wrote in message
...
On Fri, 12 Dec 2008 09:19:52 -0500, Wayne.B
wrote:

On Fri, 12 Dec 2008 06:41:55 -0500, wrote:

Next time, tap the holes to make threads for machine screws. Mount
using SS machine screws coated with TefGel.

Where do you get them ?

???

You can get SS machine screws from many sources, and TefGel is not
THAT hard to find. A little tube of it is a bit pricey, but lasts a
very long time. No marine toolkit should be without it.



Like here? http://www.tef-gel.com/ LOL

--
"j" ganz @@
www.sailnow.com

wrote in message
...
On Thu, 11 Dec 2008 18:50:26 -0800 (PST), joost
wrote:

I am investigating the best way to fasten a 4 metre long alu t-track
for my whisker/spi pole to the alu mast.

Currently I have a short length of track (1 metre) which is fastened
with SS screws. I am not satisfied with this, because the screws react
with the aluminium of the mast and dissolve the thread. The track
comes off. I also find it quite difficult to drill and tap the holes
in the mast accurately sitting in a bosun's chair.

My question is whether it would be better to fasten the track with SS
rivets dipped in some isolating compound. At least I wouldn't have the
problem of the tiny threads corroding away and loosening the
fasteners. Also I think that I have a bit more tolerance for drilling
the holes + I can reuse the existing worn out holes to put the rivets
in (instead of tapping one size up).

But, how strong is it compared to screws?

And, how would I go with off-the-shelf T-track which is made for
countersunk heads?

Any thoughts?

Thanks,
Joost.

Next time, tap the holes to make threads for machine screws. Mount
using SS machine screws coated with TefGel.



Wouldn't stainless promote a galvanic response between the screws and the
two pieces of aluminum?

--
"j" ganz @@
www.sailnow.com

wrote in message
...
On Fri, 12 Dec 2008 10:59:53 -0800, "Capt. JG"
wrote:

wrote in message
. ..
On Thu, 11 Dec 2008 18:50:26 -0800 (PST), joost
wrote:

I am investigating the best way to fasten a 4 metre long alu t-track
for my whisker/spi pole to the alu mast.

Currently I have a short length of track (1 metre) which is fastened
with SS screws. I am not satisfied with this, because the screws react
with the aluminium of the mast and dissolve the thread. The track
comes off. I also find it quite difficult to drill and tap the holes
in the mast accurately sitting in a bosun's chair.

My question is whether it would be better to fasten the track with SS
rivets dipped in some isolating compound. At least I wouldn't have the
problem of the tiny threads corroding away and loosening the
fasteners. Also I think that I have a bit more tolerance for drilling
the holes + I can reuse the existing worn out holes to put the rivets
in (instead of tapping one size up).

But, how strong is it compared to screws?

And, how would I go with off-the-shelf T-track which is made for
countersunk heads?

Any thoughts?

Thanks,
Joost.

Next time, tap the holes to make threads for machine screws. Mount
using SS machine screws coated with TefGel.



Wouldn't stainless promote a galvanic response between the screws and the
two pieces of aluminum?

No. That's what the TefGel eliminates.



Heh... I guess I should have paid more attention. LOL


--
"j" ganz @@
www.sailnow.com

On Fri, 12 Dec 2008 10:59:53 -0800, "Capt. JG"
wrote:

Wouldn't stainless promote a galvanic response between the screws and the
two pieces of aluminum?

Presumably the Tef-Gel acts as an insulator/isolator just as silicone
does. The thing I like about silicone is that you can buy it
anywhere, it is inexpensive and works very well. I first learned the
silicone trick from a professional rigger who installs hundreds of SS
fasteners into aluminum every year. He said that he'd never had a
problem with corrosion and I haven't either since starting to use it.

On 12 Dec 2008 14:44:01 -0600, Dave wrote:

On Fri, 12 Dec 2008 15:12:40 -0500, said:

Hmm. There appear to be 3 dealers in the State of NY--2 in Greenport and 1
in Montauk.

Well, I guess since you don't have access to the internet or a
telephone, you're out of luck!

Ah, but I'm just a short sail from Greenport.

Seriously, though, I wonder why there are so few dealers for this magic
elixir. I don't see any shown to be in CT.

I got mine from Sailcare. I think it was about $15 including shipping
for a 1 ounce tube. A little goes a long way. I think that works out
to about $1 a year!

It's not exactly a mass market item. I'll bet Aerospace and other high
tech manufacturers order it by the barrel.

