sealing homosoate

Discussion in 'FAQs' started by farmer ron, Feb 28, 2006.

  1. farmer ron

    farmer ron Member

    Do you need to seal homosoate with anything before using scenery or ballast on it?

    In our area homosoate is very difficult to come by and our club has not used it in the past, this layout we have located a supplyer of homosoate and and using it for track roadbed. We have not as yet laid any cork or track but are now wondering, as we have not used this product in the past, if the homosoate has to be sealed with something prior to putting the cork/track down, to prevent it from swelling with the usage of water and water based paints when balasting and scenery..thanks for your input..Ron..
  2. Ralph

    Ralph's for fun!

    Hi Ron,

    Everything I've read, as well as some personal experience with the material, tells me to seal homasote prior to track laying and ballasting. It does respond to humidity changes and moisture. Laytex paint is fine as a sealant. Choose a color that fits with your earth tones or future ballast.

  3. Gary Pfeil

    Gary Pfeil Active Member

    What Ralph said. I've glued cork roadbed to homasote, then painted the whole deal with latex paint to seal. I usually use a color close to the ballast color, or earth.
  4. stewynofly

    stewynofly New Member

    I am new here, but have had some experience with Homosote.

    I used to operate monthly at a friend's HO layout that filled his 2-car garage.
    It had literaly hundreds of running feet of homosote sub-roadbed and was fully scenic'd. None of it was sealed. There was never any sign of warpping, swelling, or buckling. Homosote seams to be pretty stable stuff. By the way, his layout was featured on the cable program Tracks Ahead. It has been a few years but I think he called it the P&WV Pittsburg and West Virginia.

    I had a one car garage sized N-scale layout with the same unsealed homosote sub-roadbed and experienced no problems in the three years that it was operating. I tore it down when I moved (I will build some form of modular layout from now on).

    The club I used to belong to did not seal their homosote and neither did any member that I talked to. I would like to mention that I live in the Tampa bay area of Florida and most of the layouts are in unheated garages. You will not find a more unstable evironment for heat/cold/humidity.

    All of that being ounce of protection may be worth a pound of cure, and as long as your preventive measure does not cause a problem then by all means seal away. If you gain nothing else from it, it will at least give you peice-of-mind.

  5. Ralph

    Ralph's for fun!

    That's interesting Stewy and I'm glad it worked out. Welcome aboard, by the way!
    My experience is with conditions in a Minnesota basement that seemed to swell and shrink unsealed homasote to the point that my straight flex track would buckle into "S" shapes. Once I painted it with latex that was no longer a problem. Hmmmmm, I should mention that this buckling occurred along a stretch of hidden track that wasn't ballasted...I wonder if the glue used in ballasting is enough to seal the homasote and prevent warping?
  6. robgoo

    robgoo New Member

    We used Thompson Water Sealer to prevent any warping from moisture. Just roll it on with one of those small 3 inch rollers.........soaks in real nice. Rob
  7. pgandw

    pgandw Active Member

    Deleted, duplicate post by mistake.
  8. pgandw

    pgandw Active Member

    Homasote has for years been accused of being unstable in the presence of moisture. Yet others have used it for years with never a problem. I read a report where a piece of Homasote was immersed overnite. It swelled while in the water, but resumed its shape when dry. I believe that part of the problem may be substitution of Homasote look-alikes by lumber yards. That happened to me because nobody had real Homasote in my area, so I use a similar substitute whose performance in the presence of humidity may vary from the real stuff. FWIW, I had no problems with my handlaid track on the Homasote substitute for 7 years and moves from coastal Oregon, to pan-handle Florida to non-air-conditioned house in Miami, FL.

    FWIW, your wood benchwork also expands and contracts as it moisture content changes. Some of the problems attributed to Homasote may in fact be problems with the structure underneath. There are 3 ways I know of to combat moisture-induce expansion and contraction:

    1) control the humidity in the layout room. Note this makes the room more comfortable for humans, too.

    2) paint or seal the Homasote or wood. This significantly delays changes in moisture content, usually enough to prevent problems, but does not totally eliminate them. You need to paint or seal all surfaces, not just the top or visible.

    3) Use a material that does not respond to humidity either along with wood/Homasote, or in place of. Foam glued to wood or Homasote will help constrain expansion/contraction.

    4) Use a combination of the above techniques.

    On my next layout, I will probably use all 3 techniques. Homasote is my preferred roadbed for handlaid track. I will use a sandwich of 1/4 inch plywood and foam for my subroadbed to reduce weight on the shelf layout. To keep family peace, my layout will hang on the walls in the living area of the house - either a spare bedroom or family room. There will likely be some humidity control. And I will likely seal the Homasote as a precaution. Don't know if the sealing is overkill, but the thought of a $100+ kit-built and modified locomotive seeking its lowest point of equilibrium (aka the floor) bothers me a lot! I'm a whole lot less interested in risk in my OF&S (Old, Fat, and Slow) years.

    yours in wood product construction
  9. stewynofly

    stewynofly New Member

    Well there you have it...I think Fred has said it all.

    While I have never had a problem with swelling or buckling. A little time and a few dollars spent at construction time could possibly save many dollars later on. It can't hurt.

    After reading other people's comments here, I will probably seal my next layout. Besides, if there is a homosote lookalike out there, how would I know if I got some? It is very hard to find here too. There is only one place in our area that carries it and the other home supply stores have never heard of it.

    By the way, what ever happend to good old lumber yards? I haven't seen one since leaving Pennsylvania.

  10. farmer ron

    farmer ron Member

    Thank you all for your valuable information, will be bringing all the comments and suggestions up at tonite's club meeting..many thanks again..Ron..
  11. Don

    Don New Member

    homasote seal

    Back in the 60's, 2 guys wrote a series of articles for MR. Off the top of my head I think 1 was named Ernie. At any rate, they sealed everything - top, bottom & all edges w/2 coats of clear shellac. I took their advice back then & its worked beautifully w/no probs. going from humid summer days to cold & dry in the winter.

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