Why are battery trays glued in with silicone?

[hughb]

A lot of builds mention using black silicone (RTV?) to glue in battery trays, whereas other things are glued in with JB Weld or other epoxy. What is the reasoning behind the silicone for battery trays?

I understand there will be a bit more flexibility with the silicone, and less likely to suddenly fail after a crash. But is the gluing/holding power of the silicone that strong in the first place? When gluing the trays in with silicone, should the bonding area be rough sanded like when applying epoxy, or would the bond be better on a smooth surface?

[Panther6834]

I'm glad you asked that question. Not because I have an answer...but, because I'm also interested in knowing. Gotta you could say it's one of those "I didn't even think to ask, so glad someone else did" questions.


~ More peace, love, and kindness would make the world a much better place

[1coopgt]

I have a feeling it's because Rtv will absorb some of the vibration. I could be wrong though.

[fweasel]

My HPR did 3.5 cartwheels on shore after a 106mph pass at last years Mini Shootout. The front end of the hull was damaged heavily. My 6S packs were strapped to lipo trays that were attached to the hull with black aquarium silicone, and there wasn't any signs of failure at the joint. I prep the hull with a light sanding, scuff the surface of the carbon trays, and clean with acetone, standard practice regardless of what I use to bond the parts with. The silicone is easier to work with for a long bond, and definitely offers some shock resistance vs. a rigid epoxy joint.

[hughb]

Thankyou for the responses, that makes sense. Fweasel was that your American Ethanol boat you are describing? That was a beautiful boat, and still is!

[plinse]

In my Baby Raptor I had the Motor-Carrier break loose after 2 1/2 years of intensive use. The carrier was glued in with epoxy and as time went by there were cracks that you don't see and finally the epoxy broke.

Carbon fiber plates are very stiff, the hulls are usually much weaker and have some flexibility when there are cartwheels, flips, whatever. As the silicone is flexible it does not break. It is great for motor mounts, battery trays, ...

[eehess81]

Would e6000 be a suitable replacement for silicone as it keeps some flexibility as well? About to mount my battery trays in my DF23 build and I have e6000 on hand.

[30nitro]

I think the E 6000 would work.....it's def not as flexible as silicone....real stinky too ! I would go with the black RTV.

[eehess81]

I'm mounting the trays on a thin piece of heavy foam so I can remove them/move if needed with a razor so I have some flex there. I'll pick up some of the rtx though

[eehess81]

RTV I mean

[Panther6834]

Which would be the better to use - Permarex Ultra Black (82180), or JB Weld 31319? Or something else?


~ More peace, love, and kindness would make the world a much better place

[fweasel]

Thankyou for the responses, that makes sense. Fweasel was that your American Ethanol boat you are describing? That was a beautiful boat, and still is!

Yessir. She's still a beauty. Body and paint work were finished in December, but unfortunately, the hull has only just now made it to my work bench for the rest of the rebuild. I've got about 4 weeks to finish it and make a few test passes before it goes back to war.

[eehess81]

While we are speaking of adhesive...I'm about to glue in some foam for flotation..should I use epoxy to add rigidity or would a more flexible silicone or e6000 be better?

[30nitro]

If it's rigid foam....i would...and have used silicone....others will chime in I'm sure...

[fweasel]

While we are speaking of adhesive...I'm about to glue in some foam for flotation..should I use epoxy to add rigidity or would a more flexible silicone or e6000 be better?

You'll gain no rigidity from attaching flotation foam to a hull. Most of mine is held in place by friction fit under the deck. If I attach pieces along the sides, I prefer a flexible adhesive like silicone.

[eehess81]

If you were to put it in with epoxy it might add a little rigidity, but that might be a bad thing. I'll go with silicone