Latex Caulk

[tomikawaTT]

Since Tom pretty well covered the waterfront, I'll just add a few comments:

• Why grey caulk?  Because most modelers use grey (or close to it) ballast, and the caulk will hide the 'holidays.'
• Anchoring the track until the caulk sets - I use 'miscellaneous weights' (phone books, canned goods batteries from battery-powered tools.)  A 16 inch length of 75 pound/yard rail is gross overkill!

Actually, I use caulk in three layers - thin extruded foam (aka fan-fold underlayment) to plywood, cardstock track template to foam, flex track (or wood ties for hand-laid specialwork) to cardstock.  The bottom, totally invisible layer can be any color, even royal purple or neon pink.  I use whatever was cheapest at Home Despot or (Madden's) Hardware last time I visited.  For the cardstock layer I prefer clear, so I can see the guide lines for the template.  The final layer is grey.

Chuck (Modeling Central Japan in September, 1964 - on foam-anchored trackwork)

[tstage]

mrazz

Hi,

I'm looking for some beginner's guidance on how to secure track and cork roadbed to a 2 in foam base. The caulking method seems to be the way to go, but all the photos I've seen use a gray color caulk. Wouldn't it be better to use a clear color caulk?

Mark,

I use DAP Alex Plus Acrylic Latex caulk.  It comes if a variety of colors and is only $2/tube at Home Depot.  White and clear are usually what they carry.

The key to using latex caulk is to spread it out thin with a putty knife - i.e. ~1/32" thick - especially if you are laying track.  I like to use a lighter color like white because 1) that's what's readily available and, 2) I like to be able to see the caulk as I apply it.

How much time do you have to adjust the track once you lay a bead of caulk down and spread it smooth. And once you lay the track, what is the best method for getting it as straight as possible?

DAP Latex caulk starts to set up in ~40 minutes so figure 15-30 minutes of working time.  For alignment, I like to draw my alignment lines BEFORE laying down the caulk.  Sometimes I place a series of push pins in my foam or cork as an alignment aid for my cork or track.

A good metal rule (e.g. 12", 24" and 36") is also a alignment good tool.  Place the rule parallel to the rail and move the track until there isn't a gap.  However, your eye is your best alignment tool.  Even if you use a metal rule, run your eye down each rail to see if the sections are indeed straight.  Sometimes I go back and forth adjusting the rail in small increments until it "looks" right.

Also, what is a good technique for drawing accurate track lines on the foam base?

Just some general questions, any info will help.

Thanks as always, Mark

Again, a metal rule works very well.  A cheap alternative is the metal adjustable shelving strips.  They usually come in 3' lengths and are nice and thin.

One more think Mark.  Make sure that you gently press down on your cork roadbed or track to seat it in the caulk.  What you don't want to do is to put too much caulk down so that it oozes up above the ties of your rail ties.  With the cork, I just use the putty knife to clean up any excess caulk along the edges.

[Edit: Once things are positioned where I want them, I use thumb tacks to secure my track and bricks on top of my roadbed to ensure that they are flat when the caulk is cured.  Heavy books will work, too.]

Hope that helps...

Tom

[mrazz]

Hi,

I'm looking for some beginner's guidance on how to secure track and cork roadbed to a 2 in foam base. The caulking method seems to be the way to go, but all the photos I've seen use a gray color caulk. Wouldn't it be better to use a clear color caulk?

How much time do you have to adjust the track once you lay a bead of caulk down and spread it smooth. And once you lay the track, what is the best method for getting it as straight as possible?

Also, what is a good technique for drawing accurate track lines on the foam base? 

Just some general questions, any info will help.

Thanks as always, Mark