Broken lag bolt removal?

[sledge]

Not much left above the stringer. Tried a drill out but broke the drill bit. I'm thinking a hole saw is the only thing left but open to ideas.

 

[Ratickle]

Need a little more info and a pic maybe? Where is it, how deep, etc.

 

[sledge]

It was an engine mount lag bolt. Probably 2.5-3" long. What else can I tell you? There's not much to take a picture of. It looks like.....a bolt with the head broken off.

 

[boatman574]

Did you Try a Left Hand Drill Bit??? Bolt Extractor??

 

[DAREDEVIL]

Engine mount lag bolt ??????? mhhh never seen that,,the ones i used and always seen are trubolted.
If its smaller then 1/2 inch,,,take a 1/2 inch drillbit and drill it completeley tru and later stick a tru bolt in there with a washer and locknut !!!!
Don't use a cheap bit.

 

[Griff]

You should be able to drill into it and use an "easy out"
I've never had a broken bolt that couldn't be drilled and come out that way as long as you have good access to it.

 

[Trim'd Up]

Engine mount lag bolt ??????? mhhh never seen that,,the ones i used and always seen are trubolted.
If its smaller then 1/2 inch,,,take a 1/2 inch drillbit and drill it completeley tru and later stick a tru bolt in there with a washer and locknut !!!!
Don't use a cheap bit.

There are quite a few boats that lag the engine mounts. They are lagged through the top of the stringer so you can't through bolt them without new mounts. My baja used to be like that.

An easy out should work just fine but your gonna have to drill into the bolt. They aren't usually hardened bolt so it should drill pretty easy.

 

[imco offshore]

leave the bolt alone, if the head is off , remove the mount modify it either lengthen it or shorten it , so a new hole can be drilled about a half inch away.obviously the stringer is sound, if you broke the head off. or use differant mounts like dd said and thru bolt them, good luck

 

[sledge]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?

 

[Ratickle]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?

My thought is, I wouldn't. Unless you modify the mount as George said, you'll want to go directly back in the same location. Stainless is a b-t-h to drill......:ack2:

 

[Knot 4 Me]

No thru bolt mounts, and highly unlikely that a factory Volvo engine mount will get modified for relocation.

It's a stainless bolt and it's not giving up easily. My buddy tried a bolt extractor but broke the bit inside the bolt.

No thoughts on using a hole saw to extract and then dowel/resin/glass the hole?

Do you have enough surface area to just rotate the mount one direction or the other and just drill a new hole to lag into? The mounts can be installed crooked as long as the verticle stud remains in roughly the same location. Mine from the factory were mounted as crooked as a dog's hind leg on the stringer block.

 

[imco offshore]

Do you have enough surface area to just rotate the mount one direction or the other and just drill a new hole to lag into? The mounts can be installed crooked as long as the verticle stud remains in roughly the same location. Mine from the factory were mounted as crooked as a dog's hind leg on the stringer block.

that was my thinking also. i haven,t seen a mount that couldn.t be swivelled to drill a new hole,

 

[Audiofn]

I would try and weld a bolt to it and then twist it out.

 

[PayCheck]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

 

[Chris]

Hole saw is a bad idea. Previous post is a good one- saddle mounts.

 

[sledge]

Thanks guys. FWIW, this is for a buddy's cruiser. Twisting the mount is IMHO the best/easiest, but dude's a little retentive so we'll see. Doesn't help that the whole reason we pulled the lag bolts was because the mount nuts would not budge. Yet he things everything will just drop back in without having to adjust them....you can only lead a horse so far...

Paycheck, nice drawings! But the friggin' stringers on this pig are 8 inches wide. Just too much material and effort.

The weld thing works easy when it's a steel bolt...in a nice safe non-flammable area. Even if it was worth trying to get a TIG in there, not sure I'd want to weld on a bolt in wood and fiberglass? Plus, it's stainless with a steel core (see broken drill bit above) .

 

[Buoy]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

That's exactly what I did on my Baja.

 

[DAREDEVIL]

Thanks guys. FWIW, this is for a buddy's cruiser. Twisting the mount is IMHO the best/easiest, but dude's a little retentive so we'll see. Doesn't help that the whole reason we pulled the lag bolts was because the mount nuts would not budge. Yet he things everything will just drop back in without having to adjust them....you can only lead a horse so far...

Paycheck, nice drawings! But the friggin' stringers on this pig are 8 inches wide. Just too much material and effort.

The weld thing works easy when it's a steel bolt...in a nice safe non-flammable area. Even if it was worth trying to get a TIG in there, not sure I'd want to weld on a bolt in wood and fiberglass? Plus, it's stainless with a steel core (see broken drill bit above) .

OK,,,,,NOOOOOOWWW,,,wait a minute here and back up.......DO U REALLY WANT TO GET IT OUT ,,OR ARE U JUST TRYING TO FIND EXCUSES WHY U DON'T GET IT OUT ??????

:rofl::sifone::icon_bs:

 

[Griff]

With an 8" wide stringer, rotate the mount and be done with it. That or tell your buddy to fix it himself or pay somebody.

 

[old377guy]

Cut the thing off flush with the stringer and put an L bracket in there:sifone:

my 302 Formula had those cheesy lag bolted mounts. I had L-brackets made similar to what paycheck indicated; really the only way to go short of true offshore mounts. good luck