Rabbithole Alert !! MC meter SG selection - Confusion w SYP and SPF "Softwood"

[Marc Jeske]

Re: Softwood species confusion and affect on MC meter readings -

I fully understand MC meter readings are approximate for MANY reasons, but I'm talking about up to like 5% range problem here.

This refers to posts #6 and #7 in the below linked thread -

https://www.sawmillcreek.org/showthr...rn-yellow-pine


Malcolm and Adam are spot on in their posts.

That's why I walk away shaking my head when I try to measure SPF and SYP MC at the Lumberyard.

Often have no clue what to set the SG to.

All I know is somewhere in the about 48 - 64 range.

The range above shows about a 4+% difference on same piece of wood.

Ligno says SYP - 64.

Now that I have learned more, it seems they are guessing on that one..WAY at the top of Pines.. would think they would pick a lower # closer to mixed species average.

So like when going through a pile and getting like up to 4% variations, I do not always KNOW if it's a different species, OR different MC's between the boards.

I suppose in the same just unbanded pile they should be close in MC, but it still ends up being potentially false guessing.

Worse yet .. after the piles been gone through, mixed up w old stock, flipped around,ALL bets are off unless you're Gene Wengert.

Any magic solutions besides devoting a week to study discriminating between SYP and SPF varieties, and even then being often unsure ?

I have a Ligno Scanner SD, and far as I know this confusion would affect all MC meters, not just my model.

Oh, and FYI - Wagner has an amazingly huge SG database - Marc

https://www.wagnermeters.com/specific-gravity/



Marc

[Phillip Mitchell]

What exactly are you asking?

[Marc Jeske]

Asking what others do in this situation to help insure they know what MC they are buying.

Marc

[John K Jordan]

Asking what others do in this situation to help insure they know what MC they are buying.

Marc

Everything I know about moisture meters for wood (I use a Wagner pinless) indicates that the numbers you get are approximate at best. There are simply too many variables, special conditions, and variability of within a species or even within the same board. For a pinless meter simple variations in density make a big difference in readings.

For an accurate MC nothing I know beats the oven-dry method. This is, of course, not very useful at the lumberyard. But even back at the shop the precise moisture content varies depending on where you cut the board!

With a sawmill here I don't often buy lumber (except for 2x construction lumber, PT posts, etc. where the precise moisture doesn't matter) but I do use the meter to check boards and woodturning blocks after air drying. The exact moisture content is not as important to me as the approximate MC. I'll check multiple places on the same piece of wood and get a good idea if it's dry enough to use.

Since you mentioned Gene Wengert, perhaps you have read the article on moisture meters authored by on the web site he is associated with (under Knowledge Base, Electric Moisture Meters). There are also threads that discuss the issue you mention. Perhaps ask Google for something like "how accurate are wood moisture meters?".

JKJ

[Marc Jeske]

John - Thank you for the reply, but I am still lost.

I am NOT concerned about "Exact" MC.

Like you explain, there really is no such thing even, just close average approximations.

But the 5% range I'm getting is not "close" .

I sed in OP Post - "I fully understand MC meter readings are approximate for MANY reasons, but I'm talking about up to like 5% range problem here."

You sed - "I'll check multiple places on the same piece of wood and get a good idea if it's dry enough to use."

So, a 5% range would be close enough for you?

Like maybe 8 - 13% ??

Isn't that pretty darn wide?

Or, in real life, is it good enough?



I'm thinking the reason I'm not getting a solution to my query.. Is that you Guys probably 99% of the time know the species you are checking, hence the SG input #.

And barely anyone here is using Softwood.

For me and my project.. I live in a geo area where the locals are romantically enamored w " "Texas "Pines" " (including other species that look same to their layman eye) and that's my market.

They want Pine, NOT Padauk.


In MY case problem, I am checking mixed piles of SPF, and SYP, usually not knowing the EXACT species board I am measuring within the allowed species assortment of the above where to set my SG #.

