There are some portions of my new layout that I would like to construct the subroadbed of plywood. But what sort of plywood these days is worthy?
I had thought this 'blondewood' at Lowes looked like pretty good quality. But I just ran across this posting that gave me pause.
Below is the best explanation I've seen as to why Blondewood is nowhere near the quality of Baltic ply. The writer below is correct, the glue layer for veneers is way more susceptible to delamination than the regular plies. I suspect that is the effect of absorbing humidity more easily and water content breaking down the glue. http://www.prosoundweb.com/ I've used blondewood from Lowes for cable cadillacs and didn't like it much. It DOES NOT have water resistant glue, the wood itself is very porous because trees near the equator grow VERY fast, definately not "Old Growth" dense like the cold climate Russian, Baltic birches; hence it warps quickly. It also has a veneer ply, unlike 13 ply birches. This is signifigant because when I tested 90 degree wood joints before I started this project, EVERY glue failure WAS a veneer failure! Even good old Titebond glue held better than the veneer glue. The only two glues to fail the plywood laminations were Gorilla glue and Marine grade epoxy. Also worthy to mention, blondewood failed miserably compared to birches. 35 ft lbs to break a blondewood joint compared to a whopping 335 ft lbs to break a Russian birch joint. This was all done with a calibrated torque wrench with a peak hold feature. If all the layers are hardwood, my rule of thumb may be broken but anything that is very heavy implies lots of resin and chips rather than wood. MDF is the perfect example, excessively heavy and no structural strength to speak of. Plys gain their strength from alternating layers of wood which has long fibers. A good gauge of strength/quality of ply is to look at a stack which has been open for a while. If the boards are warped and twisty it has little integrity. There is one sheet of 3-layer ply in my garage that was left over from a job 20 years ago and it is still flat. Rarely do you see sheets of 3-layer ply at HD or Lowes which are not warped. Younger trees is probably the reason, the fibers are nowhere near as long.
I was really hoping to utilize a good quality plywood that would resist warping in a relatively thinner thickness than heavy 3/4" . I was hoping that the better grade would allow the use of 1/2" thickness.
Brian
My Layout Plan
Interesting new Plan Consideration
"Furniture grade" has more to do with how smooth and defect free the surface is rather than how strong it is. Any reasonable BC grade plywood is fine for subroadbed. Look for 7-ply if you can find it. Don't buy 3-ply.
I'm not sure about 1/2" though - especially since you mentioned 24" centers for support in one of your other posts. Are you making a table top type structure or are you cutting out "ribbon" subroadbed just wide enough for the track? 1/2" might be ok for a table top application, but I'd use 3/4" for ribbon.
I have the right to remain silent. By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.
I started building my current double deck 10' by 19' layout around 2007. At the time, Lowes sold a 1/2" plywood product they called "hardwood plywood." This product was smooth sanded on both sides, had seven (7) plies, and no voids. I used this product to construct all of the single and double cantilevered open grid benchwork. Ten years later, all of this bechwork is still perfectly square with no sagging or warping and, best of all, rock solid.
About two years ago, I wanted to add a small yard (about 1' by 7') off one side of the layout. I went back to both Lowes and Home Depot only to find that their plywood quality had dropped to abysmal levels. Since the yard needed to be supported only by its ends to fit the available space, this meant a 7' free span. There was no way I was going to trust the current big box crap to do that. Instead, I went to Ganahl Lumber and picked up a sheet of 1/2" Baltic Birch plywood (at three times the price of the "hardwood plywood" I had previously used). I'm glad I did!
Bite the bullet and shop "real" lumber yards to make sure you get decent plywood. The investment is well worth it!
Hornblower
Ordinary plywood, 1/2" and even 1/4" is just fine for subroadbed on a flat table type surface, particularly if you screw or nail it in place. Only important thing is for the smoothest surface to be facing up assuming cork roadbed is going to be nailed or caulked into place. Of course this assumes it is flat and not warped when you get it, or that you do not introduce your own warp by improper storage before use. I have not tried this blondewood product but even fairly utilitarian plywood is OK for subroadbed, again so long as one surface is smooth.
I agree that 1/2" is likely too thin to be self supporting with 16" joists or centers. BUT ... I have seen it done with seeming success. But I know nothing about the type or quality or pre-treatment of that plywood in question. The problem with rolling the dice on that is that you won't see a failure or problem until after it is just so painful to do anything about it.
Some years ago when my mother passed away I had to dismantle my childhood 4x8 "train table" circa 1960, which she had been using for storage. That 5/8" plywood was amazing (and yeah, a bit thicker than today's 5/8" plywood): after 40+ years in rather damp conditions it was flat as a pancake and no separation between plys. Ditto for the 1x4s my dad used to frame it (and again they were larger than today's 1x4s) -- straight as an arrow, and virtually knot free. Plywood and dimensional lumber was different stuff circa 1960 that is for sure.
