Alphacool nexxxus radiator leaks

[_tucker_]

hi I have 5 new alphacool nexxxus radiators and 1 second hand but never used radiator that I bought from a mate and he had it stored and never got round to water cooling.

Problem is 1 of the ports on the new and 1 of the ports on the old radiator is leaking when I air test them, I rubbed soapy water and they are deffo leaking air, it’s very frustrating as they are pretty new and never used. I bought them a while back so I can’t return them unfortunately.
Any idea how to get around this? I was thinking of using some ptfe tape around the fitting thread so it screws it tighter this hopefully sealing the thread better rather than relying on the o ring to seal it.
I tried different plugs to see if it was that but they all do it leading me to suspect it’s the thread for certain.
I can either ptfe tape the thread or use a small dab of silicone around it and try that.
Has any of you had this problem and resolved it?
I can probably return the new radiator but finding all the bits and box is a pain as I recently moved house.
Must admit I have used alphacool rads in the past and they have been fine but this is very annoying being 2 out of 6 radiators

 

[MikeTimbers]

Before o-rings on fittings, I always used PTFE on barbs. If you've got any thread issues, PTFE is about the best solution for it. And it's dirt cheap of course.

 

[LePhuronn]

Fernox LSX. I've sealed up the front ports on my UT60 360 with headless grub screws and lashings of LSX and it's holding fine. Also doesn't set hard so you can remove at a later date.

 

[_tucker_]

Before o-rings on fittings, I always used PTFE on barbs. If you've got any thread issues, PTFE is about the best solution for it. And it's dirt cheap of course.

I’m a builder so I have some ptfe to hand so I think I’ll try that, I was just worried as you m not sure how strong the thread is on the war radiators I didn’t fancy stripping them out completely

 

[_tucker_]

Fernox LSX. I've sealed up the front ports on my UT60 360 with headless grub screws and lashings of LSX and it's holding fine. Also doesn't set hard so you can remove at a later date.

Where did you use the grub screw? I wasn’t to sure on using joint compound as I thought it would discolour the the coolant I’m using?

 

[LePhuronn]

Where did you use the grub screw? I wasn’t to sure on using joint compound as I thought it would discolour the the coolant I’m using?

Those at the front. I don't have enough space in my mod to allow proper plugs so I used a pair of these

And a splodge of LSX to seal the threads. LSX is 100% safe with drinking water so I just assumed it'd be fine with coolants. I've not finished building yet so watch it completely mess up the blue I have planned!

 

[_tucker_]

Those at the front. I don't have enough space in my mod to allow proper plugs so I used a pair of these

And a splodge of LSX to seal the threads. LSX is 100% safe with drinking water so I just assumed it'd be fine with coolants. I've not finished building yet so watch it completely mess up the blue I have planned!

Hahaha well fingers crossed buddy it works out for you. I’ll be honest tho the coolant will come into contact with the lsx and whilst it’s not poisonous coolant is very sensitive to ph levels and I’ve seen some horror stories of coolant going a nasty colour just from a bad ph level from rads so if I was you I would seriously consider filling the rad first with some and let it sit on the inside of the plug you used and leave it for a few days and see what happens before you commit to filling the whole loop. It does dry hard tho so who knows

 

[LePhuronn]

It does dry hard tho so who knows

It doesn't, it's more like a soft plastic so you can unscrew and clear it out.

But yes, fingers-crossed I don't have issues when I'm finally built (in 2025 at this rate, it's a 3 year project as it is) because I'm screwed (no pun) if I have to use screw plugs, there's no space in the mod for them. I'm going dyed blue, not a pastel, so hopefully there won't be any reaction. But then the original idea was either solid black, transparent blue or just plain water for the crystal look, so I don't lose much if I have to go plain ol distilled.

 

[_tucker_]

It doesn't, it's more like a soft plastic so you can unscrew and clear it out.

But yes, fingers-crossed I don't have issues when I'm finally built (in 2025 at this rate, it's a 3 year project as it is) because I'm screwed (no pun) if I have to use screw plugs, there's no space in the mod for them. I'm going dyed blue, not a pastel, so hopefully there won't be any reaction. But then the original idea was either solid black, transparent blue or just plain water for the crystal look, so I don't lose much if I have to go plain ol distilled.

Ahh ok did you buy the silicone version then? I assumed you used the old fashioned brown putty version. I just popped to the shops and bought some of the silicone based lsx because ptfe tape didn’t seal, it still leaked air.
Problem is I’m using a stop plug and the thread isn’t very long at all so there’s not much room to tape or seal to, I would use a grommet like you have but on one of the radiators it’s leaking on a port where I have to connect a inlet fitting so that has to seal no matter what.
I’ll try lashing lots of this lsx on the thread and see how that goes, might as well take the o ring off as well as that’s clearly not doing anything so the lsx should have more surface to adhere to.

 

[LePhuronn]

Yeah, Fernox LSX is a clear silicone-style substance. I also used it on my DIY air tester because I'm too cheap to properly source parallel threaded components, so mixed BSPP and BSPT, still works nicely.

On my rad, I applied the LSX with my fingertip to both the port threads and screw threads. Used enough to fill the threads and then slowly inserted just to make sure the stuff doesn't go everywhere. LSX goes watertight in about 2 hours I think, faster if it's in contact with water. I left mine about 4 before testing and it was gravity-tight (grub screws + PTFE tape would drip if I held the radiator up on its end). I didn't actually air test it until 3 years later when I had a custom-designed DDC pump top made, still no issues.

 

[_tucker_]

Yeah, Fernox LSX is a clear silicone-style substance. I also used it on my DIY air tester because I'm too cheap to properly source parallel threaded components, so mixed BSPP and BSPT, still works nicely.

On my rad, I applied the LSX with my fingertip to both the port threads and screw threads. Used enough to fill the threads and then slowly inserted just to make sure the stuff doesn't go everywhere. LSX goes watertight in about 2 hours I think, faster if it's in contact with water. I left mine about 4 before testing and it was gravity-tight (grub screws + PTFE tape would drip if I held the radiator up on its end). I didn't actually air test it until 3 years later when I had a custom-designed DDC pump top made, still no issues.

Well I applied some and let it dry over night and I air tested it to 0.6bar and it held very well! I managed to fill my system up with coolant last night and it’s still the correct colour this morning so I think we are on to a winner. I would like to see your build tho it pumps like your putting in some time and money.

 

[LePhuronn]

Good to hear it's working for you so far!

My sig is a link to the project log

 

[LePhuronn]

Any colour change after 3 days, _tucker_ ?

 

[_tucker_]

Not yet all is good, I mean over night the blue changed colour and went a slightly deeper blue but I think that was just air mixed into the pastel coolant making it appear pale but since then nothing’s changed so I think we are all good.
I had major problems at first tho finding a leak on the same loop, I thought it was the lsx not holding up but turned out it was a new 90’ elbow fitting.
Your build looks dope I actually remember looking at it a while back when you had the custom top made. Good work! I’ll post my build log soon once I get chance to use the computer, mine has taken like 6 months but it’s madness