Foam board question

[Anonymous]

Ok gang, here's one that I feel a bit silly asking, but here goes. I am using 2" foam insulation board for my top. It comes with a very thin plastic sheet. Do I peel that off or leave it on the top?

I am planning on painting the top with a laytex paint and will also add a masonite sides to protect the foam from damage. I am excited and making progress. I have glued down the top to my frame work and am very happy with the results. I am going to like this foam board top as it will ease my transportation needs.

Thanks for your help.

[tstage]

pastornick,

I don't think I've ever seen any extruded foam board with a thin plastic sheet on it. What kind is it and where did you pick it up? At any rate, peel it off. I have 1-1/2" for my top and really like the stuff. [^] [tup]

Tom

[orsonroy]

I've never seen 2" foam with a backing plastic, but I do use 1/2" foam that has it. I remove the top side so I can more easily carve and sand the foam. If you're planning on sanding through any of the layers with the plastic backing on it, I'd recommend removing it first.

[Anonymous]

Peel the plastic sheet off!

I bought some 1" with the plastic sheet, and glued some cork roadbed to the plastic sheet. Guess what, the plastic sheet peels off, along with the cork!

Avoid the pain, peel it now. Have the kids do it, they'll enjoy it!

Mark in Utah

[nbrodar]

Did you get the right insulation? I've never seen foam with a plastic sheet. Although, Dow or Owings-Corning makes a special type of heavy duty extruded foam insulation. That could be what you got by mistake.

Try peeling the plastic off.

Nick Brodar

[rrinker]

I believe they both make products with the extra plastic layer, although I think it's more common onthe Dow blue foam line. When used for the intended purpose of insulation, the plastic forms a vapor barrier. For our purposes, peel it off. The stuff without the plastic film is probably a buck or two cheaper, if you have the choice, but I know some people are lucky to be able to buy ANY sort of foam insulation board. I can get the 2x8 sheets in allt icknesses, but not 4x8 sheets which I could cut myself and save some money.

--Randy

[dgwinup]

pastornick,

Randy is right, the plastic sheet is a vapor barrier for the isulation when used as originally intended (as insulation! What a novel idea!).

Just peel it off and start carving and painting.

Good idea to use masonite for fascia panels. It's light enough for portability and will really protect the foam. It usually accepts paint well, but you might want to lightly sand the finished surface first to give the paint more 'tooth'. A friend of mine once built a garage using Masonite brand pre-primed siding. He couldn't get paint to stick to it. In the end, the factory rep concluded that the factory finish was too hard. Masonite paid to have the whole surface lightly sand-blasted AND paid for the painting, too. After that, no problems with peeling paint.

When are you going to post pictures? A lot of us are probably drooling with anticipation to see your progress. Remember, you included us in your project and we feel like we are working right alongside you on it!

Darrell, mopping up the drool, but quiet...for now

[Anonymous]

Thanks guys. I bought the insulation at Lowes. It was in the insulation isle and was a 4x8x2" sheet. I don't remember the name. I will check that out and let you know tonight. I will also try to post a few pics tonight. NOt much to look at right now. Thanks again for all your help.

[rrinker]

It's pretty obvious - if it's blue, It's Dow, if it's pink, it's Owens-Corning. But it really doesn't matter, both are essentially the same material. Home Depot here stocks Owens-Corning, so until I paint the table I am modelling on the pink prairie. Sort of kicking myself for not buying all 4 gallons of that nice brown 'oops' paint at HD, I only bought 1, which is plenty to do what I have built so far, but thent here's the expansion....


--Randy

[selector]

Randy, you're such a fibber. I know darned well you are no closer to finishing your layout than you were six months ago. (SNORT) "extension"...yeah, right.


[(-D][:D]

[rrinker]

This is true. I have to get my father in law to stop using it as a workbench extension. I think he has enough passenger cars now!

At least I got a track plan worked out now!


--Randy

[Anonymous]

As a new R.R. modeler I found building tips on the D.I.Y. web site. all of there basic landscspine was done with thw white foam you can get at lowes. At first I didn't like it becauls it was hard to get a clean edge. I removed the silver plastic sheeting and used the side with all the printing to draw all my cut lines. Cutting a little outside the line with the large X-Acto mider saw I then sanded the foam to the out lines. That was after i went through 1 & 1/2 4x8 sheets and 3rd. platform trying to get it right, and yes, peal off the plastic. This make's snow scens very easy.

[dgwinup]

cad4u2,

If you use WHITE styrofoam, it was the wrong insulation material. White styro is 'beaded', made up of tiny 'beads' bonded together under heat and pressure. I think it is called 'closed cell' styrofoam. When you cut it, the little beads pop off and won't cut smoothly.

What you want to use is 'open-cell' styrofoam, which is either pink or blue in color. It is denser than the white stuff and cuts a lot cleaner. It will sand to a smooth finish, but it make a LOT of dust when you sand it.

I have used the white styro to add extra height to my mountains, but it is sandwiched between layers of blue foam so it doesn't get much trimming.

Hope this helps.

Darrell, dustily quiet...for now

[Anonymous]

Well, it seems like I goofed and have used the white beaded stuff which Darrell has mentioned above. Oh well, it's guled down and painted. I bought a sheet of some kind of lamenated stuff that looks like paneling. It's really nice and covers up the sides well. At this point I hate to think about tearing it all apart so I am thinking that I will just keep on with what I have unless this is a disaster waiting to happen? Let me know what you all think.

[tstage]

pastornick,

You know what you can do? Glue another thinner (1/2") layer of extruded foam insulation (EFI) board over the top of the white stuff. The EFI board is much better. I like it because I can test out my layout ideas on it much easier than I can on plywood. You only need a rail spike to hold the sectional track in place. Holds pretty well, too.

Tom

[dgwinup]

pastornick,

No, no, don't tear out all the work you've done! It won't cause you any problems in the future. It might be easier to dent or tear than the other foam, but it will be just as easy to repair.

As my brother said to me when we were remodeling a rental house, "Let's do it. If nothing else, it will be a learning experience". He's in Special Ed, you know. (Do you think he was treating me 'special'?) LOL

Chalk it up to a learning experience! And remember, we are all waiting for pictures!

Darrell, special, but quiet...for now