Rivets or Machine Screws When Splicing a Mast?

[stormalong]

Originally Posted by Chotu

I remember that line of discussion. What I don’t understand is why everyone has a different opinion. This sucks.

The easiest thing would be to weld it. I have a welder working on it.

The majority here say that machine screws are better.

Second place minority says that rivets are better.

What the hell? This is crazy. There’s no answer to this.

There should be a right way and a wrong way to do this.

But nobody’s mask falls apart. The only thing that we have heard about falling apart is the boom. Done with machine screws.

Yet machine screws are the most recommended item in the thread.

My frustration level is getting pretty high because there’s no answer. But there should be an answer. He is finished making the section tomorrow. He’s going to be starting whatever the next day. I need to figure this out.

I really wish we could do welding. Because it would be easy and he knows how to do it really well. That’s his main business.

But it seems like machine screws have won out in the thread. That’s kind of a good pun. Ha ha

The true answer is that if done properly any of these options will work. Don't loose sleep over it.

[SVPP]

Originally Posted by neilpride

This puzzle me out, im really curious on how to reach those nuts once the mast its joined, aluminium nuts welded ? couple of windows on both sides?

My mast is spliced in two locations, one 500mm section on the lower end. You can reach the nuts by reaching inside the mast.

The other join is in the middle of the mast - I have no idea how they he'd the nuts as there is no opening/window nearby. But just read in an old sailing journal that the mast was broken in the 1978 Sydney to Hobart yacht race so am guessing that is when it occurred.

[col50]

Chotu, your mast is made of 6061 Aluminum. This is one of the most weldable alloys there is, and there is nothing wrong with welding your splice when properly done. My mast has one splice in it and it is tapered for the last 15ft by cutting a wedge out of it. All of it TIG welded. It is still there after 45 years.
Please go to Wikipedia search for 6061 aluminum and read all about it.

https://en.wikipedia.org/wiki/6061_a...m_alloy#6061-O

[boatpoker]

Originally Posted by col50

Chotu, your mast is made of 6061 Aluminum. This is one of the most weldable alloys there is, and there is nothing wrong with welding your splice when properly done. My mast has one splice in it and it is tapered for the last 15ft by cutting a wedge out of it. All of it TIG welded. It is still there after 45 years.
Please go to Wikipedia search for 6061 aluminum and read all about it.

https://en.wikipedia.org/wiki/6061_a...m_alloy#6061-O

Welding new aluminum and welding old aluminum
are two different animals.

[col50]

Originally Posted by boatpoker

Welding new aluminum and welding old aluminum
are two different animals.

Not if the material is clean and corrosion free. We are not talking about castings here.

[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:

[Chotu]

Wait a second!

EVERYTHING is welded onto this mast already !

The tangs, the holders for the winches at the mast base, the holders for the cleats at the mast base, the gooseneck, the spreader receptacles….


If you guys were right, the mast would have broken decades ago when it went up on the original boat.

Instead, it circumnavigated and ended up in the USA after starting out in Europe.

You can’t be right about the welding, because this mast is ONLY welded everywhere. There are no rivets or bolts holding anything together except the bolts that go clear through the mast from one side to the other to hold the stainless tangs in place.

EVERYTHING else is welded on.

Explain that.

[RaymondR]

I have far more faith in welded aluminium than I could ever have in welded stainless steel??

[Baby tug]

Where are you located if you’re anywhere near Southwest Washington coast I know a couple people that can help you with your mast

[Chotu]

Originally Posted by Baby tug

Where are you located if you’re anywhere near Southwest Washington coast I know a couple people that can help you with your mast

Southwest, yes!

Washington, couldn’t be farther.

I’m in southwest Florida.

How could they help me? How can they help me more than the Welder/fabricator that I have now?

All I need to do is give them instructions. But this thread has screwed me up royally. I don’t know what to tell my metal guys to do. Welding would be the best for them since that’s what they are best at.

They are awaiting my instructions TODAY and I have nothing but a hurricane of confusion from this thread.

There is no answer. Stressed out of my mind.

Question: couldn’t I remove nearly all the non-compression forces from the joint by moving the position of the double diamond spreader termination down to the bottom of the mast? It’s currently near the bottom of the mast. My extension would have been unsupported if I left it where it was. I could move that termination point all the way to the bottom and that would keep the mast in column.

But anyway. This sucks. It took me almost a ****ing year to get this metal appointment set up and now I don’t know what to tell him. Because this thread has me confused more than I have ever been in my life about anything.

There is absolutely no answer here. Every single person has a different idea of what to do. Usually threads coalesce onto something. This one is not doing that.

Does anyone know of a service that comes to you with those little x-ray machines and can identify the aluminum alloy? Then maybe they can just weld it. Because that is the best option if it’s possible. I’ve been searching for something like that for the last 20 minutes. I don’t seem to find one anywhere near me. Near Fort Myers.

[neilpride]

From Practical Sailor.


The “T6” alloy is weldable, but doing so anneals and weakens the area that’s welded. This is one of the reasons why, when splicing two sections together, a doubler is added internally that overlaps the junction. Excess heat buildup during the plug welding process that joins the sections is kept to a minimum. Some manufacturers mechanically fasten the junction using machine screws or heavy duty pop rivets.

[neilpride]

Call this guys...

386-462-3760
800-928-0786

US Spars Inc.
6320 NW 123rd Place
Gainesville, FL 32653

Welding a sleeve question goes to Us Spar.

[neilpride]

There is no answer. Stressed out of my mind.

Question: couldn’t I remove nearly all the non-compression forces from the joint by moving the position of the double diamond spreader termination down to the bottom of the mast? It’s currently near the bottom of the mast. My extension would have been unsupported if I left it where it was. I could move that termination point all the way to the bottom and that would keep the mast in column.

But anyway. This sucks. It took me almost a ****ing year to get this metal appointment set up and now I don’t know what to tell him. Because this thread has me confused more than I have ever been in my life about anything.


Haaaaa! no offense mate,but such kind of project should be done by a competent rigger, many variables involved, calculations etc... we just know the metal guy involved,, you hired a rigger?

[Chotu]

Originally Posted by neilpride

There is no answer. Stressed out of my mind.

Question: couldn’t I remove nearly all the non-compression forces from the joint by moving the position of the double diamond spreader termination down to the bottom of the mast? It’s currently near the bottom of the mast. My extension would have been unsupported if I left it where it was. I could move that termination point all the way to the bottom and that would keep the mast in column.

But anyway. This sucks. It took me almost a ****ing year to get this metal appointment set up and now I don’t know what to tell him. Because this thread has me confused more than I have ever been in my life about anything.


Haaaaa! no offense mate,but such kind of project should be done by a competent rigger, many variables involved, calculations etc... we just know the metal guy involved,, you hired a rigger?

I already have a Rigger. This is not what they do. They don’t know how to do this. I’m trying to move the boat up to the Rigger so they can do the rigging. This is different.

I have an appointment 200 miles away. This adds to the stress.

But if you are talking about moving the termination of the double diamond down, it only makes sense. That’s just leave it where it was before. So I will do that for sure.

[neilpride]

No, moving the lower shoruds from the diamond to the bottom of the mast dont solve the compresion issue, in fact the area compresed from the diamonds is out of reach from the joint, you say the joint its at deck level, to gain extra feet on the mast, so, the compresion forces are coming from your cap shrouds, forestay.

If you by pass the sleeve area with a new tang in the bottom of the mast then you are adding more compression load to the joint.