Sealant for compressed air fittings

[Mr Otford]

I have an Aldi compressor: http://www.einhelltools.co.uk/pdfs/store/WAC3050.pdf which was supplied with Euro fittings. As all my air tools have PCL fittings I decided to replace the Euro fittings on the compressor. Bad move!

The fittings have 1/4" BSP male threads and the manifold on the compressor has 1/4" female thread and I managed, probably through excessive use of PTFE thread, to split the manifold. :-( Einhell are sending a replacement manifold FOC but, clearly, I don't want to repeat the mistake.

Who thought it a good idea to arrange things such that a tapered fitting is screwed into a thin-walled zinc casting??? My other compressor has a male thread on the manifold and therefore takes female PCL fittings which is so much more sensible.

Anyway, to avoid a repeat of my stupid mistake, what thread sealant should I use with the new manifold? There are various air and brake line sealants on eBay:

http://www.ebay.co.uk/sch/i.html?_f...ne+sealant.TRS0&_nkw=airline+sealant&_sacat=0

However, none the above specify a maximum working pressure

or there is this:

http://www.laco.com/slic-tite-paste-with-ptfe/

which claims to withstand pressures far in excess of the 8 bar of my compressor.

(available from Wickes)


TIA

Richard

 

[optima21]

you could use ptfe again, you only need to just nip it up so it doesn't leak. In the past I've also used epoxy adhesive from the pound shop if I know I'll not be taking it apart again. if I think I'll need to take it apart again I use loctite 572, as it has a weak bond, but it also take a while to cure

http://www.loctite.co.uk/loctite-4087.htm?nodeid=8802627158017

although Im only a hobby user, so a real engineer may come along and say Im doing the wrong thing.

 

[the snooper]

i would say if it had a tapered fittings then you just tightened it up too much ptfe or not, just put 1 layer of ptfe on and don't over do it

 

[Bill Edwards]

PTFE tape, and be very gentle. It shouldn't require much force to seal, and as you've found out those manifolds are rubbish.

 

[Mr Otford]

My previous experience - with the male mainfold compressor and associated air tools - is that a surprising amount of torque is required for an air tight seal.

 

[Mr Otford]

PTFE tape, and be very gentle. It shouldn't require much force to seal, and as you've found out those manifolds are rubbish.

What about PTFE thread rather than tape?

 

[awemawson]

I swear by the two Loctite thread sealants. They do one for up to 3/4 BSP and another more gooey one for larger than 3/4" BSP.

I use them for air, water, diesel, and hydraulic circuits. Not had a failure yet. Huge advantage is that you don't have to get the parts screwed absolutely tight, so you can align them where you want them rather than where they happen to tighten.

 

[rtbcomp]

I'd use parallel threads and Loctite too.

 

[CompoSimmonite]

I use PTFE paste. http://www.rectorseal.com/index.php/rectorseal-tru-blu/ Got mine from Toolstation but also have some Screwfix "own brand" that seems just as good

 

[gordon stephenson]

As above, or you could even use just a drop of paint to seal the threads.

 

[Hitch]

I use loctite thread sealant quite a bit now, think its Loctite 577...It was spec'd on a high quality job I did back along, and was very impressed with it.
A slightly yellowish anaerobic liquid, seems to work well without excessive tightening up.

Bit on the spendy side, but a bottle goes quite a long way.

 

[gordon stephenson]

Rocol used to make a product called Gas Seal,The clue is in the name, used for threaded gas fittings, it was the consistency of a thick paste, You can also get liquid PTFE for thread sealing, Just give the fittings a decent firm nip, Do not rely on over-tightening to create a seal, you will damage something.

 

[captain-destructo]

i have only ever used ptfe tape or boss white

 

[Mr Otford]

I swear by the two Loctite thread sealants. They do one for up to 3/4 BSP and another more gooey one for larger than 3/4" BSP.

I use them for air, water, diesel, and hydraulic circuits. Not had a failure yet. Huge advantage is that you don't have to get the parts screwed absolutely tight, so you can align them where you want them rather than where they happen to tighten.

Could you specify which Loctite, please? I have picked up some Slic-tite from my local Wickes (just because it was easy to do so) and will experiment on the working compressor fittings. Looks as though it is similar to Rectorseal.

I think that the fittings on the Aldi compressor were sealed with a variety of Loctite judging from the crumbly brown/yellow residue on the threads.

Thanks for all your advice. I'll report back on how well or badly the Slic-tite performs.

Regards

Richard

 

[daleyd]

http://www.screwfix.com/p/no-nonsense-ptfe-liquid/40302

Not loctite but This is screwfix own version, should be perfectly adequate for general thread sealing.

I've also used jet v2 paste from b and q previously, which is thicker but does the same job.

 

[Mr Otford]

http://www.screwfix.com/p/no-nonsense-ptfe-liquid/40302

Not loctite but This is screwfix own version, should be perfectly adequate for general thread sealing.

I've also used jet v2 paste from b and q previously, which is thicker but does the same job.

Splendid, thanks. Funnily enough, it was while looking at the Screfix No Nonsense stuff that I found that Screwfix stock Slick-Tite.

Cheers

Richard

 

[Bill Edwards]

What about PTFE thread rather than tape?

I've never used it, sorry!

 

[jordan1]

I use Loctite 55 to seal any threads, plumbing and air. As has been said only tighten enought to seal