Kraton Dented, leaking ESC capacitor

[iLikeRCs]

So i dropped my ESC and dented one of its caps. It's now leaking a yellowish transparent fluid. Can I just add a cappack and not worry about that capacitor or do I need to replace it? It would be very hard to replace or remove as it's on the ESC itself, inside the waterproof silicone or whatever...

It's a max8 btw

 

[Camaroboy383]

Oof! Imminent death for that thing if the cap Is leaking.. it most likely will only power up one last time, and that will be short lived ..

Extremely difficult to get the potting off the esc, even harder to do so without destroying the case or board ..

 

[iLikeRCs]

Oof! Imminent death for that thing if the cap Is leaking.. it most likely will only power up one last time, and that will be short lived ..

Extremely difficult to get the potting off the esc, even harder to do so without destroying the case or board ..

Oh no does a leaking cap just short?

 

[Camaroboy383]

Oh no does a leaking cap just short?

They burn up, breaking the circuit..

 

[iLikeRCs]

They burn up, breaking the circuit..

What if I rip it out?...well try to

 

[Camaroboy383]

You can rip it out, the problem is getting one back onto the board..

Had a blx pop all the caps from a massive amp draw.. what I did was break the potting around the cap.. then I pulled straight up on the cap with pliers.. if you pull straight it will pull the pins out of the cap and leave them in the board..

Those pins are insulated with a coating.. it must be burned off with a torch then the pins need to be prepped with acid, or vinegar and salt before they will take any solder..

It's hackery in the end, but it may work for you..

 

[iLikeRCs]

You can rip it out, the problem is getting one back onto the board..

Had a blx pop all the caps from a massive amp draw.. what I did was break the potting around the cap.. then I pulled straight up on the cap with pliers.. if you pull straight it will pull the pins out of the cap and leave them in the board..

Those pins are insulated with a coating.. it must be burned off with a torch then the pins need to be prepped with acid, or vinegar and salt before they will take any solder..

It's hackery in the end, but it may work for you..

Does the board actually need all 3 caps to even power on? On my fpv and airplane ESCs caps are usually just added for extra filtering and the ESC would work without....like adding a cappack to car ESCs

 

[slick2500]

Does the board actually need all 3 caps to even power on? On my fpv and airplane ESCs caps are usually just added for extra filtering and the ESC would work without....like adding a cappack to car ESCs

If I remember correctly the esc will not power on even with 1 cap broken or missing.

 

[iLikeRCs]

If I remember correctly the esc will not power on even with 1 cap broken or missing.

well sh... Can't even afford a new one atm. If I try turning it on now, would that make things worse?

 

[Camaroboy383]

Does the board actually need all 3 caps to even power on? On my fpv and airplane ESCs caps are usually just added for extra filtering and the ESC would work without....like adding a cappack to car ESCs

So, yes and no... If you pulled that cap and crossed the 2 leads it should work.. the problem will be that when you pull some large amperage the other 2 will likely pop

 

[iLikeRCs]

So, yes and no... If you pulled that cap and crossed the 2 leads it should work.. the problem will be that when you pull some large amperage the other 2 will likely pop

As of right now it still turns on btw..tried it without a motor connected though. Maybe my cap is fine after all? It definitely leaked a bit though.

Anyways if not I have some cappacks with 35v 470uf caps in them, could I just take one of those to replace the 35v 390uf cap on there?

 

[Camaroboy383]

Ok, put a halt to everything said above at this point.. the cap may still stay alive if it has enough oil left in it to remain cool and stable..

Honestly I would take some alcohol on a q-tip and clean the rupture.. then apply a little rtv over the area... Let it dry completely for 24hrs then give it a go . It may live..

 

[iLikeRCs]

Ok, put a halt to everything said above at this point.. the cap may still stay alive if it has enough oil left in it to remain cool and stable..

Honestly I would take some alcohol on a q-tip and clean the rupture.. then apply a little rtv over the area... Let it dry completely for 24hrs then give it a go . It may live..

What's rtv?

 

[slick2500]

What's rtv?

Silicone sealant for cars. https://www.walmart.com/ip/Permatex...Q83mBtSuK0qwUkJeyMhoCxn0QAvD_BwE&gclsrc=aw.ds+

Autozone, Napa, Carquest and Oreilly should all carry this as well.

 

[Camaroboy383]

Room, temperature, vulcanizing silicone...

Gasket maker for automotive purposes.. any auto parts store will have rtv...

 

[Jerold]

Ok, put a halt to everything said above at this point.. the cap may still stay alive if it has enough oil left in it to remain cool and stable..

Honestly I would take some alcohol on a q-tip and clean the rupture.. then apply a little rtv over the area... Let it dry completely for 24hrs then give it a go . It may live..

That stuff inside the caps is very toxic and maybe caustic/acidic too. You don't want anything to do with it. Personally, I would cut your losses save the cancer for later. What I don't know is that stuff inside the caps is very toxic and maybe caustic too. You don't want anything to do with it. Just cut your losses save the cancer for later.