So that's why I get my roughly 5% range problem.


I will read the Wengert article you mention again.

Marc

[Danny Hamsley]

For SYP, use .48 specific gravity. The commercial southern pines are predominantly loblolly and slash and shortleaf. Not much longleaf being harvested. The specific gravity of these three species can range from .46 to .51.

For SPF, use .40 specific gravity. The spruces, lodgepole pine, and the firs are not as dense as SYP. SPF comes largely from Canada, and the most common components are lodgepole pine, and the spruces. There is a way to separate the firs from the pine and spruce by checking the end grain with a hand lens for the presence of absence of resin canals. The pines and spruces will have them, the firs will not.

[John K Jordan]

So, a 5% range would be close enough for you?
Like maybe 8 - 13% ??

Please note that I am not even close to an expert on this and I rarely build furniture - when I do I wouldn't call it fine furniture.

I do use some softwoods, some virginia and white pine, quite a bit of eastern red ceder. The virginia pine can give different readings on the same piece depending on the orientation of the rings to the pinless meter.

An MC reading range of 8-13% would be fine for me. For an air dried 4/4 board without obvious figure, crotches, cracks, and other things that can effect the density the range might be tighter. For thicker stock, such as a turning block with my pinless meter I will typically see much larger variations at some points due to non-homogeneous issues, for example, end grain vs side grain.

One thing about wood for me - besides cutting boards and slabs on my sawmill I process much of my domestic wood into turning blanks and let it air dry inside the shop. I mark the date on each piece. From experience I have a "feel" for how long some common species take to air dry inside before I can use it without getting significant distortion from shrinkage. Also, with experience I can literally feel when the moisture on the surface is too much for certain species. Species are vastly different - sassafras, for example, dries very quickly, cherry longer, dogwood/osage orange/black locust is much longer. The larger pieces of dogwood I'm using now has been air drying for over 10 years. I can use thin pieces of ERC very quickly after cutting, white pine almost as quickly, virginia pine takes longer.

I'm thinking the reason I'm not getting a solution to my query.. Is that you Guys probably 99% of the time know the species you are checking, hence the SG input #.
And barely anyone here is using Softwood.

For domestic hardwoods and softwoods, I almost always know the species, especially since I usually cut the wood from the tree or at least the log and I've seen the leaves and/or the bark. If I am unsure of hardwood species, I check the end grain as per Hoadley's book "Identifying Wood" along with other clues such as color, density/hardness and occasionally fluorescence under UV light. Softwood ID is an entirely different issue and I personally have no experience - I understand to differentiate between some softwood species requires deep examination under high magnification. Hoadley's book might be interesting to you, or at least look at the various pines on the online Wood Database. They have nearly 30 listings for pine. I don't see Texas Pine anywhere - is that an actual species? Perhaps it just means any pine that grows in that area.

Hobbithouseinc.com is another web site I use. They have a nice article on wood ID plus thousands of photos of side and end grain. What hits home with this site is how different boards of even the same species look. After spending a few hours on that site you have to chuckle when someone posts a picture of the face of a board and asks for a species ID!

As for looking at boards of different species, I'm not surprised you see different readings. From my experience, the meter setting is a rough one that cannot possibly cover all the variations seen in wood, even that of the same species.

But your second comment is probably right - I don't see woodturnings or fine furniture made from pine posted often on the forums I read. I see almost no pine in show and tell at the clubs and symposiums.

I agree with not wanting Padauk - the color change is horrible! BTW, pine is in high demand in some other areas for the look. I visited a woodworker in northern Italy who showed me pictures of decades of furniture he made for homes and companies - almost all of it was pine. The late Jim King from Peru mentioned that the US demand for purple heart wood was puzzling - they used it for floor joists and studs where he lived. The most sought after wood in his area was "knotty" pine! (also not a species but a look).

