Depends on which manufacturing process was used and the degree of "temper" the tempered hardboard has.
I have always refered to is as "Masonite" but like Kleenex, this proper noun has been used to refer to all hardboard products.
Wikipedia has this to say about the smooth/coarse surface:
Hardboard is produced in either a wet or dry process. The wet process, known as the Mason Method,[5] leaves only one smooth side while the dry processed hardboard is smooth on both sides. Masonite is produced using the wet process only.
I have found some of the "Melamine" finished hardboard to be pretty flexible especially when cut to the 18" you propose. Take a look at that to see if it would meet your needs. Or maybe you can shop around and find the Masonite brand which may bend easier?
http://www.lowes.com/ProductDisplay?partNumber=16605-46498-300&langId=-1&storeId=10151&productId=3015239&catalogId=10051&cmRelshp=req&rel=nofollow&cId=PDIO1
Good Luck, Ed
How much does 1/8 or 1/4 inch Luan plywood underlayment cost in Your area? I would rather use that then Masonite....will bend easier...one side smooth. Get a sheet of it 4X8 and cut it Yourself, then sand the cut edges, to smooth out the cut line...180 grit.
Take Care!
Frank
Here in central texas, I got my 3/16" masonite like (one side smooth) material at Home Depot. It is Eucaboard by Eucatex and I found it online using a search ("tempered hardboard") at my HD store online. It is also available in some Missouri stores ((I picked one near St Louis).
I used this for my relatively short background. It bends well, I recall I bent it to about 11" radius.
http://www.homedepot.com/p/Unbranded-Hardboard-Tempered-Panel-Common-3-16-in-x-4-ft-x-8-ft-Actual-0-155-in-x-47-7-in-x-95-7-in-832780/202404545
Paul
Modeling HO with a transition era UP bent
Single smooth sided hardboard is very readily available in the Pacific Northwest. Virtually every big box hardware store and local lumber yards sell it. I haven't looked for any at Loew's but I'd bet they have it.
Try lumber yards in your area.
When I built the lower level of my layout, I used 1/8" smooth-one-side Masonite for the layout fascia, and was able to easily bend it to an 8" radius, as seen if the photo below. When I recently built the upper level, only the smooth-both-sides stuff was available. It bent easily, too, but since the upper level is wider than the lower, the corner radius was about 11". Still, I'm sure that it could be bent to a tighter radius if needed.
I used it for coved corners on the backdrop, too, but the curves there are much wider.As for "tempered" hardboard, I was told at the lumberyard (not a big box place) that it refers only to the hardness of the surface, and has nothing to do with flexibility. I save the tempered stuff for the top of work benches, where it performs well.
Wayne
Hello All,
Try several hardware/home improvement centers.
I've discovered that Lowe's stocks different products compared to Home Depot. They both may carry "Hardboard" but the difference in the two products might be night and day.
There are also several True Value hardware stores in our area. Some carry lumber some do not.
I'm lucky enough that there's still an independent building supply center and they often carry what the chains don't.
What you are looking for is out there, you just need to find a source close to you.
Good luck on your search.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
A wide variety of stuff gets sold under the name of hardboard. I have encountered some hardboard used for shipping large appliances that is surprisingly brittle and all but unbendable. If dropped it can chip almost like ceramic. I also found a tawny colored hardboard like substance at one big box store that was slightly fuzzy feeling, like a peach, even on the smooth side and while very bendable, it is also very prone to just crumbling.
Dave Nelson
Tempered hardboard is smooth on both sides and has a higher resistance to absorbing ambiant moisture. I have used hardboard in signs in both 1/8" and 1/4" thickness. It resists the outdoor enviroment for several years. The"regular" hardboard is good only indoors if you are looking for something flexable. It is called screenbacked because of the pattern on one side. When it is made it is dried on a screen type material and not pressed as much as the tempered which is pressed more to squeeze out the moisture before it is dried, being pressed also makes it more brittle. If you compare the two serfaces you will notice the screen backed's smooth side is slightly fuzzier. Cheaper brands have moe fuzz and require priming and a light sanding to seal the surface. If using screen backed I have always painted the back side with a good oil base paint, and use it on the front also. There are primers made for priming masonite exclusively, works great.
Just some advice from an old signman. Take it's worth for what you paid for it. 73
God's Best & Happy Rails to You!
Bing (RIPRR The Route of the Buzzards)
The future: Dead Rail Society