Stanchion re-bedding. Gaskets?

[djousset]

I will be tackling several lifeline stanchion re-bedding (fiberglass deck) and have noticed dried/cracked white "gaskets" sticking out from the base edges. I intend to remove and clean everything thoroughly and have a fresh start for re-bedding.

My questions:

Are these gaskets now old school? I like the idea of them as a protective layer between stainless and fiberglass. I've read that they are great to help minimize deck stress, then read that they allow too much movement and therefore water intrusion. What to believe....

Butyl tape seems popular, and plenty of nods in the direction of sikaflex, 4200, 5200 etc. Liquid versus solid? Cost? Longevity? Ease of application? What to believe......

Stanchions flex right? So bedding should be capable of flex too?

Aside from watching for any rot/moisture in the core, anything else I should be paying attention to when the bases are opened up?

Thx in advance.

[Tortuga's Lie]

There WILL be some flex to these bases and that's why I would go for butyl tape, the only downside is that butyl oozes a bit when it warms up so there will be some trimming to do once this occurs and it may occur more than once or twice depending upon the temperature when you installed it. But that being said, it is very flexible and watertight. How easy is it to access underneath the base plate? Will you be able to snug up on the bolts when the temps warm up? This will help minimize the number of times butyl will ooze.
I would stay very far, far away from using 5200 in this application for it is a permanent bond and it will be a nightmare if you need to ever remove the base, plus 5200 is not UV protected so any exposed edge will degrade.
I am assuming that you have a base that is separate from the stanchion? I like to drill a weep hole on the downhill side of the vertical socket at the base (not underneath the base but on the side) which will allow water to seep out and not gather where it could potentially corrode the stanchion tube in an anaerobic situation. I don't know why the manufactures don't do this anyway???

[John_Trusty]

Butyl tape - see guide from Mainesail: https://marinehowto.com/bed-it-tape/
BTW: he sells that brand from his on-line store and it really is good quality (unsolicited plug). As Tortuga's Lie notes, stay away from 5200 "the Devil's glue", and any silicone product as it is impossible to remove later. I re-did several to clean up some damp spots, and it is both not fun and satisfying when completed - perfect winter boat job.

[fireant]

John Trusty.
I'm getting ready for work on my new boat and wonder how the Butyl tape you reference
compare to the Butyl tape you can buy at Amazon as an example?

Thank you,

[coopec43]

I have my stanchions already made up and wondering how to mount them too. I have considered raising the area of the deck under the stanchion by (say) 5mm to avoid leaks. (The raised mounting area could be just a few layers of fiberglass)

[henryk]

I made stanchions bases from the 1/2 thick fiberglass plate from McMaster&Carr.

[NYSail]

Originally Posted by djousset

I will be tackling several lifeline stanchion re-bedding (fiberglass deck) and have noticed dried/cracked white "gaskets" sticking out from the base edges. I intend to remove and clean everything thoroughly and have a fresh start for re-bedding.

My questions:

Are these gaskets now old school? I like the idea of them as a protective layer between stainless and fiberglass. I've read that they are great to help minimize deck stress, then read that they allow too much movement and therefore water intrusion. What to believe....

Butyl tape seems popular, and plenty of nods in the direction of sikaflex, 4200, 5200 etc. Liquid versus solid? Cost? Longevity? Ease of application? What to believe......

Stanchions flex right? So bedding should be capable of flex too?

Aside from watching for any rot/moisture in the core, anything else I should be paying attention to when the bases are opened up?

Thx in advance.

I use nothing but butyl tape from mainsail. Great stuff...... is your boat a Pearson??

Greg

[Spot]

I am looking at stanchion mounting repairs on mine too.

Poor initial bedding that led to moisture ingress and damp balsa coring.
Outside on deck is still gel coat so I am hoping to do any core and glassing from the inside that is exposed and painted. Remove bad core, replace core, glass, over-drill holes, fill with epoxy, re-drill holes, re-mount bases with fresh butyl.

Free Range Sailing on YouTube added risers to much of their deck hardware this last refit, some sort of composite board but I cannot remember which. Sounds like a good idea for areas known to puddle around deck intrusions.

[LittleWing77]

Originally Posted by fireant

John Trusty.
I'm getting ready for work on my new boat and wonder how the Butyl tape you reference
compare to the Butyl tape you can buy at Amazon as an example?

Thank you,

If you read the Marine How-To website's article, you would probably choose his tape.

Boy, does that guy know his s*#t!

Good luck, Fireant and Diane (guess you found the leaks, eh?) Right on.
Warmly,
LittleWing77

[djousset]

Originally Posted by LittleWing77

Good luck, Fireant and Diane (guess you found the leaks, eh?) Right on.
Warmly,
LittleWing77

Littlewing, stanchions were on the list and may have contributed a bit but I think it is mostly bow-high blocking and anchor locker drainage. Last check all was ok. I've got antifreeze in the bilge and knot meter/transducer removed. (When I return home I may rig a tent cover for the anchor locker.) Thx for asking!

[Sailmonkey]

Originally Posted by fireant

John Trusty.
I'm getting ready for work on my new boat and wonder how the Butyl tape you reference
compare to the Butyl tape you can buy at Amazon as an example?

Thank you,

Not even comparable.

The normal RV stuff is more of a putty. It weeps an oily ring around what it’s sealing, and sort of crumbles after a while.

The bed it stuff is more like a rubber gasket than a putty. Far superior.

[Pegu Club]

Use Mainesails butyl tape, it works! Butyl at the big box stores is not the same product, it is a “type” of butyl tape, but not the same product. We Rebed our bow and stern pulpit/ push pit, cleats, and stanchion bases five years ago, no leaks.

Fair winds,

[searoom]

After stabilizing and repairing any deck cracks at stanchion base I normally bed with 3M 5200 before thru bolting.

[Spindrift NH]

I have the same rubber gaskets under the stations on my Pearson. My experience is that while the outer edges are cracked and deteriorated by the sun, under the base plate the rubber is fine and doesn’t allow water to get through. I have had to remove a couple stations for other reasons and have gone back with butyl. When I buy butyl from mainsail I always buy 2 rolls, I love having the extra around, I seem to find many uses for it. Example: I removed an exhaust stack from my cabin top as the heater was removed before we bought the boat and it was leaking. As a temporary way to seal the hole, I cut a round piece of isinglass and applied a bead of butyl to it then covered the hole, it never once leaked.

[Gary Mc]

The butyl tape from Mainesail is thinner and stickier that the tape you might buy somewhere else. Since it is thinner and stickier it does not ooze out as much, so less clean up and a better seal.

I used the tape from a local marine store and thought it was OK until my son gave me some of Maine's tape.

Will not use anything else now.