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Medium thread locker for lag bolts

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bluedog225

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Is there a good way to keep a lag bolt from backing out or getting loose?

I’m bolting a right angle piece of steel to a double LVL. I can’t through bolt due to the Simpson bracket on the other side. Or I’d have to drill a hole of the Simpson bracket which might not be the end of the world, but seems unwise.

I don’t want to use epoxy. Seasonal expansion and contraction of the wood might lead to the need to snug them up. Similarly, I don’t want to use PL premium.

I was thinking a few drops of some reputable wood glue like tite bond would keep it in place while allowing for tighten in the future. I’ve also considered just throwing some sand in the hole.

Or is a tight pilot hole all I need to have in order to keep it in place?

Any ideas? Thanks
 
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wssix99

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The friction of the threads against the wood keeps it from coming loose.

Just put the lag bolt in until it hits the plate on the other side. Then unscrew the bolt and then cut it to the precise length needed to extend fully through the LVL. Once you have started the bolt, you no longer need the tip when you screw it back in.
 
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bluedog225

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wssix99 said:
The friction of the threads against the wood keeps it from coming loose.

Just put the lag bolt in until it hits the plate on the other side. Then unscrew the bolt and then cut it to the precise length needed to extend fully through the LVL. Once you have started the bolt, you no longer need the tip when you screw it back in.
Click to expand...

That‘s a reasonable idea. Though I’ve sized the lag bolts to avoid exiting the other side or hitting the Simpson bracket.
 
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strength_and_power

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How much weight will this angle iron be supporting? Can the Simpson hanger be removed? Could you remove the bracket, through drill your hole then using a paddle bit, enlarge the hole behind the Simpson and use a washer and a Nylock or cone nut then reinstall the Simpson?
 
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bluedog225

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strength_and_power said:
How much weight will this angle iron be supporting? Can the Simpson hanger be removed? Could you remove the bracket, through drill your hole then using a paddle bit, enlarge the hole behind the Simpson and use a washer and a Nylock or cone nut then reinstall the Simpson?
Click to expand...

That hadn’t occurred to me. There’s plenty of wood. Good idea. Thanks

It’s for a tie down. Hard to say what the uplift would be in a wind event. Though a through bolt is always my go to. Never liked lag bolts for structural stuff.
 
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Codyboy

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Ive never seen a lag bolt get loose in its hole.

However the steel your lag bolting could become loose due to the beam shrinking which could leave a minimal gap . But the lag is not loose.
No amount of glue or thread locker will prevent shrinkage.
If this is indoors and climate controlled it may shrink a little more as it will draw out more moisture in the wood.
To acclimate it if inside may take a very long time , months(?) Idk.

The steel brackets on my garage door rails are lag bolted to the framing and in 20 years have never become loose.

I think its a nothing burger. But if you must , use a split washer or even a pigtail spring washer.

ETA. Even through bolted will not change the characteristics of wood. It will shrink.
 
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bluedog225

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My garage door lags have worked loose. I tightened them up with a wood insert into the old hole. No issues since.

I think it’s a combination of letting them age in place, using an appropriate pilot hole, and proper tension. If they develop any play, for whatever reason, it just gets worse.
 
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PWC Repair

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If you've EVER had any knockdown particle board furniture, like a computer desk, you know screw threads CAN become loose in wood. Generally only by a lot of movement. My go-to is plain jane wood glue on the threads. Works like a champ.
 
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duneslider

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I have some big old lags holding brackets on the front of my house and none of them have loosened even a little. Make sure you use the correct size pilot hole for the lag you are using, if the lag has a shank it will require a pilot for the threaded section and a pilot for the shank. I believe with LVL you use the pilot hole spec'd for "hardwood" but you might want to verify that. My engineer called out the lags for me and what holes I should be drilling. Properly done and it shouldn't loosen up. I have put wood glue and slices of wood into buggered up wood holes before and that has worked well.
 
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duneslider

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65ranchero said:
What about a correct sized grk rss structural screws?
Click to expand...
I think the biggest structural wood screw I have seen is 3/8". If you need something bigger than that the only option is a lag. I think the ones I used to support my porch were 3/4" diameter lags, no simpson or GRK's that big. The lags that size were a pain though, in my case if I were to do it again I would have through-bolted. Bolting it would have been faster and easier.
 
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manwithtools

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duneslider said:
I think the biggest structural wood screw I have seen is 3/8". If you need something bigger than that the only option is a lag. I think the ones I used to support my porch were 3/4" diameter lags, no simpson or GRK's that big. The lags that size were a pain though, in my case if I were to do it again I would have through-bolted. Bolting it would have been faster and easier.
Click to expand...
GRK Rugged Structural Screws or FastenMaster LedgerLok screws installed in the recommended pattern and quantity can replace up to 1/2" diameter lag screws. In my experience they are far superior to lag screws in holding power and ease of installation.

This thread cracks me up; threadlocker in a wood fastener application :)
 
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