Dave Nelson
1/2" G1S should be fine over spans of about 18", provided you are changing grades and need a slight sag or hump. However, I would support that type of plywood over about 16" if possible....or less as seems reasonable to do.
In my current build, I found I had a clearance problem with a track that was to pass below one rising. Instead of continuing to use the 1/2" sub-roadbed, I resorted to a good quality 1/4", but now supported no more than 11" between risers. Meant more work getting the butt joints to align vertically, but shims solve that problem.
Notice I said sub-roadbed...the cookie cutter stuff. For roadbed, itself, and as opposed to cork or foam products for roadbed, I would look for 3/8 for height, but see no reason why a decent quality 1/4" couldn't make the fall of ballast look good.
These days they size the plywood down to 32nds of an inch, so instead of 20/32 for 5/8, you get 19/32. Instead of 1/2" you get 15/32"
For subroadbed, as long as it has one halfway decent side, it will be fine. It's going to get covered by roadbed, ballast, ground foam, dirt, etc., it's not something that needs to be stained and look like fine furniture.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I actually used 7/16th OSB on my last layout and the main staging yard had open grid framing with cross members 24-inches apart. I had no problem with sag between. The OSB was sandwiched with 1/2 inch Homasote on top to which I spiked my track.
Rio Grande. The Action Road - Focus 1977-1983
I used 5/8" for my cookie-cutter 2-level layout, with 1x4 supports at 16" centers, adjusted as desired for planned locations for Tortoises on turnouts. I wanted more conservativism than 1/2" but that may have been overkill if a good quality 1/2" were used.
I forget the specifics of the plywood, other than I can see it is 5-ply. Probably B/C but I can't see a stamp underneath. I passed on the lower priced 3/4", regarding extra weight and not trusting that I understood the quality aspects regarding warping, etc. (It was made on Oct 11th, so I can recommend that vintage if you can find it).
Paul
Modeling HO with a transition era UP bent
I used mostly 3/4" firply, good-one-side, for my cookie cutter sub-roadbed. It cuts nicely with a jigsaw, takes screws well, and hasn't fallen apart in the 25 years-or-so that it's been in place....
I used carpenter's glue to affix cork roadbed for the mainline tracks, while industrial sidings and staging are nailed directly to the plywood or pine boards on which it's laid....
Framing is open grid, 1"x4" select pine on 16" centres, and the grids are all supported on dimensional lumber...2"x4"s, 2"x6"s and some 2"x8"s, all of it "left-over" from building my house.
For the partial second level, added a couple of years ago, I used 5/8" t&g spruce sheathing plywood - it doesn't have a discernible "good side", but I opted for the tongue & groove to better utilise the sheets. With careful planning, any longitudinal joints took advantage of the t&g feature, so ballast, scenery foam, and the glue and wet water used to hold it all in place doesn't run through onto the portion of the layout below, which is fairly close to being "finished".This plywood is supported on open grid framing, too, but only the front face and ends of the segments utilise 1"x4"s, while the rest is 1"x2"s, all, as on the lower level, select pine. The upper level framework is screwed to the wall studs, and also supported by several custom brackets welded together using 1"x1" and 1.5"x1.5" angle iron - these are lag-bolted to the wall studs. Again, the mainline tracks are on cork roadbed, with industrial track and staging spiked or glued directly to the plywood. All gluing involving track and cork was done with contact cement, as was also used where the track is rail glued to Central Valley tie strips, also glued to either the cork or plywood.
Wayne
I bought 1/2" AC grade plywood from the local lumber yard, then had them ripped in to the widths I wanted, which was either 24" or 30". I use it all for subroadbed. However, I've built my frames on 12" centers regardless of width. I let the wood acclimate to the room for at least a week, then painted it to seal. I painted the C side white so when I need to work underneath and use some lights, the white helps to increase my view of what I'm doing. I did look into the Home Depot 'Sandeply', but the reviews were not stellar. I don't mind spending more for quality. The room that I have my layout is climate controlled and I have no issues. Also, with the way I have built my layout, I can lean or lay on it (I'm 200 lbs.) with no issues.
