Bench top, Plywood or Foam ?

[Anonymous]

Well,I'm ready to lay down my bench top. I'm leaning toward cookie cut plywood with 2"foam as my mountain base with mold castings.Then, I pick up another article on woven cardboard with plaster dipped towels.Any +'s or -'s from past attempts?

[MisterBeasley]

Well, I'm using just the 2-inch foam, no plywood underneath. I've got 16 inch separation of the cross-rafters, and it's holding up very nicely. Easy to work with, if a bit messy, but it's a breeze to slice through the roadbed and foam to install a Peco switch motor.

My layout is a five-by-twelve table, with casters under the legs for portability. I'm very conscious of weight, because I want it to roll easily for access, since my arms are not quite 5 feet long. Foam fits the bill, and it's a lot cheaper than plywood. I will likely use plywood for climbs and tracks at higher elevations, just for the stiffness when I get down to narrow strips under the tracks. For the flats, though, the foam is terrific.

[canazar]

MC,
I am also going to 2: foam on my new lay out. The last one, I did a combo of partical board then 1" foam on top. But as time went one, I quickly realised that the 2" has lots of bonus. Easy wiring, just punch a whle trhough, no drill. Easy to make scenery cuts into the foam for creeks, low spots, or roads. True it is messy, but it cleans up super easy too.

Good luck,
John K.

[selector]

I support the advice above. I used 1" layers on top of 5/8 " plywood, overkill to be sure, but found the layering of 1" foam tedious. I will use 2 or 3" next time.

When I needed to wire up through the foam, I did use a drill with a 1/4" bit (wood type does a good job) and liked the clean holes. A punch or screwdriver works, but tends to displace the foam rather than remove it. If you don't get the wire up/down the hole soon afterwards, it will have closed to an extent.

[rayhippard]

I've had several layouts using wood benchwork and plywood on top and always had the
expansion and contraction problems whenever the humidity changed. This always
caused track alignment problems. We are using steel benchwork and 2'' extruded
foam with no wood to stop the problems. I definately recommend this method. As
stated above, this is plenty strong with 16" spaced supports.
Ray Great Northern fan and modeler.

[Blind Bruce]

No one has mentioned that the sound deadening is better with foam also. I am considering 2"foam over 1/4" plywood just so I can mount tortoises from below.
BB

[Anonymous]

I have a 2" extruded polystyrene foam base supported by 1" by 3" on 16" centres. To "drill" holes through the styrfoam I use brass tubing with a wood dowel filler so the drill jaws don't cru***he tube. Push out the "foam plugs with the dowel.

[rrinker]

Good idea for drilling. So far I've only needed to drill holes for feeder wires, and for those just use a small drill bit in my hand, it doesn;t quite go all the way through the 2" foam, but that's another reason why my feeders are solid wire not stranded - I just poke them through.
I don;t need switch machine holes because I moutn my Tortoises from the top. A router bit in the Dremel takes care of that opening.

--Randy

[canazar]

I have found a great method for drill foam, all though maybe not the best for every one.. I took a 6 penny nail and put a lighter to it for a bit then useing the pliers I wa sholding it wit, push it trhough the foam. No displacement, no mess, plus it melts the interior of the whole and gives it a small crust. but helps cut down on the snag factor with wires.. Bit of a radical approach but does work.

John k

[Anonymous]

QUOTE: Originally posted by mcjcne

Well,I'm ready to lay down my bench top. I'm leaning toward cookie cut plywood with 2"foam as my mountain base with mold castings.Then, I pick up another article on woven cardboard with plaster dipped towels.Any +'s or -'s from past attempts?

[8D]Keep the cards and letters coming.So far It looks like 2" foam w/ elavated plywood for riser areas.Thanks for the wiring hole drill tips and tortise's wre in the budget plan.I"m having a time finding extruded foam,Home Depot is a no sale. Ideas?

[selector]

Can you have HD order some for you (transfer from another store?) I say this because extruded foam isn't cheap, so if you order a batch of 8-10 sheets HD minght be more agreeable to getting some in for you.

Find a builder supply that isn't as jobber oriented as HD. Call a building contractor or reno guy and see what they say.

[Bikerdad]

In Phoenix, you'll want to go to a commercial insulation supplier who deals with walk-in freezer installations. You may actually need to contact a commercial refrigeration contractor to find the insulation supplier. Every 7-11 and MickeyD's is going to have walk-in coolers and/or walk-in freezers, somebody's putting them in, and they require extruded polystryene insulation.

http://www.northernarizonarefrigeration.com/index.html
http://www.hugoshvac.com/

[Anonymous]

I'm building my layout right now. The benchwork is 3/4" CDX plywood on a 2X4 frame. After I build the risers I plan on overlaying the entire thing with 1" foam.

