Homasote implementation

[ocalicreek]

I stumbled across this discussion and just couldn't resist. I know in politics the facts don't always mean much. But hopefully, here in the world of model railroading, accurate data from the manufacturer should count for something. From the Homasote website:

Water absorption by volume (max.):
2 hrs. immersion 5%
24 hrs. Immersion 15%

Expansion from 50%-90%
relative humidity (max.): 0.25%

Don't overlook the decimal point in that last statistic. That's one quarter of a percent relative expansion. And the absorption data is even more compelling. The material absorbed only 15% after 24 hours IMMERSION in water. Do we really think the relatively small amount of moisture in our balast glue is going to make homasote swell and warp and buckle like a piece of kid's construction paper? I DON'T THINK SO!!! Especially after we've glued it to plywood - which is more likely to warp and swell and bend than the homasote. If anything, the homasote will stiffen the plywood!

There used to be a page on the homasote website with a sheet that had been framed to a sample stud wall and left outdoors year round. They finally took it down after a few YEARS because it hadn't degraded or warped or lost structural integrity. And this is in the New Jersey weather. 24-7-365. It's amazing stuff!

:hey: I am prepared to be proved wrong by anyone who can demonstrate, in a reproducable way, that homasote swells and warps and causes track misalignment, and that the homasote itself is at fault. But so far, in the past few years since I issued a similar challenge in a similar thread, I have yet to see ANYONE step up to the plate. Don't go on hearsay or suspicion that since it's a paper product it's automatically going to warp. Check the manufacturer's specs or do your own test. Until then I don't want to hear anymore nonsense about warping homasote!

Galen

[ocalicreek]

<!-- m --><a class="postlink" href="http://www.homasote.com/applications/hobby.aspx">http://www.homasote.com/applications/hobby.aspx</a><!-- m -->

They even say it's 'waterproof' on the website!!

What's it gonna take, people?!?

Galen

[FCIN]

Galen;

For the past 30 years, every layout that I've constructed (but never finished) was built using Homasote laminated to at least 3/8 inch plywood, because it was widely reported that Homasote would warp. Homasote is readily available here, but 1 inch or thicker foam board isn't. I always loved the fact that I could spike code 70 track directly to the Homasote with or without cork roadbed and how well it held the track in place and how easy was was to make changes before I put down any ballast. But it was a lot of work to laminate the Homasote to the plywood then cut out the roadbed areas. This time I'm just going with plywood/cork/ballast for my proposed layout. Mainly to save time and money and don't see any problem with just plywood/cork/ballast with glue holding everything.

Anyway, here is a side view of an HOn3 display track that I threw together about 10 years ago, using only Homasote as a base. I built up some contours using cardstock glued to the Homasote and then put a thin layer of plaster (mixed to the consistency of pancake batter) over that and finally affixed some grass/dirt/ballast to that by spraying it with a matte medium.
--- EDIT ---
In my brief description of how I constructed this display/test track I completely forgot one step in the process. After putting the plaster on the contour areas, I then applied a coat of thinned earth colored latex paint over the entire top surface and at the same time, sprinkled on the Woodland Scenics earth stuff. After that had dried to the touch, I came back and sprinkled on some WS grass - glued on a few pieces of lichen here and there and then sprayed on the thinned matte medium. Sorry about that oversight. Since the plaster did not cover the entire piece of Homasote, but was primarily in the center of the piece and then I covered the whole thing with thinned latex paint, I can't say if it would have been the plaster or the paint that caused the warp.
--- END EDIT ---

As you can see (or I hope you can see) in the photo, this was the result the next day. This 3 foot x 4 inch piece of Homasote had warped up in the center 1/2 inch.    
I never did try to flatten it back out as I sort of liked the rise in the center when showing off my little brass Climax locomotive on it, but were I to do it again, I'd have sure laminated the Homasote to plywood or foam board.

Not trying to prove that Homasote is not a good base for building a layout, I love the stuff, but just show that it will indeed warp when it gets wet and I would not consider using it without laminating it to plywood or perhaps even foam board where it available here. I never had any problem with it expanding/contracting/warping when laminated to plywood, even on sections where the roadbed base was cut as thin as 1-1/2 inches wide. But would never consider just using Homasote without a sub base. All my layouts have been constructed using 1x2 l-girders with joists spaced on 16 inch centers. My posting will no doubt incur some ire, but so be it.

