How to properly attach fittings to mast?

[AZ-Oldguy]

I want to attach two cheek blocks and two cleats to my mast (35 ft Endurance) for a lazyjacks system.

I could pop rivet, but I read that screws into threaded holes is the proper way to go.

• do I need a tool to thread holes in my mast, or can I use self taping stainless screws? I would assume that if I use self tapping, I would run them in, remove and coat, and then reinstall screws with hardware.
• What do I use to protect against galvanic corrosion? both for the screws and also the back of the cheek block?

[HappyMdRSailor]

There was a very fun and helpful thread adressing this very issue...

The vast majority would never use self tapping screws for attaching mast hardware... drill and tap, or rivet... definitely coat the fasteners...

And...in case nobody else mentions it... remember there is a LOT of stuff inside your mast that you DO NOT want to drill/tap/screw into !


http://www.cruisersforum.com/forums/...or-156150.html

[AZ-Oldguy]

So what do I coat with? Does Blue locktite work to isolate? or get something else?
and, am I attaching the blocks and cleats with Machine screws (little threaded bolts) ?

I can buy the right size bolt and then go to the hardware store for a correct size drill bit, tap and oil.

Glenn

[HappyMdRSailor]

Originally Posted by AZ-Oldguy

So what do I coat with? Does Blue locktite work to isolate? or get something else?
and, am I attaching the blocks and cleats with Machine screws (little threaded bolts) ?

I can buy the right size bolt and then go to the hardware store for a correct size drill bit, tap and oil.

Glenn

FORESPAR Lanocote Corrosion Inhibitor | West Marine

I personally wouldn't use loctite, but others do...

Yes... threaded bolts... drill bit and tap... These make it easy...
Greenlee DTAP10-32 Combination Drill and Tap Bit, 10-32NF - Countersink Bits - Amazon.com

No reason not to use rivets either with this "low load" lazyjack system...

[Cheechako]

Drill and tap. Use coarse thread in aluminum. Coat liberally with lanocote, lanolin or one of the purpose formulated goos. Nothing wrong with good pop rivets. Spar makers usually use SS ones if they use a rivet.

[HappyMdRSailor]

Originally Posted by Cheechako

Drill and tap. Use coarse thread in aluminum. Coat liberally with lanocote, lanolin or one of the purpose formulated goos. Nothing wrong with good pop rivets. Spar makers usually use SS ones if they use a rivet.

Greenlee DTAP10-24 Combination Drill and Tap Bit, 10-24NC - Countersink Bits - Amazon.com

[gjordan]

Buy, or make some kind of a DRILL STOP. You wont find those at your average Harbor Freight, but limiting the depth that the bit can go can save you much grief later. The tendency for a drill bit is to surge when it breaks through, and as mentioned before, that can damage wiring, or halyards. You dont want to be asking yourself at some later date WHY DONT MY SPREADER LIGHTS WORK??? Good Luck _____Grant.

[Clivevon]

If you use rivets, make sure they are made of Monel metal.

[Nanamuk]

I use NC machine screws - hex head if possible- hand tape - coat with Tef-Jel or other isolating product - put a thin isolation pad such as nylon sheet under the fitting if it is stainless (not needed under the cleats if they are nylon or aluminum).

Is your Endurance one of De Kleer Bros?

[Cheechako]

Originally Posted by Clivevon

If you use rivets, make sure they are made of Monel metal.

[ausnp84]

+1 for drilling and tapping. That's how I fit all my mast hardware (steps, winch pads, cleats, clutches, etc etc).

Drill the hole, run the tap through it (I use a hand tap, rather than one for the drill as I find it gives me better control), test fit the stainless machine screw / bolt, back it out, coat any stainless surface with anti-corrosive paste (Dura-lac is my poison of choice), refit equipment with machine screw / bolt, wipe up any mess you've made... done!

n

[Terra Nova]

Drill & tap. Use Tef-Gel.

[Wulf]

Originally Posted by Clivevon

If you use rivets, make sure they are made of Monel metal.

+1

[thudbranch]

Pop rivets are great if they are (1)The right length for the total material thickness, (2) the hole size is correct for rivet used, and (3) the same kind of metal as what they go thru. The bolts are harder to drill out if they ever do break off. I always tap over the back side of the block or hardware using one or two layers of wide electrical tape as an electrical isolator between dissembler metals. "Lanocote" or other isolation for the threads on threaded fasteners is also a requirement. As for the drill stop previously mentioned; I find a very tightly applied winding of ordinary electrical tape applied to a CLEAN drill bit works great for a few holes. And the drill stop is a very good idea.

[pcmm]

Strongest fitting will be drilled and tapped. but remember the strength of a threaded joint comes from the number of threads to spread the load with. you want FINE thread taps for aluminum and don't over torque or you'll just strip the threads. use tef-gel to inhibit corrosion and a thin pad between the SS and Alu. roll up cutting boards from the dollar store work well here and are inexpensive.