Boom Bolt?

[BigDogg11]

Rookie Question. What is this bolt called that attaches the boom to the Mainsheet? Mine seems loose so I tried to tighten in but it doesn't tighten just continuously spins. I wanted to research up on this a bit, but having a hard time figuring out what this part is called to do some research.

 

[Tally Ho]

My boom isnt attached like that, but I believe you probably need to remove the end cap (drill out the rivers), tighten the nut on the backside of that bolt (boom bolt is as good of name as any ) And the reinstall the end cap. You could thread the jokes in the boom and use screws to attach it in case you need to get back in there...

Greg

 

[heritage]

Is the bolt actually loose or are you just not able to seat it tightly to the boom cap? The bolt is designed so that it should never be tightened all the way... that would resist your main sheet from moving laterally.

 

[JoeWhite]

I believe it is supposed to be loose do that it can swing when the boom goes port or starboard.

 

[twalker H260]

How loose? It looks like the metal strap there connects down to the main sheet? If so you likely don’t want the bolt “tight” as it would prevent the strap swinging as the boom goes from side to side. If the strap was to bind it would likely lead to failure of the strap.

 

[jssailem]

@BigDogg11 I have a Cal so not exactly the same but here is what I suspect. The bolt is an inexpensive method of securely attaching the sheet to the boom. I have 2 screws where you have rivets. The rivets hold the boom cap in place. The strap pivots on the bolt. I think you will find, if you drill out the rivets and pull the cap that there are 2 nuts on the bolt internally. These lock up and stop the bolt from coming out of the boom cap.

The strap is not tight/fixed so that the sheet block can move and orient to the boom in any location.

In the image it looks like the strap has received a little damage. If you want to replace start by removing the end cap from the boom. You may find the bolt and nuts are bent or frozen. You may need to replace them as well. Just get a new bolt of the right length. Be sure the strap can rotate as the boom moves through the arc letting out the sheet. You’ll be good. Locktite 2 nuts on the inside of the cap. Thread the holes where you removed the rivets. Install a couple of SS screws using some lanacote or other lubricant/anti corrosion goo. Your back in business.

 

[Ron20324]

Is the bolt actually loose or are you just not able to seat it tightly to the boom cap? The bolt is designed so that it should never be tightened all the way... that would resist your main sheet from moving laterally.

... Inside the cap, the bolt to nut may be welded and/or hammered so it will not unscrew.

 

[justsomeguy]

What is this bolt called that attaches the boom to the Mainsheet?

It's called a strap bolt.

 

[Joe]

My Catalina 27 uses the same method of attachment. You want the bolt to rotate to allow the metal tang to swing when the boom moves side to side. If you pull the cap you'll see how it is fixed. I made the mistake of trying to tighten the bolt.... and it eventually released! Pretty hectic for a few minutes but using the vang saved the day.

When I pulled it off to repair, I drilled a hole in the end of the new bolt to accommodate a cotter pin, and used a nyloc nut for extra security. A double nyloc nut with a washer would work well, too. In addition.... I wrapped a nylon webbing strap (a sail tie, actually) externally around the boom and through the mainsheet's shackle. I saw this done on number of racing boats. Anyway it's held for at least 20 years now.. I'm happy... Just thinking about the subtle swinging the boom makes when docked or at anchor, besides when you sail, justifies the movement allowance. The reason your tang is twisted is because the bolt isn't allowing this free movement.

Finally,,, you could consider converting to some kind of bale through the boom end, as I did, for like 10 seconds, but then realized the nylon strap was the simple and best answer. It's easy to inspect and replace too.

Oh.... I forgot to mention this. If you are able to remove those stainless rivets without damaging the boom... which will be a challenge, for sure... use short self tapping machine screws with locktite for replacement. It is important to not damage the aluminum end casting... Good luck. Don't forget the STRAP

 

[justsomeguy]

Okay, tang bolt.

 

[BigDogg11]

@BigDogg11 I have a Cal so not exactly the same but here is what I suspect. The bolt is an inexpensive method of securely attaching the sheet to the boom. I have 2 screws where you have rivets. The rivets hold the boom cap in place. The strap pivots on the bolt. I think you will find, if you drill out the rivets and pull the cap that there are 2 nuts on the bolt internally. These lock up and stop the bolt from coming out of the boom cap.

The strap is not tight/fixed so that the sheet block can move and orient to the boom in any location.

In the image it looks like the strap has received a little damage. If you want to replace start by removing the end cap from the boom. You may find the bolt and nuts are bent or frozen. You may need to replace them as well. Just get a new bolt of the right length. Be sure the strap can rotate as the boom moves through the arc letting out the sheet. You’ll be good. Locktite 2 nuts on the inside of the cap. Thread the holes where you removed the rivets. Install a couple of SS screws using some lanacote or other lubricant/anti corrosion goo. Your back in business.

Thank you all, very helpful responses.
@jssailem you got it exactly. This all came up when I noticed the strap was damaged/bent, and wanted to remove the bolt and replace, but realized the bolt couldn't be loosened to get to strap. As many people mentioned, this seems to be a bit more of a project then I had originally anticipated.

 

[jssailem]

this seems to be a bit more of a project then I had originally anticipated.

Do not fret. You can do this. It is straight forward. Take it one step at a time. Some might suggest it is easier if you remove the boom from the boat and lay it across some saw horses or a table to get it at a stable good working height.

1. Remove the main sheet and blocks
2. Drill out the rivets
3. Grab the boom cap and pull it out. You likely will need to wiggle the cap out. It should be a snug fit. With the rivets removed only friction is holding it in place
4. Remove and replace the bolt
5. Put the pieces back together
6. Tap the holes where the rivets were removed
7. Install screws in place of rivets

Untie the lines and go sailing.

Take pictures along the way so you can put things back the way they were came apart.

If in doubt ask questions here or of local boater in your area.

My friend comes down to the dock and sees me sitting contemplating the boat with a drill in my hand. Comes up behind me and say “The hole won’t magically appear. Just drill it already. “

So far nothing bad has happened.

 

[Ron20324]

Can't you just bend the strap in place? It does not look damaged.

 

[Project_Mayhem]

Depending on the age of the bolt, it may have some significant wear and could be due for replacement. Only real way is to remove it for inspection/replacement. If it's newer, I would bend the tang back as @Ron20324 mentioned.

 

[Ward H]

While the strap may be bent a little it won't affect its function.
As others have said, it's meant to be loose and you'll need to remove the cap to inspect the nut inside.
My C30 has the same bolt and strap and it is bent to align it self with the topping lift attached to it.

 

[Ron20324]

IIRC, it was my Oday 222 or my B235 I put two such tangs under that bolt head. One for the topping lift, and one for the main sheet.