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To hold the cheap white styrofoam–the kind that makes little white balls when you cut it–to plywood?
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To hold cork to white styrofoam?
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To hold track to cork?
I was going to use Elmers for 1 & 2 and acrylic latex caulk for #3.
I’d skip the foam, unless you’ve some need of it. The cork can be cemented to plywood using white glue, yellow carpenter’s glue, or contact cement.
Contact cement will also affix the track to the cork, or you could also use track nails instead.
I get the feeling I’ve missed something here, though.
Wayne
White or yellow glue should do fine, provided it is left to dry for at least a full day, maybe longer, before you stress it laterally, or flex the sub-surface and make the almost dry glue let the foam tear away from the sub-surface material.
I would use the DAP Alex Plus with silicone here. I found, at least locally, and 8 years ago, that the ‘dries clear’ variety holds better than their white version. I’d otherwise use yellow glue, my go-to, but again, let it cure! Pinning roadbed to friable styrofoam, the beaded kind, might not be a very rewarding experience, and you’ll need to do that while the adhesive, whichever kind you use, sets up.
Track to cork, now two layouts in a row for me, was DAP Alex Plus with Silicone, ‘clear’.
Cheap latex caulk should do it all, be sure it’s foam compatable.
Good luck,
Richard
I agree with Richard. I use Dap Dynaflex 230 for all but attaching cork to plywood, where I use yellow wood glue.
Indeed, the caulk should work for it all. But yeah, I’d avoid using a layer of the white messy foam. If you want something you can carve ditches into, even in your area you can probably get pink, blue, or green in the thinner sections. Might be tough finding the 2" stuff in warmer areas, but the thinner stuff is used for more than just absolute insulating value.
Foam to plywood is the one that will take a significant dry time, as it’s tough to get air in to dry the glue. Foam to foam is even worse since neither surface is porous. When I built my last layout with 2 layers of 2" foam, it took a week for the second layer of foam to be stuck on. For building up pieces of foam on foam for scenery - hot glue seems to work well. At last year’s Reading Modeler’s Meet, a guy gave a scenery demo clinic and built a diorama with foam and hot glue in the course of a 1 hour clinic - not even really waiting for the hot glue to fully set, and yet it still stayed together
Using caulk to glue down the cork and then also glue the track to the cork may in some way contribute to keeping the noise down - no solid setting adhesive, and no nails linking one layer to the other. And no, adding ballast did not change that, at least not using my mix of glue and alcohol instead of water - the hard water here prevents even the “few drops of dish soap” trick from working, and since I had the alcohol (70% - so there is still 30% water), I just mixed the glue with that - the alcohol seems to react with the PVA glue (white Elmer’s) and when it dries it is kind of rubbery instead of the typical solid mass of a dried puddle of Elmer’s.
–Randy
A few considerations for these adhesives:
Does the bond have to be ‘stronger’ than the substrates, and if so by how much? Does the area of the bond (or penetration of glue into the substrate) affect the strength of the result?
Does the bond have to be functionally waterproof, or resistant to humidity changes?
Does the bond need to be flexible?
Is the bond subjected to significant shear as well as ‘separation’ force?
Your condition #2, Styrofoam to harder material like benchwork, is of interest here because the surface is irregular and the bond strength limited to the internal strength of the foam. Here you need a glue that ‘wets’ the surface effectively and has enough elasticity not to progressively pop beads on the surface loose or start cracks into the foam that lead to effective spalling. Note the characteristics attributed to Elmer’s thinned with alcohol in this respect…
That styrofoam has ridiculously low strength so almost any adhesive will be strong enough.
That DAP acrylic caulk cures more than dries, stays flexible and is more than adequately strong.
I guess I may learn otherwise but my observation of conventional benchwork is that it is way, way overbuilt for purpose. I understand the possible benefits but really, 1x4 joists and beams topped by 3/4" plywood is far heavier than needed to support a couple of pounds of train.
Ditto the adhesives that seem to be popular. Yellow or white glues are tremendously strong and suitable for this benchwork. Everywhere else these glues are way overkill.
The white glues are very adaptable, they even glue most plastics quite well for our purposes. I’m particularly impressed by Woodlands Scenic’s Foam Tack version of white glue. It’s a very versatile adhesive and combines the strength of white glue with the flexibility of caulk.
Being able to dilute white glues into very weak adhesives is also pretty handy. Possibly the cheapest and perhaps most convenient adhesive for the proposed purpose would be very diluted PVA white glue. You don’t need much strength in relatively large area laminating applications. Air pressure is your friend there. There’s almost no sheer loading and tension loads are extremely low also. If no air can get in between the layers the two laminated surfaces are pressed together by 15 psi of normal air pressure and just ain’t coming apart. That’s basically how low strength contact cement works. Contact cement is almost useless except for its intended purpose.
For track underlays and track itself for that matter the DAP stuff is pretty handy. Water cleanup. Very long curing time so making adjustments is quite feasible for up to a day later. Peels up AND resticks for several weeks after curing which is another quite a handy feature.
Cheep matters but I agree with Randy, I would avoid white foam, even if it were free.
