rrebell Plywood expands about 10x that of nickle silver, and you wonder why there is a problem?????????????
Plywood expands about 10x that of nickle silver, and you wonder why there is a problem?????????????
zstripe rrebell Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of. Rebell, Sorry....But that statement about Homasote, is not true!
rrebell Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of.
Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of.
Rebell,
Sorry....But that statement about Homasote, is not true!
Rich
Alton Junction
Hi,
My current layout (11x15 HO) was constructed in 2008. I bought decent A/C 1/2 inch (current equivalent) and it sat in an insulated garage for a few months before being used. I finished up the benchwork, roadbed, trackage, wiring during the spring/summer/fall months. Of course, here in Houston every day is humid to one degree or another............
During winter, one day I went into the layout room (2nd floor spare bedroom) and (expletive deleted).....what happened??? In 14-16 spots the tracks were seriously warped. The obvious reason (in my case) was the plywood finally was in a rather low humidity area and just dried out and shrunk. And it doesn't take much shrinkage to warp a set of rails.
The good news was that most of the warps were quickly fixed by running a Dremel cutting tool and putting a slice in each rail. Amazing how they snapped back in place. But as I recall, 3 places had to be cut out and rebuilt.
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
Hi all
A lot of this thread seems to be dealing with wood and humidity etc.
Well its recomended the timber is left a week or two where it going to be used,
not somewhere else then moved.
Then the wood cut and layout built after its played its silly games.
If after that it is still going to play games.
I would have thought the sensible thing to do would be to seal the timber with a good quality sealer as each section is completed.
After that once all the boards are made the grab some cheap earth tone house paint and paint the lot only after that build a railroad on it.
Leaving the pretty finish how ever you happen like that untill it can be applied without spoiling anything or being spoiled.
I may not be the sharpest tool in the shed,
But I always seal my layout bench work where humidity or dryness may be an issue particularly if I know the material will soak in moisture or may dry out to much.
regards John
zstripe rrebell hobo9941 I have had problems with track expanding and buckling for several years. There is no plywood in my layout. My unheated garage can go from 100 degrees in the summer to minus 20 or even minus 30 last winter. Thats a 130 degree difference. It only takes less than 1/8 inch expansion in soldered track to buckle it. My track was cork roadbed over homosote, with the track glued to the cork roadbed with white glue. The track in some places lifted upward, breaking away from the cork roadbed, and some places went sidewise. I have seen gaps open up and close in a matter of several hours, when I heat the garage to work out there. It is not humidity doing this, at least in my case. Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of. Rebell, Sorry....But that statement about Homasote, is not true! http://www.pakline.com/homasoteboard/homasoteboard.html Have not experienced any expansion/contraction on My layout in going on 32yrs. Kiln dried white pine 1x3's, 1/2 exterior grade ply, with flat area's covered with 1/2 Homasote roadbed, cut Myself. All glued, screwed and newer sections, used an air-brad nailer, instead of screw's.....faster and just as strong. DC 3-cab control, with around 45 blocks.....not once have I had a problem. It's in My attic, in a burg. in ''Chiberia''. Attic has not always been temp. controlled. When You build with cheap green material...You reap the results. Take Care!! Frank
rrebell hobo9941 I have had problems with track expanding and buckling for several years. There is no plywood in my layout. My unheated garage can go from 100 degrees in the summer to minus 20 or even minus 30 last winter. Thats a 130 degree difference. It only takes less than 1/8 inch expansion in soldered track to buckle it. My track was cork roadbed over homosote, with the track glued to the cork roadbed with white glue. The track in some places lifted upward, breaking away from the cork roadbed, and some places went sidewise. I have seen gaps open up and close in a matter of several hours, when I heat the garage to work out there. It is not humidity doing this, at least in my case. Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of.
hobo9941 I have had problems with track expanding and buckling for several years. There is no plywood in my layout. My unheated garage can go from 100 degrees in the summer to minus 20 or even minus 30 last winter. Thats a 130 degree difference. It only takes less than 1/8 inch expansion in soldered track to buckle it. My track was cork roadbed over homosote, with the track glued to the cork roadbed with white glue. The track in some places lifted upward, breaking away from the cork roadbed, and some places went sidewise. I have seen gaps open up and close in a matter of several hours, when I heat the garage to work out there. It is not humidity doing this, at least in my case.
