Which side up?

[jmmmn]

Hi all,

A question about masonite hardboard. I plan to skin the roof and galley hatch with aluminum and my plan calls for 1/8" masonite hardboard underneath. Which side do you put up--the smooth or the rough? I haven't decided whether to dry mount or glue yet, but if I do use glue, will the rough side be too porous or the smooth shiny side not porous enough? Your wisdom is welcome--thanks in advance!

Jim

[IraRat]

I've heard that masonite isn't good stuff to use for TD construction. Don't know why, but I seem to remember that.

[mikeschn]

Masonite is not a good material to build with. The first time it gets wet it'll turn into mush.

You're far better off using 1/8" plywood for that.

Mike...

[Chris C]

I agree with both previous posters. Masonite is a paper product. Moisture (even human perspiration at night) will most definately degrade it and in extreme conditions can turn it into wet tissue paper! It definately is not a good product to use in these small trailers. Stick with plywood construction for strength and durability.

[GeorgeT]

Hi all,

A question about masonite hardboard. I plan to skin the roof and galley hatch with aluminum and my plan calls for 1/8" masonite hardboard underneath. Which side do you put up--the smooth or the rough? I haven't decided whether to dry mount or glue yet, but if I do use glue, will the rough side be too porous or the smooth shiny side not porous enough? Your wisdom is welcome--thanks in advance!

Jim

Masonite isn't a good construction material where strength is needed. Good for decorative where you need a nice smooth flat finished surface mostly for interior use. Artists have used masonite to make panels to paint their smaller paintings on. Even then they use a good framework behind it because of the tendency of masonite to bow and warp out of shape. It lasts a long time if you finish both sides. Signs that I have seen for exterior use utilizing masonite don't last long and have a tendency to warp or bow even though there is a good framework behind it and coated on both sides with paint and sealer. Even if you use masonite for interior use it should be sealed on both sides. You can buy tempered masonite which is shiny on both sides but it still has the same problems but you can get a good shiny smooth finish on both sides if need be. If you use masonite it should definitely be mechanically fastened. Masonite that has been glued only can be ripped or twisted from its framework fairly easily pulling big chunks of the masonite up with it leaving the front surface intact. Again demonstrating its lack of strength. Masonite is also very heavy compared to plywood of the same thickness. As stated above your better choice would be plywood.

[IraRat]

Yeah--like one of my pet peeves is I absolutely refuse to deal with countersinking screwheads when I can get away with it, because I stink at doing it correctly.

Luckily, I'm doing a woody, so this isn't an issue for my outer skins. But my wood deck has a few boltheads (bolt through plywood, through frame, through steel) that are agonzingly not well countersunk, and although I plan on using a piece of carpeting, and there's NO way you're going to feel that rise of the bolt through both the carpet AND the foam mattress at the VERY outer edge of the deck, I was considering using a piece of masonite to cover the cabin floor, just for the heck of it.

But now that I think about it, I'm not even going to bother.

Thanks for talking me out of it, guys. You just saved me like 8 bucks.

[jmmmn]

Thanks for the good advice. I knew of these properties of masonite, so I wonder why these plans call for it. I'll change my plans to plywood.

Jim

[SteveH]

It's interesting that we think of masonite as being such a bad building material when so many of the original teardrops used it in the roof area. I have a friend here that has an original 1947 Kit that has masonite as the roof material, covered with aluminum, and is still in good shape.

Let's see....2005 minus 1947...that's 58 years! Must not be too bad.

[GeorgeT]

I've also seen masonite used in interior work that has worked out okay as you say concerning the insides of TDs. I'm sure it will still work well in that application. But if I had my druthers, I'd go with plywood mostly because of weight savings and the thin plywoods are pretty flexible.

Where'd that stuff come from anyway?

