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"Lugged" half-dovetails as cabin corner notches?

Started by jake pogg, May 30, 2021, 10:49:18 AM

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jake pogg

I screwed up the above post,sorry.
What i meant to add is that kerfing of whatever sort to direct the future checking is a very good idea.

Unfortunately it is yet another instance where the D-logs prove to be a misbegotten concept:The way they're cut to begin with already does that-directs all checking toward the inside of the house. 




 
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

jake pogg

 

 

As the project advances i discover yet more nonsense about D-logs in general.
The latest-and most destructive by far-is that a D-log wall will always tend to lean outward.
I should've foreseen that,obviously the round side of a timber cut asymmetrically and with heart left in will shrink more than the opposite side,tangential shrinking,duh...

I'll probably wedge the outer seam temporarily while building,and after the tin is on will have to resort to some form of medieval Eastern European method of chinking,something along the lines of a hemp rope....Beetle and chinking iron,the works...
(i'll to forge the irons,no problem with that,just feels ridiculous already.....). 



 
<>

My solution to covering up the butt-joints is working ok,incites a lot of questions,i'm learning to get creative in inventing all sorts of exotic reasons for that.
Some of the outrageous lies that i've invented so far have began to actually seem interesting,like loading and using these somehow,i may grow them out towards the inside in an arch towards the top of the wall and throw a beam across...

"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

kantuckid

Jake, I thought about your D-log concerns with checking to the heart and for a good bit since. Given my EWP source for D-logs is dicey at this moment I was looking on FB Marketplace and have made a few calls to logger/sawmillers near me.

My own log home is YP, built green 40+ yrs ago, 6" thick & 8.5 to 12" dia. with two peeled sides.
 I may do a survey on interior and exterior log ends and tally them up for heart cracks where.  

In looking on FB I see at least 3 sellers with a pile of D logs and several others with sawed timbers. Hardly scientific but 2 piles are milled T&G EWPO so more likely to be KD. Then I've looked at more than a few dried logs myself over the years. The tendency seems to lean heavily toward the crack appearing on the side where the surface is closest to the heart- IMO, of course ;D 

On that crooked wall opinion I'll defer to more experienced log builders. My own challenge was decidedly not that but rather given the 6" thickness being straight off a circle mill (even with a very experienced sawyer!) so height at the corners was a constant check item, while plumb didn't come to hard.  
Kan=Kansas;tuck=Kentucky;kid=what I'm not

Don P

The major check does tend to follow the path of least resistance which is the face closest to the heart.

I have had to resort to power planer and laser (or a transit would work with a helper) to re-establish a flat plane when the wall is trying to roll. We even had dealings with one milled log home company that I found out finally from a driver was trying to nurse a worn out molder bed. The logs were out of square so began a roll as you stacked. I found a light setting on the planer running it down one side of the bottom and then the relief down the middle bottom kept it plumb, tight and flat. All depends on how much fussing you want to do. As well a checked face is shrinking but is not changing in overall height, the shrinkage is mostly happening in the check not in the timber's overall dimension. The unchecked face is shrinking and is losing dimension. So aside from the radial/tangential issue there is a checked and unchecked face issue piling on as well.

We would set up story poles in the corners that were plumb and braced in both directions for D logs. I would tape measure across them and record the measurements and diagonals on the poles and check them periodically to make sure we were coming up plumb.

jake pogg

Thank you,gentlemen,all the info above is very edifying and reassuring.

Kantuckid,i believe you're very right about the check running the shortest path heart to outside...Many a full-scribe guys kerf their logs in part based on that assumption

That bit about checked/unchecked dimensionality is brilliant,Don,i wish i was organised enough to take notes of important data like that...

And yes,reference posts/knees are very handy,i'll end up using some devices of the sort,now that i know that i must watch these sticks like a hawk.

