For those who use Homesote for roadbed, do you paint it before gluing it down and adding ties and track?
I only used Homasote under my yards. Didn't paint it; but, maybe should have. It does seem to swell and shrink with temperature; or, humdity.
NP 2626 "Northern Pacific, really terrific"
Northern Pacific Railway Historical Association: http://www.nprha.org/
I painted it on all sides and edges before mounting over plywood with screws @ 12" o.c.-no glue. The plywood was also painted on all sides and edges. For mainlines I added Homabed over the Homasote by tacking it down with brads-no glue. It, too, was painted after installation and filling of kerfs with drywall joint compound. The W/S Code 83 flex track was spiked to the Homasote/Homabed-not nailed or glued. All has held-up very well after 2-2/3 years. It is in a climate-controlled room.
Dante
Just to be up front I own Cascade Rail Supply which makes Homasote roadbed.
You are going to get a multitude of opinions on this question and I think it depends on a number of factors. What is the Homasote product you are using, where you live, and where your layout is being the most important.
What is the Homasote product? Are you using Homasote sheets at 1/2" thick, are you making spline roadbed or are you using milled Homasote roadbed like I make? All of these react differently to their environment. Which leads to the second factor, where do you live. I am in the Pacific Northwest and I personally see no need to paint the Homasote because I have neither the temperature nor the humidity swings that might make painting beneficial. However, others who live areas with more extremes especially with humidity report that painting is of some benefit to them. Where your layout is might negate or emphasize the previous point. If your layout is in a spare room in a climate controlled house I wouldn't see the need. However, if it is in the garage then you might want to paint.
Well, then why not paint just to be safe? There are a couple of points to think about here. Does paint really stop or slow moisture transfer? I do not have the definitive answer and you will get a variety of opinions. If you paint then any adhesive will be stuck to the paint and not to the Homasote which will give you weaker glue joints. May not be a big deal after ballast is down but when will that step occur? I believe it was Jim Hediger who recommended shellac to seal the Homasote. I think that is a pretty good solution for sealing but it will make the Homasote a little harder to spike into if you are handlaying.
Long answer to a simple question but the short answer is simply, "It depends....."
Paint it before laying track. Not because of moisture but rather to keep it from emitting dust.
My rather large layout is open grid and parts of it are just flat. Built with 1 x 3's that I cut myself on my table saw, with 1/2 inch exterior one side smooth plywood, on top is 1/2 inch Homasote. The framing is screwed and glued in sections, bolted together with carriage bolts. The plywood is attached with drywall screws every six inchs. The Homasote is just screwed again with drywall screws to that. My roadbed is homasote that was cut on the table saw, before attaching it to the plywood, it was cut at a angle to represent roadbed slant, on curves, I cut kerf's in it to make the curves. On the flat area's, I just put the homasote over the plywood without any roadbed, but the homasote. All is perfectly flat without any type of transitioning from mains to yards, which is the way I wanted it and my trackwork is derailment free. Before I laid any track, I air brushed the roadbed colored area's with the ballast color I was going to use with solvent based paint. I have not had any issue's at all with any type of swelling, or movement going on 30yr's. The layout, is in my attic, which for the past 15yrs has been temp. controlled, I live in the Midwest. I use all Atlas code 83 flex track spiked, not nailed, the ballast glue which is Woodland scenic's mixed with denatured alcohol does the rest.
I like to use Homasote for the ease of installing what ever I want, nailed, screwed or even glue. A lot of sections are even hand laid track, which is also easy with Homasote. I live very close to a Mom & Pop lumber yard, so it is easy for me to get, high grade material.
Take Care!
Frank
NP2626 I only used Homasote under my yards. Didn't paint it; but, maybe should have. It does seem to swell and shrink with temperature; or, humdity.
I have used Homasote both painted and unpainted.
As for the swelling thing! -
I have a Swing Bridge to get into my layout room.
It is made out of welded angle iron.
There is NO swelling or movement due to temp and Humidity changes with this all Steel Bridge.
I have Homasote sub-base for the track and it is cut right at the edge of the steel bridge.
IF - this notion of swelling Homasote were TRUE -
Then - the HOMASOTE would swell up enough to cause problems with my bridge opening and closing.