[ocalicreek]

Thank you for sharing that enlightening picture, Ed! Question: Could it be the cardstock that warped? That's where I'd put my money...unless you've got another picture showing just the homasote by itself. And a second question - is it the actual homasote brand or a generic fiber board? Not trying to challenge your results, just wanting to clarify the results. Also, what did you use to glue the cardstock to the homasote (and to itself between layers?).

Now we're getting somewhere!

Galen

[rrinker]

No way a thin layer of cardstock would have enough force to warp the homasote. I'd think maybe the plaster adhered and pulled it up, but plaster tends to shrink not expand, and shrinkage on top would have bowed it the other way, I'd think.
I've never had it warp on me from moisture, but I do dispute the whoel idea that homasote 'holds' spikes. Maybe witht he little tricks of a dab of matte medium or some other adhesive before you drive them - but I built a small N scale pike on a 2x4 sheet of homasote, and I was able to drive many of the track nails in, through cork roadbed, with my fingers. When it came time to dismantle that pike to build larger one, I simply pulled up the track pieces and the track nails pulled right out with hardly any force, and without breaking a tie, so I was able to reuse it all. There was no ballast because I never got that far. Bottom line, the homasote sidn't homd anything, at least not plain non-ridged nails.It held enough to keep things from moving on their own, and ballast would have truly locked the track in place, but long term without the application of ballast I would not think it owuld last. With handlaid track, the ballast isn;t goign to hold the rails in place, but it has always been my opinion that the spike into the wood tie does more to hold the spike in tightly than the spike's penetration into homasote.
Tough I would say it is - my neighbor, some 45+ years ago, built a playhouse for his kids, and sheathed it with homasote rather than plywood. It's been kept painted, and still stands and is in no way deteriorated to this day. This in a climate that has a true 4 seasons, with summers reaching 90+ and high humidity to dry winters with sometimes a foot or more of snow, and it has stood up all these years.

--Randy

[Ralph]

...but I do dispute the whoel idea that homasote 'holds' spikes. --Randy

That's odd. I had to drive my track nails in using a tool to push them into the homasote. I see the material holding spikes quite well on my HO layout.

Ralph

[rrinker]

I guess my comparison is to driving nails/spikes into wood - generally you cannot pull them out with your fingers. But into homasote - fingers work.

--Randy

[FCIN]

Thank you for sharing that enlightening picture, Ed! Question: Could it be the cardstock that warped? That's where I'd put my money...unless you've got another picture showing just the homasote by itself. And a second question - is it the actual homasote brand or a generic fiber board? Not trying to challenge your results, just wanting to clarify the results. Also, what did you use to glue the cardstock to the homasote (and to itself between layers?).

Now we're getting somewhere!

Galen

Galen;
I'd doubt that the cardstock had anything to do with it. Thin layers added to the Homasote with Elmer's glue - then as stated a layer of semi-thick plaster added over top of that to blend it all together. Finally, some assorted Woodland Scenic materials affixed with a thinned spray of matte medium. And yes, this is the real Homasote brand.

I threw that whole thing together in one evening, waiting just long enough between things for the glue and plaster to set up. At the time, I never gave any thought to it warping, in spite of all the warnings I'd seen and heard.

Tell you what I can try if you like, since this display/test track was going to be thrown away (I actually thought I had done so a long time ago), tomorrow or the next day, I will turn it over, lightly spray the bottom with water, try and get some clear photos and see if it will warp in the opposite direction. Might be a fun experiment :-)

[tetters]

Interesting discussion.

I used Homasote for my roadbed this time around instead of cork. I think the Homasote does an excellent job of grabbing the spikes compared to the cork. But that is like comparing apples to oranges.

My method of tacking the Homasote road bed to the 3/4 ply deck was to apply a thin layer of PL Premium Construction Adhesive spread out with a putty knife. I then used drywall screws to hold it in place until the adhesive fully cured, then I removed the screws. After which I painted the entire surface a dirt coloured brown. So far so good after about a year. Half of the track work has been thoroughly soaked during ballasting thus far. The whetting agent plus the 1:1 glue/water mix it didn't seem to hurt the trackwork. Although I think painting of the roadbed and track work prior to ballasting it helped seal it pretty good though. I've found though that its actually pretty easy to take up too. I've modified one section of track and simply used a putty knife to lift the Homasote off the plywood deck. It came up fairly easy considering the PL stuff I used to glue it down. Mind you there was a fair amount of material that had to be scraped off the deck which came off with a bit of elbow grease.

