Battery Box Query

[BlueSovereign]

I've just had some custom-designed wooden battery boxes made.

To eliminate the need to lift the 12v heavier ones (for my Genset and Engine) within a very confined space, I had that box made with a removal side (which is secured by 4 SS bolts) so that the batteries can be "slid into place" rather than having the very difficult task of trying to "lift" them within that very confined space (trust me this makes total sense).

While all my batteries are sealed AGM/Gels, I suspect (though don't know) a NZ Cat1 inspector will still expect the box to be sealed in some manner on the box/removal side area. Thus, I need to have some sort of gasket between the box face and the adjoining removal side face, that would I assume be "acid resistent".
Anyone have ideas as to what I might use?

My one idea to avoid the "gasket" approach above was to simply fiberglass the 3 sides of the box face and epoxy resin the adjoining removal side face and allow the tight securing of the bolts to form a "quasi-sealed" joint. Any thoughts on this idea as well?

BTW, all the interior joint areas will be epoxy resin sealed, and the external corners (as per N Calder) fiberglassed.

[FreeSail]

I made my battery box out of plywood and some scrap fiberglass I had. I did epoxy everything and then varnished it. I had the varnish that is why I used it. In fact everything that I used for the box was scraps I had saved.

An idea for a gasket might be bytal tape, cheap and easy to use and remove.

[BlueSovereign]

Do you mean "butyl" tape? If so it's great for many things but is not acid resistant!

I found a company in the US that makes a 2-part epoxy resin that is supposedly acid resistant, and sell it in 1 & 5 Gal quantities, and I need perhaps a 1/8 pint!

However, while thinking this through, and having read N Calder, who recommends using epoxy resin with a filler to seal the internal joints of a box, I'm wondering whether idea #2 above would work?

Still would value the thoughts of others ...

William

[mesquaukee]

We used to use rubber or neoprene gloves to handle acids.
Perhaps a piece of an old neoprene wetsuit would work as a gasket.

[BlueSovereign]

Originally Posted by mesquaukee

We used to use rubber or neoprene gloves to handle acids.
Perhaps a piece of an old neoprene wetsuit would work as a gasket.

Your post got the "lateral thinking" juices flowing. The result is the following chart which clearing indicates Flourocarbon resins are the best bet while your neoprene is not so hot:

Chemical Resistance Chart

I might be forgiven for thinking this chart might come in handy for a lot of posters!

[mesquaukee]

Interesting chart.
It is for long term exposure however. How long would it need to be contained?
You were saying you wantedto be able to remove the side of it for access.

Santoprene, on the extreme right of the chart, has an A rating. It comes as a flexible rubber tubing. Perhaps it could be used as an O-ring type seal.
See OMEGAFLEX® Santoprene Flexible Rubber Tubing it is mailorder.

[BlueSovereign]

Originally Posted by mesquaukee

Interesting chart.
It is for long term exposure however. How long would it need to be contained?
You were saying you wantedto be able to remove the side of it for access.

Santoprene, on the extreme right of the chart, has an A rating. It comes as a flexible rubber tubing. Perhaps it could be used as an O-ring type seal.
See OMEGAFLEX® Santoprene Flexible Rubber Tubing it is mailorder.

Great idea, however given the box design I doubt "tubing" is the way to go. I also note that the tubing doesn't appear to be very flexible circumference -wise.

Another problem is I'm "down-under" in NZ ... variety and selection are not words that are part of this country's vocabulary

If you can find flat pieces of this stuff it would be apprciated.

I too noticed the sanopene rating, but have been preoccupied with other matters to research further.

Really appreciate your assistance with this.

Regards

William

[Steve Pope]

I would suggest just using silicone, but you will probably find that the cat 1 inspector will be quite happy with them the way they are, as long as the battery (s) can't fall out if the boat is inverted.. I made mine out of ply then glassed them but didn't have the clever idea of having a removable panel so have to lift them in and out.

[BlueSovereign]

Originally Posted by Steve Pope

I would suggest just using silicone, but you will probably find that the cat 1 inspector will be quite happy with them the way they are, as long as the battery (s) can't fall out if the boat is inverted.. I made mine out of ply then glassed them but didn't have the clever idea of having a removable panel so have to lift them in and out.

See attached photo of battery boxes I designed, and then had constructed.

Note they are elevated 9mm from the box base, and with cleats proving 15mm spacing all around, to ensure adequate air-space.

One side removable with wing nuts, plus a bolt wing nut design to secure them in the box in case of a "roll".

Cleats are also positioned on the sole to ensure if/when you remove the boxes they can be returned to the exact same position to be re-secured to the sole.

Also attached is the larger (6 batteries) of my two new House Bank battery boxes

[FreeSail]

Yes I meant "butyl" tape.

[gonesail]

Nitrile rubber gasket

[BlueSovereign]

Originally Posted by gonesail

Nitrile rubber gasket

Correct me if I'm wrong, when researching this it appears to be more oil resistant than acid resistant.

[Cheechako]

Geez, maybe just see if the inspector notices it...? What a pein you guys have to go through....

[john540]

You can purchase "acid-proof paint" from Aircraft Spruce & Specialty. I think it only comes in black. I usually see it on aluminum battery boxes.
RANDOLPH ACID PROOF BATTERY BOX BLACK PAINT #345 from Aircraft Spruce

[BlueSovereign]

Originally Posted by john540

You can purchase "acid-proof paint" from Aircraft Spruce & Specialty. I think it only comes in black. I usually see it on aluminum battery boxes.
RANDOLPH ACID PROOF BATTERY BOX BLACK PAINT #345 from Aircraft Spruce

Thanks for this.

I wood like to think that an ordinary paint would surfice on the inside as long as all the joints are sealed with expoxy (even Sulfuric acid would take some time to eat its way through 3/4 marine ply). I've posted the B48 builders inquiring what they use .... everything is done "top of stds" on a B48.

Also keep in mind the batteries are sealed so the probability of acid leaking from AGM/Gels is significantly reduced (unless the casing cracks which is highly unlikely).

That said, acid-proof paint on the adjoining ends of the box and the removal side won't be adequate as I want a "sealing effect" of some sort.