Neal
Fancy risers there Wayne, French Curve and all!
rrinker Fancy risers there Wayne, French Curve and all! --Randy
Yeah, although I can't remember what the heck I made that would leave scrap in that shape. Most of the risers are made from scraps, and almost all of the layout is supported by risers, due to the constant up and down track profile necessary to allow two-level operation without overly steep grades.
rrinker These days they size the plywood down to 32nds of an inch, so instead of 20/32 for 5/8, you get 19/32. Instead of 1/2" you get 15/32" For subroadbed, as long as it has one halfway decent side, it will be fine. It's going to get covered by roadbed, ballast, ground foam, dirt, etc., it's not something that needs to be stained and look like fine furniture. --Randy
I agree with Randy.
Plywood is structurally manufactured the same. Same adhesives same laminating process.
The only difference. AB, AC, BC. Nothing really. An A Graded side of plywood has a beautiful hardwood face that can be stained used for furniture like Randy said. It looks pretty, but you don't need pretty.
BC, a lower grade, even has little football cut outs to fill defects in the face of the sheet. As long as it's smooth it's just fine.
Pick through the stack and find a good B face. Spend less money and you're all good.
Track fiddler
From that original quoted passage in my original posting that opened this discussion,..
There is one sheet of 3-layer ply in my garage that was left over from a job 20 years ago and it is still flat. Rarely do you see sheets of 3-layer ply at HD or Lowes which are not warped. Younger trees is probably the reason, the fibers are nowhere near as long.
doctorwayne I used mostly 3/4" firply, good-one-side, for my cookie cutter sub-roadbed. It cuts nicely with a jigsaw, takes screws well, and hasn't fallen apart in the 25 years-or-so that it's been in place.... Wayne
Lowes has 1/2" & 3/4" Blondewood(beech??) hardwood ply for $27 & $35 a sheet. It looks like good 13 ply, rotary cut veneer. Bought a sheet of each, still in the suburban(rain)! Curious to see how it compares to the $25 china-ply from HD. Used 2 sheets of that stuff making carts for the shop. Every time I made a cut, I never knew which way it would warp!!! Had to force it to stay square. Saved some of the worst for clamping
http://www.sawdustzone.org/forum/discussions/bargain-alerts/19257-blondewood-hardwood-ply-lowes
Another link I found that was not too encouraging,..http://www.sawmillcreek.org/showthread.php?58698-Blondewood-Plywood
(What a shame, this stuff looks so great on the showroom floor)
Welcome to the world of China ply or Formaldeply . 14 years ago the plywood you bought was a different product than what you saw all warped up . A large portion of the suspect panels are made up of Poplar core with Poplar skins that at first glance to the casual looker may look like Birch . My guess is the moisture content in the plywood is higher then optimal , perhaps from shipping or the mfg process itself . It is a wonderful product and can be used with great success and with no warpage problems , if you screw them to box car walls .
14 years ago the plywood you bought was a different product than what you saw all warped up .
A large portion of the suspect panels are made up of Poplar core with Poplar skins that at first glance to the casual looker may look like Birch .
My guess is the moisture content in the plywood is higher then optimal , perhaps from shipping or the mfg process itself .
It is a wonderful product and can be used with great success and with no warpage problems , if you screw them to box car walls .
http://forums.finewoodworking.com/fine-woodworking-knots/wood-and-materials/no-more-home-depot-lowes-plywood
I haven't bought any plywood in a long time. When I did buy plywood I always bought the exterior glue plywood. It does better in my basement. No warping at all. Is the exterior glue ply not available any more?
How about random strand board? Or particle board? ( the stuff that looks like sawdust glued together ) Maybe pressure treated plywood. Has anyone tried any of these alternatives to regular plywood?
Be picky when you select your plywood. I bought some recently, and they replaced it because the plies weren't consistent from side to side. I use 2 1/2" wide strips for my subroadbed, and couldn't figure out what the problem was until I looked at the strips lengthwise; from side to side, the plies varied from 3 to 5 plies.
Marlon
See pictures of the Clinton-Golden Valley RR
SouthPenn How about random strand board? Or particle board? ( the stuff that looks like sawdust glued together ) Maybe pressure treated plywood. Has anyone tried any of these alternatives to regular plywood?
Yes. OSB. Oriented strand board. I used this on my third layout 37 years ago. I had mentioned this layout on my first thread on this forum. It had way too tight radiuses and way too steep grades, it was a barn burner and ended up being stored in the garage rafters for 35 years. When I took it down it looked exactly the same as when I put it up there with exception of being faded in color. The garage had extreme cold and dry Winters also extreme hot and humid Summers. It's certainly stood the test of time.
HDF high-density fiberboard used for subfloors. MDF medium density fiberboard used for furniture. Either one would be a way better choice than particle board. Particle board expands and bloats from moisture and water. MDF and HDF is a very rigid, smooth and a perfectly flat straight product. It's very heavy but I think would work well. I would put an oil-based sealer on it though. Water from ballasting isn't exactly it's friend either.
