Carriage bolt turns (I can't tighten it)

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Adamv
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Location: Owen Sound, ON Canada

Carriage bolt turns (I can't tighten it)

Post by Adamv »

I feel a bit silly about asking this, but I ran into a bit of a problem. When I try to tighten the nut on the brass carriage bolt that my seat hangs from, the darned bolt turns. Any tips on how to make sure it doesn't turn while I try to tighten the nut? The head is countersunk a smidge in the mahogany gunnel, so I can't grip it with pliers.

The only thing I can think of it epoxying the bolt in the hole, but I really don't want to go that route.

http://www.avoisin.com/album/canoe/slid ... 20339.html

Cheers,
Adam
Who travels not by water knows not the fear of God --- 17th Century Sailor
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Glen Smith
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Post by Glen Smith »

If it is possible, I would remove the carriage bolt and check the threads for damage. Repair or replace and make sure you can thread the nut on the bolt with just your fingers before installing the bolt. If you are using a locking nut, these are sometimes quite hard to install and require a lot of torque which could cause the bolt to slip in the hole. If this is your situation, I would switch to using a flat washer, lockwasher and non-locking hex nut.
sedges
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make the hole new

Post by sedges »

carriage bolts resist turning by having a square step under the head that presses into the wood the first time you tighten it. The top of the hole should now be square. If that square hole gets rounded, as they often do, the bolt will spin making impossible to tighten the nut. This often happens when gunwales start to get soft and rot, but yousr look to be in very nice condition.

If this is the case. Remove the bolt, fill the hole with epoxy resin, let it harden and cure and drill a new hole.
Rehd Brown
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Post by Rehd Brown »

Adam

I partially agree with sedges. I would pull the bolt, thicken some epoxy or just wait until a batch starts to gel, then put it in the hole with the bolt partially inserted. You don't necessarily need the epoxy down in the entire hole, just at the top where the square part of the shank has turned in the wood. With the partially cured epoxy around the bolt, pull the bolt the rest of the way into it's place and allow a few minutes for the epoxy to continue to cure. Set some aside to time it... When it's fairly firm and holds it's shape, then work the bolt out and let it harden. That way you get your square hole at the top to hold the bolt when installed later.

A few things you can do to help would be to enlarge the top part of the hole to allow more epoxy build up.. and possibly wax to the bolt to aid in removal from the partially cured epoxy. Also, if your bolts are threaded all the way to the squared off top, then you should put some tape around the threads where it may be in the epoxy. If the epoxy gets into the threads and starts setting up down in the hole, you will have to turn the bolt out, and again, damage the square hole at the top. You need to be able to slide it straight up through the hole.

Hope that makes sense..?


Rehd
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Adamv
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Post by Adamv »

Thanks for the tips guys

Looks like I'm probably going to go with the epoxy in the hole technique to secure the square just below the head of the carriage bolt. One question about this. My gunwales have been well oiled. Will the epoxy be able to adhere to the wood, or will the oil interfere prevent it?

Thanks,
Adam
Who travels not by water knows not the fear of God --- 17th Century Sailor
Rehd Brown
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Post by Rehd Brown »

Yes.. the oil is going to be a problem. Could be the reason the bolt spun in the hole in the first place..
As I mentioned, you can take a slightly larger drill bit and drill down just a tad to clean the oily wood out where you need the epoxy to stick. Keep it smaller than the head of the bolt, and go just deep enough to get epoxy around the entire square portion of the bolt shank.


Rehd
Oshan OkaPini
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Carriage bolt problem

Post by Oshan OkaPini »

Try this, it might work.

Tighten the nut on the carriage bolt until the bolt moves. If there there is still enough thread showing, carefully grip the end of the threads with a pair of vicegrips so that the teeth in the vicegrips are somewhat parallel with the threads. Holding the bolt this way, tighten the nut as tight as you need.

If you need to remove the hardware in the future, the nut should repair the threads as you back it off.

I would use new hardware each time you have to remove it.
Right now, there is no cure.
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ealger
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Spinning bolt

Post by ealger »

If the bolt extends below the nut perhaps 1/4", file 2 flats on the end of the bolt bolt to accept a wrench (cresent type would work).
Ed...
Ed Alger
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Adamv
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Post by Adamv »

Thanks again all. I just gave the situation a more thorough examination, and discovered that the nut must have striped the bolt when I put it on (or else it seized somehow), because I can't even get it off, and the end of the bolt is flush with the nut. Thus, I can't grab the end of the bolt with pliers or a wrench. Bottom line is I'm unable to get the nut off, and have no bolt to work with.

Maybe I'll just have to cut the bolt through the middle, but I'll also have to cut the seat hanger, which I'm not too excited about doing.

Cheers,
Adam
Who travels not by water knows not the fear of God --- 17th Century Sailor
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Glen Smith
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Post by Glen Smith »

If you know an auto mechanic, perhaps you could borrow a nut cracker. This tool will split a nut without even damaging the bolt threads. If you do a Google search for "nut cracker tool" you will see that there are a couple of designs and they sell in the 20$ to 30$ range.

I am not sure though if you have enough access to the nut to get the tool in proper position. :rolling eyes
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Bud
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Post by Bud »

Adam,
You could try cutting a wood spacer that fits over the bolt head and sticks up just above the surface of the gunnel. Then clamp a length of wood over the top of the spacer so it puts enough downward pressure on the bolt so that it won't turn. Hope this works for you.

Bud
Last edited by Bud on Fri Feb 29, 2008 9:44 pm, edited 1 time in total.
"Canoes don't tip. People just fall out of them!" Omer Stringer
Rehd Brown
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Post by Rehd Brown »

Adam

Before you start cutting things... Carriage bolts aren't usually case hardened, so you could punch the top center and drill down through the head with a bit the size of the bolt shank, and when the head comes off, just drop the bolt out the bottom.
No damage to the boat that way. Just need a replacement bolt.


Rehd
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Adamv
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Post by Adamv »

Just to follow up, I figured out an easy solution. I used a cut-off wheel on my Dremel tool to cut a slot in the head of the carriage bolt. Then I could use a slot head screw driver to hold the bolt while I loosened the nut and then while I put on a new one on. I was able to do this in about ten minutes, and even saved the bolt (I can live with the slot in the head as it doesn't look that bad)!

Maybe next time I make up a batch of epoxy I'll put a bit in the bolt hole as per Rehd's solution. But for time being, all is good.

Thanks everybody.

Cheers,
Adam
Who travels not by water knows not the fear of God --- 17th Century Sailor
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