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[email protected] October 25th 05 09:53 AM

Mast Repair
 
While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.


Len October 25th 05 12:09 PM

Mast Repair
 
On 25 Oct 2005 01:53:40 -0700, wrote:

While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.


Welding on an alu mast affects the strength of the material.
I've never seen a mast with anything welded on it.
It is just the extruded alu profile and everything else is mounted ss.
But I'm no expert so you could specifically ask an expert if I'm
right. Ask a rigger in stead of a welder.
My 2 cts is: when your shroud-tensioners can handle the difference in
length I'd use the first method you described. When you use ss rivets
you should use Duralac or some other zinc-chromate paste. You could
also use monel rivets, they are less prone to galvanic corrosion.
If your tensioners can't handle it, I'd look further to avoid welding.
Recent years a lot of heavy duty ways of connecting alu have been
introduced. Maybe you could try
http://groups.yahoo.com/group/rebuiltaluminumboat/
These guys are experienced in this field and are always willing to
help.

HTH,
Len,
S/v Present



MMC October 25th 05 01:55 PM

Mast Repair
 
Look up. Is your mast head formed by welding pieces of aluminum together?
Mine is and so are all I remember.
"Len" wrote in message
...
On 25 Oct 2005 01:53:40 -0700, wrote:

While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.


Welding on an alu mast affects the strength of the material.
I've never seen a mast with anything welded on it.
It is just the extruded alu profile and everything else is mounted ss.
But I'm no expert so you could specifically ask an expert if I'm
right. Ask a rigger in stead of a welder.
My 2 cts is: when your shroud-tensioners can handle the difference in
length I'd use the first method you described. When you use ss rivets
you should use Duralac or some other zinc-chromate paste. You could
also use monel rivets, they are less prone to galvanic corrosion.
If your tensioners can't handle it, I'd look further to avoid welding.
Recent years a lot of heavy duty ways of connecting alu have been
introduced. Maybe you could try
http://groups.yahoo.com/group/rebuiltaluminumboat/
These guys are experienced in this field and are always willing to
help.

HTH,
Len,
S/v Present





MMC October 25th 05 01:56 PM

Mast Repair
 
Bigger rivets? SS screws? Sounds like pretty minor damage. I wouldn't cut
the mast.
wrote in message
oups.com...
While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.




DSK October 25th 05 02:24 PM

Mast Repair
 
wrote:
While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.


Not sure what you mean by "ally welded". Welding does affect the
strength of aluminum. If your plan is to take a piece of identical
extrusion, and cut it so that it can be placed inside the mast at the
point of failure with the surfaces matching up exactly, then that will
provide sufficient strength although a welder may object to having to
put a bead up inside the thing. Then you could it back in the same
bracket with the poprivets or small bolts.

I think this is pretty close to what you're calling option two? It's the
class way to go, a bit more expesnive of course but plenty strong.

Fresh Breezes- Doug King


Don White October 25th 05 03:41 PM

Mast Repair
 
MMC wrote:
Bigger rivets? SS screws? Sounds like pretty minor damage. I wouldn't cut
the mast.
wrote in message
oups.com...

While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.




I've got a minor repair to make also. The PO of my sailboat must have
used steel rivets to hold the bailer (re boom vang) to my mast. The mast
was dented right at that point also. The rigger at a local marine
supply store suggested I get a couple of stainless steel bolts long
enough to go through the mast, rather than try to re-rivet elongated
holes. ( for me, about 2&3/4" or 3" length should do)

Doug Dotson October 25th 05 03:52 PM

Mast Repair
 
My mast has all kinds of fittings welded to it. Spreader brackets, winch
pads, masthead brackets, etc.

"Len" wrote in message
...
On 25 Oct 2005 01:53:40 -0700, wrote:

While recently lowering my mast it fell forwards partially pulling the
rivets out where the mast joins the bottom bracket. I think that I have
two options to repair this. One is to drilll out the rivets cut off the
botton 1cm ,or so, of the mast to a point just above the old rivets &
redrill & rivet. This will mean putting a block under the tabernackle
so that the stay/shrouds can remain the same length.
Option two is to get the bottom of the mast ally welded to repair the
damage & also attatch the bottom of the mast to the ally bracket.
Does anyone have views on the suitability of both repairs? The second
is the easier option as it will be done proffesionally.


Welding on an alu mast affects the strength of the material.
I've never seen a mast with anything welded on it.
It is just the extruded alu profile and everything else is mounted ss.
But I'm no expert so you could specifically ask an expert if I'm
right. Ask a rigger in stead of a welder.
My 2 cts is: when your shroud-tensioners can handle the difference in
length I'd use the first method you described. When you use ss rivets
you should use Duralac or some other zinc-chromate paste. You could
also use monel rivets, they are less prone to galvanic corrosion.
If your tensioners can't handle it, I'd look further to avoid welding.
Recent years a lot of heavy duty ways of connecting alu have been
introduced. Maybe you could try
http://groups.yahoo.com/group/rebuiltaluminumboat/
These guys are experienced in this field and are always willing to
help.

HTH,
Len,
S/v Present





Brian Whatcott October 25th 05 06:33 PM

Mast Repair
 
On Tue, 25 Oct 2005 17:47:44 +0000, Len
wrote:

Odd, on every mast I see here all fittings are ss and bolted on.

Perhaps it's cause you ammies invented Tungsten Inert Gas welding.
I happen to know that came to Europe many years later. LOL

Len
S/v Present

On Tue, 25 Oct 2005 10:52:07 -0400, "Doug Dotson"
dougdotson@NOSPAMcablespeedNOSPAMcom wrote:
My mast has all kinds of fittings welded to it. Spreader brackets, winch
pads, masthead brackets, etc.


Meredith at Northrup invented TIG in 1940, but Linde picked up the
patents and turned it from Heliarc to the tig we know.

It echoed one of the earliest methods, which used a graphite rod
initially.

Brian Whatcott

Len October 25th 05 06:47 PM

Mast Repair
 
Odd, on every mast I see here all fittings are ss and bolted on.

Perhaps it's cause you ammies invented Tungsten Inert Gas welding.
I happen to know that came to Europe many years later. LOL

Len
S/v Present

On Tue, 25 Oct 2005 10:52:07 -0400, "Doug Dotson"
dougdotson@NOSPAMcablespeedNOSPAMcom wrote:
My mast has all kinds of fittings welded to it. Spreader brackets, winch
pads, masthead brackets, etc.


[email protected] October 25th 05 06:57 PM

Mast Repair
 
I've taken pics of the damage, which I suspect is minor(?). However I
don't know how to publish the pics so I'm going to need help on this
one too!



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