It's been very tough,a one-man crew to do everything to these logs that they need.
And i'm in a race against the time as well,before say mid-October i Must have the tin on,even in the rudest/most basic config.
12-14 hr days is all i can squeeze out of this wreck of a body,and so far it's not looking great-maybe a course in 3-4 days.
My boom-truck is late in coming over to the site,so far has been moving everything on the platform by hand.the 20'-ers are not exactly pleasant to handle,even as aged as they are.

Hoping to survive until window height where i'll start burning up the badly twisted ones in short sections.
Once i get through that i'll be nearly done with this set of logs.
It'll be a mixed blessing-milling my own will bring much more control over quality,but will add time and work.

The totally unusable ones i'll take to the mill to make small dimension lumber for trusses,in effect trading these awful,several year old sticks for the greener ones i caught drifting(very poor drift run this year,on top of everything,but i did get a few,maybe even enough to finish this project.

I absolutely Love fussing about with wood in general,but can ill afford too much of that at present juncture,so sadly,no draft-dam on the corner notches,nor a few other niceties i kinda hoped for.
For pegs i settled on 1 3/8" sq. i re-saw on the tablesaw from my greenish lumber in a 1 3/4" hole,half in the bottom/half it top log,trying to orient the grain of the peg with that of the log to help prevent eventual splitting.
Hope springs eternal(alas our summers here don't).   
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

kantuckid

Cuss D logs all you desire as you chase the AK weather horizon, but the fact remains that the relatively flat surface on the inside wall is kind of handy to keep plumb? Lots easier to hang a picture too! Or fasten cabinets onto... etc. etc, etc,... :D
Kan=Kansas;tuck=Kentucky;kid=what I'm not

jake pogg

Oh YES,:)
i loves them Vertical flats,they're wonderful.

Everyone who Could do so,did- flattened the inside and the outside,for a myriad reasons,all of them good.

8 years ago i built a place with a friend,we 2-sided timbers to 8" thickness and scribed them,came out very decent.
(wonder if i got any pictures left anymore...?).

So decidedly yes,but only on the vertical-seems literally crazy to do so on bearing surfaces... 

Some of my catch from a couple weeks ago,a few decent trees in there,i may have about 3 dozen+ good size ones for the mill...

It's a crying shame to mill these to 8" height-wise,as stacked and scribed the rise at each course would amount to nearly a third more...

And still perfectly flat on the inside and outside.





And here's a photo of a place i built 20+ years ago,"russian"-scribe,at the client's wishes.
What we mean by that is simply that the notches are round-not the best way to join round logs as the one inside the notch will always shrink,and the fit at the notch form a gap.
However the reason they did it that way over there is that there was this general tradition to make all joints-notches and lateral-open out,wedge-like,to the outside.
That was so a specialist chinking crew can come behind the builders and literally caulk all seams,boat-like.
They caulked it so tight that often,in consequent chinking(it was a periodic maintenance procedure,done once every 20-30 years),they actually levelled the building with it,adjusting the position of whatever logs they chose.  



    
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

Joe Hillmann

I am also in the process of building a cabin with D-logs.  As they are drying in the pile I am finding the top and bottom surfaces aren't staying parallel.  I left an extra 1/4 inch of thickness to be able to put each log back on the mill once dry to do a clean up cut.  But I have also considered using lots of shims to keep the walls going up straight and even.

Because the d logs normally have so little space for chinking I am thinking of using twine for calking it.  But if I end up using shims there may be a large enough gap to use a cement based chinking.  I am going to have 10 foot eaves all the way around the cabin so I can be less concerned about weather resistance than if I had normal eaves.

kantuckid

I used what was a new at the time product on my home in 1979/80-Norton Sealants, log foam strips. They are now in widespread use. and I'll do a similar product again -if i ever get some logs... Corr-Tenn in Knoxville has several choices priced right. 
Kan=Kansas;tuck=Kentucky;kid=what I'm not

jake pogg

Quote from: Joe Hillmann on June 20, 2021, 10:40:14 AMBecause the d logs normally have so little space for chinking I am thinking of using twine for calling it.  But if I end up using shims there may be a large enough gap to use a cement based chinking.  I am going to have 10 foot eves all the way around the cabin so I can be less concerned about weather resistance than if I had normal eaves.


