PBO #603 P84: Vaseline FFS

12v battery terminal are just the same as delicate electronic stuff, aren't they ? Or perhaps they have not come across the word dielectric. Or perhaps the editor had a day off. Or ...
 
nigelmercier said:
The article "Mending a B&G masthead unit" advocates the use of Vaseline on electrical connections. Have the editors learned nothing regarding modern products in the last 20 years?

It is blunders like this that make me question renewing my subscription.
Click to expand...
Rich, coming from a man who professes to know about MD22s, but doesnt.
As it happens I have used Vaseline on connectors in places like this for years. It works! If he hadnt been so keen to take the pis s he would have seen that the instrument wasnt working properly, after I gave it the treatment it did! So?
Stu
 
So what product do others use? I have used vaseline on connections at the masthead, with no problems. I am not sure that Electrolube actually does any better. I have used ACF50 to get a switch working again by cleaning the contacts. Don't blame the editors. The writer of the article was reporting what he did, not what someone else thinks he should have done, and it seems to have worked for him exactly as it has for me.
 
Norman_E said:
So what product do others use? I have used vaseline on connections at the masthead, with no problems. I am not sure that Electrolube actually does any better. I have used ACF50 to get a switch working again by cleaning the contacts. Don't blame the editors. The writer of the article was reporting what he did, not what someone else thinks he should have done, and it seems to have worked for him exactly as it has for me.
Click to expand...
Thank you. Thats exactly what I did, boat in Albufeira, SWMBO up mast, Vaseline, instrument started doing what it should do and still is 6 ish months later! PRACTICAL Boat Owner!
Stu
 
I've no idea why Vaseline should be a no-no; perhaps someone could explain?

I have a tube of Contralube which I tend to put on any connection I make (electrical, that is!) :rolleyes:
 
I've always used Vaseline for battery and other connections as recommended in my Haynes repair manual. Also useful for chapped lips and other things too which Contralube won't do.
 
The only job of the grease in the connector is to keep moisture (and salt) away from the conducting metal bits, and pretty much any waterproof grease can do this job. This works well because no moisture means no corrosion, and it's the corrosion that leads to failure, because most corrosion products do not conduct electricity so the connection surface gets smaller and smaller and the resistance higher and higher until things stops working and some poor bastard has to climb up the mast and wiggle the plug.

Vaseline is a trade name for a series of skin care products made by Unilever, some (but not all) of which are made of petroleum jelly. As everyone who has ever read the instructions on a condom knows, you shouldn't use petroleum based lubricants on natural rubber (latex based) products, because it will attack and dissolve the rubber and gets you STDs and/or babies. That's also the reason Vaseline is not recommended for use on rubber gaskets, seals etc. - although most of them contain little or no natural rubber anymore.

If you look at a material compatibility table, you'll find that Vaseline and other petroleum based products do harm certain elastomers and slightly attack certain plastics (ABS). Some of these materials may be present in the rest of the connector, i.e. the plastic screw-on caps, rubber seals, or Butyl sealant which is often found on boats. Therefore while petroleum jelly will do the job, it is not ideal and can cause harm to other components, although in most cases it would take years to make a difference, except to Butyl. Spray a bit of WD-40 on some Butyl tape for an experiment and you'll have the messy results sticking to your fingers in seconds (clean up with more WD-40 or white spirit, i.e. other petroleum products).

So for electrical conductors I'd recommend Silicone grease instead, or if you must, an overpriced branded version of it, such as Contralube. The difference in most cases does however not warrant climbing up the mast in wild panic to go clean off the vaseline (Butyl tape is excellent for bedding deck fittings, but I've not seen it used on masts much).

By the way, neither of these greases have particularly good dielectric properties, they're simply insulators, and that's the way you want them to be. Dielectric (able to be polarized) material would be undesirable in most connectors, unless you wanted to build a capacitor in there (you don't). The term "dielectric grease" is therefore a bit misleading and should go in the same bin as "AIS transponder" (they're transceivers). :)
 
Yngmar said:
Therefore while petroleum jelly will do the job, it is not ideal and can cause harm to other components, although in most cases it would take years to make a difference, except to Butyl. Spray a bit of WD-40 on some Butyl tape for an experiment and you'll have the messy results sticking to your fingers in seconds
Click to expand...

I don't know what bike inner tubes are made of, but I once used an old one cut into strips as "springs" on a home-made contraption that was initially lubricated with vaseline. The vaseline ate away the rubber in a matter of days.

Pete
 
prv said:
I don't know what bike inner tubes are made of, but I once used an old one cut into strips as "springs" on a home-made contraption that was initially lubricated with vaseline. The vaseline ate away the rubber in a matter of days.

Pete
Click to expand...

STDs and/or babies. Home made contraptions. Rubber inner tubes. Vaseline ..........................The mind boggles :) :)
 
Yngmar said:
The only job of the grease in the connector is to keep moisture (and salt) away from the conducting metal bits, and pretty much any waterproof grease can do this job. This works well because no moisture means no corrosion, and it's the corrosion that leads to failure, because most corrosion products do not conduct electricity so the connection surface gets smaller and smaller and the resistance higher and higher until things stops working and some poor bastard has to climb up the mast and wiggle the plug.

Vaseline is a trade name for a series of skin care products made by Unilever, some (but not all) of which are made of petroleum jelly. As everyone who has ever read the instructions on a condom knows, you shouldn't use petroleum based lubricants on natural rubber (latex based) products, because it will attack and dissolve the rubber and gets you STDs and/or babies. That's also the reason Vaseline is not recommended for use on rubber gaskets, seals etc. - although most of them contain little or no natural rubber anymore.

If you look at a material compatibility table, you'll find that Vaseline and other petroleum based products do harm certain elastomers and slightly attack certain plastics (ABS). Some of these materials may be present in the rest of the connector, i.e. the plastic screw-on caps, rubber seals, or Butyl sealant which is often found on boats. Therefore while petroleum jelly will do the job, it is not ideal and can cause harm to other components, although in most cases it would take years to make a difference, except to Butyl. Spray a bit of WD-40 on some Butyl tape for an experiment and you'll have the messy results sticking to your fingers in seconds (clean up with more WD-40 or white spirit, i.e. other petroleum products).

So for electrical conductors I'd recommend Silicone grease instead, or if you must, an overpriced branded version of it, such as Contralube. The difference in most cases does however not warrant climbing up the mast in wild panic to go clean off the vaseline (Butyl tape is excellent for bedding deck fittings, but I've not seen it used on masts much).

By the way, neither of these greases have particularly good dielectric properties, they're simply insulators, and that's the way you want them to be. Dielectric (able to be polarized) material would be undesirable in most connectors, unless you wanted to build a capacitor in there (you don't). The term "dielectric grease" is therefore a bit misleading and should go in the same bin as "AIS transponder" (they're transceivers). :)
Click to expand...

One of the best and most informative posts on the subject I've seen. Ta muchly :)
 
During our two season trip in Scotland, Ireland and the IOM the bow lamp failed.
I managed to repair it but the rubber gasket was US. This is what caused the failure-seawater got in.
After cleaning it up and getting it back together working I discarded the gasket and sealed all the areas where water might get in with a thick bead of pound shop petroleum jelly.
We took plenty of green over the front crossing from Arklow to Newlyn and a week later Brixham to Cherbourg and finally Cherbourg to Gosport. The lamp stayed dry and working. Where dollops of green had hit the lamp it was possible to see the petroleum jelly had been re-shaped, but the seal remained intact.
I really think it is a good thing to have on board
 
You must log in or register to reply here.

Share this page

Top