If I were in your shoes and determined to chase down the moisture content I would probably do my own analysis. Perhaps acquire a variety of 4/4 boards available at the lumber yard, take them home and weigh each carefully, take some readings in various places and write them on the boards, then sticker indoors in the dry (where the humidity is relatively constant) and wait a few months and weigh again. If the moisture doesn't change in a few months, the wood is likely at MC. If it does change, repeat.

You can do this a lot quicker if you test each board immediately after with the oven dry method using a slice cut from the center of the board. Some experience with this would probably give you a good "feel" for what to expect from the meter. If you can distinguish between different species or groups by appearance, you could go a step further and derive your own meter settings for each type - oven dry to get the precise MC then change the meter setting until it reads that MC on the board. If doing that, I might even cut a meter test piece adjacent to the oven-dry test strip wrap or bag it to preserve the MC during the oven drying and weighing. Sounds like an interesting experiment!

Alternatively, you might measure the exact SG of a piece of wood directly by machining a block carefully into a rectangular solid, precisely measuring, and weighing with a precision scale. Remember the SG values given in wood charts are usually at some moisture content, such as 12% so you have to account for that. This sounds far trickier for wood! I use this method sometimes to identify unknown plastics and metals where the moisture content does not apply.

Again, I'm not an expert at this nor did I stay in a Holiday Inn Express lately. Perhaps someone who knows their pines and moisture meters will answer. Or ask on the other forum mentioned - is Wengert still around?

JKJ

[Mark Bolton]

Asking what others do in this situation to help insure they know what MC they are buying.

Marc

Not sure why you wouldnt just find a source for #2 common KD 6/4 or 8/4 pine (sub species of your choice)?

There are numerous threads in the archives about cherry picking entire packs of construction grade lumber to find the few vertical grain boards or the dry-"ish" boards. But I cant imagine what you'd be making that would allow for use of such low grade material yet require such attention to moisture content in a material that is in no way milled or dried to any level of precision. I got a chuckle out of the Gene Wengert reference and envisioning someone in the home center isle probing stick after stick with a moisture meter.

We dont have a good local source for KD softwoods but if we were using it in any capacity we would want the MC to be much lower than framing material and would at the very least want the pitch set. Even the best KD framing material Ive dealt with in 30 years in the trade is "sticky" to the touch compared to KD softwoods with the pitch set. You really feel it in the chips.

Id think finding a good source for KD would allow you to put your moisture meter in the drawer and save the time of picking, probing, testing, researching, and worrying, and leave you oodles of time to get in the shop and do what you love making things out of wood. A couple of hundred$/MBF on average for #2 framing lumber is cheap but you may find a source for slightly more with a lot less headache.

[Ted Reischl]

The OP has not stated what he will use the wood to build.

So I am at a loss as to why the MC being more accurate is so important to him?

Heck, I build furniture out of SPF all the time and don't even own a moisture meter. And no, my stuff does not fall apart, crack, etc. When I buy big box spf I buy quite a bit, then it sits around my shop for a long time before being used. My thought is that no matter what a meter says, that wood will be the mc it wants to be after sitting in my shop for six months.

I am pretty sure the Newport furniture makers did not have any fancy moisture meters either.

[Mark Bolton]

Heck, I build furniture out of SPF all the time and don't even own a moisture meter. And no, my stuff does not fall apart, crack, etc. When I buy big box spf I buy quite a bit, then it sits around my shop for a long time before being used. My thought is that no matter what a meter says, that wood will be the mc it wants to be after sitting in my shop for six months.

I am pretty sure the Newport furniture makers did not have any fancy moisture meters either.

Framing lumber left in the shop for 6 months does not make it KD or stable to a point where its not going to move especially in the world of soft woods. The pitch has never been set, and if your lucky in the six months its sat in your shop (hopefully we are talking a basement shop which is fully conditioned 365 days a year) it may be a little bit drier than when you bought it but its in no way kiln dried with the pitch set.

