Seacocks - Loctite 275 or 277 or ???

[Sailfree]

On previous threads Loctite 275 was mentioned and someone complains of too short setting time.

Talking to someone today they said use loctite 277.

Looking up data sheet it gives a setting time of 25 min for brass.

Anyone got any comments?

 

[sailorman]

what would a plumber use on pipe fittings

 

[Sailfree]

what would a plumber use on pipe fittings

But a plumber tightens them up until watertight.

A sailor tightens the seacock up until the handle is in a convenient position.

Thats my understanding of why professionals on boats use loctite.

I ask the question as i'm a seacock virgin!!

 

[sailorman]

But a plumber tightens them up until watertight.

A sailor tightens the seacock up until the handle is in a convenient position.

Thats my understanding of why professionals on boats use loctite.

I ask the question as i'm a seacock virgin!!

I always have my handles facing to where i need them.
bear in mind pipe fitters need fitting`s tight & facing the correct way as well

 

[nigelmercier]

Surely you hold the inner fitting, and turn the outside one?

 

[doug748]

"Anyone got any comments? "


Unless you are really skint, buy Blakes.

If you are really skint, use Silicone from down the Pound shop.

 

[Chi34]

During March last year, I used
Loctite 275 (cheap off ebay)
Loctite 7471 activator
Loctite 7063 cleaner

You can set the skin fittings with this http://www.bainbridgemarine.com/Item.aspx?Item=PRD-900419&PartNo=BO413344 Not messy, unlike some sealants which get everywhere.

No problems at all, but there were two of us. I can see that it could turn to worms. You won't move it easily once it sets.

A cheap cone cutter in a drill removes the flange of the skin fittings under control with no damage.

Good luck.

 

[Plevier]

Loctite 572.
It is designed for the purpose. It is a slow setting thread SEALER.
Loctite 275 is a quick setting thread LOCKER. It is the wrong product for the job.

I have spoken to Loctite and 572 is their recommendation (or 577 if you want it to set quicker).

http://www.loctite.co.uk/fullproduct-list-loctite-4995.htm?redDotUID=1000000IXOY

Plenty of it on ebay BTW.

 

[Sailfree]

During March last year, I used
A cheap cone cutter in a drill removes the flange of the skin fittings under control with no damage.

Good luck.

What sort of cone cutter needs to be 19 - 38mm in size for my boat- thats the first time I have seen a cone cutter mentioned? Was opting to loosen inside nut and use a metal blade on a Fien multitool after reading Galdriels post and didn't fancy grinding off the outside as previously suggested

 

[sailorman]

What sort of cone cutter needs to be 19 - 38mm in size for my boat- thats the first time I have seen a cone cutter mentioned? Was opting to loosen inside nut and use a metal blade on a Fien multitool after reading Galdriels post and didn't fancy grinding off the outside as previously suggested

how about a 2nd cut file

 

[Sailfree]

Surely you hold the inner fitting, and turn the outside one?

Not a lot of thread exposed on my current fittings. With thru hull sealant both outside and inside I think it could get quite messy. Suspect its best to bed down thru hull fitting first the screw down stopcock (need to check always room to revolve!).

 

[ghostlymoron]

I've never used sealant or locker. What's wrong with ptfe tape?

 

[nigelmercier]

Loctite 275 is a quick setting thread LOCKER. It is the wrong product for the job.
I have spoken to Loctite and 572 is their recommendation ...

Which is interesting, because they told me the complete opposite.

The trick to delaying the set is not to nip it up until you are ready to tighten.

 

[superheat6k]

Loctite 572.
It is designed for the purpose. It is a slow setting thread SEALER.
Loctite 275 is a quick setting thread LOCKER. It is the wrong product for the job.

I have spoken to Loctite and 572 is their recommendation (or 577 if you want it to set quicker).

http://www.loctite.co.uk/fullproduct-list-loctite-4995.htm?redDotUID=1000000IXOY

Plenty of it on ebay BTW.

+1

277 is a high strength 'thread locker', not a 'thread sealant'. 577 IMHO and professional experience is the best thread 'sealant' bar none, and will provide sufficient resistance to vibrational loosening. With 277 there is a possibility the thread will never come undone without damaging the fitting whilst holding it with a mechanical tool and in a tight location get the grinder out.

But having said all this for a seacock you require flexibility in the fitting itself and for this reason i would use Sikaflex 291.

 

[ChiPete]

I've never used sealant or locker. What's wrong with ptfe tape?

Is it simply that you might not be able to line up the ball valve and hose lead to suit?

I'm currently changing the raw water and stern gland fittings from brass to bronze. I plan to use Sikaflex291 for the external sealant but am in two minds the the internals. The options seem to boil down to:

PTFE
Loctite 572
Sikaflex 291

Decisions decisions! Any thoughts?

 

[Plevier]

Which is interesting, because they told me the complete opposite.

Just look at the published information. It's clear. Somebody must have mixed up the numbers.

http://www.loctite.co.uk/fullproduct-list-loctite-4995.htm?redDotUID=1000000IXOY

Loctite 572 for metal, slow cure thread sealant

Your benefits

Suitable for coarse metal threads
Ideal where slow cure is required for adjusting the alignment of fittings


Loctite 275
http://www.loctite.co.uk/fullproduct-list-loctite-4995.htm?redDotUID=1000000I9M9


Loctite 275 high strength, high viscosity, large threads threadlocker

 

[ghostlymoron]

Is it simply that you might not be able to line up the gate valve and hose lead to suit?

If you put on 4 or 5 layers of ptfe, you can position the valve handle anyway you want. I don't use gate valves.

 

[nigelmercier]

PTFE tape is excellent stuff. Seals the threads well, as long as you use enough: at least 20 turns of the thin stuff. It also makes it very easy to undo the joint.

It is for this reason that it should never be used anywhere near a sea-cock or skin fitting.

 

[Chi34]

I just used what the boatbuilder used and stuck with that.

Other Loctite numbers may be better, according to what you want to achieve perhaps.

However, I won't worry because the 275 spec sheet says -
"LOCTITE® 275 is designed for the permanent locking and
sealing of threaded fasteners. The product cures when
confined in the absence of air between close fitting metal
surfaces and prevents loosening and leakage from shock and
vibration. Typical applications include the locking and sealing
of large bolts and studs (M25 and larger)."

The largest diameter on my boat was 32mm. I can't help with a 38mm cutter.
Why are 38mm valves used anyway? The spigot in a 38mmm hose is 32mm.

 

[Plevier]

Isn't ptfe tape intended only for taper thread joints?
It certainly won't lock a parallel thread joint very well.