Question for the group:

Will 2" of blue foam over the plywood give much better sound deadening than 1"? I;m thinking not, but I'd LOVE to hear some feedback.

Mark in Utah

[Medina1128]

Keep your eye out for construction projects (homes, commercial buildings). They always have some scrap pieces of foam, and most contractors are happy to let you "dumpster dive" and help yourself. I was lucky and found a new source of white foam board (sure it's a bit messier, but it's free). Some friends that work at a grocery Wal-Mart distribution center get loads of it in their perishable trucks, and they usually just throw it away. Make friends with someone that works at one, and they might bring it home for you.

[selector]

Mark, the short answer is no. In fact, I now believe that how you support the track, or even how you anchor it is a huge factor in noise propagation. Other factors are how you ballast and how you glue the ballast.

For example. I have a low trestle to which I did NOT anchor the flextrack that crosses it. Rather, the track merely rests on the wooden joists. The point is that it is nearly dead silent when the traIn crosses!

More foam will just mean more expense.

[siberianmo]

QUOTE: mcjcne Posted: 11 Apr 2005, 18:13:30
Well,I'm ready to lay down my bench top. I'm leaning toward cookie cut plywood with 2"foam as my mountain base with mold castings.Then, I pick up another article on woven cardboard with plaster dipped towels.Any +'s or -'s from past attempts?

Pictures tell a much better story ..... check these out ...... varying thicknesses of insulated foam board adhered to a plywood board with latex caulk w/silicon ....

My HO layout is sectional in design with steel, folding card table legs for support - two sets to each section. There is a "facia" board around the edges of each section - works great for bolting them together ......

Check it out (click to enlarge)









Hope these pix help ...... you may want to check out the rest at the url shown.

Good luck![tup][;)]

[simon1966]

There is a huge difference in the sound deadening capability of the foam if it is attatched to plywood. I have one small section where the foam has no plywood underneath and there is a noticable increase in sound as the trains pass over this section. I used 1" foam as I was able to get it for free in the form of large scrap sheets from a siding contractor.

[Anonymous]

It's good to know that a plywood backing helps to reduce the sound. I'll stick with 1" foam.

As for the trestle being quiet, I've heard that from several people. The reasoning is that there is no "sounding board" to resonate as the train passes.

I want a QUIET layout when I'm done, so I can hear the sounds I want.

Mark in Utah

[ED336]

WELL I HAVE WONDERED WHAT TO USE FOR A WHILE TOO!!! FINALLY DECIDED TO USE 1/4 IN LUAN CONTACT CEMENTED TO 1/2 IN HOMOSOTE ON L-GERDERS AND JOISTS 16 ON CENTER AND NARROWER.. VERY QUIET AND EASY TO WORK WITH, VERY FIRM... DRILLS AND HOLDS SWITCH MACHINES GREAT.. FOAM MOUNTAINS CAN BE GLUED WITH PL300 ADASIVE, THEN SHAPED.. IT WORKS FOR ME!

[grayfox1119]

I am using 3/4" plywood with 2" foam on top. Thinner plywood will do Ok in dry, low humidity, locations, but as I am inthe basement level, and have humidity control, I would rather err on the side of strong table base ( I may need to crawl on it at times) , you cannot do that with just foam, or foam over thin Luan or thin plywood because it will either break or flex too much and cause track problems. If you have only 24" of width, you will never need to crawl on top, so that will not be an issue. However, when you start getting widths of greater than 24", you had better start thinking about stronger bases in my opinion. I plan to use 4 feet in some areas with lift outs in strategic locations, that is why I went with 3/4" plywood. Sure, you pay more per 4x8 sheet, but guys, you buy the table once, and look at the VALUE that will sit on top!! Why skimp?

[Anonymous]

We went down the path of a hollow-core door, 2" pink foam and then woodland scenics risers/inclines (with plaster cloth... here we decided the stuff from Amaco (sp?) was easier to work than the woodland scenics stuff.

Makes for a reasonable-sized n-scale layout and it's still very light.

[Anonymous]

I built a 4 sectional 8x12 HO bench work with 1/2 inch plywood base topped with 3 Inches of extruded blue foam. Since I did a lot of cut outs in the plywood and had 1X4 stringers under neath, the 4 sectiions came out very light weight. I can disassemble and move and set the whole thing up by myself with no help. All four sections bolt together. I couldn't be happier with the results. I went with the 3 inch foam (Expensive) because I wanted to cut deeper areas and rivers. and most important, the layout is strong enought to stand on. I have already don't this for a few hard to reach area. I just put down a 2 or 3 foot oiece of plywood on top of the foam to stand or kneel on so it dosen't dig intom the foam. Works great.

Hope this helps. The layout is also free standing. I have posted some pics in the last free weeks if you want to check it out.
DON