I have had problems with track expanding and buckling for several years. There is no plywood in my layout. My unheated garage can go from 100 degrees in the summer to minus 20 or even minus 30 last winter. Thats a 130 degree difference. It only takes less than 1/8 inch expansion in soldered track to buckle it. My track was cork roadbed over homosote, with the track glued to the cork roadbed with white glue. The track in some places lifted upward, breaking away from the cork roadbed, and some places went sidewise. I have seen gaps open up and close in a matter of several hours, when I heat the garage to work out there. It is not humidity doing this, at least in my case.
http://www.pakline.com/homasoteboard/homasoteboard.html
Have not experienced any expansion/contraction on My layout in going on 32yrs. Kiln dried white pine 1x3's, 1/2 exterior grade ply, with flat area's covered with 1/2 Homasote roadbed, cut Myself. All glued, screwed and newer sections, used an air-brad nailer, instead of screw's.....faster and just as strong. DC 3-cab control, with around 45 blocks.....not once have I had a problem. It's in My attic, in a burg. in ''Chiberia''. Attic has not always been temp. controlled. When You build with cheap green material...You reap the results.
Take Care!!
Frank
richhotrain rrebell Plywood expands about 10x that of nickle silver, and you wonder why there is a problem????????????? zstripe rrebell Homasote is wood!!!!!!!!!!!!! Requires 3/16" between panels, a little less than ply, depending on the wood the ply is made of. Rebell, Sorry....But that statement about Homasote, is not true! Is it only me,or have others noticed that certain keys, such as the question mark and exclamation point, seem to be stuck on rrebell's computer? Rich
Is it only me,or have others noticed that certain keys, such as the question mark and exclamation point, seem to be stuck on rrebell's computer?
rrebellTrue but that is because I don't want to learn the other ways of making a statement stand out.
Rrebell,
I guess You didn't read about paper pulp and wood in the link I posted and what makes them different!?..................................Now My button is stuck! LOL
Take Care!
As a previous poster indicated, you can seal the plywood beforehand. But remember, that means painting BOTH sides and edges and IMO, it would take two coats to work.
For a small layout, that would be fairly easy, but for anything large it would be a project of size and time. I believe I had 7-8 sheets for my layout, and I thought the wood was dry as it sat for two months in an insulated garage.
If I had known of the impending problem, I might well have taken the time to paint it beforehand - both sides of course.
I read it and so what is different than what I said, even after you kilm dry wood fibers they remain active and will absorb and expell moisture, even after being sealed (just ask any furniture maker).
It's KILN dried wood not fibers. The true Homasote registered trademark brand is made from recycled newspaper pulp... I have yet to see any paper expand/contract!
Believe what You want....That's Your prerogative. Been using it for quite a number of yrs. in interior work and never experienced any problem's without painting either side and I do not leave any gap. I would only leave a gap, if I was attaching it to an exterior wall, whereby what it is attached to, will expand/contract.
I have never seen or heard of any furniture maker who use's any Homasote made with recycled newspaper.
zstripe Rrebell, It's KILN dried wood not fibers. The true Homasote registered trademark brand is made from recycled newspaper pulp... I have yet to see any paper expand/contract! Believe what You want....That's Your prerogative. Been using it for quite a number of yrs. in interior work and never experienced any problem's without painting either side and I do not leave any gap. I would only leave a gap, if I was attaching it to an exterior wall, whereby what it is attached to, will expand/contract. I have never seen or heard of any furniture maker who use's any Homasote made with recycled newspaper. Take Care! Frank
Plywood is kilm dried wood, why would you argue with their own instalation instructions, the Homosote company dose not come up with them for no reason, sure in a controled enviorment nothing moves but in uncontroled they do. This also brings up why I use 1x4's in benchwork as their expantion is less than ply expanding mostly on the edges and not the ends and it is covered in foam only so that surface dosn't move for all practical puposes with what we use it for.
I think the capitalized KILN was to draw attention to the correct spulng. It's "kilN," not kilM. That aside, fibers won't expand with moisture as they are like hairs. Pulp will. Not sure about homasote since I have never used it.
selector I think the capitalized KILN was to draw attention to the correct spulng. It's "kilN," not kilM. That aside, fibers won't expand with moisture as they are like hairs. Pulp will. Not sure about homasote since I have never used it.
