Rivets or Machine Screws When Splicing a Mast?

[boatpoker]

Originally Posted by Chotu

Damn. Just bought $40 of locktite. Good save. Thank you.

Gotta find TefGel locally.

I had no idea the guy was going to be doing the machine screws already. He’s really moving right along.

Glad to hear you are making progress

Meanwhile DIRT FREE has been stuck in Great Bridge VA with a blown engine. We were Bahamas bound

It cost us $6k and 6 weeks to get it out and dismantled only to find that Westerbeke does not have the parts we need and won't tell us the OEM so we can get them elsewhere.

We just ordered a new Beta for $18k with a four to six month delivery
(best we could find). So another 6 months of dock fees plus the cost of installation.

On top of that, Canadians are allowed only 6 months in the US and we just applied for an extension at a cost of $1100 for biometrics exams (digital photos, fingerprints, retinal scan). That stuff goes to the FBI and they might let us stay a few months if we come up clean.

So here we sit in VA with nowhere to go. Wanna trade places ?
Still love the cruisin' life

[Chotu]

Originally Posted by boatpoker

Glad to hear you are making progress

Meanwhile DIRT FREE has been stuck in Great Bridge VA with a blown engine. We were Bahamas bound

It cost us $6k and 6 weeks to get it out and dismantled only to find that Westerbeke does not have the parts we need and won't tell us the OEM so we can get them elsewhere.

We just ordered a new Beta for $18k with a four to six month delivery
(best we could find). So another 6 months of dock fees plus the cost of installation.

On top of that, Canadians are allowed only 6 months in the US and we just applied for an extension at a cost of $1100 for biometrics exams (digital photos, fingerprints, retinal scan). That stuff goes to the FBI and they might let us stay a few months if we come up clean.

So here we sit in VA with nowhere to go. Wanna trade places ?
Still love the cruisin' life

Oh boy. That’s pretty rough. Blown engine. Wow.

Hope you are liking the location. It has to be pretty chilly up there. That visa extension is seriously overpriced and quite invasive. Sounds more like a rectal scan. Lol.

Where is that thread about boats being way cheaper to live on than land? Ha ha ha.

Good luck with everything. I hope it goes smoothly.

[boatpoker]

Originally Posted by Chotu

Note: upthread ItDepends says he did this with blue loctite and it was good 10 years later when he removed screws. Thoughts?

I got red locktite of course

My corrosion training says no.

[Chotu]

Originally Posted by boatpoker

My corrosion training says no.

OK. Does TefGel do any thread locking?

I think that’s probably something I would need to make sure the fasteners don’t work loose. Yes?

[s/v Jedi]

Originally Posted by Chotu

Note: upthread ItDepends says he did this with blue loctite and it was good 10 years later when he removed screws. Thoughts?

I got red locktite of course

Keep steady, don’t switch to tef gel. You need a thread locker, tef gel is the opposite.

[thinwater]

Originally Posted by s/v Jedi

Keep steady, don’t switch to tef gel. You need a thread locker, tef gel is the opposite.

^^ This. Tefgel is great stuff, I use it a lot and have tested it against other products as anti-seize. But in fact is one of the best anti-lockers and screws will loosen unless tightened snugly. I've also seen lots of Locktite Blue on spars, furlers, and outboards, and it seemed to work (I could get 30-year old fasteners out with just a little extra effort).


You might read this for an experience.
http://svmatilda.blogspot.com/2016/0...s-duralac.html


"Having just completed several long passages, you can imagine my horror as I needed to keep re-tightening nuts and screws on the rigging during a passage. Then the odd machine screw and bale rained down from different parts of the rigging mid ocean. Yes I would say it was lube crated failure...."

[team karst]

Did 7075 Al fasteners come up in conversation? i read Ti a few pages back, but 7075 is even stronger and might not cause mast corrosion. It does have more Cu in it tho.

[stormalong]

The anti seize to use is Duralac. Unlike Tefgel it does harden up enough to hold screws in. I have had the same problem with Tefgel. I almost lost my gooseneck mast fitting mid ocean. Washed out the Tefgel and replaced with Duralac. Many years ago, no problem since.

[boatpoker]

Originally Posted by Chotu

OK. Does TefGel do any thread locking?

I think that’s probably something I would need to make sure the fasteners don’t work loose. Yes?

No, Tg will not lock threads. I know of no product that does both.

Options - Live with corrosion. - Tighten screws once a year.

[col50]

Originally Posted by s/v Jedi

Welding 6061 is very different from welding 6061-T6.

In fact, you loose 70% of it’s strength, a quick search on Google:

On the positive side, after welding 6061-T6 there is still more then enough strength left to do the job if the joint is designed properly.
As the saying goes, "the proof is in the pudding".

[RaymondR]

The non permanent Loktite is fairly commonly used on the grub screws used in the joining sleeves of furler foils, it appears to be very effective at both keeping the screws in place and preventing their becoming corroded in place.

Duralac is also a good product for preventing corrosion between steel and aluminium, I used it on the aluminium mooring cleats of my previous steel boat and thirty years later there was still no corrosion of either steel or aluminium.

[s/v Jedi]

Originally Posted by col50

On the positive side, after welding 6061-T6 there is still more then enough strength left to do the job if the joint is designed properly.
As the saying goes, "the proof is in the pudding".

Unfortunately not, 70% of strength is lost and an internal sleeve is needed to restore that strength. If regular 6061 was strong enough, they wouldn’t have gone through the effort and expense to temper the mast to T6.

But yes,with internal sleeve, strength can be brought back to that of a continuous mast. The catch is that there are hard spots and a gradual bend at the position of the sleeve isn’t possible anymore.

[col50]

Originally Posted by s/v Jedi

Unfortunately not, 70% of strength is lost and an internal sleeve is needed to restore that strength. If regular 6061 was strong enough, they wouldn’t have gone through the effort and expense to temper the mast to T6.

But yes,with internal sleeve, strength can be brought back to that of a continuous mast. The catch is that there are hard spots and a gradual bend at the position of the sleeve isn’t possible anymore.

And that's why I said "if the joint is designed properly". A properly designed sleeve is part of that joint.

[Chotu]

Originally Posted by RaymondR

The non permanent Loktite is fairly commonly used on the grub screws used in the joining sleeves of furler foils, it appears to be very effective at both keeping the screws in place and preventing their becoming corroded in place.

Duralac is also a good product for preventing corrosion between steel and aluminium, I used it on the aluminium mooring cleats of my previous steel boat and thirty years later there was still no corrosion of either steel or aluminium.

Thank you. I guess I will have to bring my red Loctite back and get some blue.

[Chotu]

These machine screws were blisteringly expensive. Wow. $700. For screws.