We all so often include Everything in a word "chinking": Weather resistance/air-infiltration,insulation,and with these darn "D-logs" now the structural element to shim the wall straight...

Instead of cement-based mortar that you mention you may consider one of the latex-based products.Water-based,it sticks to the logs very well,and has a very great degree of elasticity.It can last many years without the maintenance that cement mortar mixes would require(though it's comparatively costly).

Quote from: kantuckid on June 20, 2021, 02:41:39 PMI used what was a new at the time product on my home in 1979/80-Norton Sealants, log foam strips. They are now in widespread use. and I'll do a similar product again -if i ever get some logs... Corr-Tenn in Knoxville has several choices priced right. 


That sounds interesting..I wonder if it's akin to the so-called "backer-rod",made in varying diameters of a soft,open-cell foam?
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

Don P

The foam gasket kantuck is talking about is an air infiltration gasket that goes in the relief groove. It is too far in to act as a backer rod.

A backer is just behind the caulking/chinking. Ideally that joint is adhered to the upper and lower log and is tooled thin over the bond breaker of the backer. This 2 point adhesion and thinner non adhered center section creates a joint that can stretch with log movement. The typical "pump it full of goo" caulk joint has what is called 3 point adhesion. It is thick and stuck to everything so when things need to move it really cannot stretch and has to tear loose somewhere. On stuff too tight to backer even a strip of mylar tape will create that bond breaker and create a 2 point joint with a stretchy area in the middle.

On cement, portland based cement doesn't allow drying so tends to create rot. The old lime based chinks and renders usually behave better with wood if you want to go that route. Usually that is for wider jointed chink style buildings though. Personally I've never shimmed flat on flat logs, i think it works better to remove the offending high stuff and get things to sit down tight.

jake pogg

Thanks,Don,that's very interesting about the modern sealing systems.
Portland cement as well.
That wide-seam/dove-tailed style common in S.E. US is very attractive,and practical.Always wanted to try it out,and don't understand why more people,if they must have two-sided sawn logs,don't do That with them...

As far as shaping the flats to fit-if they shrank differentially once,then what's to keep them from doing so again?

Possibly,humidity inside relative to outside  et c. differs across the country,but here,and with the woodstove heat especially,even the most "seasoned" logs will not attain that degree of shrinkage that they will later,once the house is closed in and heated.

So maybe only some form of over-scribing would work...(sounds even weirder than wedges tho...)...  
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

jake pogg

P.S.

Apropos of nothing in particular other than chinking in general,
i helped a friend last year to build a tiny,8'x12' sauna.
We milled a bunch of cottonwood(Balsam poplar) for the walls,and i nagged him out of using any synthetic crap in it,plywood or plastic or anything that'd off-gas as it'll get hot.
For chinking i made him order that wool "rope" stuff,always wanted to try it.
At $150 per 10# box it sounded very expensive,but turned out there's a Ton of it length-wise,we never used a quarter of that box...
I fell in love with the stuff,it just felt Lovely...And was incredibly sturdy-you could Not rip it by hand,insanely tough stuff,and evenly shaped,and Everything about it was uber sexy...(no idea how it's used and by whom...). 
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

Joe Hillmann

Quote from: jake pogg on June 21, 2021, 12:43:04 AM
Quote from: Joe Hillmann on June 20, 2021, 10:40:14 AMBecause the d logs normally have so little space for chinking I am thinking of using twine for calking it.  But if I end up using shims there may be a large enough gap to use a cement based chinking.  I am going to have 10 foot eaves all the way around the cabin so I can be less concerned about weather resistance than if I had normal eaves.


We all so often include Everything in a word "chinking": Weather resistance/air-infiltration,insulation,and with these darn "D-logs" now the structural element to shim the wall straight...

