Installing a boom bail

[Louis]

I am looking to install a bail on my boom and mast for a boom vang. I have a Hunter h23. There are many threads on where to place the bails, but no information on how to actually fasten them. What is the preferred method of attaching it to the boom and mast? Rivets? Screw & bolt sound like they would better, but how does one reach into the boom or mast to attach the bolt? How about tapping a screw thread into the boom and mast? I believe they are made of aluminum - would the metal be strong enough? Advice greatly appreciated!

 

[Ed Schenck]

Attaching a bail.

My Kenyon boom has a couple of bails. They are attached with one long bolt through the boom. The first time you do an uncontrolled jibe anything else will rip out.

 

[Dave Groshong]

I've never had anything rip out, just using machine screws; I drill a pilot hole first.

 

[sailaway78]

Bails

I also have two bails on the boom, and both are through bolted. While a tapped bolt may work, I feel like the through bolted will be much stronger.

 

[Neil McDonald]

Adding any serious load (particularly in tension) to a bolt tapped into a thin aluminum section is just asking for trouble. Heavy loads needs to be transferred to the other side of the boom or mast. If through bolting is not an option, consider some form of strapping around the section to transfer load to the other side. A bail mounted on the opposite face could then effectively stop this strapping from sliding.

 

[Hermit Scott]

What is a bail? I haven't heard about this yet. I am still working on motor and hull stuff, I haven't got to sails and rigging just yet.

But if something is under any load, it is not advisable to thread trough thin aluminium and screw in a bolt. A bolt through is preferable. Rivits should be ok though. I haven't dealt with them much except for cosmetic coverings, but they hold aluminium air planes together. I would trust rivits.

 

[Benny]

Yes by all means use a through bolt with self locking nut and nylon washers on the ends. For a V-Bang the bail is positioned at 1/3 of the length of the boom behind the goose neck. Before drilling ascertain where the lines on the inside may be running through if that is the case.

 

[JBerger]

I agree with using bolts. I installed a triple bail configuration for a traveler. Used 5/16" Stainless steel hardware and bolts. You can get this at www.RigRite.com

 

[sailingdog]

It really depends on the spar wall thickness. Many are not thick enough to really tap for high loads successfully, and must be through-bolted with a compression sleeve between the two sides.

Hermit Scott—

A boom bail is something that looks like this:

 

[Ross]

I would install rivetnuts.

 

[Prime Time]

Install options

I think self tapping sheet metal screws are the last choice.
One could drill and tap for machine screws.
On my Flying Scot boom, (which has a very large main), pop rivets are used for most attachments. Use stainless and not aluminum for strength. These are very easy to use and are quite strong. The different metals should be isolated from each other with something like Tefgel.

 

[Manny]

The boom bails on my 27's boom are through bolted. I cant see a tapped screw holding in that situation, stainless rivets may be okay...

Manny

 

[Ken Prichard]

Have a look at this:

http://www.seoladair.com/rollingbails/index.html

 

[BobM]

It sounds like a personal decision now. For a boat under 25 feet, you may be able to get away with drilling and tapping, or machine screws, but it is probably easier to through bolt and it is stronger...you probably just need a very expensive long stainless bolt. Were it me, I'd probably take it to a machine shop and have them drill the through hole, just to be on the safe side, or at least build a jig to hold the boom in the correct orientation and use a drill press and a nice sharp bit with plenty of lubrication during the drilling.

Mainesail probably has a treatise on drilling aluminum somewhere around here...

 

[sailingdog]

Drilling aluminum isn't all that difficult... Stainless steel on the other hand can be PITA. If you do through-bolt, you really want to have a compression sleeve on the bolt itself, so that the boom can't collapse when you tighten the nut and bolt. A large compression sleeve will also help prevent the bail from tearing the aluminum skin of the boom.

 

[shemandr]

Not that this thread isn't long enough, but I have another question for the group. I am thinking of putting a whisker pole eye http://www.westmarine.com/webapp/wc...t+eye&storeId=10001&catalogId=10001&x=24&y=11
on my mast. Through bolting is probably not an option - at least not until I take the mast down. The area in front of the mast is presumably where wires and halyards run since it is a Selden in mast furling system. I don't want to drill into a wire or halyard. I don't want rough ends of hardware for the wires and/or halyards to abrade on. So ....... that leaves machine bolts of a bit short of the thickness of the mast wall and pole eye hardward combined. Fortunately, the boat is a Hunter with only a 110% jib to pole out and I don't expect large forces on the hardware. Any comments, tricks or advisories?

 

[sailingdog]

Shemandr-

I'd recommend using stainless steel pop rivets, rather than machine bolts.

 

[s sauer]

Resopnse to Shemander:
Typically the 'Eye' has four holes; Locate one and drill thru the aluminum with the drill sized for a Tap for the fastener size that fits the holes in the hardware. Tap that first hole and fasten one round head machine screw - loosly. Mark and drilll the hole at teh opposite diagonal corner and tap the threads. With two fasteners in loosly, mark, drill and tap the remaing two holes. The length of the machine screws should just penetrate the mast thickness plus maybe 1/16". Use a dab of sealant on the threads of each fastener as you do the final install as a dissimilar metals separation between the S.S. fasteners and the aluminum an dto reduce oxidation around the holes.
Self taping screws are faster but more coarse threaded and may leave a sharp pointed fastener on the inside near halyards and wiring. I used a short section of 1" track and 1/4x20 machine screws plus an adjustable car with the eye. Your fixed eye should be located at clew height of the sail you most likely will be using with the whisker pole.

 

[Rick Webb]

A Stout Eye Strap Riveted on is All You Need

That is how the vang and main sheet are attached on my 23.5.

What brand of spar is it?

 

[shemandr]

Re: A Stout Eye Strap Riveted on is All You Need

The mast is Selden.
The ajustability of the track may be worth the extra effort.