Topic: I want to seal up a hole in the top of my battery case...

[grcamna2]

I had a small component get hot on top of my plastic battery case and melt a hole into the top of the plastic case,the black plastic 'cap' they use to seal-up a new one;this is the area way above the 'upper level'.I applied some JB Weld but it's starting to leak a bit now. The battery is only about 8 months old and still in 100% cond. & I'd like to save it for a bit longer until I get a new one later.

What's a good kind of strong epoxy to use that's tough enough for the job ?

[strynboen]

can you melt some plastic..and move it bach in the hole...??i have tryed all types of glue/silicone..nothing holds...melting some battery housing and mold it back in the hole..must be the best

[ekpent]

Be careful as fumes from a battery can be flammable. Sparks can be a danger also 

[grcamna2]

The JB has held for 8 months until it started leaking a little;I'd just like to find a stronger type of Epoxy and 'prep it' as well as I can.  I don't expect a 'miracle cure',that's for sure..,but a little longer would be good.

[Sami1987]

Epoxy putty should work well.
It's made for plumbing and is
Very hard.

[grcamna2]

Thanks Sami,
They have a plumbers supply right up the road here;do you think they sell it in very small quantities ? I don't think I'll have too many uses for it once I do a temp. fix on this

                                     Thanks Again ! 

[FuZZie]

I'd go for "apo" type of hot melt glue, saying that I'm sure some backup will be required..... 
http://en.wikipedia.org/wiki/Hot-melt_adhesive scroll down to "Amorphous polyolefin witch should stand up better to the vibration on a bike (has flex) and may have a much better resistance to battery acid.

Should be a easy fix if you can find some, cheap, also easy to clean and redo if needed.

[grcamna2]

Oh,you mean a hot plastic glue gun ? is the stuff a form of plastic ?

[ekpent]

The band aid type patch sounds like a better idea than filling with goop as it will cap and patch better. Whatever you use prep up all the plastic well with a good cleaning and scuffing up well with some sandpaper to get a good bond with the adhesive of your choice.

[grcamna2]

Thanks,I appreciate these choices

[FuZZie]

Oh,you mean a hot plastic glue gun ? is the stuff a form of plastic ?

Yea, just just that simple as long as you get apo base.

[TwoTired]

Epoxy needs a coarse surface to grab onto.  If the plastic has a mirror surface, either heat/melt blend with the patch, or make the surface irregular to give hot melt glue or epoxy "hooks" to grab onto.

Um, no sparks or flame for the exposed wet cell chamber, ok?

Does it need to be said that the surfaces bonded must be clean?

[grcamna2]

Epoxy needs a coarse surface to grab onto.  If the plastic has a mirror surface, either heat/melt blend with the patch, or make the surface irregular to give hot melt glue or epoxy "hooks" to grab onto.

Um, no sparks or flame for the exposed wet cell chamber, ok?

Does it need to be said that the surfaces bonded must be clean?

TT,
I was going to remove the old JB Weld(coarse sandpaper) and then use some coarse sandpaper to rough up the black plastic & then clean it off w/ alcohol before applying the new stuff;do you think I should use baking soda lightly on a rag to finish prep before applying the new stuff ?

[TwoTired]

I'd wash it before you sandpaper.  Sandpaper will just push any contamination into the scratches, and make it harder to clean.  Shouldn't need to acid neutralize in that case, and therefore not risk messing up the electrolyte inside.
  Imo....

[faux fiddy]

I was told acetone works better at cleaning up than alcohol for this purpose, and hot glue gun. Not sure how long it lasted.

[grcamna2]

fiddy,
How about paint thinner ? I'm getting ready to do this tonight.

[FuZZie]

You should only use water like a damp cloth. The battery is like 35% sulfuric acid and distilled water (or electrolyte).
I think the acid could react with some of the stuff and that could be a problem.

This is why I'm think whatever you do it should be acid resistant 35% solution is enough to blind tread carefully my friend!

[TwoTired]

If you use the right plastic, acetone will melt/ blend your patch to the battery case plastic.  The only issue there is that acetone also leeches some solvents out of the plastic.  So, for bonding ABS plastic to ABS plastic, MEK is a better choice.

Some paint thinners leave an oily film behind after evaporation takes place, which is not good for bonding.

[faux fiddy]

fiddy,
How about paint thinner ? I'm getting ready to do this tonight.

I think paint thinner leaves an oily residue.  (what he said) Acetone all goes into the atmosphere.

Alcohol would be better than paint thiner.

[grcamna2]

I only have alcohol at this time.
I'm going to leave some of the original JB Weld in the hole since it's partially sealing it now and cover over it w/ some 'plumbers epoxy putty' and hope for a lasting repair(I can always do another/better repair later)at this time.I'll clean it w/ alc. & then heavy sand it and apply the 'epoxy putty'  it's Ace Hardware brand item#:4027116  I'll let it fully cure and then file it down just a bit when done.

                Thanks for your good feedback guys