DAP ALEX Caulk has failed me

SackOHammers Feb 18, 2016

  1. SackOHammers

    SackOHammers TrainBoard Member

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    About 6 years ago when I did about half of my track laying, I read many threads about what adhesive to use. Everything from nails to white glue to liquid nails, and various caulks (silicon and acrylic latex). I settled on using DAP ALEX caulk. Well, life happened and I stopped work on the layout for about six years. I never got to ballast. Well now about half of it is loose. And if I mess with it, more of it just comes right up. I had used to to glue down the Woodland Scenics foam roadbed, the Evergreen Scale Models plastic strips for superelevation in the curves, and the flex track and turnouts to the foam roadbed.
    It was very tedious laying track. I have kind of a tight fit where I'm trying to use relaxed curves and really maximize my space. This means that I don't have a lot of wiggle room to fudge things and I had to spend a lot of time laying the track "just right". It pains me to think I would have to rip it all up and start again. Can you guys think of a way to shore it up? Some parts aren't attached, but enough are that the curves have their shape and the turnouts are in the right spot. I went to the hobby store today to get a fresh bottle of the woodland scenics spray glue (mine was about 7 years old and chunky). I was thinking maybe I could hose things down. Maybe lightly pry up the edge of the roadbed in places and squirt a shot of glue under there.

    What are your thoughts? Am I bound to fail? Is there a better way?
     
  2. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    Is it the just caulk letting go? Or is the foam road bed also any part of this failure issue?
     
  3. rsn48

    rsn48 TrainBoard Member

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    Some are finding the foam road bed can break down over time.
     
  4. SackOHammers

    SackOHammers TrainBoard Member

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    No, the foam roadbed is as solid as it was when I first put it down. The thin layer of alex caulk just isn't holding.
     
  5. Arctic Train

    Arctic Train TrainBoard Member

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    Dang that is weird. I've been using that same stuff to hold my roadbed down as well as track to roadbed with no problems what so ever. What kind of material are you using for your bench? Has it been treated with something that is incompatible with the caulk? I've had good luck when used on untreated plywood and pink foam. When you applied your caulk did you spread it out with your finger (or other tool) in order to get a smooth layer or did you just lay the roadbed/ track directly to the bead of caulk? My experimenting with ALEX is it doesn't have good adhesion qualities if left in a thick bead. It sticks like crazy though if you spread it out in a paper thin layer.

    As far as how to proceed from here, how much track are we talking about? If its a small amount I'd be tempted to tear it all up and start over again. If its a whole bunch then you might try hot glue to affix the roadbed back down. That may leave the roadbed less than level though depending on how hot you can get the glue without melting the foam. I would shy away from spray glue for fear you may make a huge mess on your tracks trying to get the glue in between the roadbed and bench top. If someone makes a spray glue with a tube applicator (ala. WD40) that would be my next choice. Maybe an epoxy that can be squirted through a tube under the roadbed? But regardless, if you have primed your bench top with something that is incompatible with caulk then it's probably going to repel any adhesive.

    $.02
    Brian
     
  6. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

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    I have seen caulk fail which was not a fresh tube- One that was opened and not used up soon thereafter starts losing it's capabilities.
     
  7. Jeepy84

    Jeepy84 TrainBoard Member

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    Wouldn't ballasting glue it down if everything is in the right spot?

    Sent from my XT1585 using Tapatalk
     
  8. SackOHammers

    SackOHammers TrainBoard Member

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    When I did this, I spread the caulk thinly. Some guidance I had read ages ago suggested just thin enough that you can still make out the pencil marks on the foam underneath. This was put down on regular foam sheets from the big box home improvement store. I used a combination of putty knife and my finger to spread it out. Then when I laid down the roadbed, I made sure to move it back and forth a little to spread it and make good contact and bond. Then I pinned it down with macrame pins and sometimes put soda cans on top of the tracks. I used a fresh tube. They were cheap so I bought like 5 of them. I laid it all over the course of 2 weeks and used the same tube. Now, for some of it, I used clear silicon caulk. I saw in some spots I glued the track to the roadbed using DAP Dynaflex 230. Those parts are solid. It's just where I used the white ALEX caulk for putting down the roadbed and some places where I put the evergreen strips for super elevation on top of the roadbed.
    Taking up all the track would be a huge nightmare and take many hours to get it back down correctly. I remember how tedious it was to get it perfect. I'll never get it that good again, especially since the parts with the really tough curves (S curves or places where curves were close together and spacing was critical) are all now soldered together at the rail joiners to prevent track joints kinking. I used a lot of different gauges, templates, and patience.
    My only hope right now is that woodland scenics spray glue you use when ballasting. You hose everything down, then wipe off the rails and tops of the ties with cloth or paper towel and let it dry. But my hope that somehow a bead of that along the edge of the roadbed being enough seems... optimistic.
     
  9. Arctic Train

    Arctic Train TrainBoard Member

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    That is weird. You've got me worried now as I have around 75 feet of roadbed and track affixed with this stuff. So far no signs of it pulling up from the plywood or foam. (fingers Xed) A bead of caulk along the sides of the road bed or even better a bit extruded under the loose edges may do the trick. Not familiar with the woodland scenic spray glue you refer to. Is it a water based glue? I am imagining it a huge mess to clean up after. Just curious, what is the environment like where you have your layout? Is it exposed to large changes in temp and/or humidity?

    Brian
     
  10. mikegillow

    mikegillow TrainBoard Member

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    You might want to consider doing something like what hoyden describes here. Not sure it will work but should be easy enough to try on a section and see how well it holds after it dries.
     
  11. SackOHammers

    SackOHammers TrainBoard Member

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    Brian, the woodland scenics is a "wet glue". It's basically diluted white glue that also includes a wetting agent. A wetting agent lets it break surface tension and penetrate and wick into areas. Mike, interesting idea about the syringe.
    I think just spraying this stuff along the track will hold the track to the roadbed. It's the roadbed to the foam that I'm more worried about... getting it under there. A syringe might do the trick. I'd have to get a pretty fine needle, but not so fine that it clogs up. Thanks for the ideas, guys.
    Edit: Wow, I had no idea these things existed.
    http://www.amazon.com/Creative-Hobb...8&qid=1455984479&sr=8-1&keywords=glue+syringe
     

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