Battery Glue

[Speedy Builder5Participant @speedybuilder5]

I ordered a new 6 volt lead acid car battery, but the top of the battery was split around one of the posts when it arrived. The supplier accepted responsibility and another one arrived today. Seems a shame to chuck the damaged one on the scrap heap. Anyone know of a glue / gunge that may seal cracks above the "water line". There must be one as the lid of the battery is sealed against the tub.
BobH

[Speedy Builder5Participant @speedybuilder5]

Sulphuric acid resistant glue

[Clive Brown 1Participant @clivebrown1]

I'd think of trying a hot melt glue gun. Might be an idea cut a vee-groove along the length of the crack if possible.

Assuming the case is plastic, as most seem to be.

Edited By Clive Brown 1 on 17/10/2018 14:40:46

[mark costello 1Participant @markcostello1]

Batteries used to be rebuilt here using roof tar for resealing. Don't know if roof tar has changed over the years.

[Robert Atkinson 2Participant @robertatkinson2]

Normally plastic battery cases are heat (friction, ultrasonic) or solvent welded. The join around the different materials of the teminal posts may use adhesive. I'd suggest standard (not rapid) Araldite epoxy. This has reasonable acid resistance so should be OK if not immersed.

[SillyOldDufferModerator @sillyoldduffer]

About 1978 I fixed a punctured car battery with a blob of standard Araldite as Robert suggests. Don't know how permanent the fix was but it lasted at least a few years before I scrapped the car. (Rust got it.) Also, although they look the same, I don't know if modern battery cases are made of the same plastic as old ones. Worth trying though.

The cause of the puncture was quite odd. A spiral wire-bound tube fed warm air from the manifold into the air filter to warm the engine quickly from cold. The tube rubbed against the battery and after about 10 years wore through the steel wire. Then the nicely sharpened wire dug a neat 3mm hole into the battery and let the acid out!

Dave

[Ian S CParticipant @iansc]

Roofing tar was mentioned, the tar, or as it was called pitch, also used for roading was a by product of the coal gas production, and this seems to have disappeared in most if not all parts of the world. There are places where it appears naturally, I don't know if that is used in place of coal tar.

Ian S C

[Speedy Builder5Participant @speedybuilder5]

Interesting that silicon sealant which has acetic acid ?? as the activator has not been mentioned. I have to admit that Araldite was going to be my first choice , Black liquid metal (Would that be an electrical conductor) was also an idea. Anyway, thanks for the ideas.
BobH

[SillyOldDufferModerator @sillyoldduffer]

Posted by Speedy Builder5 on 18/10/2018 15:49:17:

Interesting that silicon sealant which has acetic acid ?? as the activator has not been mentioned. …

Some silicon sealants evolve small quantities of Acetic Acid as they set. It doesn't mean they're necessarily proof against other acids.

While it's true silicon sealants are resistant to chemicals I don't know how well one would cope with Battery Acid. However, the main objection to using sealant to fix a battery case is it's weak – sticky rather than adhesive and rubbery with low physical strength.

Araldite is a safer bet – it's adhesive, acid resistant, an excellent insulator and strong.

Dave

[Speedy Builder5Participant @speedybuilder5]

Sounds like Araldite wins the day.

[Ed DuffnerParticipant @edduffner79357]

Use a soldering iron to gently weld the crack.

Ed.

[GeorgineerParticipant @georgineer]

The one possible problem I can see with araldite is that it is rigid when set. If there is any possibility of movement, or if the casing material is at all flexible, I would go with hot-melt glue, or try Ed's suggestion of welding with a soldering iron.

George

Edited By Georgineer on 19/10/2018 11:03:24

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