What brand of DAP to use for laying foam/ cork roadbed and track ?

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I can not find any grey acrylic caulk. I used the white but ugly on the black foam and could show up near switch points or areas after adding gravel.
They have Clear but that is shiny .. which do you use flat white or glossy clear ( paint before adding ballast?


Active Member
I am planning on using 3M Super 77. If I had to use a caulk I would use GE silicone Black , silicone will last much longer thing else its just more expensive.Most of the other caulk products are loaded with fillers but they are less expensive .

An alternative to Super 77 would be contact cement , its more or less the same stuff just not in a spray can and may not cure as fast. its used to bond formica counter tops and make labels you have to pry off with a screwdriver. I like it because It apparently is not very evironmentally friendly , the can I have is about 30 years old and is still good, so it must last more than 100 years!


Well-Known Member
The DAP Alex Plus with Silicone (clear) is shiny, but it's all I use. I ballast my tracks, so it isn't visible once it is covered by ballast. The idea is to use just enough to affix the track ties to the roadbed. Any more is a waste. With just a thin sheen in place, the ballast will easily cover it.


Active Member
I used DAP alex plus, in the clear version [white when applied], and it's held up well, over six years now .. for foam to wood, and track to foam , just a thin film is all that is needed, spread with a scrap piece of foam or something like that .. no paint needed, just ballast over the top ..


I run foam track bed over foam board; to attach the bed to the board, I use Loctite Foamboard adhesive. Happy with it so far, shoot it on with a caulking gun, smooth it with a putty knife, then apply the foam track bed. Then I use a small plastic roller I found at a craft store to smooth it down (I think it's called a "seam roller"). Adhesive is tacky enough to hold the bed in place without weights or pins, yet slow enough drying to allow some adjustment and repositioning before drying. Also works well for securing foam board together for scenery purposes.

For attaching the track to the foam bed, I use thinned white glue, drawn under the track with isopropyl alcohol. This does require weighting down or securing the track and allowing to dry overnight.



Active Member
I use whatever is the cheapest paintable latex caulk is for cork roadbed. The few times I've used it under track, I used clear latex applied very thin. Its only shiny for a while, then as ballast and dust accumulate it tones down.

If you are really intent on needing a color, caulk can be tinted with latex paint to match any color you want. Just a matter of how much trouble and cost you want to go to.


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