A Roadbed Adhesive Experiment

I’m getting back after 20 yrs


Folks on several sites reported successful use of Silicone caulk for attaching roadbed to the sub-roadbed. I was skeptical. I carried out this experiment:
Two sub-roadbeds: one plywood; one Pink Foam (Owens Corning FOAMULAR ½”)
Roadbed: ½” Pink Foam 2” strips
Adhesive: Caulk (DAP Alex Plus)

Elmer’s Wood Glue (yellow);
Construction Adhesive (Locktite PL 3X)

Conditions: 62 deg, 60% humidity
@15min all 6 samples were workable

@60min: Caulk still workable, both Elmer’s samples were somewhat firm with the wood sub-base a bit firmer, Locktite were both rock solid
@3hrs both Locktite were rock solid – Elmer’s to wood was solid, Pink to Pink was firm
@18hrs both Elmer’s and both Locktite were rock solid. Caulk was still plyable.


Locktite is about twice the cost of caulk. That’s what I’ll use.

 

What are you going to use, the Locktite????

Just a little fyi, the DAP Alex Plus that dries white is a terrible product. At least, the batch that I had was not very adhesive. Their same stuff that dries clear is much better. However, I would advise you to go even more cheaply and don't bother with the silicone additive. I found PL300 and simple DAP acrylic latex caulk to do wonders with foam and wood, foam on foam, foam on wood, wood on wood, etc.

 

If you mean sub-RB ( that ballast eventually gets glued to), like cork on plywood or homasote on ply or even foam 0n foam, white or yellow glue is all that is needed. They both dry solid. If you are referring to laying track then that's another story.

 

Liquid nails has worked the best so far. Tried all of the above, to some disapointing results with both track and roadbed (cork). The only setback with liquid nails is removing rail without totaly destroying it. But the rails have stayed attached to the layout, weather I want it to or not.:uhoh:

 

Honest, I don't know what the problem is.. I never used liquid nails. I have HO (and N in yards) cork (a wooden material with a rubber content; not sure of that, but it is a vegetable), white glue glued solidly ( as in solidly ) onto my sub-roadbed, 1/2" ply, open-grid bench work. Cork, ply and glue are all organics which adhere to one another beautifully. Then, until I get to white gluing ballast onto cork, in and around ties, I have it all spiked in the middle holes. These spikes hold track good enough until then and will be easily extracted eventually.
I don't see how you can have a bad result using these materials. Further, yellow glue mates like it's welded in wood gluing bench work parts!! All organic and 100% mate well. (I.E. no plastics, which DO cause adhesion hassles at times). Hello !
Mark

 

UPDATE: The caulk was dry after 24 hrs. I believe attaching "foam to foam" with caulk is not a good choice. The Locktite (also Liquid Nails or other construction adhesives) seems the best choice. The Locktite provided at least 2hrs of working time. Yellow Wood Glue (Elmer's - Titebond) works as well providing a bit more work time and is less expensive.

Agree with all above responses.