Masonite was developed in Laurel, Mississippi in 1920 by William H Mason, an expert on wood derivatives and an associate of Thomas Eddison. At this time timber mills in the USA were burning huge quantities of waste wood, wood thought to contain too much bark to be of any use. Mason knew that the timber waste contained the same fibres that give wood its tensile strength so it followed that in some way this timber waste could be utilised for other purposes. In the early 1920's, Mason began to experiment ways of utilising this timber waste. He heated a closed vessel loaded with waste chips. When the temperature and pressure reached a high point he opened a valve which caused the chips to literally explode and to form a feather light fibre.

After extensive trials and research, Mason developed a process, quite by accident, to condition this fibre into a high density material. The accident occurred when Mason went to lunch forgetting to release an experimental 19th century press. The press had a leaky valve, resulting in heat and pressure being applied for an unusually long period of time. When he returned Mason found that the fibre, which had originally been intended as an insulation board, had been pressed into a dense, thin, tough sheet. The sheet did not crumble, split, splinter nor crack. The word was then introduced to the versatility and practicality of hardboard, which became known world wide as MasoniteTM. The breakthrough had occurred and in 1924 Mason established the worlds first hardboard plant, The Mason Fibre Company. A year later The Mason Fibre Company changed its name to Masonite Corporation and in 1935 Masonite shares were listed on the New York Stock Exchange. In 1988 Masonite Corporation was taken over by International Paper Inc.

In 1940, William H Mason, the founder of Masonite, passed away and over the period following the Second World War the company undertook extensive research and development to create a whole new family of products including, grained wall panels, moulded door facings and a raft of different coated products.

[angib]

Excellent history, George, and it also confirms what I've suspected - what you guys call Masonite is what we call hardboard (contrary to the 'company PR line' in George's piece!).

Andrew

[OkieSailor]

Too late! Is in and will stay in, local artist wants to cover with mural inside the teardrop. Sure hope you guys are wrong????

[Norm]

My interior ceiling and front wall are masonite. Sealed it with urethane. One year later it still looks the same as when i installed it. It was good enough for the Midget Trailer back then, so i figured it was good enough for me.

Norm

[WarPony]

I used Masonite to cover the outside top and the interior walls of my TT. I'm going to cap the top with aluminum skin and do the inside walls with an automotive carpeting. If you seal everything up to keep the water out, what is the big deal with using Masonite?! I've seen alot of people using it in their projects here. I think by now somebody would've warned us about the problems of using this. I'm with OkieSailor, mine's in. Screwed, glued and tattooed.

[SteveH]

Just one last comment on Masonite. In 1993 I built a deer blind covered with 1/4" "treated" masonite, and then I painted it. Don't know how it was treated or what it was treated with, but it was labeled as "treated". About three years ago I repainted it. It has been out in the weather all this time and is still good.

[Larwyn]

Just one last comment on Masonite. In 1993 I built a deer blind covered with 1/4" "treated" masonite, and then I painted it. Don't know how it was treated or what it was treated with, but it was labeled as "treated". About three years ago I repainted it. It has been out in the weather all this time and is still good.

As many of you know, I am building outside. I built a 4 X 8 foot glue up table which evolved into a storage bench. Lots of tools and stuff on the bottom shelf and sheet goods stored on top. I covered the plywood top with 1/8" Masonite in order to have a good flat and smooth surface to work on. I cover this table with a large tarp when not in use.

To get to the point. Moisture got traped between the bottom sheet of plywood and the Masonite table top. I spent a week out of town so it sat there soaking and cooking under the tarp for several days. The Masonite developed a "swolen" area resulting in something of a slight bubble about 12" across, the plywood above it buckeld and delaminated in an area about twice the size of the bubble in the Masonite. The Masonite is still quite useable, a good portion of the plywood ended up in the fire pit.

I know this was not a scientific experiment, wasn't even an experiment at all. But the results of this accidental discovery has me leaning toward the use of tempered Masonite as the outside roof covering (under aluminum) for my Escape Pod.