Loctite 577 troubles

[Aire]

Any of you guys have trouble with loctite 577 not sealing on heating systems? I've had two jobs now where I've had to go back to rad inserts leaking a couple of weeks after install. Been bone dry on day of install and even a few days after but seems to start leaking for no reason. I'm always leaving it a couple hours to set before filling up and I'm putting plenty on. Is it something to do with the heat?

 

[ShaunCorbs]

Nope wouldn’t say heat is your issue are the threads going in tight and stopping when tight or threads going in loose eg by hand

 

[Aire]

Going in by hand then a tighten up with rad spanner. Both systems have been pressurised and I've took them to 2.5 bar on both occasions before bleeding rads. I've continued to work on the bathroom for a couple days after and not had an issue while I've been there but then getting called back a couple weeks later

 

[ShaunCorbs]

Very strange new rads and new valves ?

 

[Aire]

Yeah new on both occasions. Strangely enough they was both on traditional chrome towel radiators, the ones with the white collum type radiator in the middle and both had chrome decorative valves. I wonder if the loctite is struggling to bond to the valve insert.

 

[oz-plumber]

I don't use any form of sealing paste on dis similar metals.
I find it ok with brass to brass, steel to steel, but won't use it on a mix of brass to steel.

I've had a few issues in the past and that's all I can put it down to

 

[Aire]

Hmmm, guess I'll have to be careful in future where I use it then

 

[Chalked]

Can’t understand why your having trouble.
We must have done thousands of rad tails, with zero problems.
Where are you applying the sealant?

 

[Scott_D]

Does it go out of date?
Any oil or residue in the rad threads?

 

[ShaunCorbs]

Does it go out of date?
Any oil or residue in the rad threads?

Don’t think so I bulked buy about 18 month ago still good upto now
[automerge]1570042980[/automerge]
The only time I get problems is when the threads are loose and I disturb the joint when I tighten up the valve side, so I do both at the same time now if the threads loose

 

[Aire]

Where are you applying the sealant?

At the beginning of the valve insert.

 

[quality]

It does weaken with higher temps but not any that you will find in a heating system. I would say its the decorative rad thread

 

[Stigster]

It does weaken with higher temps but not any that you will find in a heating system. I would say its the decorative rad thread

I sometimes run a 1/2" BSP tap through the thread before putting a rad tail in, especially if re-using an old rad and it's full of crud.

Model Engineering and engineering tools online from RDG Tools Ltd Home Page (Engineering Tools) Tel 01422 885069 /884605

Also I've had them where paint is getting into the thread when they painted up the rad at the factory. If there is paint in the thread it can break down over time and cause a weep later on.

Always worth checking there's no paint or debris in the tapping pre-assembly.

 

[Lou]

I found those on Amazon too Might be a bit cheaper? Amazon Link

 

[Stigster]

I found those on Amazon too Might be a bit cheaper? Amazon Link

Actually a bit more expensive on Amazon but those with vouchers or credit on their Amazon accounts might find that link useful. Cheers.

 

[Aire]

I sometimes run a 1/2" BSP tap through the thread before putting a rad tail in, especially if re-using an old rad and it's full of crud.

Model Engineering and engineering tools online from RDG Tools Ltd Home Page (Engineering Tools) Tel 01422 885069 /884605

Also I've had them where paint is getting into the thread when they painted up the rad at the factory. If there is paint in the thread it can break down over time and cause a weep later on.

Always worth checking there's no paint or debris in the tapping pre-assembly.

Got a set of those already, only needed to use them on cheap towel warmers when the valve wouldnt thread in. I guess I'll start using them more often.