View Full Version : OT Just what is Masonite made of

Spin Doctor
07-29-2004, 05:28 PM
The tempered smooth surface on both sides. Just need some info

07-29-2004, 05:41 PM

07-29-2004, 06:01 PM
Mostly trash I think... They put all kinds of things into the slurry.


Milacron of PM
07-29-2004, 06:42 PM
A rigger recently told me he uses masonite when moving machinery via skates over otherwise impossible surfaces, like carpet. Also useful as a "step" to roll the skates over uneven/different level surfaces. The rough side helps keep it from slipping on the floor and the smooth side lets the skates roll with less resistance than plywood. Says it will usually withstand 6,000 lbs on carpet before it snaps, much more on concrete or wood floors.

07-29-2004, 08:48 PM
Wood,bark,dirt,newsprint,resin and tincans I think http://bbs.homeshopmachinist.net//biggrin.gif They have a plant up the road that makes tempered,Mdf and Hdf up to 2" thick.

07-29-2004, 09:02 PM
They were experimenting with plastic additive, read that trash.. and... tires in both masonite and shingles.

The only place around for hundreds of miles that bought used tires.

I still got 600 of them to dispose of.


07-29-2004, 10:22 PM
I did some work for US GYPSUM, 50 years ago at the plant where they made their version of "Masonite". May be different today.

The basic product was huge logs floated into a pond. Run through a "chipper" made into a slurry. Binder was added, the board that was to be 1/4 inch finished was about 3/4 to NE inch thick. one long sheet was on a conveyor belt many yards long, through stem cookers. The result was very soft, no strength at all. it was cut and stacked in sheets, run through a press. I have no idea of the actual pressure involved, the RAM was about 18 inches diameter. The ram would break at times and thermite welded on the site. The pressures must have been extremely high, The finished product was dry very heavy, slick on both sides or the non oil treated had a grid.

It stands weather very well- old "trailers" (RV trailers today) were mostly 2 x 2 inch studs, with Masonite covering. NOT at all like MDF or HDF today. It would bend in large radius curves but break if bent too sharply. I'd guess a 3 foot radius was about all you would design for. The oil tempered Masonite lasted many years in the Arizona sun and Louisiana wet. I do not recollect boats being made of the stuff. It held up better than even marine plywood (no rot, no swelling) very stable product. I have no idea how GYPSUM pressed board compared to the real Masonite. So far as I know they were very comparable in all respects- no visible difference. The plant I was familiar with was in Greenville Mississippi.

I have seen in use Masonite (brand unknown) over an inch thick used for work surfaces and they were durable. Gouge marks were the only problem. Too deep and they grew in size. As some one else mentioned, it is good rigging material- smooth hard and if supported by a hard backing, does not break down except under very high point loads. I would guess it is at least as hard as concrete (which ain't saying much really).

Particle board? I hate it, Masonite used to be very good stuff, and I liked it.

Evan's link leads me to think the process is/has not changed very much.

BTW it has a sort of "grain" stronger one way than the other.

Spin Doctor
07-30-2004, 06:09 PM
When I hit the link (I had also stumbled across it myself after posting) I printed it off. For the ingridients all it basically is, is wood fibers pressed and heated. The natural wood cellulose and lignin (lignin is what binds the cellulose fibers together in the wood) are combined so that the fibers are randomlly oriented and then pressed and heated to 350*F. As I understand it the heat causes the lignin to re-activate and bind the cellulose fibers together again. If linseed oil is applied to the surface it only penetrates slightly into the surface.

PS Thanks for the link anyway Evan

Alistair Hosie
07-30-2004, 06:30 PM
OLD DEAD MASONS http://bbs.homeshopmachinist.net//biggrin.gif Alistair

07-30-2004, 09:36 PM
My brother is a supervising ER nurse at the hospital in Luarel,Ms where the masonite plant is located.He said they had many unique accidents from the plant come in.

One was what is called a "de-gloving"injury,plant forman was walking along one of the continuous press lines and saw something fixing to run under the rollers,metal I suppose and didn't want it to screw up the line,so he reached in and tried to pick it out only his finger tips stuck to the hot and also very sticky masonite sheet and pulled his hand through the scoring knife that scores the sheets,thankfully the knives are spring loaded and the kinves seperated instead of lopping off his hand,but they did cut the skin nearly all the way around his wrist and the masonite pulled the skin off like a glove http://bbs.homeshopmachinist.net//eek.gifHe said there was very litte blood and the hand looked just like the pics in the anatomy books.They loaded the guy up in a medivac chopper and flew him to Jackson where a plastic surgeon recovered his hand by slipping the skin back over and re-attaching it at variuos points.Luckily his co-workers didn't panic,they retrieved the skin and put it in ice which saved it,My brother said the guy made a full recovery except for a patch of skin along the pinky edge that died before it was re-attached.