My latex caulk isn't working

[ICG/SOU]

After being gone for a few days, and not having laid track in over a week, I started to remove the pins holding the roadbed and track in place, and within a few minutes the roadbed (Woodland Scenics) would separate from the blue styrofoam, and the track would separate from the roadbed.

I got the DAP non-silicone latex caulk (ALEX) from Home Depot. So far, the only places that seem to stay in place are the spots where I had to repair the roadbed and caulk the seams. I am doubtful, though, that the caulk will hold that in place in the long term.

So far the Woodland Scenics Foam Glue is holding other repaired areas. Unfortunately, most of what I laid is soldered, so I'm looking at having to rip everything up and start again. Would Elmers white glue work just as well as the WS Foam Glue (the WS glue is $12 a bottle)? Did I buy the wrong caulk? Would cork adhere better than the Woodland Scenics roadbed?

Thanks for the help. I'm a little frustrated now that I can't seem to move forward on the construction and rough scenicking since I'm always repairing track.

 

[Selector]

I can't say you bought the 'wrong' caulk, but you wanted acrylic latex caulk which often runs about $3.00 a tube, give or take as much as a full buck, depending on if they want to move stock. If your stuff is still essentially muddy, you have the wrong stuff, the wrong ambient humidity, or it just needs a lot longer...for some odd reason. I used the DAP white acrylic latex and spread it very thin...like a skiff of margarine on a piece of bread. Once whatever I wanted fixed in place was pressed there and left to dry with some weight atop it, I could generally go back and remove the weights or nails inside of two to three hours. My basement is humidity controlled and never exceeds 66%.

I am sorry to hear of your troubles. Hopefully you don't have a bad batch for some strange reason, but I can't think what it could be.

 

[Larry]

When I use to use foam board on my layout on grades I always used Elmers white glue. I always put weights on the track after I tacked it down for alignment w/T-Pins. U have to let it sit for at least 1 or 2 days. I always buy my glue in gallons & the new Elmers works a lot faster than the older stuff from 2 yrs. back. I use about 2 gals a year on my layout & it's $11 a gal at Home Depot.

 

[jbaakko]

Did the tube say "caulk" or "adhesive caulk"? The latter is what you need, plain caulk is simply not tacky enough.

 

[CP9302]

I would say Josh is correct. It needs to be an adhesive caulk.

This is the stuff we use at my club:

http://www.homedepot.com/webapp/wcs...langId=-1&catalogId=10053&productId=100661917

You don't have to buy it by the case though!

 

[NWCanuck]

I used Dap Acrylic Latex brown caulking for my layout. I have a 2 inch pink extruded foam base over 1/2" plywood. I used the Richard's wire brush in the photo that I bought in a 3 pack at Home Depot to rough up the pink foam before laying a 1/4" bead of caulking. I spread that out with a 2" putty knife and then laid the "cork" roadbed onto the caulking. Then I took a roll of packing tape and rolled over the roadbed to press the roadbed down and squeeze out the excess caulking leveling the roadbed at the same time. I then used two 1 3/4" quilters "T"pins (Bought at Michelle’s) every 4 inches to hold the roadbed down while it dried which only too a day or less at 40% humidity. The excess caulking that squeezed out while rolling it was spread down the sides of the roadbed. The roadbed isn't going anywhere. I think the key with the extruded foam is to scuff up the surface a little with a wire brush to give the caulking a place to bite, the cork roadbed is porous enough to allow the air to reach the caulking allowing it to cure properly. I have never tried the foam roadbed. Not sure how porous it is and whether or not the air can get to the caulking, maybe that is why they push their own type of adhesive.

That being said I did by a tube of White GE Silicone II with a good expiry date on it. The stuff would not setup even when a dab was put on a piece of wood and left out in the open air to dry. It was just a defective tube of silicone. Best of luck!

View attachment 14491

 

[jbaakko]

I use the tubes of Dap Kwik Seal from Wal*Mart, the non-caulk gun style, because I'm too cheap to buy a caulk gun.

