Sourcing Cable Glands of a specific type

[GazzParticipant @gazz]

Sorry if this is the wrong forum for this,

I picked up a PCB bubble etch tank cheap because it leaked, the leaks are from cracked cable glands that are used for the air pipes from the air pump to the tank base,

Simple enough to replace i thought, but bloomin eck i'm having a hard time sourcing them in the UK,

They are the type that have a female thread, and a male fitting screws down compressing a rubber donut that seals to the cable… or in this case 6mm pneumatic semi rigid tube.

They have a M12 x 1.5 thread on the end, and i've found them referanced as Mpoz 12-1 glands, by 'Rose Bopla'

This is what they look like, i only need 6 of them:

 

I've found plenty of the standard cable gland types with a male thread and male domed type nut that goes over the fitting, but i don't think those will work in this application… i.e. sealing in a few litres of ferric chloride in my workshop.

 

Does anyone know of a source of these in the UK? the M12 x 1.5 threads seems to add complexity to them, found electrical sellers that do the M16 and up sizes, but none this small

Edited By Gazz on 25/02/2021 18:40:08

[GazzParticipant @gazz]

[GazzParticipant @gazz]

Oh yeah, they must be plastic / nylon, found some metal ones, but they wouldnt last very long exposed to the tanks contents.

[Anonymous]

Not identical, but it is M12:

Cable Gland

Plenty of others on Farnell and I expect RS will be similar.

Andrew

[GazzParticipant @gazz]

yeah, i found loads of the standard dome type cable glands, but i wonder if there was a reason they used the other type in this application,

The 6mm nylon pipe passes through the whole gland at the base of the tank, so the seal must be perfect.

[peak4Participant @peak4]

A bit like these by any chance?
https://www.digikey.co.uk/products/en?keywords=12151800&v=1757

Bill

[GazzParticipant @gazz]

those are the exact ones

6 of them will cost me £7.68

But it seems digi key are in the US, but they say for £12 they will get them to me in 4 days,

so that's an option if i can't find them available in the uk,

[MichaelRParticipant @michaelr]

Anything here suitable Link    M12 x 1.5 Here Link

Mike.

Edited By MichaelR on 25/02/2021 19:24:37

Edited By MichaelR on 25/02/2021 19:29:21

[GazzParticipant @gazz]

they list one at M13… didnt know that was a standard size… wonder if they mean M12… thos i think the 1.5 thread pitch of thee make them a bugger to get even more

[Ed DuffnerParticipant @edduffner79357]

They look similar to FP200 cable glands, but the glands we used had a 20mm thread.

I believe they are commonly called Stuffing Glands. There are a few here at CEF

Ed.

FP200 was (is) a substitute for MICC "Pyro" fire resistant cable.

[Anonymous]

Posted by Gazz on 25/02/2021 18:50:50:

but i wonder if there was a reason they used the other type in this application

Not really, although slightly less bending of the cable if it moves.

Andrew

[Tim StevensParticipant @timstevens64731]

Ferric chloride is pretty fierce stuff, and whatever you get might be prone to cracking of the plastic, too. So perhaps – at least for the short term – it would be better to buy twice as many so you can be ready for the appearance of brown dribbles. And don't think for a moment of storing your etchant in the tank.

Cheers, Tim

[Robert Atkinson 2Participant @robertatkinson2]

The straight type of cable gland shown by the OP applies axial load to a short fairly thick wall rubber seal. This makes a very good seal without crushing the cable / pipe running through it. The "dome" type use a thin wall seal compressed by fingers under the dome. This puts high local pressure on the cable / pipe. Many years ago I actually used the straight type with silicone grease to make a waterproof seal on a switch shaft.

Digikey have a UK office, per the link Price is plus VAT but there is no duty or fees to pay. If you mke it up to £30 odd pounds with other items shipping is free.

Robert G8RPI.

[GazzParticipant @gazz]

Thankyou, i deffo need the same type of glands then, i was thinking that the domed type with the fingers might not have been used for a reason

it's looking like i will be ordering them from digikey then, they claim 4 days to get them to me from america,

6 of them cost £7.68, then vat and £12 postage, so £23.62!! so now to find other things i can buy off them to get to the free shipping level (i will order more glands than i need)

 

Bod knows how old this bubble etch tank is, it's an RS components branded unit, stock number 556-806, but the controls are flat on the front side of it and they haven't sold ones like that for many years,
It's only really the very end of the cable gland that gets the ferric chloride in contact with them, i think they cracked from the heat cycling over the years.

But i only paid £25 for it, and the heater works fine, just it was leaking 'slightly' which was the air pipe glands that had cracked.

When not in use It will be living on the floor of my workshop under a bench, i think i will get a plastic container that can contain the amount of ferric chloride it takes (i'm guessing 2 or 3 litres?) and it will sit in that all the time, a sort of bund solution.

All these years i've been etching pcb's in a small tupperware container sat in a larger one of hot water, and manually dunking the pcb in and out of the ferric chloride with tweezers.

It'll be nice to use a bubble etch tank of my own.

Edited By Gazz on 25/02/2021 21:17:07

[Martin KyteParticipant @martinkyte99762]

On our last but one bubble tank we had issues with the bubble bars clogging up so I made a demountable bubble unit from stainless tube and fed it from the top. Basically a long U shape fitting the bottom of the tank with small holes and a riser on one of the legs and the other blanked off. If you knocked up a blanking pug for the original bubble bar feed you could do that on yours. We haven't used wet etch for a few years now since we got the PCB mill.

regards Martin

[Michael BriggsParticipant @michaelbriggs82422]

The original glands are an older design rated at IP65, the dome type are generally IP68, a higher level of protection against moisture ingress. If you replace like for like they will probably fail, I would upgrade. The dome type will not exert excessive pressure unless you overtighten them.

Regards Michael

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