I used sheet cork, Elmers glue and insulation foam for my yard. I covered it with wax paper and weighted the cork, because Elmers glue bleeds through the foam. I had some areas where the cork didn’t stick, maybe because there was an air bubble or inadequate weight. A syringe, needle and more dilute white glue fixed those areas.
Ken Patterson has found that Liquid Nails eats into the foam. He uses Gorrilla Glue, which needs water added or Great Foam spray insulation foam to stick foam to foam, or in the case of Gorrilla glue, foam to wood, as well.
Both EXPAND. The Great Foam expands Greatly, more than you would think possible.
Do not use silicon caulk that has frozen over winter in the garage. It never sets up.
My whole layout is foam on top of 1x4’s, never a problem. Use caulk for everything, white for 1 and 2 and clear for 3, all acylic. Be careful on three to use enough caulk but not too much so that it will hold but not sqish up .
On my first foam layout, I did indeed just build a 1x4 frame and glue the foam to it, no plywood. I used yellow glue for that, then used caulk to glue the roadbed to the foam and track to the roadbed.
Kind of think I used yellow glue to attach the first latyer of foam to the plywood on my last one, then caulk to glue the two sheets of foam together.
–Randy
Because my methods are not typical, and do not include foam… I am almost reluctant to reply.
But here goes,
Lastpikemike suggested our benchwork is over built - maybe, maybe not. For me benchwork needs to support me, all 230 lbs worth. Because I build layouts with deep scenes, and deep benchwork, 3-4 feet deep typically, sometimes deeper. The new layout will have an urban scene that will vary from 5’ deep to 9’ deep in a corner. It will havea rear aisle/hatches for access.
So the materials on top the bench work need to support me. That leaves out foam.
I need to be able to lean on the bench work, pop up thru access hatches, support temperary work platforms without damaging the substrate of the layout.
3/4" plywood works nicely. So does hard shell scenery supported by wood blocks.
I lay track on homasote roadbed or wood roadbed. In fact, in 53 years I have never built a layout for myself using cork roadbed…
Most recently I install that homasote roadbed or wood roadbed with a pneumatic brad nailer. It is fast and accurate, at least for me since it is a tool I use almost daily.
For yard and such, large sheets of homasote.
I glue flex track to my wood or homasote roadbed with adhesive caulk. Not Alex or other “painters caulk”.
I work in the constructon trades, there are good reasons why they sell more than one kind of caulk…
I use adhesive caulk, like PolySeamSeal or Phenoseal. It is an adhesive, it takes a tack quickly, it is strong. It is not intended for those of you who plan to reuse track.
I do not glue down turnouts, they get a few track nails, but generally are held in place by the track around them.
Just a side note, in my daily work restoring houses, which does include painting, we don’t use any kind of caulk with silicone… the two products listed above are far superior to any kind of silicone product for showers, counter tops, drop in sinks and
Made me look.
TBH, the title to this topic is click-bate because it is open end. Thanks for another made-me-look topic. Cheers.
If you want it permanent the best glue to use is 2 in 1 Poly-Seam-Seal.
I have removed that but it’s hard. If you want to change your mind someday (Maybe), Just use Alex Plus caulk.
But you do have two glue down questions you’re asking here and I think I basically answered them both
TF
Yellow glue is pretty much unbeatable for gluing wood. It’s certainly adequate to stick foam to wood.
The forum owners are quite happy about that.
Oops. My bad.[*-)][:$]
Sorry I didn’t get back to you yesterday. I was tired.
The foam is for two main reasons: sound and scenery. I had a layout that was half on plywood and half on foam. The track clacking was significantly different.
I have a stream that drops below grade, and the softness if it makes it so I can say, try trees in different positions.
Got it. White glue and DAO Alex Plus eit Silcone.
Yes, I prefer my foam intact.
Dap Dynaflex 230. Got it.
We have the pink at Home Depot. I’m going to try to exchange the white for pink. Unfortunately, I lost the receipt.
[quote user=“Randy”]
Foam to plywood is the one that will take a significant dry time, as it’s tough to get air in to dry the glue. Foam to foam is even worse since neither surface is porous. When I built my last layout with 2 layers of 2" foam, it took a week for the second layer of foam to be stuck on. For building up pieces of foam on foam for scenery - hot glue seems to work well. At last year’s
I took back the white foam and got two sheets of pink and a gallon of white glue.
The foam is really dirty and dinged up. I’m going to have to wash down with a hose at least, and maybe scrub it before I can glue it down.
Can anyone suggest a dilution rate? I’m thinking 3:1 glue:water.
Don’t dilute the gluwe to glue to foam to the wood, or foam to foam. The water has to come out to cure it, so the more water you start with, the longer it will take to dry. The foam to wood won;t be a problem, since wood is porous, but foam to foam will take much longer because it’s hard for the water to evaporate out.
I wound’t worry about it being dirty, you’re going to paint it with a dirty earth colored paint anyway. Guess they don;t move much foam in Arizona. Around here, you might get a dirty sheet if it’s the last one on a pallet at the bottom of a stack, but usually it comes in and goes out fast enough that it doesn;t have a chance to collect dust and dirt from the goings-on in the store.
–Randy