Instead of cement-based mortar that you mention you may consider one of the latex-based products.Water-based,it sticks to the logs very well,and has a very great degree of elasticity.It can last many years without the maintenance that cement mortar mixes would require(though it's comparatively costly).

I am not a fan of the looks of the latex chinking.  And if it was cheap I would probably go that route, but it expensive and ugly(in my opinion) so I want to avoid it.
I want to play around with using twine to calk it like old wooden boats were calked with hemp. 

Joe Hillmann

Quote from: jake pogg on June 21, 2021, 10:11:53 AM
P.S.

Apropos of nothing in particular other than chinking in general,
i helped a friend last year to build a tiny,8'x12' sauna.
We milled a bunch of cottonwood(Balsam poplar) for the walls,and i nagged him out of using any synthetic crap in it,plywood or plastic or anything that'd off-gas as it'll get hot.
For chinking i made him order that wool "rope" stuff,always wanted to try it.
At $150 per 10# box it sounded very expensive,but turned out there's a Ton of it length-wise,we never used a quarter of that box...
I fell in love with the stuff,it just felt Lovely...And was incredibly sturdy-you could Not rip it by hand,insanely tough stuff,and evenly shaped,and Everything about it was uber sexy...(no idea how it's used and by whom...).
Could up put up a link to the type of material you are talking about?

jake pogg

Quote from: Joe Hillmann on June 21, 2021, 12:44:16 PMCould up put up a link to the type of material you are talking about?


This stuff right here:https://www.loghomestore.com/product-category/sealants-and-chinking/insulation-wool/wool-rope-insulation/

And i hear you on synthetic goops and putties,i'd prefer to not mess with them if reasonable alternative was practical.
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

jake pogg

P.S.

Looking up that wool chinking this has popped up:
Amazon.com: Sioux Chief Brown Oakum (963-15PK2): Garden & Outdoor

Seems kinda weird-$23 per lb?...(not that i've any earthly idea of how far oakum would go in an average log seam...).

By sheer accident the gal i'm building for has come up with,completely out of the blue, a roll of hemp/manila cordage.
It's a 1/4"(so about 3/8" dia),3-strand twisted stuff,and looks about Ideal for the outside seams that i'm ending up with...
I may try an experiment,but maybe wait another course or two,to give the logs above some mass to counteract the forces of wedging this stuff in there.

Wonder if such oakum-ish stuff was also soaked in oil,or ...? It'd make a good matrix to hold something oily or sticky...
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

kantuckid

To see a large number of re-located old hewn log buildings in one spot, visit- The Museum of Appalachian, just off I-75 in Clinton, TN just N of Knoxville, TN.
It was established by John Rice Irwin some years back. He essentially rescued many old log buildings, barns, homes etc., and placed them on the property. Most all represent superior original craftsmanship and have been setup using hand rived shingles, old style mud chinking and have rived rail fences around them with livestock inside. There is a museum building full of Appalachian cultural items which is very well worth your time besides the outdoor items.
We used to visit yearly for the October Fall Festival which had days full of music, sorghum mill, fence making, apple butter, etc. displays, crafts booths and food, but now discontinued. Over the years I met and enjoyed the many people who came each fall to help put it on-many are gone now along with their skill sets they displayed. An old sawmill was operated each year during the festival onsite too.
There's still a restaurant on site with a retail store still operating.

From my many visits there it seems that the old mud chinking is fairly durable?

Check out their website: Home - The Museum Of Appalachia to see the place.
 
