We have the heat, but not the humidity in sunny Scottsdale, Arizona, as Big John can tell you. Well, during the Monsoon season, which just ended the humidity can get up to 25 percent, but the dew point is over 50.
I bought 3 8,000 BTU air conditioners and am having a contractor fur out the outside wall (cement block) and install fiber glass batts and drywall. He will cut 3 windows up near the ceiling so the cool air will flow across the room and drop down. I don't want cold air blowing on me. The units have remotes so they can be programrd as to temperature and o/off times. Now I can build there and enjoy it all summer long. I am also going to apply the HD garage door insulation as well.
spidge wrote: I do have a question about wood expansion in the humidity. If the wood expands, wouldn't the gaps expand as the layout gets bigger the tracks would expand along with it. Maybe i'm just a bit crazy but I could never understand the wood expansion theory. I know it can cause problems but it does not seem to jive.
I do have a question about wood expansion in the humidity. If the wood expands, wouldn't the gaps expand as the layout gets bigger the tracks would expand along with it. Maybe i'm just a bit crazy but I could never understand the wood expansion theory. I know it can cause problems but it does not seem to jive.
Becasue of its cell structure, wood absorbs or gives off moisture in attempt to reach equilibrium with its environment. If the wood is absorbing moisture, the cells expand - considerably more across the grain than with it. If the wood is drying, the cells contract - again more across the grain than with it. When wood is drying, often the cells contract unevenly, which is what causes warping. Closer-grained (harder woods) don't expand/contract as much.
A great example of this absorbtion/drying is putting a wood-planked boat into the water in the spring after sitting on land all winter. It will leak like a sieve (and you better have some good pumps!) for the 1st few hours. The leakage will drop to half its rate in about 6 hours, and it normally takes 2-3 days for the planking to swell to its normal water-tight size, at which point there are no more leaks.
Painting slows the moisture transfer into/from wood.
Controlling the moisture content of the air through air conditioning, dehumidifying, and humidifying is a preventative measure.
Preventing warping by fastening the wood can help. Glued joints/edges apply uniform pressure and work best. Designing wood structures so that different pieces of the structures oppose movement of other pieces (such as L, T, I girders) reduce the effect. Plywood's glued construction helps.
Not sawing the lumber in the 1st place (both at mills and at home) until it has reached moisture equilibrium helps.
my thoughts, your choices
Fred W
jsmaye wrote:Hey FloridaFlyer - one problem nobody has mentioned that you'll have in central Florida, as I had in Houston, is bugs. Flies, ants, moths, spiders, roaches, every kind of beetle imaginable, little gnatty flying things that wind up dead on the benchwork by the hundreds. I had to curtail the use of Sculptamold - I would find craters where roaches had feasted on it.
Argh! Good point JS. I have/had the same issues with buggies.. Or as the kid and I like to play, Alien Invaders. I had to go through and block up all the small cracks and openings I could find. Aquick shot of some good bug spray along he main door seems to keep it down. Out here, Crickets are the ones that can eat everything. Little ers will even eat foam! I used to love opening my main door at night when I worked, but will all my lights in the garage, I would attract bugs from down the street! No more for me unfortunatly
Best Regards, Big John
Kiva Valley Railway- Freelanced road in central Arizona. Visit the link to see my MR forum thread on The Building of the Whitton Branch on the Kiva Valley Railway
Thank you Tony, I thought I may have become a bit touched in the head as my garage layout has many expansion gaps that close in the summer. I had a spot in a siding 4 feet long ( n-scale ) that expanded enough to buckle and become unglued from the roadbed. Now, it did get to 114 here and even with an attick fan the garage was not tolerable.
John
Virginian wrote: Despite all the dire warnings, the length change in nickel silver flex track over a straight line distance of twenty (20) feet, through a 100 degree temperature change, will be less than 0.002". That's two (2) thousandths of an inch. In laymans' terms, that's "not much at all".
Despite all the dire warnings, the length change in nickel silver flex track over a straight line distance of twenty (20) feet, through a 100 degree temperature change, will be less than 0.002". That's two (2) thousandths of an inch. In laymans' terms, that's "not much at all".
Permit me to disagree with the above: the coefficient of expansion of nickel-silver is between 16 and 17.1 x 10^-6 per degree C, or almost exactly 0.2" in the above scenario. It is significant!
My experience on my 6' x 8' layout is that my rail joints open up in winter, and close in summer - with a change of about 25 degrees C maximum (= 45 degrees F). The biggest problem is that the rails tend to creep, so winter often means some gaps stay closed, while others take all the shrinkage, leading to occasional large gaps!
Tony.
grayfox1119 wrote:Mr B!!! What are you doing up so Late???You have to go to work tomorrow !!
Tuesday is hockey night. I relax after the game with a responsible number of my favorite beverages, but I'm really wound up and I typically can't get to sleep until 1 or 2 in the morning. (I'm a goalie, and there's nothing like hockey pucks flying by to get your attention and keep it.) Not good when I get up at 6 for work.
It takes an iron man to play with a toy iron horse.
The humidity and the wood are your biggest concerns. I lived in coastal North Carolina - probably every bit as bad as Florida. I found that a good coating with enamel exterior paints sealed the wood very well, to the point I did not experience any problems after doing that. My construction was flex track, on cork, on 7/16" Homasote, on 1/2"plywood, over 1" x 3" and 1" x 4" framing
There was a discussion a while back in which somebody mentioned their reasonably-scientific investigation of expansion and contraction of track due to temperature change. The result was that it is relatively insignificant. What is a problem, though, is plywood's reaction to changes in humidity. It would seem that the best material to use is 2-inch pink or blue insulation foam. Great stuff. I use it for my layout in Massachusetts, where I have the advantage of a nice interior space with good temperature control. I don't worry about the expansion and contraction problems, but I still find it a terrific material to work with.
The problem, of course, is getting insulation foam in Florida. You might be able to special-order it from Home Depot.
It sounds like your temperature will be similar to what I have to deal with in my garage, but our humidity problems are opposite. What you would think of as extremely low humidity would probably be higher than anything I'll ever see here in the desert.
To control temperature, insulation is key. I was amazed what a difference it made to insulate my east-facing metal rollup garage door. By all means, install an air conditioner, but take some of the load off it by insulating the space first.
My solution to the warpability of wood products (which don't take kindly to changes in humidity) is to build my main benchwork structure from steel studs. So far, expansion hasn't been a significant problem - I just leave a little extra gap at the end of each section of flex track. (I don't solder rail joiners, but I do install jumpers around them.)
Happy layout building (and watch out for hurricanes)
Chuck (who lives in one seismically active area, and models another)
a few ideas:http://home.earthlink.net/~mrsvc/id42.html
Layout Design GalleryLayout Design Special Interest Group
What kind of benchwork are you planning? I ask because of humidity and the potential for wood expansion/contraction.
Lynda