. Then you can adjust them up or down accordingly before you screw them in place. I used 2x4’s for my legs and made some levelers out of 3/4" bolts on the bottoms. My floor is REAL uneven. This way I can tweek it all up or down as it settles.
If I read your post correctly you do not have legs on your frame yet so this is not a leg length issue.
Assuming that you have checked your floor for being flat (level is not necessary but flat is) my guess would be that the plywood is warped. This is quite common for typical, standard grade plywood. If the plywood you bought was graded C-D or exterior then it is almost guarenteed to be warped.
Warp is not an issue in building construction since the plywood would be nailed with large nails to heavy framing members and the house framing would pull the warp out of the plywood.
In the lighter weight construction that we do for layouts obviously the warped plywood has more strength than the 1x4 frame and the frame bows.
Personally I think that 3/4" plywood is real overkill in most layout situations. If do want to go with a heavier plywood then you need to go with a higher quality cabinet grade plywood that is designed not to warp.
I think Crandell hit the nail on the head - OK, stop the booing and groaning. Like anything else, benchwork gets better with experience. Don’t be frustrated, the suggestions posted are all good ones - replace the really bad pieces and use something to adjust for floor variations. Before building your next benchwork piece, study what you have already, try to determine why it doesn’t meet your standards, figure out some options to use on your next piece and give it a go. After a while your ability to choose the straightest pieces of wood and make minor adjustments while assembling a piece will improve and you’ll be a benchworking master - of course that usually comes when putting together that last section lol. Don’t give up!
Oh, by the way, when you buy plywood that has already been cut then you have to accept or allow for loss by the cutting process.
A full sheet of plywood is usually exactly 48" by 96" but a saw blade is typically 1/8" of an inch thick. Two cuts with a saw and you loose 1/4" of wood.
Sorry I shoulda mentioned this is just the frame/plywood.
The frame is the source of the warp, not the plywood. When I square up the frame and clamp it to let the glue dry before screwing the length pieces to the width pieces via the glue block is when it goes ‘off kilter’
The plywood I used was some single side sanded stuff from Lowes, I don’t remember the grade but it was better than the exterior stuff, and pre-cut to length (in my case, 2’ x 4’) but later when I measured it discovered it to be about 1/4 inch short each dimension. It was what I was recommended back when I started this great adventure. I didn’t cut my own from a 4’ x 8’ sheet as I didn’t have the tools/knowledge to do it or a vehicle that could easily haul it from the store.
It could be that the 1x4s I’m using were warped, not the plywood. I don’t remember if they were higher than construction grade or not exactly. Sadly I bought this stuff in February and just ‘got around to it’ this month. The wood was stored off the ground in my garage and didn’t get wet/run over or anything.
Since I’m not going to modularize the layout my current plan is when I bolt the sections together pre-legs I’ll use that to ‘straighten’ everything out I think. Then I’ll decide if I want to leg it, or mount it to the wall.
the width of the plywood may have been off, I’d have to go measure it but after typing 3/4 I think I meant 3/8th.
Or perhaps have the legs equipted with screw plates that can be adjusted up or down to match that particular corner until your level on top says it’s level or nearly so.
Nothing in my home is level or anywhere in my state lol. It’s level when you uncouple from a car and it stays there.
Cheer up. keep at it.
One of my corners at the end of the 11 foot 8 inches wall is about 100 degrees instead of 90 and the other wall corner is roughly 87 degrees. Instead of tearing my hair out I cut down one inch around benchwork away from wall. Planning curved backdrops into those corners.
3/8 plywood is thin and will warp easily when cut into small strips. Large pieces will warp too, however if it is adequately supported by a solid frame it will straighten out. I’m using 3/8 fir as my decking, however I used 2x6’s that I ripped into 2x3’s for most of my bench work. I can crawl my 200lbs across the top of the decking and it doesn’t move at all.
Perhaps what you need to do is stiffen up the frame some more.
Okay, then Rusty is correct. And it is a surety your boards that are warped/twisted, but it may be that the plywood contributes somewhat. It happens.
I selected the best timbers I could find at my hardware store, and then I piled them atop one another and stacked them in my basement for a week to see what would happen. I wanted to see what they would do once acclimated to the conditions that are kept within a much more narrow range of temps and humidity. Happily, they all stayed true, although some had a gradual warp to them. I ripped the worst ones in two and then used the two halves as the top part of the L in L-girders. I would force these thinner slices into alignment and then screwed and glued. Once dried, they kept the shape and orientation that I had forced on them. Then, these fairly straight girders became the bases for my four modular frames. Now, a 18 months later, the entire layout sits like a good dining room table. It isn’t the prettiest thing you have ever seen, but it is considerably better than my first effort…I had learned. For one, go light. We tend to build 55T main battle tanks to support 60 lbs worth of stuff scattered here and there.
I’m a bit surprised at 1x4s pulling 3/4 inch plywood that far out, unless they were well beyond a little warped. Is it too late to put the plywood on the other face of the frame, instead? Another thing to do might be to make sure the frame and plywood are flat when you put them together.
Reading further, are the glue blocks not square? That would give you a frame out of skew. It sounds a bit backwards, but if we assume the plywood is flat, I’d be tempted to attatch the frame pieces to the plywood first, and then fasten them together and block the corners.