Just down the road from my home here in KY the Daniel Boone NF has a smaller setup of some old farmstead buildings at the Gladie Visitor Center, near Stanton, KY. other than the interpretive main bldg, the buildings were moved in from the NF off of old farmsteads and fully restored. I used that location to provide gifted & talented kids from my school with programs related to their culture and brought in local arts & crafts people, plus myself and a few other school staff. Neat place, especially if ya like old buildings! 
Kan=Kansas;tuck=Kentucky;kid=what I'm not

jake pogg

Quote from: kantuckid on June 22, 2021, 08:08:44 AMTo see a large number of re-located old hewn log buildings in one spot, visit- The Museum of Appalachian, just off I-75 in Clinton, TN just N of Knoxville, TN. It was established by John Rice Irwin some years back. He essentially rescued many old log buildings, barns, homes etc., and placed them on the property. Most all represent superior original craftsmanship and have been setup using hand rived shingles, old style mud chinking and have rived rail fences around them with livestock inside. There is a museum building full of Appalachian cultural items which is very well worth your time besides the outdoor items.


That sounds like a Wonderful place,how i'd have loved to visit there...Especially if one was to ever try to build in this style...Sounds like an incredibly valuable resource.
(i've met a man once,long ago,who built like that commercially,(in a small way,with just his wife as crew);i believeve he said he spaced everything to where the timbers rested on a 2" thick polystyrene foam,then that space got screened and chinked).
  
And separate Thank you for participating in hands-on educational programs.I don't believe there's anything more valid or important than the passing on of old understanding of materials,through use of hand-tools and other ways.
I've done a little of that too,as the occasions came up,mostly forging,and most often for the young...
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

Joe Hillmann

Quote from: jake pogg on June 22, 2021, 09:21:55 AM;i believeve he said he spaced everything to where the timbers rested on a 2" thick polystyrene foam,then that space got screened and chinked).
 

I had thought of doing something similar to that as well.  I doubted the Styrofoam could hold up to the weight of the cabin above without crushing long term.  So then I thought I could put wooden blocks the same thickness as the foam along the length of the logs.  But then I still need to account for tapering shrinkage of the logs and leaving room for chinking would mean the strips are a ways back and would maybe cause the logs to be more likely to tip outward.
By the time I gave it some real thought I figured it got so complicated it wasn't worth bothering with.  On the bright side it would allow me to get by with 3 or 4 less rows of logs because of the added thickness of the Styrofoam.

Joe Hillmann

Is there a reason other than look you are hiding your butt joints where the ends of two logs come together not at a corner?

My main plan is to avoid butt joints as much as possible.  I have about a dozen full length logs for below and above doors and windows and I hope the short logs will work in the smaller spaces between the doors and windows.  But I still figure I may have as many as 20-30 butt joints.   I plan to stagger them so they don't end up near each other.  Other than that I plan to just spike them together and leave them exposed and eventually chink that gap as well.

kantuckid

I have a few butt joints in my home and never an issue other than if the builder doesn't like to see them when finished. They are always staggered and always not where an opening needs several logs for support or nearby an opening edge. 

I saw an interesting ad on FB in MI. The seller/producer had white cedar in natural round, hand peeled logs, ~10"dia original, that had a double T&G on them. No price given but would take trailer load to me and ~750-800k down here one way. I don't suppose EWC is any more resistant than ERC in the round? 
Kan=Kansas;tuck=Kentucky;kid=what I'm not

Don P

I'm not understanding how you can have a molded T&G on a hand peeled random width timber ???. No sapwood is decay resistant. That is pretty big for northern white cedar.

The logs in an Appalachian chink style are full length but it is not uncommon to see wood blocks between logs helping to support the logs. Usually when I've run into old clay chinking it has been home to various critters where the old slack lime/ river sand chinking was not a hospitable home for them.

The backer rod here was organic  :D. You can see the remnants of the first clay chinking... Now some folks would call the corn cob the chinking and the clay the daubing, so we nicknamed this one cob and daub. The white crumbles are from the next remodel with lime/sand chinking made with a "hot mix" of unslaked freshly burnt lime, lots of pieces of unslaked course limestone in it. The final rechinking was from the 70's in modern mortar, poorly detailed, it funneled in and trapped water, by '02 there was lots of damage.


 

I think old time oakum for boatbuilding was treated with thinned pine tar for both stickum and preservative. At least on the decks it formed a dam in the cracks, then hot pine tar was poured in each seam.