 

[kenw]

Personally I would avoid silicone for this purpose, it is overkill and any silicone that does get in bad places is a booger to remove. The latex caulk will be easier to paint over later as well.

I used cork roadbed on foam, in some places I roughened it a bit with sandpaper, but found that when using carpenter's glue (Elmer's, yellow) it wasn't necessary. A few weights (books, boxes, whatever...) on the roadbed for a few days was all it needed. As others mentioned, a thinner layer of glue (or even caulk) is going to work a lot better and dry much faster. Using more won't make the joint any stronger.

 

[oplholik]

I bought some Dap Rely-On Vinyl Latex Caulk at my local hardware store, $1.79 per tube. I haven't gotten to doing the cork roadbed yet, but it worked very well putting the Dow blue foam down on top of the plywood. I did go over the foam board on both sides with some 60 grit sand paper I had first. So hopefully it will work just as well on the cork roadbed.

Paul

 

[RCH]

I'd recommend using PL300 foamboard adhesive:

http://www.stickwithpl.com/Products.aspx?ID=300-Foam-Board-Adhesive

This stuff is easy to work with (works with a caulk applicator) and provides very solid adhesion. You have to clamp it in place while it dries, but after a few hours, you've got a good bond. I used it to laminate sheets of 1" foam board together for a scenery base of my Free-mo module, to attach the foam directly to the plywood base and I used it to attach the cork roadbed to the foam. I've transported it around quite a bit and it's survived temperature swings from the 30°s to the 100°s without any delaminating.

Latex adhesive caulk is good for attaching track to the roadbed, but I wouldn't rely on the bond you get from it when it comes to structural elements of your layout.

 

[tankist]

i had a piece of foam i though i glued down separate on me while cutting. really annoying. i found that foam needs good scrubbing before glue and even then elmers take more then 2 days to bond completely (it still wet but already holds).

hmm, i used dap quick seal i had left over from bath project to glue down rail to my test piece. it holds firmly and since it is a test piece i really tried to separate it. i just looked it up however and it does appear to be adhesive caulk. what do you know.
but thanks for the warning, i picked up a tube of latex caulk in walmart for less then a buck. not sure if it is the adheceve kind, will need to test it before use

 

[ICG/SOU]

Thanks for the replies.

My issue is the WS roadbed. If I use the sheets (in the yard), and the sheets aren't perfectly flat (usually bowed up in the middle), then the caulk won't hold over time. The caulk will stick to the blue styrofoam, but when I remove the roadbed to reglue, all the caulk stays on the blue styrofoam, not the roadbed.

Same thing is happening with the track.

I thought at first it was a heat issue (room can get into the mid 80's since we've had some 100+ days), but humidity has been almost nil, since we've been in a drought. Later I thought it was because I wasn't putting enough caulk on, but that isn't the case either. Many problem areas are where two pieces of styrofoam meet up, and figured that even though the styrofoam is caulked together and to the plywood, that it still shifted or expanded a little. Unfortunately, now I have places where there isn't any stress on the roadbed or track, and I can quite easily pull it up, if it hasn't curled up already.

I'll look to see if I can get some adhesive caulk or the foam glue that was posted here. I'm just going to have to pull up some of my track, unsolder it, and then resolder it in place after I re-lay the roadbed.

 

[Larry]

Anton, I use the WM cheap caulk to glue pine bark to the sides of my mountains & it works good for that, but, it's not an adhesive caulk like liquid nails or regular white adhesive caulk. I also use the cheap stuff to attach trees, rocks & other stuff. It's fairly easy to remove later after the heat gets to it.

 

[stationmaster]

One BIG reason I use plywood. I have no adhesion problems with ANYTHING I use, Elmer's, DAP adhesive, Liquid Nails. It ALL works. And ceiling panels work great for scenery too. Of course my modules tend to be a bit heavy, but they're STUCK.

Bob