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Discussion Starter #1
Hello

This is a new mast I have ordered. It was my understanding that 6000 series aluminium is extruded for masts in the shape since welding weakens the aluminium. Here it is two pieces being welded together.

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Thoughts anyone?

Dennis
 

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I'm not an engineer, but assume the weaker weld has been taken into account. Not unlike a knot weakens a rope. You oversize the rope, so the degraded knot is still sufficient. Intuition tells me a vertical weld is different than connecting lengths horizontally.
 
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a good welder, the person behind the machine, is the key. While often not cost effective, a good welder and fabricator can manufacture things as strong or stronger than the extrusion. Sleeves, welding and collars as well as fabricated attachments (i.e. - radar mount, antenna mount, shroud mounts and line handling, etc) may be used as well.

Key thing is to uncover why the extrusion failed in the first place?
 

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Welds on 6000 aluminum does change the condition of the aluminum near the weld which can make that area loose some strength but does not mean that it is not strong enough to do the job the designer has intended it to do. 6000 series is used in a multitude of ways to build a mast . when masts get large they are usually welded fabrications of formed sheet stock. just as they weld aluminum sheets together to form a hull of a vessel they weld them together to make a mast. extruded masts are used in the smaller sizes because it is economical if you are making thousands of masts all the same size. Over about a 12" section they would become very expensive to produce because of the size of the extruding machine and the small quantity. extruded masts can also have many welded on pieces such as mast heads, bases, sleeve boxes, spreader attachments and other components.
 

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The bottom line is, yes it can be welded, and safely. Millions of over the road truckers are pulling aluminum trailers loaded with 50k lbs of cargo right now today. Different application, but same concept: welded structures are engineered to account for the weakening created by welding.

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Discussion Starter #6
I'm not an engineer, but assume the weaker weld has been taken into account. Not unlike a knot weakens a rope. You oversize the rope, so the degraded knot is still sufficient. Intuition tells me a vertical weld is different than connecting lengths horizontally.
Great input thank you. Makes sense.
 

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Discussion Starter #7
Welds on 6000 aluminum does change the condition of the aluminum near the weld which can make that area loose some strength but does not mean that it is not strong enough to do the job the designer has intended it to do. 6000 series is used in a multitude of ways to build a mast . when masts get large they are usually welded fabrications of formed sheet stock. just as they weld aluminum sheets together to form a hull of a vessel they weld them together to make a mast. extruded masts are used in the smaller sizes because it is economical if you are making thousands of masts all the same size. Over about a 12" section they would become very expensive to produce because of the size of the extruding machine and the small quantity. extruded masts can also have many welded on pieces such as mast heads, bases, sleeve boxes, spreader attachments and other components.
I appreciate the input. Not to say I lack trust, but a second, third or fourth opinion when learning is always good.
 

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Discussion Starter #8
a good welder, the person behind the machine, is the key. While often not cost effective, a good welder and fabricator can manufacture things as strong or stronger than the extrusion. Sleeves, welding and collars as well as fabricated attachments (i.e. - radar mount, antenna mount, shroud mounts and line handling, etc) may be used as well.

Key thing is to uncover why the extrusion failed in the first place?
Ahh very good point. i just started welding aluminium myself, and it would be a few years before I would trust myself doing something as important as this.
 

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Discussion Starter #9
I appreciate the input. Given that a mast and boom are key to a safe vessel along with the cost associated of each, I want to make sure things are done right.
 

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Are you going to tell us what boat this is going on? Is that also your boom there? I like how it is similar to a Park Avenue style with the wide cage on it. Should help with lazy jacks and flaking the sail into a low profile. Since they are welding it anyway, if it is a fractional rig, you might consider having them cut a wedge out and taper the top of the mast above the hounds. Will save a few pounds and less windage.

Mark
 

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Are you going to tell us what boat this is going on? Is that also your boom there? I like how it is similar to a Park Avenue style with the wide cage on it. Should help with lazy jacks and flaking the sail into a low profile. Since they are welding it anyway, if it is a fractional rig, you might consider having them cut a wedge out and taper the top of the mast above the hounds. Will save a few pounds and less windage.

Mark
Hi Mark, here is our future floating home. http://instagr.am/p/B1vYynnATq7/ Yes the boom is ours too. Thanks for the input.
 

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For a mast and that extent of welding, I would ask to see weld inspection procedures. For example, gasoline tankers and the welds on them are subject to inspection procedures. If you get a deer-in-the-headlights stare or excuses, I would have a problem with that. At the very least, there should have been test welds that were broken.

On the plus side, those length-wise welds are under very low stress, except at the mast head, spreaders, and goose neck.
 

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Hi Mark, here is our future floating home. http://instagr.am/p/B1vYynnATq7/ Yes the boom is ours too. Thanks for the input.
That's a nice boat! If I had a monohull, it would be similar to that.

Must be a stout mast they are building you - it doesn't need any wires holding it up! :D

Lombard designed some nice catamarans too.

Mark
 

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Discussion Starter #14 (Edited)
That's a nice boat! If I had a monohull, it would be similar to that.

Must be a stout mast they are building you - it doesn't need any wires holding it up! :D

Lombard designed some nice catamarans too.

Mark
lol:)
Mast will be ok i'm sure;)
 
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