I'm rebuilding the Port Light on a Tartan 30. It consists of two
aluminium bezels and a plexiglass "window". The two bezels are held
together by barrel nuts and bolts, and overlap the coach sides and the
plexiglass.

I believe I need to seal the outer bezel to both the plexiglass and
the outside of the cabin top with some sealant. It looks like the job
was done with silicone by the factory, 30 years ago.

I've seen some claims that there are good and bad forms of silicone
for this. Other claims that something like Boatlife is a better
choice.

Obviously, I want to use something that can be undone if it leaks
again - no 5200!

Suggestions?
--

"Marc Auslander" wrote

Obviously, I want to use something that can be undone if it leaks
again - no 5200!

Suggestions?

SikaFlex 295U

Lew

On Oct 2, 6:16 pm, Marc Auslander
wrote:
I'm rebuilding the Port Light on a Tartan 30. It consists of two
aluminium bezels and a plexiglass "window". The two bezels are held
together by barrel nuts and bolts, and overlap the coach sides and the
plexiglass.

I believe I need to seal the outer bezel to both the plexiglass and
the outside of the cabin top with some sealant. It looks like the job
was done with silicone by the factory, 30 years ago.

I've seen some claims that there are good and bad forms of silicone
for this. Other claims that something like Boatlife is a better
choice.

Obviously, I want to use something that can be undone if it leaks
again - no 5200!

Suggestions?
--

Dow 795.

Oh No!
Never Silicone. Silicone is terrible.
SikaFlex 295UV is the right stuff. My Opinion.

Dow 795.

"Dan" wrote:
..
Oh No!
Never Silicone. Silicone is terrible
..
SikaFlex 295UV is the right stuff. My Opinion.

Dow 795.

What does SikaFlex295 have to do with silicone?

Lew

On Oct 9, 1:21 pm, Dan "dhapp-at-gotsky,com" wrote:
Oh No!
Never Silicone. Silicone is terrible.
SikaFlex 295UV is the right stuff. My Opinion.


Hey there......

Dow COrning 795 aint your grandpa's silicone seal........... think
"structural" silicone. Really heavy duty industrial hold twin tower
windows in w/o fastners really thick kinda silicone.

get their spec sheet and check the lap strength for diffrent materials
and strech numbers. I used it when I fabricated my 7"x15"x 3/8"
polycarb dead lights. Min DC 795 thickness :1/8". Of course fastned
with ten 316L 1/4"x20 PH MS.



Bob

Nothing Lew, that;s why it's good. Silicone bad. I hate silicone and
won't use it on a boat. Period!

What does SikaFlex295 have to do with silicone?

Lew

"Bob" wrote in message
ps.com...

Dow COrning 795 aint your grandpa's silicone seal........... think
"structural" silicone. Really heavy duty industrial hold twin tower
windows in w/o fastners really thick kinda silicone.

get their spec sheet and check the lap strength for diffrent materials
and strech numbers. I used it when I fabricated my 7"x15"x 3/8"
polycarb dead lights. Min DC 795 thickness :1/8". Of course fastned
with ten 316L 1/4"x20 PH MS.

At the risk of (1) being exposed as a boatbuilding dunce or (2) even worse,
starting a thread as hotly contested as the hypotheteical 40' vertical
sal****er still, the comment about Dow Corning 795 leads me to ask a (naive)
question.

Could this high-strength, high-grab, somewhat flexible adhesive, or one
somewhat similar, be used to build a boat from aluminum panels, somewhat the
way epoxy is used for stitch-and-glue with plywood?

I realize there would have to be a lot of modifications to the construction
process. But is the concept reasonable with today's adhesives? Certainly DC
795 seems to have no trouble bonding to aluminum.

(Dow says 795 is not for use on surfaces continuously under water, so that
would be a problem for anything except trailered boats or dinghy-type uses.
But again, I'm just raising the question, not proposing it as a real option.
And there may be other adhesives that would be OK for underwater
applications.)

Alex

"Alex" wrote:

At the risk of (1) being exposed as a boatbuilding dunce or (2) even
worse, starting a thread as hotly contested as the hypotheteical 40'
vertical sal****er still, the comment about Dow Corning 795 leads me to
ask a (naive) question.

Could this high-strength, high-grab, somewhat flexible adhesive, or one
somewhat similar, be used to build a boat from aluminum panels, somewhat
the way epoxy is used for stitch-and-glue with plywood?

I realize there would have to be a lot of modifications to the
construction process. But is the concept reasonable with today's
adhesives? Certainly DC 795 seems to have no trouble bonding to aluminum.

(Dow says 795 is not for use on surfaces continuously under water, so that
would be a problem for anything except trailered boats or dinghy-type
uses. But again, I'm just raising the question, not proposing it as a real
option. And there may be other adhesives that would be OK for underwater
applications.)


You might want to contact SikaFlex tech service (Metro Detroit) and ask some
of these questions.

Lew

On Fri, 12 Oct 2007 20:39:24 -0700, "Lew Hodgett"
wrote:


"Alex" wrote:

At the risk of (1) being exposed as a boatbuilding dunce or (2) even
worse, starting a thread as hotly contested as the hypotheteical 40'
vertical sal****er still, the comment about Dow Corning 795 leads me to
ask a (naive) question.

Could this high-strength, high-grab, somewhat flexible adhesive, or one
somewhat similar, be used to build a boat from aluminum panels, somewhat
the way epoxy is used for stitch-and-glue with plywood?

I realize there would have to be a lot of modifications to the
construction process. But is the concept reasonable with today's
adhesives? Certainly DC 795 seems to have no trouble bonding to aluminum.

(Dow says 795 is not for use on surfaces continuously under water, so that
would be a problem for anything except trailered boats or dinghy-type
uses. But again, I'm just raising the question, not proposing it as a real
option. And there may be other adhesives that would be OK for underwater
applications.)


You might want to contact SikaFlex tech service (Metro Detroit) and ask some
of these questions.

Lew


Years ago I read an article about a British engineering student who
built a race car as his "Theses". He wanted the body to fail
progressively and ended up gluing the aluminum body panels together
using an adhesive made by locktite. You might have a look at their
literature.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)