Attaching jammer to mast

[Akapeterc]

I want to attach a jammer to my mast to run my topping lift thru to make it a simple task to tighten it when letting the main out while sailing. Is it safe to drill 2 holes in the mast then tap a thread in them and bolt the jammer on? Two small holes won’t effect the strength of the mast will they? I need to tighten the topping lift as it tends to swing around when it is loose and in the past has broken my HF aerial. The mast is for inmast furling so the forward section is clear of sail.

[roverhi]

No problem drilling and tapping, If possible try not to drill in same level as other fasteners but not really a big deal if you can't avoid it if there is separation of a few inches between the fasteners.

If your mast has internal halyards it will have significant holes cut into to exit the lines. A few small holes are a fly speck.

[B310Racer]

Should not be a problem so long as you have nothing inside the mast to be damaged by the drilling or any excess thread sticking out inside the mast (recommend bolts only long enough to go through the material with a thread or two excess). FWIW, our topping lift line runs down the mast (inside) exits at the bottom and is run to our bank of cleats (halyards, etc) at the front of the cockpit so it can be adjusted from there as needed. Would think having to go forward to monkey with it at the mast would be inconvenient.

[BSMS]

A few small holes will not effect the masts entegreaty, But make sure you coat the stainless steel screws with something like loctight or neverseeze so the stainless is isolated from the aluminum or else you will creat a galvanic cell

[Chris777]

I would suggest pop-rivets. My Selden mast on a HR 36 has all the hardware attached with pop-rivits. I just did attatch a jammer on my mast and pop-rivits or self taping aluminum srcews is just fine. I did put a thin nylon washer between the jammer and the mast.

[Qayaq]

I single hand and everything is led back to the cockpit, so for halyards and topping lift I have fitted cam cleats/jammers taped and bolted to the mast above the deck turning blocks, so for instance I can pull up the stay sail and lock it off in the jammer, go to the cockpit and as soon as I pull on the halyard it pops out of the jammer and I can winch it up tight.

[stormalong]

If you have in mast furling do you also have a rigid boom vang? Could you eliminate the topping lift altogether?

My 44 footer has a hydraulic vang and no topping lift. A lot easier on the leach of the sail and no adjustment issues. On earlier boats I have sailed we used to disconnect the boom topping lift and secure it out of the way. Every once in a while we would forget to re-attach it and drop the boom along with the sail. Rigid vangs are so much nicer.

[roverhi]

Self tapping screws in aluminum are a recipe for failure. Have had anumber of P.O. installed self tapping screws strip out. The threads are two course so only one two are biting into aluminum. Drill and tap course threads if you want the fitting to stay in place.

Bet the spar builders use pop rivets mainly because they for are faster to install. Really nice to have Popeye forearms for installing them if you don’t have a pneumatic pop rivet tool.

[thunderhoof]

If you have or can find the installation tool, rivet nuts installed in the mast will give stronger mounting and will allow repair or replacement of the jammer. If you use aluminum rivet nuts and then SS machine screws with anti-seize you should have no long-term corrosion issue.