Look at how these guys are constructing their benchwork. Just plywood as far I can see. What are the pros and cons of using that method compared to regular wood?
Plywood - Pros:
- Dimenionally stable
- Less expensive
- Straight and true
Plywood - Cons: - You have to rip the pieces to width
- Holds fasteners poorly in end grain
1x Wood - Pros
- Ready off the shelf
- Holds fasteners well
1x Wood - Cons - Finding good wood is getting tougher
- Is often expensive
My [2c]:
Plywood all the way. I have a woodshop with the tools to machine the plywood strips. I also discarded screws in favor of air driven nails. I’ve spent many an hour picking through wood piles. With, the quality of wood is declining and the cost increasing, I doubt I’ll go back to 1x stock.
Edit:
I should also add, that my benchwork is designed to move, so weight is an issue. With the recent hurricanes, the cost of all building material is on the rise. The last time I was in HD an 8’ 1x4 cost about 4 bucks, while the same piece ripped from 3/4" A/C ply was about 2.70.
Nick
Plywood is more stable dimensionally than lumber, but it can delaminate in high humidity conditions.
Dimensional lumber can’t delaminate, but it can twist, warp, bow, and swell, again more likely in aeas where the humidity levels change significantly from day to day, like garages.
Might could be a bump in the price of plywood come spring. Katrina, Rita, and Wilma messed up a lot of roofs in a lot of states last year, late enough in the season that the rest of the industry was winding down for the winter. With recovery programs winding up to full speed, and the rest of the industry pouring pads every minute the temps arewarm enough in anticipation of getting an early start in the spring, something might have to give, like the price of any materials in temporary or longer term short supply.
It works, but I used 2x4s which are faster and easier to use. They do not cost much either if you shop around .
And always look into the scrap bin at the lumber yard. There are always good pieces in there for very cheap.
The laminated layers of plywood with alternatinggrain direction of each layer lends itself to excelent dimensional stability plus built in strength of the product. It does involve a great deal of “ripping” the sheets into dimensional lumber, and some additional reinforcing of right angle joints where the screws need to go into the layers of the plywood’s laminations.
The finished product should be exceptionally strong and dimensionally stable to support the weight of the layout, its scenery and the occasional human contact vertically and horizontally.
You would have to do some price comparisons to see if regular dimensional lumber would be more or less expensive than the resultant per piece cost of the “ripped” plywood elements. My suspicion is that despite the lack of knots and warping of the plywood would still make it more expensive, plus the added step of ripping the pieces would still favor dimensional lumber. The saw dust could be collected for use as scenery material later on in the construction process.
Will
Here in the dessicated southwest both plywood and dimension lumber can assume interesting shapes while drying to ambient humidity levels (which range from 10% to zero.) I have a sheet of plywood, 2’x4’ size, that could masquerade as a salad bowl, and several pieces of 1-by that look like pretzels.
My solution - steel. I use plywood for sub-roadbed, but beat it into submission with liberal use of angle iron to force it into straight and level position. The main frame of my main peninsula is steel stud stock, assembled in L-girder configuration with a channel around the perimeter. Viola! no twisting, bending or unexpected grade changes.
If your talking about the beams, thats not plywood.
Those are pre-stressed laminated beams.
They use those in house construction (much larger size of course) for the main beam.
You can buy those like that.
Personally, I’m using 1x3’s for framing and 1/2 inch plywood for the top. Its light and strong.
Here in the Northeast, we see high humidity at times in June, July & August, and we have some real cold winters where the humidity reaches a low of 20%, so we also have extremes like other parts of the country, in fact, I don’t know of many places in the U.S. where they have stable humidity.
So with this in mind, I use 2x4 legs and framing, and 3/4" plywood for base. I then use 2" foam glues to the plywood…this is extremely stable…no problems with tracks with this set up. As am added bonus, I can kneel on the table if need be. Some would say this is overkill to use 2x4’s and 3/4" plywood, and they are probably correct, but the cost for doing this ONCE is worth it to me, and compared to 1x4 pine…not that bad at all in my humble opinion.
David, I’m sorry to tell you that you’re incorrect in your statement regarding the ‘laminated beams’. If you go to the website and poke around, you’ll find a “Standards” page where they list the materials used in the benchwork. From the website:
"This page will document the construction standards and practices used in building the CSXT Shenandoah Division. Techniques and standard supplies used during construction will also be documented here. Articles on specific techniques may be added to this area as construction progresses.
