Thermal Epoxy Filler- Calcium Carbonate Experiment

[FighterCat57]

Just a heads up, I plan to experiment with some Calcium Carbonate filler mixed at 50% Part A epoxy resin. Essentially larger amounts of Arctic Silver epoxy.

The plan is to run two aluminum tubes along side of an ESC and simply mold the ESC and water tubes into a solid piece.

The theory is the Calcium Carbonate's thermal transfer properties will transfer heat to the aluminum tubes allowing the water to dissipate that heat, essentially turning the entire molded ESC into a water cooling block.

The second plan is to mold the ESC to an aluminum plate counter sunk into the tail of the hull where it comes in direct contact with water.

If this works as theory suggests, I think it could revolutionize the way we approach ESC water cooling.

If not, I'll have a big gooey blob of what used to be an ESC in the hull.

For testing, I'm using Suppo 125a ESC's as they are the least expensive. This may also prove to be a solution for cooling the center boards on the 200a ESC's.

[FighterCat57]

Well... so far it looks like I'm headed towards a big gooey blob!

The blob ate my swordfish!

I think it may take some time for the epoxy to set. It's only been 24 hours.

No sense in testing it until it's completely dry. Moisture has thermal capacity and will most likely skew results.
P1184341s.jpg

[FighterCat57]

Note; the patina looking areas are actually play doh that I used to seal the mold. BAD IDEA. I'll try to find a more stable modeling clay next time.

Low fat molding technique.
P1184337s.jpg

[electric]

Watching this thread for results...

[FighterCat57]

If there's any epoxy guru's out there, I'm having issues with it hardening. I've never used epoxy as a mold this thick so am not sure what to expect.

Would be nice to have more ESC's to play with. If that Suppo order ever get's here I will!

[m4a1usr]

This may also prove to be a solution for cooling the center boards on the 200a ESC's.

Other than Ray S taking apart the FET boards on his cooling scheme/ plan I have yet to see anyone address the heat generated from the second power board. Cooling one set of boards and encapsulating the entire ESC only addresses waterproofing. It does not make for a cooler ESC. It actualy makes the cooling issue worse and all heat will require conductive, not convective methods for removal. Dont be in too big a hurry to bottle up the heat unless removal is adequately addressed.

John

[FighterCat57]

Other than Ray S taking apart the FET boards on his cooling scheme/ plan I have yet to see anyone address the heat generated from the second power board. Cooling one set of boards and encapsulating the entire ESC only addresses waterproofing. It does not make for a cooler ESC. It actualy makes the cooling issue worse and all heat will require conductive, not convective methods for removal. Dont be in too big a hurry to bottle up the heat unless removal is adequately addressed.

John

The purpose of the calcium carbonate is to conduct heat not encapsulate. Essentially turning the epoxy into a thermally conductive material.

[driftah]

hey

good luck with it bro sounds good in theory and why the heck not try it lol.ps those himodel esc's were poooooched they had blown enough caps to sink a ship lol I couldnt get 5 good ones outta the ten there were, and those fets that popped toasted some of the diodes on the boards too lmao paperweights but I tried my darndest thx man.oh and trying to get the caps unsoldered needed some tiny tools very awkward hehe.

[GP73]

Have you tested the thermal conductivity?

I can't find much on the net, wikipedia lists calcium as 201 W·m−1·K−1, while this other page (http://www.ima-eu.org/fileadmin/cca/ccawhat.html) is listing calcium carbonate in between 2.4 and 9, which would be awful for your purposes.

[FighterCat57]

Calcium Carbonate is used in commercial thermal epoxy processes and is a patented process. I just need to get the mix right for my little setup.

[FighterCat57]

good luck with it bro sounds good in theory and why the heck not try it lol.ps those himodel esc's were poooooched they had blown enough caps to sink a ship lol I couldnt get 5 good ones outta the ten there were, and those fets that popped toasted some of the diodes on the boards too lmao paperweights but I tried my darndest thx man.oh and trying to get the caps unsoldered needed some tiny tools very awkward hehe.

Well, was worth a shot!

I'm really not interested in trying to make a Suppo ESC for marine use. I'm only using them because they are cheap.

The purpose of this is to determine if the Calcium Carbonate filled epoxy mix will indeed help conduct heat away from the source. If in fact it does work, there are some good possibilities for potential use with more expensive ESC's in more durable setups.

[Steven Vaccaro]

Interesting idea, I look forward to the results.

The only problem is repair. Hifei will warranty esc's by repairing them. This method removes that option.

[CornelP]

You already have thermally conductive epoxies, designed for this... They are actually thermally dissipative, but will be ok in our applications.

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=552-668+&x=0&y=0

As far as I tested this one it works ok.

[FighterCat57]

Interesting idea, I look forward to the results.

The only problem is repair. Hifei will warranty esc's by repairing them. This method removes that option.

Well... there is more than one problem. This is only a proof of concept test to help submit to real manufacturing faculties who have the capacity to test and produce real, usable products.

In the case of marine electronics, using a stable thermally conductive encasement, in theory, is viable solution to dissipating unwanted heat.

[FighterCat57]

You already have thermally conductive epoxies, designed for this... They are actually thermally dissipative, but will be ok in our applications.

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=searchProducts&searchTerm=552-668+&x=0&y=0

As far as I tested this one it works ok.

Ah, well then. There we are. That's what we're looking for. Potting compound. =)