Curious to see some more comments. I still have about a 4 x 8 sheet of the stuff, thinking sometime down the road I might be able to expand my little RR.

[P5se Camelback]

My several aborted attempts to build a model railroad have all involved laminating Homosote to half-inch C-D plywood.

The homosote was glued to the plywood using, in the first couple of attempts, good old Elmer's white glue. The later attempts, two 2'-0" x 6'-0" sections of which have been traveling with me as I moved from one state to another for over twenty years, were glued up using Elmer's yellow "Carpenter's Glue." In both instances, the sandwich was compressed while the glue set by placing such heavy objects as bowling balls (in their bags,) a sewing machine and a three-drawer tool box full of tools as "clamps."

The only "coating" placed on the homosote was brushed-on full-strength Elmer's white glue that was used to set Campbell's Profile Ties in, and that was permitted to dry for at least 24 hours prior to spiking down rail. In a couple places, moisture-laden Sculpt-a-mold was used to create landscape forms and in one instance, it took just over a week for that to dry completely. No other effort was taken to seal the Homosote.

As the photos below will visually attest, everthing is still solid after all these years ...





So there you have it ... for what it's worth ... there's nothin' happenin' here (with apologies to the Buffalo Springfield, as well as to Simon & Garfunkle.)

[ocalicreek]

Ed - that will be a fun experiment indeed! Reminds me of the first time I painted a laser cut wood wall. It was a Bar Mills Trackside Jacks/Waterfront Willys kit. I did not prime the walls in any way before painting and sure enough, the acrylic waterbased paints I used made them curl. I quickly painted some water onto the opposite side and hoped for the best. Once the wall dried it straightened itself out.

This leads me to believe the test track warp may have been due to the timing - warping while wet, then the glue dries, bonding it in that position, and it can't settle back into a true, straight form. So wetting the underside may have no effect at all. Curious to see how it comes out.

Then again wood walls have long, porous fibers arranged together by nature in a long orientation. Homasote has short fibers and is dense, with the fibers oriented differently. Hmmm...

Still, was the material you used actual homasote or some generic fiber board? I'm using a ceiling tile type fiber board for my roadbed, laminating it to a 5/8" ply subroadbed/layout base with Elmer's yellow glue, then attaching the track with adhesive latex caulk. It's not very dense and doesn't hold track nails that well which is fine since I'm attaching the track with the caulk. I'm not sure how it'll do once I balast but I'm hoping/risking/guessing it won't cause any trouble.

Galen

[FCIN]

Still, was the material you used actual homasote or some generic fiber board? I'm using a ceiling tile type fiber board for my roadbed, laminating it to a 5/8" ply subroadbed/layout base with Elmer's yellow glue, then attaching the track with adhesive latex caulk. It's not very dense and doesn't hold track nails that well which is fine since I'm attaching the track with the caulk. I'm not sure how it'll do once I ballast but I'm hoping/risking/guessing it won't cause any trouble.

Galen

Yep, it's the genuine Homasote! No question about it. I've never tried using anything else. I've seen folks use ceiling tile and other types of fiberboard like you mention, but never gave that a try. Homasote will certainly hold track spikes very well. On that test track, I spiked down the piece of Shinohara HOn3 flex track using code 70 spikes, 2 every 8 or 10 ties and even though the Homasote warped like it did, the track didn't move and after all this time is still solidly held to the base.

I'll give my experiment a try, maybe tonight as I'm very curious to see what, if anything will happen. Have to decide how to spray or brush water on the underside in a way that would more or less duplicate the original steps when it was constructed.

Incidentally, I always laminated my Homasote to plywood using contact cement. Light coat on each piece, position it and press down. Then I'd walk over it to make sure it was all making contact and was good to go! I've got a couple of small pieces of that combination still laying around, done over 15 years ago and you can't separate the Homasote from the plywood to save your life!