Treated plywood I'd stay completely away from. It comes with 60% moisture. It definitely can warp and does. I have hand nailed the stuff and actually been splashed in the face.
Take care
Edit. I need to add this comment as I just thought of it. I don't know about MDF as I've never tried it but HDF is so hard and dense it'll laugh at those little track nails bending every one of them as you try to drive them in. You would have to pilot drill. HDF is the same product as 1/8 inch Masonite used for backdrops. It's called Masonite because the wet Mason method is used manufacturing it and is only smooth on one side, where HDF is manufactured dry Mason method and smooth on both sides. It is sold in thicker varieties than Masonite.
That's why you caulk the track and roadbed, then it doesn;t matter what the subroadbed material is.
I recently tossed out a 18"x7' sectioon of a shelf layout I built more than 20 years ago. For most of that time, it has been stores standing on edge in an unheated uninsulated garage. Not even bowed. The end resting on the ground was dirty and discolored but not swelled. This stuff won;t warp, and the high density deadens sound. The downside is a sheet of the stuff is HEAVY. And the density and glue used to build it is hard on saw blades. It can chip out when sawing or drilling.
I have a 5'x8'x3/4 piece of that MDF 'stuff' sitting in my carport right now. It takes 2 big people to move it around, and I am deadly affraid of it getting wet in any manner. In fact even the high humidity we have here in FL at the moment is affecting it.
I just would NOT use this stuff in any instance. I've seen lots of furniture constructed of this crap, and its just not my cup of tea.
Technically, MDF contains a mixture of wood solids, wax, and resin bonded together under high temperatures and high pressure to create a uniform wood-like product that is far cheaper than real wood. In layman terms, MDF is sawdust held together with glue; sort of a higher quality (that’s an oxymoron, in my opinion) material that serves as the base for the piece-of-crap furniture you get from office supply stores or certain shall-not-be-named furniture chains.
On the downside, MDF tends to dull blades rather quickly, cannot be routed well (particularly since it is typically veneered at the factory) and requires pilot holes to avoid splitting. It also is very susceptible to water damage. Then there is the formaldehyde. The fine sawdust produced by cutting MDF is quite unhealthy to breathe, so one should always wear a dust mask and work in a well-ventilated area when cutting MDF. Additionally, the veneers on MDF don't prevent the urea formaldehyde from seeping through and evaporating into the air. Painting or fully sealing MDF will help stop the off-gassing urea formaldehyde, but in the case of mass-produced furniture, this step has been skipped. This likely means that every piece of cheap, mass-produced furniture in your home or office is off-gassing formaldehyde.
Then there is the formaldehyde. The fine sawdust produced by cutting MDF is quite unhealthy to breathe, so one should always wear a dust mask and work in a well-ventilated area when cutting MDF. Additionally, the veneers on MDF don't prevent the urea formaldehyde from seeping through and evaporating into the air. Painting or fully sealing MDF will help stop the off-gassing urea formaldehyde, but in the case of mass-produced furniture, this step has been skipped. This likely means that every piece of cheap, mass-produced furniture in your home or office is off-gassing formaldehyde.
The stuff I had, it's definitely not MDF, nor is it anything like what I see sold as HDF either. This stuff was more off-white in color like ordinary wood, not the brownish color of the unpainted HDF I see in stores today.
All well and good to say don;t buy the wood at Lowes or HD, but there are no other palces around here that I can find. I'm willign to drive a little bit, but even my truck can't take 4x8 sheets flat, so places that require much high speed highway travel are pretty much out. I know people do stuff like that allt he time, with the wood held in by oen tie strap, but I'm not those people.
There are actually 2 places not far from me that say they have the good Baltic Birch 12 or 13 ply stuff - however they are wholesale only. There is one independent retail lumber yard but they have little in terms of sheet goods for whatever reason. In the mean time, I've built two layouts using dimensional lumber, in one case from HD, that one lived in an unheated basement with humidity that varied from so dry that if you thought about moving you would build up a static charge to high in the summer that made it feel colder than it was. No warping. The other was all products from Lowes, that one lived in a spare bedroom so the variation wasn;t as great through the seasons. Also no warping.
I was really considering mostly plywood benchwork, cutting strips to form dimensional lumber, but I may be betteroff just sticking to standard stuff - except for the relatively small volume I needed for the previous layouts, I had to do a lot of cherry picking. Now needing at least 10x the lumber, it may tak foerver to get enough good pieces.
For a layout in an uneated outdoor shed in Florida humidity, I would suggest steel studs fro the framework and extruded foam for the base. Much like Chuck is doing to combat the excessive dryness in the desert climate he lives in.