If you plane to regain bearing now the logs will shrink more as they dry but there will be less overall gapping. One thing most folks don't think about is that shrinkage begins at the fiber saturation point. The entire amount of shrinkage happens between around 28%, the FSP, and whatever the equilibrium moisture content ends up being. And then it is common for folks to think about the FSP as something that happens to the wood all at once, it is a cell by cell thing. The outer shell may be well below FSP while the core is green as a gourd. When the core begins to shrink there is a stress reversal, the core that was in compression goes into tension. Dry wood is about twice as strong as green, so even though there is a stress reversal within the timber the stronger dry shell resists most of that reversal.

kantuckid

Obviously I miss-spoke on the hand peeled cedar being milled as well cause they wouldn't feed into a machine that way. I looked at the picture a bit too fast. :D 
The guy has 12" EWC raw logs and selling 10" & 8" milled logs that he apparently makes himself. The guy shows half round, milled corner notches.
In my own experience red cedar used outdoors is a mixed bag exposure wise. The concrete spring box where we got or home water supply for over 30 years had a ERC heartwood top covered in newsprint alu sheets that stayed perpetually wet and still intact. For the outdoor, exposed deck I built on my timber frame LR addition- I used ERC hand peeled poles as rustic railings and it was rotting away and removed within only a few years. It had the rustic look I was after but simply didn't last even when used as railings.
Corn cobs for backers sounds real inviting to critters. Those old builders just did with what was at hand and had very few mfg type materials other than a sawmill board. An old farm house we rented for 6+ years had a footlocker sized wooden crate in an old chicken house that was full of old bent nails-maybe 75 pounds of them. Makes you love store bought stuff to build with.

Kan=Kansas;tuck=Kentucky;kid=what I'm not

jake pogg

Quote from: Don P on June 22, 2021, 10:39:21 PMIf you plane to regain bearing now the logs will shrink more as they dry but there will be less overall gapping. One thing most folks don't think about is that shrinkage begins at the fiber saturation point. The entire amount of shrinkage happens between around 28%, the FSP, and whatever the equilibrium moisture content ends up being. And then it is common for folks to think about the FSP as something that happens to the wood all at once, it is a cell by cell thing. The outer shell may be well below FSP while the core is green as a gourd. When the core begins to shrink there is a stress reversal, the core that was in compression goes into tension. Dry wood is about twice as strong as green, so even though there is a stress reversal within the timber the stronger dry shell resists most of that reversal.


This is Very important stuff,and put very well,too.I stared at it last night after work trying to internalize it and apply somehow but failed,so far(for "free" time i've only a few minutes at night before tipping over and a few over the first cup of coffee,the rest of my thinking has to be done during the duller phases of carving them logs...).

When i check the weather on internet i often note Ambient humidity,in winter it often ranges from upper 60-ies to lower-/mid -80-ies.

Inside,in a Log,woodstove-heated home...i dunno...Want to say that i've noticed,when visiting friends with that electronic Temp/Humidity?et c. readout thingy on the wall somewhere in mid/upper 30-ies.

I don't own a moisture meter,and with heavy section timbers or logs it's weird anyway...I hear that you can drive a couple of 8d galvies in and put the electrodes to them,but never tried that...

I mostly build sopping green,as in go logging,come back and start building.
That place 8 years ago,8" two-sided used on the Vertical&scribed,shrank enough on the inside to break the Perma-chink in places(across the middle of compound,the bonding held to wood).
On the outside the scribe-lines remain tight.

In regards to planing:I'm about to start doing so.Just finished the 3rd course,and the twist in some timbers will necessitate knocking the top surfaces down.
However,i can't very well conceive even the planing tgo eliminate that outward-sloping deal,i've 150'+ a course,6"+ wide surface area,it seems like an insane amount of work...   
"You can teach a pig anything,it just takes time;but what's time to a pig?"
Mark Twain

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