IT DOESN"T ! Never has.
So the notion of the Homasote causing problems is Untrue - NOW the wood swelling and causing problems - that is true!
I had a Dehumidifier failure way back in 2003 and the basement got really humid - I had a section of my layout shear the glue off between the Homasote and the sub-base of OSB - it was in a yard area.
The Homasote just came loose from the wood - the track on top of the Homasote never moved as we held a couple of OPs Sessions on it before I discovered that the OSB and the Homasote had separated.
I fixed it easily by just screwing it back down.
I live in northwestern PA and we have lots of Humid days during the summer.
My layout is over 15 years old now and I have used Homasote over 98% of the layout under the trackwork.
I have had MORE problems in the areas that I used Pink/Blue foam!
I will NEVER use foam under any of my track ever again!
BOB H - Clarion, PA
I mainly use homasote under my yards and yes, paint it to resist moisture and also to give some sort of attractive base color too.
I secure my sheet homasote using one inch drywalls screws, to hold it firmly down to the half inch plywood or OSB sub base. Because Homasote can be a bit warped, the dry wall screws pull most of the warp out so it is generally nice and flat.
Yards typically are flatter in appearance and don't need the raised grade under track so it is suitable It's easy to spike or nail track down. It's easy to draw center lines on for laying track too.
Rio Grande. The Action Road - Focus 1977-1983
Bob,
Homasote certainly does move with humidity changes. Go to Homasote.com and read the spec sheet for the stuff and it is all there. The movement is about double what the APA (American Plywood Association) calls for on sheet of plywood. Over an 8' span Homasote will move about 1/8" with a 70% swing in humidity. Is that enough to affect your layout? It might but as I wrote earlier, there are other factors. If you use a milled product like my stuff that has kerfs (slots) cut in it to make it curve, I would think that the kerfs will absorb any expansion or contraction that happens. If you are using sheet Homasote and you install it when the humidity is at either extreme you might have some issues. If the humidity is somewhere in the middle of the range then your movement over 8' is +/- 1/16" and your track should be built to handle that. When you install hardwood flooring, the manufacturers spell out that the flooring should be allowed to acclimate to the conditions in the house before installing. This prevents gaps forming after installation as the wood shrinks. Probably not a bad idea to do that with Homasote especially if you are using 1/2" sheet product.
sjcox Does paint really stop or slow moisture transfer? I do not have the definitive answer and you will get a variety of opinions.
Does paint really stop or slow moisture transfer? I do not have the definitive answer and you will get a variety of opinions.
Of course it does. Otherwise we would not have to paint most wood species used to clad homes and other buildings (except for those few species that are naturally moisture-resistant).
P.S. A classic "small" example: wood doors that are not painted or otherwise sealed on all edges, including the top and bottom (often omitted by casual contractors), will almost always warp in an environment without humidity control.
Dante,
Paint certainly protects wood but it does not completely stop moisture transfer. The wood doors in your example above might not warp but they do not stop moving. They will expand and shrink some with the change in seasons and that is caused by moisture in the wood. Solid wood furniture in your house will do that also. When we are talking about painting Homasote we are asking if paint will stop moisture transfer in and out of the material due to humidity changes and stop the seasonal movement of the material. It might slow it but it will not stop it.
(Quote)
BOB H - Clarion, PA.
Bob, Please explain this comment for us.
I have never had any trouble, I use foam roadbed with the track and road bed caulked down.
Johnboy out..........
from Saskatchewan, in the Great White North..
We have met the enemy, and he is us............ (Pogo)
I know several people that use Homasote spline and they do not "seal" before using it. I handlay my track and use a Homasote/plywood sandwich (Homasote glued to plywood). I have way more problems with the plywood and 1x4's expanding than with the Homasote. I do paint my Homasote, but only for appearance, in case there are any bare spots in the ground covering or ballast. I am in the "you can't fully seal it" camp. I paint mine with flat latex interior wall paint, usually a dirt color, a grey or a black depending on the area and what I have on hand.
I elevate my main track above sidings, etc with either Homabed or the Cascade roadbed. I have some Homabed left from the previous layout and will try some Cascade product I bought when that runs out. Since I am modeling a shortline in the early 1900's the ballast section isn't that high so I use 1/8" (or so) thick roadbed under the main track.