Standards
Benchwork
Lumber
3/4" Birch plywood ripped to 3/4" x 2 1/2" for 1x3 lumber
3/4" Birch plywood ripped to 3/4" x 1 1/2" for 1x2 lumber
Birch 1x2 glued together to form 2x2
Support brackets
Support brackets will be made from 1x3 with a 48" (nominal) vertical support against the wall. There will be 1 x 3 joists attached to the vertical supports. One joist will provide support for each deck on each stud. The joists will be glued and screwed, and a L-shaped metal reinforcing bracket or a 2x2 glue block will be applied to them as well.
Plywood subroadbed
Plywood subroadbed will be 23/32" BC pine plywood supported on 1x2 and 1x3 risers as necessary."
I also agree that plywood can be used to create a very stable and strong benchwork if you posses the tools and knowledge to rip and construct the benchwork properly when using plywood. As others have stated, avoid nailing or screwing into the end plies. That’s why I use pocket hol
OK, you’re right Don. Didn’t poke around that much.
I do have one of those laminated beams in my basement though…
I have built several large layouts using 1 x 4 construction. Not L-Girder just a series of cross braced 3 x 8 or 4 x 8 boxes with cross members on 12 inch centers and smaller if needed to fill in the blanks. They were then bolted together as erected on 2 x 2 braced legs. I never had a problem, whether I lived on the East Coast or the Mid West. For that reason I think that L-Girder is overkill.
The problem is finding good straight wood that stays that way. It is a lot more expensive than what one brings home from Home Depot that rolls itself up into a ball within a week’s time. For that reason, here in dry and sunny Scottsdale, Arizona I plan to use 3/4 inch WATERPROOF plywood which costs a little more but worth it for its stability in varying humidity conditions. It is actually cheaper than good straight wood that won’t warp if you can find it. HD will give it one rip down the middle free so it is a lot easier to handle on the table saw.
In your case, it may be possible to get good lumber, if so that is the way to go to save all the ripping time, but I truly believe that plywood is the way to go if good wood is not available.
I will calculate and see what’s the best method for me here in Sweden.
Thanks guys, excellent answers as always.
Electrolove, at the lattitude that you live in Sweden, I can’t believe that humidity would be a problem…right??
The method of construction that I see in the link seems like it is over-engineered by about 50%, maybe more…I’m not an engineer. To me, 5/8" ply is plenty strong, and 1/2" would be fine for most applications. Naturally, this depends on spans and the dimensions of the ripped strips. But screwed and stayed 1/2" X 3" lengths up to 48" in length would be strong enough to build what they depict.
Humidity higher than 70% is going to have deleterious effects in the long term in any enclosure where manufactured wood products must remain for any length of time. When one finds basement or MRR layout enclosures retaining humidity levels higher than about 70%, it is time for climate control, and either air conditioning or a dehumidifier will work, barring electrical costs that are prohibitive and/or vapor barriere installation that is effective.
These layout benches must support themselves, added materials and toy trains stuff. We aren’t talking about 2 lb/in sq of loading.
You are right, it’s not a problem in Sweden. For my test layout I used wood that was stored inside of a building with the same temperature as my home. So the wood I found there that was good stayed that way when I took it home.
But the very first time I got wood from another place where they stored it outside in the middle of the winter, not thinking about what could happen. The wood stayed in shape for about 2 hours. After that I it looked like a spiral and gave me a lot of problems.
So when you get wood, think if this or it will give you problem. I learned the hard way. [B)]
Electrolove,
I have built two HO scale layouts on hollow core doors with 2"x4" framing underneath; the first was a 20 x 40 foot club layout, and the second a home layout. A friend of mine built his home layout on hollow core doors, too. We covered the doors with two 1/2" thick layers of Upson Board, aka Sound Board. On the club layout, the sound board was glued down using plain latex caulking. On my home layout, I used carpet adhesive. Plain sewing pins can be used to fasten track.
I don’t know how houses are constructed in Sweden, but here in the U.S. hollow core doors are very common. They are much cheaper than a solid wood door and are lightweight. The doors I used on my home layout were 30 inches wide and 80 inches tall, and were cheaper than plywood or compressed wood. Because these doors are constructed of primed Masonite hardboard, there is no problem with warpage or swelling from changes in humidity.
One thing no one seems to have mentioned is the grade of plywood, I would not use CDX for example, where I would use ACX. The difference is in the quality of the good side and more importantly, the quality of the glue.
So if I find some plywood, can I tell if it’s ACX or CDX just by looking at it?
I have used OSB for many many years without a glitch, it just does not look pretty but the scenery covers all that.
In the US, the plywood’s rating is stamped on it. A is the best grade, D the worst, and the X means exterior glue.
Nick