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Sycamore for beams.

Started by LeeB, May 26, 2007, 02:26:10 PM

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LeeB

I think I'm gonna try my hand at a timber frame barn and was wondering if sycamore can be used for any of the beams? I have never done any TF before so I'll have many questions as I go.
'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

Jim_Rogers

I'm sure we've covered this subject before.
Try doing a search here on on the TFG site about sycamore.
I'm sure there's lot of info or opinions out there.
Personally, I've never worked with it...

Jim Rogers
Whatever you do, have fun doing it!
Woodmizer 1994 LT30HDG24 with 6' Bed Extension

Dodgy Loner

Sycamore has twisted grain that may cause problems in a timber frame barn.  If the grain tends to twist in only one direction, the beam will "untwist" as it dries and cause severe problems.  One method that is usually used by log cabin builders to determine if a log is usable is to determine if the log has right-hand or left-hand twist.  To do this, place your right hand on the log, with your thumb and your index finger forming a "V" that points to the butt of the log.  If the grain follows your fingers, the log has right-hand twist and is probably usable; if it follows your thumb, the log has left-hand twist and should not be used.  The direction of the grain can easily be determined, as checks that form as the log dries will follow the grain.

The reason left-hand twist logs should not be used is because practically all trees with twisted grain begin their lives with left-hand twist.  If a tree has left-hand twist throughout, it will twist severely as it dries.  A tree with right-hand twist began its life with left-hand twist, so the different directions of the grain will equalize, and the twisting will not be as bad as the tree dries.  These rules apply to all trees with twisted grain, not just to sycamores.

One more thing to consider: sycamore has practically zero rot resistance, hence it should never be used in a situation where it will be touching or near the ground, or in any other location where it will be frequently exposed to moisture.
"There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey." -John Ruskin

Any idiot can write a woodworking blog. Here's mine.

Don P

That's the first time I've heard a logical explanation for the "no lefties" school of thought. Is there some more reference for this?

My luck with sycamore as 2x has been that it's beautiful but sure moves alot on the way to dry.

beenthere

Hmmm. I think Arky mentioned that a year or three ago.  Makes good sense.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

LeeB

OK. Thanks for the info. A fellow offered some logs to me, said they were going in the burn pile otherwise. A couple may be big enough for quarter sawing so maybe I'll use em for paneling or some other such interior stuff. Does any one know if horses dislike it as much as cottonwood?
'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

Don P

I've seen it written about and experienced the misery of trying to mate lefties with righties but would appreciate it if you know of a text or forest products labs article describing the juvenile twist, its reversal and causes. It's always good to be able to read from and point to the source.

Kcwoodbutcher

You mean to say horses won't chew cottonwood?
My job is to do everything nobody else felt like doing today

beenthere

Don P
Some info scattered around.
1999 Swedish article (pdf)

In this following paper, it discusses the reversal (left then to right) as the tree ages for softwoods (Champion, 1925), but not necessarily true of hardwoods. Several references cited in this paper.
Spiral vs age in White Oak

There may be additional information out there too.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Don P

Thanks  8). I've looked off and on for something for awhile, this is heading in the right direction. Please do post if you know of or find more. Lefties and strength is another area of interest.


WDH

Does it matter which face of the beam you do the "V" test on?
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Don P

No, think of it like a piece of threaded rod, which face, or end for end doesn't matter, it's either left hand thread or right hand.

Top log's a right spiral, next one is a left. Lefts seem to be harder to pull down. Mating two logs that are going to unwind in different directions as they season isn't a good idea.
Beyond that is where I've been trying to learn more.


ARKANSAWYER


  Not a good choice for beams in a barn.  Will rot and bugs will eat it up.  Horses will crib on it.  The 2x do make good inside stall boards where they will not touch the floor or get wet.
  Will spalt well and make fine inside wood.  Does move alot.
ARKANSAWYER

LeeB

'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

Dodgy Loner

Don P, the Log Construction Maual by Robert Wood Chambers provides a detailed description of right- versus left-hand twist trees.  He cites many of his sources in the back of the book, so I will look it up tonight to see if he listed the refererences for this information.
"There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey." -John Ruskin

Any idiot can write a woodworking blog. Here's mine.

Don P

Thanks Dodgy Loner, B.A. Mackie had mentioned it in his book but there were no cites. He made the strength comment also. Beenthere's links are good reading also. I start at the abstract and summary on those technical papers.

Sorry LeeB didn't mean to hijack your thread.

LeeB

All threads are for sharing information. I got my answers and you got yours so we both gained.
'98 LT40HDD/Lombardini, Case 580L, Cat D4C, JD 3032 tractor, JD 5410 tractor, Husky 346, 372 and 562XP's. Stihl MS180 and MS361, 1998 and 2006 3/4 Ton 5.9 Cummins 4x4's, 1989 Dodge D100 w/ 318, and a 1966 Chevy C60 w/ dump bed.

Dodgy Loner

I checked last night, and R.W. Chambers doesn't offer any citations, either.  He does include the Log Building Standards in his book, which do not allow for lefties to be used for floor joists or roof timbers due to their unpredictable strength.
"There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey." -John Ruskin

Any idiot can write a woodworking blog. Here's mine.

Don P

Thanks for looking DL. That's the same dead end I've hit so far. They are writing it into code and I haven't found the support yet. Please do pipe up if any of you run across the the paper this comes from.

Dodgy Loner

How often do you run into lefties?  Granted, I've only built one log cabin, but of the 50+ logs in it, I didn't find a single one.
"There is hardly anything in the world that some man cannot make a little worse and sell a little cheaper, and the people who consider price only are this man's lawful prey." -John Ruskin

Any idiot can write a woodworking blog. Here's mine.

ARKANSAWYER


  I saw two to three tractor trailer loads of logs a week and get about 1 log a week with left hand twist.  Post oak and sickymore are the two worst hardwoods and there may be 3 logs every load.  Pine will have one about every other load. 
  There was a thread on this about a year or so ago.
ARKANSAWYER

Don P

I think its come up several times, I can't remember the particulars though, didn't remember that it got into causes. The joys of oldtimers  :D

The house in the picture was my first SYP one. It was the first time I came across more than a very few. It was stamped "mixed syp" and I think it was plantation pine of one of the subspecies. I showed a chunk to a SPIB grader and he couldn't id it while we talked there for just a minute. So that was a boatload of lefties one time. Beenthere's linked paper reinforces the reason for so many lefties in that batch.

The corner logged pic I put up on another thread had EWP exterior half log siding and red pine interior half log siding. Red pine is another one noted for twisting while drying. To make the interiors sit nice I had to match twist. There were some lefties I sorted and used together. EWP is pretty calm usually.

There's a stand of predominately lefty hemlocks just over our property boundry on a neighbors. Makes me think there's genetics at play but its also the top of a cliff so it could be sun, or wind, or nutrients, or...  :D.

If you read the white oak paper, hardwoods are often the opposite and then I always think of gum when this topic comes up  :)


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