However, if you insist on cleaning this up, alcohol might work and "should be" OK. But unless you know what you're cleaning you are taking your chances, chemistry happens. So wear protective gear and be ready.

RTV (Room Temperature Vulcanization) Silicon may or may not seal up whatever is in there, it may last a day, week or forever; I dunno, but again chemistry happens, not that it will blow up but it may not stick or dry.

You would be better off to remove the cap entirely, clean up every possible place the fluid has gotten to and replace the cap. Getting every last drop is important because it's conductive and can cause a short.

 

[iLikeRCs]

That stuff inside the caps is very toxic and maybe caustic/acidic too. You don't want anything to do with it. Personally, I would cut your losses save the cancer for later. What I don't know is that stuff inside the caps is very toxic and maybe caustic too. You don't want anything to do with it. Just cut your losses save the cancer for later.

However, if you insist on cleaning this up, alcohol might work and "should be" OK. But unless you know what you're cleaning you are taking your chances, chemistry happens. So wear protective gear and be ready.

RTV (Room Temperature Vulcanization) Silicon may or may not seal up whatever is in there, it may last a day, week or forever; I dunno, but again chemistry happens, not that it will blow up but it may not stick or dry.

You would be better off to remove the cap entirely, clean up every possible place the fluid has gotten to and replace the cap. Getting every last drop is important because it's conductive and can cause a short.

Well I've already wiped the single drop of fluid that came out off. Was wearing gloves so should be fine

That stuff inside the caps is very toxic and maybe caustic/acidic too. You don't want anything to do with it. Personally, I would cut your losses save the cancer for later. What I don't know is that stuff inside the caps is very toxic and maybe caustic too. You don't want anything to do with it. Just cut your losses save the cancer for later.

However, if you insist on cleaning this up, alcohol might work and "should be" OK. But unless you know what you're cleaning you are taking your chances, chemistry happens. So wear protective gear and be ready.

RTV (Room Temperature Vulcanization) Silicon may or may not seal up whatever is in there, it may last a day, week or forever; I dunno, but again chemistry happens, not that it will blow up but it may not stick or dry.

You would be better off to remove the cap entirely, clean up every possible place the fluid has gotten to and replace the cap. Getting every last drop is important because it's conductive and can cause a short.

The thing is, I don't think i can replace that cap without breaking something.. and wouldn't pulling it out without desoldering make it leak even more?

 

[Jerold]

Well I've already wiped the single drop of fluid that came out off. Was wearing gloves so should be fine

Ok, don't lick your fingers then. It sounded like a it was smashed open.

If you try to seal it, check if often. Silicon is not resistant to all acids. The best solution would be to remove the cap and replace it,

What about sending to the MFG for repair?

 

[iLikeRCs]

Ok, don't lick your fingers then. It sounded like a it was smashed open.

If you try to seal it, check if often. Silicon is not resistant to all acids. The best solution would be to remove the cap and replace it,

What about sending to the MFG for repair?

MFG as in manufacturer? No idea, thinking that would cost a fortune? I'm also pretty sure they made it hard to repair on purpose so don't know if they would even do it.

About sealing, I have some pretty viscous silicone conformal coating for PCBs that dries under UV light, would that act the same as RTV?

 

[Camaroboy383]

That stuff inside the caps is very toxic and maybe caustic/acidic too. You don't want anything to do with it. Personally, I would cut your losses save the cancer for later. What I don't know is that stuff inside the caps is very toxic and maybe caustic too. You don't want anything to do with it. Just cut your losses save the cancer for later.

However, if you insist on cleaning this up, alcohol might work and "should be" OK. But unless you know what you're cleaning you are taking your chances, chemistry happens. So wear protective gear and be ready.

RTV (Room Temperature Vulcanization) Silicon may or may not seal up whatever is in there, it may last a day, week or forever; I dunno, but again chemistry happens, not that it will blow up but it may not stick or dry.

You would be better off to remove the cap entirely, clean up every possible place the fluid has gotten to and replace the cap. Getting every last drop is important because it's conductive and can cause a short.

Yes, it is electrolyte inside the caps.. let's not lick it..... You have a higher risk of cancer putting your cell phone to your ear...

Isopropyl alcohol will not react with electrolyte.. especially if it's just on a q-tip...

I've ruptured brand new caps to verify, and they were wiped, with no reaction, and then submerged in a bath of it, with no reaction..

MFG as in manufacturer? No idea, thinking that would cost a fortune? I'm also pretty sure they made it hard to repair on purpose so don't know if they would even do it.

About sealing, I have some pretty viscous silicone conformal coating for PCBs that dries under UV light, would that act the same as RTV?

Yes, that should work...multiple coats might prove to be best... but time is of the essence no matter the approach.. once that electrolyte starts to dry it will be game over...