If dealing with a 2’x8’ "table " it may be a challenge to pull that much twist out without removing the 1x4s and starting over. This is not to say it can’t be done though.
If you are gonna be attaching legs you can do the following. Flip the table upside down. Attach the legs with all 4 having THE EXACT EQUAL amount heading to the floor. Now take a straight 2x4x8’ and lay it diagonally on the bottom side of the plywood (you may need to trim a bit to fit) so that the 2x4 rocks on the “hump” of the table bow. Slide one end of the 2x4 against a long side of the table frame, push or stand on the 2x to get it snug against the plywood and run 2 screws (2" drywall screws or similar) thru the 1x4 and into the 2x4 end. Now go to the other end and do the same. Stand the table right side up and run a few screws thru the plywood into the 2x4.
To check for flat grab some fishing line/sewing thread or other thin string. Clamp a block of wood to each corner of the table (the blocks MUST be of equal thickness) and run a string from corner to corner DIAGONALLY on top of the blocks. If where they meet in the middle there is a gap between or one string pushes against the other then there is still twist present. Depending on the severity of the twist it may just need a shim under a leg.
The whole process (minus the lumber yard trip) will take slightly longer than it took to read this message.
I’m reading this and I think the solution is really simple. If you build a frame of 1x4s and top it with plywood the frame WILL flex and distort. Adding a couple cross members, or joists, whatever you want to call them, will keep the frame from twisting. So if you have a cross member every 12" then you’ll have a total of five 1x4s 24" long and two pieces 48" long. Hope that makes sense.
EDIT - thats probably over kill. Four cross members at 16" centers would be plenty.
I suspect the likely source of the error is that the cross-cuts on the frame are not perfectly square. You may need to “tune-up” your miter saw. You can minimize the effect of the error by keeping all the cross-members oriented the same way. The frame may be a bit of a parallelogram, but will be the same from end to end and will be flat. There is a technique called L-Girder construction which does not require such accurate cuts. Another solution is to mount the plywood on top of risers attached to the frame. The risers can be raised or lowered to make the top flat and level, even if the frame isn’t perfect. That’s what I did. You might be able to shim the plywood on the back side to remove the twist.
Also any twist in the boxed frame of 1x4s will have you wracking the frame to align the corners. As a carpenter, I always preach that nails, screws are only to hold until the glue dries. However, benchwork for our use should be only screwed. If you want any changes or need to replace a piece the job is much easier w/o the glue. It is rare to find perfect wood, when assembling any frame bowed or twisted pieces can be placed to allow defects to counteract (fight) each other as not to end up with the problem you encountered. Normally a very large or heavy frame will settle out from the weight. The forces of the wood and the light weight won’t allow this unless you anchor the leg to the floor.
The boxed frame style of benchwork can often allow this, using “L” girder (as long as the girder is straight) all but eliminates any of these issues.
Since we are talking about only a 2 x 4 layout, I would suggest that you start over. The frame is probably warped. The cost of materials of replacing the frame is probably about $4.
Lumber has constantly gone down in quality over the years and construction methods have changed quite a bit. Model Railroader has changed their recommendations as well. If you watch the Dream Plan Build Video 1, in the bosus section, they go ito a very detailed method of layout construction. Likewise in the Dec. 2007, bonus flier they repeat the method.
The method calls for use of 1/2 plywood cut into three inch strips. Thes strips are what are used for both the framing materials and legs. They are not screwed, rather they are glued and nailed together.
Any wood you buy these days is green unless it is kiln dried. As it dries, it will warp, even if you keep it off the ground. Stacking it in neat piles helps, but not a lot. There are methods of framing that can be used to keep green wood relatively straight, but it’s just easier to go with the plywood and be sure.
Take the time to do it over. You’ll like the results a lot better.
Keep in mind that dimensional lumber (lumber used in construction) is often bowed intentionally, it allows the wood to have more strength when used to hold up floors and such. The high part would be in the middle, so it would create a slight bit of an arch. At one time, you could browse thru a lumber yard and find very straight lumber, but it’s much harder now. Many people are going to using metal pieces, or cutting their own lumber from 3/4" plywood.
BTW generally it’s best to “glue and screw” the lumber together rather than to use nails. Linn Westcott’s book on model railroad benchwork is still probably the best starting point for the basics of benchwork construction; it’s been reissued many times and should be at the LHS.
I may have misread, but i thought you tack nailed the plywood to the glued and screwed cross members. Or maybe I got the two confused between that and the NTrak manual I was using.
Since then, we have come to a decision that we’ll use the benchwork book and do some wall mounted stuff to go along the walls, and maybe the NTrak stuff I’ve made as a peninsula at one point. We’re converting a spare room that has not been used for a year into a layout room, well some of it. Probably going to do an L to get started, and then add on later.
Yup. The old growth forests are largely gone. What’s being sold now is replanted stuff that’s not very old when harvested. That was dramatically apparent comparing the framing in a 70 year old house with a 10 year old “custom” home. I thought the builder used crap wood for the newer place, but all the newer houses I looked at had “junk” framing.