Crossbeam!!!!!

[Chotu]

Oh my God it’s actually happening.

Eight months later or whatever, the cross beam is being welded together. I should be able to put it on this week. Wow.

Next up I’m going to have this same place put together the extension on the mast. Because they are doing a good job and doing it quickly.

Since welds are stronger than the aluminum itself, should be no problem putting together the extension on the mast.

Standard splice.

Here are a couple pictures of the welding progress.

[Chotu]

The part it’s starting to get kind of exciting is this will hold one of my stays. The forestay. And I already have the parts to hold the other two stays, the chain plates. So that’s it! I can put a mast up!

[boatman61]

Yeehawwww.!!!

[clockwork orange]

Very happy that you finally found someone to get your welding done. but i think you are mistaken about the strength of a weld. My understanding is that weld on steel and SS are about equal to the parent metal but this is not the case with aluminum. I think aluminum welds are significantly weaker than the parent metal. Typically masts are sleeved together to lengthen them with machine screws or SS rivets rather than welding. Not a big deal as long as you can get the appropriate extrusions for the extension and sleeve.

[Chotu]

Originally Posted by clockwork orange

Very happy that you finally found someone to get your welding done. but i think you are mistaken about the strength of a weld. My understanding is that weld on steel and SS are about equal to the parent metal but this is not the case with aluminum. I think aluminum welds are significantly weaker than the parent metal. Typically masts are sleeved together to lengthen them with machine screws or SS rivets rather than welding. Not a big deal as long as you can get the appropriate extrusions for the extension and sleeve.

That’s not my understanding. I’m not a welder, but I did read a lot on it.

In any case, it’s a normal butt splice I’m going to do.

There is no appropriate extrusion, it’s out of production. So it will be made up. To the exact same size. Cut into four quadrants. Bent on a brake. Then welded together in four places (12:00, 3:00, 6:00 and 9:00) and properly butt spliced onto the mast using rivets to hold the internal section (responsible for that crucial alignment) in place.

[thinwater]

Originally Posted by clockwork orange

Very happy that you finally found someone to get your welding done. but i think you are mistaken about the strength of a weld. My understanding is that weld on steel and SS are about equal to the parent metal but this is not the case with aluminum. I think aluminum welds are significantly weaker than the parent metal. Typically masts are sleeved together to lengthen them with machine screws or SS rivets rather than welding. Not a big deal as long as you can get the appropriate extrusions for the extension and sleeve.

The main problem is the heat treatment. If it is an alloy that is heat treated for strength (and it probably is) the welding process changes the strength of the steel near the welds. Same with heat treated steels, but not with non-treated high-strength steels. Hence, the confusion. With stainless it also depends on the type (316 is not heat treated).


You may loose as much as 33% of your strength due to welding heat, probably a bit more.



----

How Does Heat Input Affect the Tensile Strength of the Base Material?

When we consider the controlled heat treatment that has been conducted on these materials prior to welding, to obtain the -T6 condition, we can appreciate their response to the arc welding process, which heats the material to the same temperatures in an uncontrolled manner. The 6061-T6 base materials, as purchased, have a typical tensile strength of 45 ksi before welding.
The AWS D1.2 Structural Code has recognized the metallurgical changes that occur to this base material from the exposure to heat during arc welding, and consequently, requires a minimum tensile strength of 24 ksi. The minimum tensile strength specified by the code is based on historical testing using a variety of welding procedures.
If we consider the fully annealed typical tensile strength of 6061 as being 18 ksi, we can appreciate the importance of controlling the overall heat input during the arc welding process. There is a direct association between the total welding heat input and mechanical properties of the base material adjacent to the weld (the heat affected zone) after welding. The higher the total heat input, the lower the tensile strength can be expected to fall.

[Chotu]

I was just looking up the same thing. And yeah. It’s all over the place. It all depends on the specific metal. And the specific welding rods.

So, we were both right. And we were both wrong. Ha ha

But, it’s good enough for me. I pretty much don’t care at this point. Lol

I’m sure my welds won’t be any weaker than all the rest of the welds in the world that hold these things together.

[clockwork orange]

Yeah, i'm not a welder either but i am a boatbuilder and over the years i have fabricated quite a few aluminum fittings but i have the welding done by people who do it every day. I just didn't want you thinking it was stronger than the parent metal. Lots of welding is done on masts without re tempering so I'm sure you will be fine.

[smj]

Looks great! Get that damn mast up!

[thinwater]

Engineers don't like false assumptions and we don't put faith in "it's over built anyway" or "other people have done this." Sometimes that works, and sometimes there are disasters followed by discovery of shortcuts.



What does help is that this is not the highest stress area on the mast. That would be the spreaders, diamond wire attachments, and the mid-points between the spreaders. Also depends on spin, jib, and reacher halyard exits.



All that said, do consider the weld location vs. the goose neck location, which is high stress in a crash jibe (which will happen). A reinforcement plate may be in order. Don't know without seeing it.

[Chotu]

Not really taking notes right now. The time for brainstorming is over. We are just putting this together now. All of these decisions are made. The brainstorming threads are long over. It’s action time.

[GRIT]

ACTION TIME!!!

Congrats.
Paul.

[Chotu]

Thanks guys!

Trying not to get too excited yet in case of disaster, but it’s getting difficult not to be.

Very excited to see what the boat will do.

[rslifkin]

Sweet!

[s/v Jedi]

It’s water melon time

(Guess nobody will get the joke haha)