Dave H. Painted side goes up. My website : wnbranch.com
last mountain & eastern hogger (Quote) I will NEVER use foam under any of my track ever again! BOB H - Clarion, PA. Bob, Please explain this comment for us. I have never had any trouble, I use foam roadbed with the track and road bed caulked down. Johnboy out..........
NOISE!
I will use it for scenery base for hopper coal loads but not for the track base.
It is just way too noisy in compairson to Homasote.
Just my preference!
I have built two layouts using Homasote. The first was 5/8" Homasote 'glued & screwed' to 1/2" plywood. This was done in the dry winter season on Minnesota. I laid Shinohara code 70 track. That summer I did have a couple of track kinks due to swelling. Fixed them in one evening. I used to tell folks that 'The plywood would move one way, the Homasote another way, and the flex track was hanging on for dear life'! The layout did hold up though.
The last layout used Homabed over 1/2" plywood for the mainline. I used cork for the sidings and yard areas. I used Titebond glue and 1/2' wire brads to hold the roadbed in place while the glue set up. I pulled the brads as soon as the glue set up, and spiked the Atlas code 100 trackage with extra long(Walthers O scale or M-E large) spikes to hold the track to the roadbed. After ballasting, I pulled most of the spikes(if I could find them). After 26 years, the track never shifted.
The new layout is going to use 1/2" plywood with Cascade Rail Supply roadbed. Not sure, but I suspect clear caulk will be the adhesive this time. Steve Cox(Cascade Rail Supply) is very good getting back to folks....
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
sjcox Dante, Paint certainly protects wood but it does not completely stop moisture transfer. The wood doors in your example above might not warp but they do not stop moving. They will expand and shrink some with the change in seasons and that is caused by moisture in the wood. Solid wood furniture in your house will do that also. When we are talking about painting Homasote we are asking if paint will stop moisture transfer in and out of the material due to humidity changes and stop the seasonal movement of the material. It might slow it but it will not stop it.
I have never said that the moisture absorption or material movement is completely, 100% stopped. Just that painting does mitigate the absorption and movement. I am a retired architect who over a period of 60+ years of education, experience and observation can confirm the knowledge developed over literally centuries of construction that painting or otherwise sealing wood surfaces of most kinds will protect and sufficiently stabilize them (always contingent upon the wood species, its environment, its use, etc., etc.). It is not simply a matter of opinion but of fact.
P.S. Your competitor at Homabed recommends painting of the product; you would be well-advised to do the same.
These are interesting observations. My experience with 'milled' roadbed(Homabed) has been that I did not need to 'seal' the product. When I used the 5/8" sheet stock, I did not seal it, and it did cause a few track kinks over the 13' length on the layout(two parallel 30"/32" curved tracks. I fixed the problem, and made a note to allow some 'gap' in the rail at rail joiners on a future layout. Both of these layouts were built using 'L' Girder benchwork made out of 1 by 4's. The lumber for the 1st layout was purchased from a lumber yard in the mid 60's. The second layout was built in the mid 80's using 'Big Box' store(Menards) dimensional lumber.
Our club used Homasote sheet stock to cover the plywood in the staging tracks and painted it with a yellow latex paint to 'seal' it. 3-4 months later, we had 6 tracks in one curved area buckle. At that point a decision was made to use cork roadbed on foam for the actual 'on stage' layout. The club layout is in a temp/humidty controlled 27' by 27' room on an office park complex. The framing under the staging level was 1 by 4 grid construction with 3/4" plywood. The Homasote was glued/screwed to the plywood.
Somehow I feel that the thinner Homabed I used at home does not have the moisture issues that the sheet stock has. I have had trouble contacting the Homabed/California Roadbed company(I understand he has been having medical problems).
I sent an email to the Cascade Roadbed company about a month ago when I found out they existed, and got a response within the hour. He even 'measured' his stock with a caliper for me! I just sent off a $150 order and will let everyone know how the product looks. I really like Homasote roadbed on wood sub-roadbed - very quiet & solid. And it sands great without all of the 'mess' when cutting sheet stock.