Unfortunately, it can have hidden dilemmas (toxicity and allergenic)… To some, it’s just slightly annoying if at all while for others it can be down right dangerous…
Most all wood is toxic to some degree, more so for wood dust… For some, there are no to only slight issues, while for others, it can cause major adverse health issues…
Always remember that wood is hygroscopicand MC is something you need to be aware of when doing your projects… As a wood’s MC percentage changes the wood changes dimensionally accordingly… (shrinks/expands)…
Shrinkage can easily result in loosened joinery, splits,warping and a host of other mischief that can cause malfunctions/problems in woodworking. …
We often use it believing it to be the best solution for a wide range of issues…
BUT - not all PT is created equal…
There is a wide variety of treated lumber available in a wider range of sizes and applications. Knowing the different types is important to making sure you select the right product for your project, saving you money and the headaches later on.
Here is some in-depth information on the types and their applications…
To make pressure treated wood, lumber is first placed in a pressure chamber comprised of a horizontal steel cylinder (called a “retort”) that resembles a rail car. Once the lumber is properly secured in the retort, a vacuum removes the air from the cylinder and from the cell structure of the lumber. The retort is then flooded with treatment chemicals under pressure. Using 160 pounds of pressure, the treatment chemicals are driven into the cell structure of the lumber.
A lot of us use Baltic Birch… My personal favorite…
a very stable, strong and easy to use high quality plywood…
because of the high ply counts thinner panels can be used over the normal plys you may be use to…
for me to use MDF and the like in my shop, OSHA had entire governing book(s) of expensive rules and regulations when/for using it, a lot more than real wood…
the upgrades to PPE and dust collection were quite costly…
Repairing broken MDF pieces or components is about impossible to do reasonably well… broken MDF home or office furniture, bookcases or cabinets??? the best way I’ve found is to replace them…
I personally do not use MDF…
One more thing… it sure is rough on tooling…
PPE – Personal Protection Equipment… ie; respirators, HEPA level dust collection, etc…
MDO is my go to plywood for all my shop cabinets and drawers, After years of using it for concrete form plywood I just love the stuff. For concrete walls it will give an Architectural finish and can be used over and over. Great plywood for exterior use and paints up like a dream. Totally waterproof. It can be had in melamine coated one side or both sides there is a small price difference between the two. There is a good reason that the sign companies use it for exterior signage. It will weather for years. Signs and concrete work uses mostly 3/4" thick, I use 1/2’ thick for shop plywood. It has solid cores ,no voids.
The Downdraft box I show here is all MDO.
Herb
Preheat conventional oven to a temperature of 215°F digitally or 218°F analog… Check it often and adjust it accordingly…
One rack goes to the bottom of the oven w/ a baking pan on the bottom rack to catch the drips… (resins)… Cover the pan w/ aluminum foil to help w/ the clean up,
Another rack in the center of the oven for the wood and oven thermometer… Put the thermometer in the far back corner…
If your oven has a convection fan, turn it on, airflow is a major plus…
The wood goes on the middle rack, bake for one hour… Don’t let he pieces touch so that you get more of a uniform drying… If you chose to stack it, sticker it…
Test the moisture content after an hour, reheat for in increments of 15 minutes until you reach your target MC… Once the MC level is stable remove the wood and allow it to cool… Use a cooling rack… Your target MC should be around 6%…
Apply a sealant or wood stabilizing solution after it cools to room temperature so that it remains dry… After drying wood acts like a sponge and suck up humidity like a sponge…
Drying wood can cause it to crack or warp… Dry larger/longer and more pieces than you need or you may have to do the process again w/ more wood…
If you have a digital moisture mere you are golden… Take readings before during and after…
If not - weigh it before during and after…
Weighing for MC… (the numbers are hypothetical, not the formula) Moisture Content %() = (weight of water removed ÷ by ovendry weight of wood) x 100
Wet weight is 120.00g and oven dry weight is 99.99g, then the loss is 20.01g. The MC is 20.01 divided by 99.9, which equals .200. You then multiply by 100 to get it into percent form, since we always talk about “percent MC.” (So the answer, in this example, is 20.0% MC.)
Typically a MOISTURE SECTION is about 100 grams (g), so you need a balance scale that weighs to/in 0.01 grams if you are to get the most accurate readings. However, 0.1 is fairly close (within .2 percent MC usually)…