Just looked it up, hair dose expand and contract with moisture, who knew?
All of this talk about how wood expands and contracts, not only dimensional lumber but also plywood sheet and homasote and whatever, ignores the specific issue raise by the OP - - - a single piece of flex track bending out of position. As I mentioned earlier, the very same thing happened to me.
Expansion and contraction of wood aside, the problem in this instance is a too tight connection of two sections of flex track giving way under pressure. If expansion and contraction of the plywood occurred, a whole lot more than just one section of flex track would be involved.
I'm thinking more that the latax caulk had a lot to do with what He experienced and that the sections in question were too tight from the get-go and the thin layed caulk couldn't hold it in place any longer. I don't use caulk for track adhesive, so I'm guessing.
richhotrain All of this talk about how wood expands and contracts, not only dimensional lumber but also plywood sheet and homasote and whatever, ignores the specific issue raise by the OP - - - a single piece of flex track bending out of position. As I mentioned earlier, the very same thing happened to me. Expansion and contraction of wood aside, the problem in this instance is a too tight connection of two sections of flex track giving way under pressure. If expansion and contraction of the plywood occurred, a whole lot more than just one section of flex track would be involved. Rich
Reb, I am not contending that the nickel silver rail is expanding at all. A simple examination of a piece of flex track will reveal that if pressure is applied at both ends of the flex track, it will bend and give. So, if you place a section of flex track too tightly between two connecting sections of flex track, it will give under pressure. That is why it is not recommended to solder each and every flex track connection.
I've only ever had this happen once at a rail joint to a bridge crossing. I took a bit more off each rail end and have never witnessed it again. I keep my layout room temperature down a bit, its in the basement.
Lynn
Present Layout progress
http://cs.trains.com/mrr/f/11/p/290127/3372174.aspx#3372174
richhotrain Reb, I am not contending that the nickel silver rail is expanding at all. A simple examination of a piece of flex track will reveal that if pressure is applied at both ends of the flex track, it will bend and give. So, if you place a section of flex track too tightly between two connecting sections of flex track, it will give under pressure. That is why it is not recommended to solder each and every flex track connection. Rich
rrebell There is no pressure on the ends if they don't expand once installed, the ties have breaks in them and so there is not a problem there, cork dosn't expand or dose foam (in the context of what we do), with the powers of elimination, that leaves one culprit, the wood!!!!!!!!!!!!!!! (and yes I did use multiple "!")
There is no pressure on the ends if they don't expand once installed, the ties have breaks in them and so there is not a problem there, cork dosn't expand or dose foam (in the context of what we do), with the powers of elimination, that leaves one culprit, the wood!!!!!!!!!!!!!!! (and yes I did use multiple "!")
Too bad that you are wrong.
This from a cork website:
Just like other wood products, cork is subject to the phenomenon of expansion and contraction in response to climactic conditions. During the heating season, moisture levels diminish, causing cork to contract. When humidity levels are higher, cork will expand.
Of course cork expands with moisture. If you take two brand new wine bottle corks and submerge one overnight in water, it will be noticeably larger than the dry one. That's why we store our wine on end.
When lumber is cut at the mill, it comes off the green chain the way it was cut from the tree, with the grain all the same way. When you take it off the pile at the lumber yard, the grain should also be the same way. So when I built my 6' x 18' bench I did two things that I had learned along the way.
One was two use two 1" x 4"s as the main spine(s) of the bench instead of one 2" x 4". Making sure I flipped and turned end to end the 1" x 4"s so they faced with opposing grain before joining them together. This way as they dry out they keep each other in check and will remain straight. The second was to clamp all the 1" x 4"s together and run them through the Radial Arm saw making cuts for lap joints. These were then glued and screwed.
Lap joint.
Here is the underside.. All done with lap joints and making sure the lumber had opposing grain where two 1" x 4"s make one 2" x 4".
This bench is as square and level as the day it was built.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Accually the cork we use only looks like cork bottle cork, is is way different and is not made from premium cork and has a lot of resin in it, also the way it is manufactured, so even though it is wood, for our purposes in the way we use it in the hobby (for the most part as I have seen some weird things), it's expantion amount is not worth considering.