"Wayne.B" wrote in message
...
On Fri, 12 Dec 2008 10:59:53 -0800, "Capt. JG"
wrote:

Wouldn't stainless promote a galvanic response between the screws and the
two pieces of aluminum?

Presumably the Tef-Gel acts as an insulator/isolator just as silicone
does. The thing I like about silicone is that you can buy it
anywhere, it is inexpensive and works very well. I first learned the
silicone trick from a professional rigger who installs hundreds of SS
fasteners into aluminum every year. He said that he'd never had a
problem with corrosion and I haven't either since starting to use it.



Basically, they're substituting Teflon for silicone, because they claim that
silicone will evaporate?

--
"j" ganz @@
www.sailnow.com

On Fri, 12 Dec 2008 15:34:40 +0100, "Edgar"
wrote:


"Bruce In Bangkok" wrote in message
news
On Fri, 12 Dec 2008 10:30:28 +0100, "Edgar"
wrote:


"Wayne.B" wrote in message
...
snipped

If you end up using rivets, these are the ones you want:

http://www.airsuppliers.com/Aircraft...R_AIRCRAFT.htm

I find it strange that the information on this site about rivets tells you
everything except the piece of information you most want, namely what the
'nominal diameter' actually is.


The rivet part number tells you the nominal diameter #4 = .125, for
example. the second number is the length. Google on +rivet +part
number for more details.

Thanks. I suppose anyone in the aircraft business is supposed to know this
because if you click the link for more details it still does not reveal the
nominal size, just that.
# 4 is nominal, 5 and 6 are oversize. All of them seem a bit large for
fixing a whisker pole track to the mast.



No, I said to google on rivets and the part number. That will lead you
to a several sites that explain the rivet size coding's. But you are
right, anyone who's life is banging rivets in the side of an airplane
will be likely to understand rivet sizing (Size is in 32nds of an
inch).

But you don't need to use cherry rivets you can also use aluminum "pop
rivets". You may need to space them a little closer but they will hold
unless your track is tremendously over stressed.

The SS machine screws suggested will also work. Just coat them with
any of the various sealants - 3M 5200, Sekaflex, maybe even house
silicon sealant. They may be a little stiff to remove but I've been
doing it for years with no corrosion and no problems in removal.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Bruce In Bangkok wrote:



No, I said to google on rivets and the part number. That will lead you
to a several sites that explain the rivet size coding's. But you are
right, anyone who's life is banging rivets in the side of an airplane
will be likely to understand rivet sizing (Size is in 32nds of an
inch).

But you don't need to use cherry rivets you can also use aluminum "pop
rivets". You may need to space them a little closer but they will hold
unless your track is tremendously over stressed.

The SS machine screws suggested will also work. Just coat them with
any of the various sealants - 3M 5200, Sekaflex, maybe even house
silicon sealant. They may be a little stiff to remove but I've been
doing it for years with no corrosion and no problems in removal.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

I kinds have an issue with screws in the mast.
Unless the wall thickness is at least 2x the diameter, there just isn't
a lot of thread in the mast.

Properly sized pull rivets would be a better choice for structural
reliability.

Maybe a big pain to install, but more secure...

FWIW...

Richard

Richard wrote:
Bruce In Bangkok wrote:



No, I said to google on rivets and the part number. That will lead you
to a several sites that explain the rivet size coding's. But you are
right, anyone who's life is banging rivets in the side of an airplane
will be likely to understand rivet sizing (Size is in 32nds of an
inch).

But you don't need to use cherry rivets you can also use aluminum "pop
rivets". You may need to space them a little closer but they will hold
unless your track is tremendously over stressed.

The SS machine screws suggested will also work. Just coat them with
any of the various sealants - 3M 5200, Sekaflex, maybe even house
silicon sealant. They may be a little stiff to remove but I've been
doing it for years with no corrosion and no problems in removal.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

I kinds have an issue with screws in the mast.
Unless the wall thickness is at least 2x the diameter, there just isn't
a lot of thread in the mast.


I don't think you need that much, 3 full threads should be sufficient.
Even at that you are probably correct, the wall is not thick enough for
even that.

I have a compound rivet tool that will let me install 1/4" shank rivets
with hand pressure alone.

Cheers
Martin

On Fri, 12 Dec 2008 14:54:43 -0800, "Capt. JG"
wrote:

Basically, they're substituting Teflon for silicone, because they claim that
silicone will evaporate?

Should have made this clear I guess, I'm talking about silicone
bedding compound/sealant, not spray silicone.

http://www.wholesalemarine.com/p/BOA-1140/

Or similar.