type of rivets to use on aluminum mast and stainlessfitting
Kevin Blanc
Whatever you do, get some bedding in between them. I'd use stainless
rivets - they are MUCH stronger. When I added mast fittings, and
rethreaded/rebedded some older ones which were causing corrosion, I used
3M 5200. I'm not certain it matters particularly what you use - I'll bet
a liberal coating of Locktite would be fine, but get something between the
dissimilar metals...
Kevin
In article <4lt1cs$r...@newsbf02.news.aol.com>, boris...@aol.com
(BorisP1080) wrote:
> im installing a new stainless spreader bracket on my aluminum mast.i am
> supposed to rivet it to the mast with1/4 inch pop rivets.Do i use aluminum
> or stainless rivets.?what type of caulk,if any, do i use between the
> bracket and the mast.
> a bad day of boating beast a good day going to work,boris
BorisP1080
Mark Ray
You should use monel or stainless 316 rivits. the important prat is to try
and insolate the riviets and the spreader bracket form the alu. mast. the
white 3m is good even a rubber pad will do. you can also dip the rivit in
caulking before you put it in the hole and pull it. the thing to be
careful of if the stainless to alu. contact. minimise it.
Al Gunther
In article <Blancs-2704...@endc5.laurel.us.net>, Bla...@us.net
(Kevin Blanc) wrote:
> Whatever you do, get some bedding in between them. I'd use stainless
> rivets - they are MUCH stronger. When I added mast fittings, and
> rethreaded/rebedded some older ones which were causing corrosion, I used
> 3M 5200. I'm not certain it matters particularly what you use - I'll bet
> a liberal coating of Locktite would be fine, but get something between the
> dissimilar metals...
Lock Tite forms in the absence of oxygen, so it works well for coating the
threads of selftapping screws and will create a perfect insulation between
the two metals. I bielieve Practical Sailor confirmed this with their
tests, the US Navy uses it extensively in their repair depots, and they
constantly deal with salt water corrosion, and I've had excellent results
with it personally. 5200 might prevent water from entering and could
reduce movement in a riveted joint, so it certainly would help, and in a
riveted joint, it might be the best choice. If there is any movement in
the riveted joint, the Locktite would most likely loose it's
effectiveness, so it might depend on how strong the rivet is and how
tightly it is installed.
Al in Kingston, WA <----- 47 52.78 N / 122 30.84 W
"Corleto", C-27, #4944, out of Bainbridge Island
Building "Al's 26", reviewed in WoodenBoat #127
Jeff Thompson
Kevin Blanc wrote:
>
> Whatever you do, get some bedding in between them. I'd use stainless
> rivets - they are MUCH stronger. When I added mast fittings, and
> rethreaded/rebedded some older ones which were causing corrosion, I used
> 3M 5200. I'm not certain it matters particularly what you use - I'll bet
> a liberal coating of Locktite would be fine, but get something between the
> dissimilar metals...
>
Don't put Stainless pop rivets in an alum. mast - use MONEL - a
copper-nickel alloy - harder to find and West won't carry them for some
reason. They are not as electrochemically reactive with alum as S/S. Do
not use alum rivets - they have no strength.
Don't caulk between the mast and the bracket - use a plastic barrier -
even black PVC electrical tape carefully applied works well.
Check with prof riggers, some sailmakers, etc. near you for MONEL rivets
- make sure you get them long enough to go through the mast wall and the
spreader base and 1/4" longer. Cherry Fasteners makes them (others do
also but Cherry is a well known US co in the fastener business).
You will need a full-sized professional pop rivet tool to pull them -
one of the big accordian-type ones.
For threaded fasteners (bolts) in alum masts - don't use 5200, use the
proper anticorrosion compounds - either a ground metal paste in a tube
called Alumalast (looks like Never Seize stuff but thicker, I use Never
Seize when I can't get the other), or an aircraft product - a yellow
paste in a tube (some chromium product I think). In either case, I've
taken s/s bolts our of my alum. mast 7-8 years later without a problem.
Without them, 2-3 months and they're corroded in place forever.
Graham Moss
I was about to reply and found that someone had already done it - the
above is 100% correct - use monel rivets - They ARE hard to find and are
expensive. In fact if anyone knows a good source for these, I would like
to know.
Finding a rivet gun is not that easy either - we purchased ours for
about C$200.00.
Graham Moss
Windjammer Sails, Box 23004 Amherstview PO Kingston Ont.
Canada K0H 1G0. (613) 389-4349 FAX (613) 389-4762
"Everything for sailing - At a good price!"
MAIL WEB SITE
wind...@fox.nstn.ca http://fox.nstn.ca/~windjamm/