The Newport furniture makers likely paid far greater attention to their construction methods given the known wood movement issues from season to season and conditions upon manufacture. Course wood heat was the best case situation. Some rooms were toasty and others freezing. Our cabinetry and furniture today would be an insurance nightmare lol. Gaps in door panels, face frames cracking, interior doors falling apart, etc.. lol what a stomach ache. :-)

The Newport furniture makers never envisioned homes that would be humidified in the dry winter months with 15-20 thousand dollar heating systems, electronic air cleaners, steam humidifiers, and then DE-humidified in summer with refrigerant systems able to pull gallons of liquid water out of the conditioned air per hour.

[Mike Henderson]

For those who are reading this and may not know what the abbreviations mean:

SYP = Southern Yellow Pine
SPF = Spruce, Pine or Fir

Unfortunately, our woodworking ancestors, including the Newport furniture makers, did not always properly take wood movement into consideration. For example, they attached molding cross grain on chests of drawers and nailed the molding in place. We have examples of chest of drawers with split sides because of expansion and contraction of the wood and the cross grain molding.

I think it would be fair to say that the Newport furniture makers never expected that their furniture would survive as long as it did.

Mike

[Mark Bolton]

For those who are reading this and may not know what the abbreviations mean:

SYP = Southern Yellow Pine
SPF = Spruce, Pine or Fir

Unfortunately, our woodworking ancestors, including the Newport furniture makers, did not always properly take wood movement into consideration. For example, they attached molding cross grain on chests of drawers and nailed the molding in place. We have examples of chest of drawers with split sides because of expansion and contraction of the wood and the cross grain molding.

I think it would be fair to say that the Newport furniture makers never expected that their furniture would survive as long as it did.

Mike

You have to wonder if they didnt properly take wood movement into consideration "at todays level" or if they just dropped the ball. Not that Im trying to defend the Newport style, but there is the argument that their furniture likely would have remained stable throughout its life but they would never have anticipated an environment as dry as what we deal with today. That being said, their work may have remained stable for its respective life span in the environment in which it was made. I dont think anyone in the "old school" of wood work and furniture making world would have, or could have, built in anticipation of a MC swing into the low double, or in some cases single, digits.

[Phillip Mitchell]

Let me just say that, assuming you have a trusted moisture meter, if you're getting readings from 8-13% in a single stick then I wouldn't call that stick dry. I usually feel confident if it's pretty close (1-2%) in multiple places in the board. That being said, there are so many variables with testing using a moisture meter that it's hard to speak absolutely about it.

Like others have asked, what are you building and why are you using framing material and being so picky about the MC? Why not find some good Kiln Dried stock from somewhere you can trust?

[Marc Jeske]

Trying to get out to work, so I'll be brief now, and read through everything tonight.

I have not given up yet, but it seems the closest source for KD to a furniture level is about 140 miles from me.

Houston.

So, I have to pay freight, or drive there.

I don't drive alot anymore, so it would be the Freight $

And still, someone ELSE will be picking, not my eyes.

So, I have to live w my culls, OR pay a higher price for better stock.

So now we're up to a bunch more $ than my local yard.


I have very clear "SYP" at my local yard @ $1.70/ bd ft s4s.

Also they have a "knotty" grade, still totally suitable for my "look" I want, for about 90 cents.

The problem is "19%"

I am finding the variance I originally explained in the stock above.

Hence my OP.

Will read/ respond further later. Marc

[Mark Bolton]

How about building a small dry box at your shop and you load small quantities in and compress the stack with spring loaded all thread and apply a small heater to the stack for a couple weeks? I have long thought of building a small dry box in the shop to flash off a couple hundred feet of material thats been in the wood bay (not conditioned) for a while. Could be done on the cheap with some 2" XPS and ply. You'd likely not get to temps to set the pitch but you could easily drive small quantities of material down to single digits and you'd know that every stick is where you want it when you opened the door.