Thread: Lag Bolt

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Working on a tree house for the grandkids and finally decided I was ready to bolt the first support to the tree - 3/4" lag 6" long. Drilled a 7/16" pilot - do you know how hard it is to drive a 3/4" lag?? Do you know how ticked off a guy gets when he twists the first one off cinching it down to the support??
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Not sure yet if I shift over 22degrees, move up a foot or so, or shift to a different tree. One thing I do know is that the next one will get a bigger pilot hole and some vegetable oil lube!!

i use a 3/8 impact to drive them. think i used a 1/2 in pilot hole.

Roger---simply measure the root diameter of the threads----do not try to put a bolt with a diameter bigger than the pilot hole into a seasoned tree---same goes for depth--also might want to drill the hole to the size of the thread for the first inch or so----

If everything elso fails--drill all the way thru, use a threaded rod with nut and washer on back side of tree

Yeah, after it was 2/3 in and really tightened up I got bull headed and tried to force it. Pulled a portable compressor out and strung air hose to the tree - old 1/2" impact would not budge the *amned thing, which should have been my stopping point but nooooo. The tree's 20" diameter, so drilling through is really not an option. Bigger pilot hole, knowing that the tree is going to grow the hole tighter in a short time anyway.

I was kidding about drilling thru

Originally Posted by jerry clayton

I was kidding about drilling thru

Thought you probably were, but someone else seriously suggested that to me....

liquid hand soap works great for wood

Originally Posted by cffisher

liquid hand soap works great for wood

Won't hurt a live tree?

Originally Posted by rspears

Won't hurt a live tree?

Not if it's anti-bacterial

Mike

I was going to recommend K-Y Jelly, but after yesterday it's liable to be in short supply for awhile.

Originally Posted by Bob Parmenter

I was going to recommend K-Y Jelly, but after yesterday it's liable to be in short supply for awhile.

My solution was to move down on the tree about a foot. Just finished the first one - 1" starter 1/4" deep to eliminate mushrooming at the top throwing the bracket out of square; 3/4" hole 1.5" for the smooth shank, then 5/8" hole 6" deep. Coated the lag with vegetable oil and drove it with a 1/2" ratchet, then cinched it with a 2' breaker bar. Not easy, but it worked! Fitting the second bracket now, to account for minor angle variations, and will have it drilled and in place shortly after lunch.

The root of that lag bolt should be about a half inch. Pilot it to about 5 to 5-1/2 inches with a 7/16 or 1/2 inch bit, then counter bore for the length of the shoulder with an 11/16; then drive the bolt home with a BFH, and give it a twist or two with a wrench to seat the threads. This from an old "Clumsum" who has driven far too many lags into old dead trees (power poles).

Rumbler beat me to it. An old, wiser guy than me, said to drill the pilot hole then drive them in with a hammer to seat. Driving them in makes the tree fibers ''angle in'' around the lag bolt as it drives into the tree & adds extra holding power, sort of like a ring shank nail.

See, there you go thinking like a mechanic. The head of a lag bolt is what you use to take them out! A sledgehammer is how you put them in ok? Ask any old carpentor over a couple pbrs' and he'll patiently explain how all that works.

Originally Posted by ojh

See, there you go thinking like a mechanic. The head of a lag bolt is what you use to take them out! A sledgehammer is how you put them in ok? Ask any old carpentor over a couple pbrs' and he'll patiently explain how all that works.

Reminds me of a story my Dad told about Henry's early assembly line. The story was there were a couple of big Swede's responsible for hanging the doors, held in place with a couple of lag bolts on each hinde, threaded into the white oak framing. As the line increased in speed they found it difficult to keep up until they revised their installation procedure - one held the bolt, while the other drove it into place (no pilot hole here) with one blow from a ten pound sledge. Worked fine, until six months or so when the cars were returned to the dealer to replace the wood so the doors would stay on.....

Not sure it's a true story, but it sounds good....