Can Liquid Metal be used on 100% Copper IHS/Heatsinks?

Rev_Night · 19 Aug 2020 at 17:44

Hi all,

I am about to tackle a few liquid metal projects (1 cpu, 2 gpu) using TG Conductonaut and I thought I had all my bases covered. Now I am reading that TG only recommends using it on nickle-based copper IHS/heatsinks. All 3 of the intended items are 100% copper, not nickle based. Does this mean that I can't use liquid metal on 100% copper? Will it need to be replaced in a year? I have zero interest delidding this yearly. A few reddit threads are saying that GA + CU = CU Alloy, can lead to issues.

FYI, I will be using Kapton tape around all dies/heatsinks to help protect the pcb. Delid will be sealed in the 4 corners by crazy glue.

CPU: I7-6700K Delid. Copper IHS from Rockit 88

GPU 1: Sapphire Pulse 5700xt

GPU 2: Sapphire Nitro 480x with Arctic Cooler Twin Turbo II

LtMatt · 20 Aug 2020 at 03:47

Yes it can be used on copper without issue, it just leaves a stain which does not harm performance but will not come off.

I used liquid metal on my Sapphire Nitro+ 5700 XT with great success.

Toothy1911 · 20 Aug 2020 at 06:52

I've avoided it because of the staining. I feel people wouldn't understand come resale for waterblocks. Otherwise it's fine, providing you only get it on the die.

Rev_Night · 20 Aug 2020 at 14:46

LtMatt said:
I used liquid metal on my Sapphire Nitro+ 5700 XT with great success.

Can you define that please? How much of a less of C in both core and temp?

LtMatt · 20 Aug 2020 at 15:04

Rev_Night said:
Can you define that please? How much of a less of C in both core and temp?

Roughly 10-15c core/junction improvement for me, but the paste on my 5700 XT was drier than one of Ghandi's flip flops.

Prior to using LM, there was a 30c difference between the temps, afterwards a peak of 15c difference, sometimes close to 10c or less with a undervolt.

Rev_Night · 20 Aug 2020 at 15:52

lol. thanks man. I'll run a 3dmark firestrike/furmark before and after, with the same fan curve, and post the temps.

Rev_Night · 24 Aug 2020 at 15:19

LtMatt said:
I used liquid metal on my Sapphire Nitro+ 5700 XT with great success.

curious, did you do any sort of polishing on the heatsink before you applied the LM?

LtMatt · 24 Aug 2020 at 15:55

Rev_Night said:
curious, did you do any sort of polishing on the heatsink before you applied the LM?

Nah, far too much effort. Just cleaned the old paste off and applied new to the GPU core and then the heatsink and re-attached it.

Rev_Night · 24 Aug 2020 at 15:59

perfect, thats all i did. I obviously used several coats of 99% rubbing alcohol to make it nice and pretty, but not anything fancy