! Log house building...need help selecting proper auger / drill bit + insulation between logs

Hi folks!

Youtuber from sweden? I believe, named Project highlander - https://www.youtube.com/watch?v=ybMZq_gAYZo - has a nice set of videos how to build a log cabin using likely one of the simplest of methods. I will be replicating it, but for a 20' x 16' size.

I need to figuer out two things:

- he uses a common method of drilling through two horizontal logs and then hammering in a dovel of sorts. I wonder...what type of drill bit I need to get? Meaning what should - is it called flute? - the drill bit needs to have. if it is about 1 1/2 or 1 3/4 in diameter and about 16" long?
I want to get the right one so I don't get something used in typical house building to make holes for wires in studs...and then this bit will be getting stuck due to bad design and too much friction...

- There is a type of insulation that folks lay between each log...it looks like felt, but I am unsure. I am on an extreme budget, being on disability and my house burned down, so I have to be creative. If I have to buy something I will...but often I find people are creative and they know an industry where such and such is a waste or is sold cheaper than walking to home depot for a specific item...

I can do research no problem...but I am asking for the community for some guidance what to look for.

Thanks a miilion!

Hary,

When we were erecting heavy timber roof structure for my house, we have been using WoodOwl Tri-Cut bits. They are triple fluted and drill aggressively. If used on thin lumber they would destroy the material, but on anything with at least 15x15 cm (6x6") they drilled swiftly and smoothly. I have used corded Metabo drill and Kanzawa drill guide.

Hary -

Chris Schwarz also likes the Wood Owl recommendation from Cristobal for general timber construction.

In his "Log Construction Manual", Robert Chambers recommends augers from Northwest Manufacturing.  However, the proprietor has passed away, so you would be limited to existing stock from retailers.  Chambers also recommends carbide tipped augers from B&A:
https://www.bamanufacturing.com/page_ii.htm
Chambers uses (used? - I guess he's mostly retired, now) all-thread though his walls from top to bottom to anchor the plate to the sill.  He also recommended auger flutes 24" long, but seems to have mostly built using large diameter Douglas fir logs.  Smaller logs mightn't need such a long auger flute.

I do have a pawn shop Milwaukee 1/2" Hole Hawg (the reversible right angle model with the mechanical two-speed transmission).  Plenty beefy enough to spin the auger - and through you off a swing stage!  But, no power auger bits, as yet.

If augering the holes manually, Scotch eye augers seem to be favored.  Eric Grankvist used a Scotch eye auger to peg his now-YouTube-famous cabin together.  As Josh from the Mr. Chickadee YT channel explained it to me, Scotch eyes come into their own at anything bigger than 1-1/2" diameter, but he typically uses a wimble brace for anything smaller (which would require a separate auger bit, maybe one of the above), at least when "in the field" - though he does use boring machines, too.  On Josh's recommendation, I acquired and used a Fray pattern wimble brace to poke a bazillion (OK, maybe 100!) holes in construction lumber this past fall, for screw access.  You get the hang of it, after a while.

So, I only have old Irwin bits, and a couple of raggedy Scotch eyes, but have used none of them to make deep holes, such as for pegging cabin logs together.

Either way, an auger file to keep them sharp will be helpful.  Or, possibly a diamond file, for a carbide tipped model.  Not sure what's available in that regard.

I'll let others chime in on the seal between logs, in a modern context.  Historical solutions would have included moss, wool (old socks, etc.) and oakum (tarred hemp).

Probably not much help, but it's what I've got.

These still exist, but are hard to find. This is a centerless ship auger. They drill as fast as you do, don't clog, like more modern bits, which seem to be wound too tightly to clear reliably in wet wood, or maybe because electric drills (operators) spin them too fast, dunno.
These were sold bare, the owner supplied his own handle. Dieter Schmid out of Germany, sells the modern version, but I believe they are like most current augers which typically have a spur and single cutting edge. Not nearly as easy to sharpen. This one rocks. Those multi-edged WoodOwls look pretty nice.
Fiberglass insulation is used to chink machined or tight fitting logs.

Early 70's, my dad bought a cabin on the south edge of the BobMarshall Wilderness, right on Arsenic Creek. The original part of the cabin was built in the 40's. The logs were very well fitted, and chinked with brick mortar. When I don't know. Obviously, after it had settled a bit. The logs and the mortar were oiled, with something called Val-Oil. Left a finish like heavy linseed oil.
My dad looked in vain trying to find the product, the empty 5gal cans were still around, but Chevron? had stopped making it sometime in the 60's.
We built a little dam up the creek about a 1/4mi., we stuck a pipe in to pressurize the cabin. Propane Servel fridge and lights, really sweet  wood/propane split two oven stove with a thermosiphon water coil for a hot water tank in the bathroom.
This was the place.

I have some vintage auger bits with the crossbar loops and they work, but something powered would be so much easier Irwin #3043016 and a Bosch #nklt24 might be what you are looking for.

Thank you everyone for your thoughtful answers. I am going through the various posts and links and advice.

I realized I failed to say that I am looking for a bit to go in my dewalt cordless drill. I am alone building and don't object to a blend of traditional techniques and modern tools. Too many holes to drill.

I know how drilling such deep holes can get the bit stuck and it can break your wrist...that is why I use only high end cordless tools, not the weekend warrior type they sell in Home Depot :). I have the drill with 16" or so side handle to precisely prevent wrist breaking.

Still I realize the bit is important to get the right one and your answers pointed me in the right direction - thank you!

Still need to figure out however the insulation between logs...

Cheers beautiful people!