Forty seven years house building and remodeling, foam eventually shrinks a little. There is no building material that is 100% stable. Everything deteriorates, just glance at the mirror next time you walk by. We would all be grateful to only expand or contract by 16ths and 32nds.
hon30critter IDRick, It took me a while to decipher the title to your thread. Has the foam shrinkage affected your track? Thanks, Dave
IDRick,
It took me a while to decipher the title to your thread.
Has the foam shrinkage affected your track?
Thanks,
Dave
Hi Dave, my title was a bit cryptic... Sorry about that! Love your Rotisserie thread! Cliff notes would be good!
Did not really impact the trackwork as the foam seams were not near track joints and I had not soldered rail joiners so was some available slack for slight movement. The foam separation along the fascia was more bothersome to me based on appearance.
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
maxmanHow do we know that the frame isn't expanding?
It's free floating on the frame, not glued down. The track should hold it together. In fact the track does hold itself together but there are gaps between the foam.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddyKen Patterson (Youtube) claims his foam shrunk just as you describe. That's not what the foam manufactures say, but as he just lays it on the table, one can't blame the benchwork.
How do we know that the frame isn't expanding?
IDRickThe author states that two layers of foam are better than a single layer for preventing separation and that joints should be offset vertically and horizontally.
Sounds like a lot of work to cut the foam and glue in that manner, and depending on the dimensions, wasteful of foam.
Ken Patterson (Youtube) claims his foam shrunk just as you describe. That's not what the foam manufactures say, but as he just lays it on the table, one can't blame the benchwork. I believe he thinks that painting the foam prevents that, but I can't swear to it.
David Popp uses glue and a nail gun for the MR projects.
Honestly, I'd just go with my good old drill and screw bits if the only use of an expensive tool is going to be benchwork assembly. The hundred bucks I'd spend on the Kreg jig or a nail gun could go towards the layout instead.
I'll use a nailgun because I already own it. But, I bought it for home projects, so it gets more use than getting sidelined as soon as the benchwork is done.
Some quick questions:
Read an anecdotal article (non-MR related) today on foam separation issues. The author states that two layers of foam are better than a single layer for preventing separation and that joints should be offset vertically and horizontally. Is this true for a MR layout and is it worth the effort?
My layout is a 5x9 tabletop with two foam seams (1 inch extruded foam over 1/2 inch plywood). It is in the basement, temperature does not vary greatly, never above 70 degrees with low humidity. After 20+ years there is a 1/16 inch wide crack at the seams. Foam separation from the fascia is now 1/16 to 1/8 inch. Double layering and offsetting may have prevented or maybe not...
The next layout will be wall-mounted with narrow shelves and will be built in sections. Would double layering prevent cracks at the seams or any tips to prevent cracking at sectional seams?
Finally, putting together an open grid box, should I use a Kreg pocket jig or an air nailer on the butt joints of the open grid? I will need to purchase the selection and it would most likely only be used with model railroad benchwork.
Thanks!