I want to make removeable thermal epoxy

Melectricus

Senior member
Feb 2, 2003
420
0
0
I've read a while ago you could mix thermal epoxy with thermal paste to create a removeable epoxy. Need to put heat sinks on a VGA card. Does anyone know proportions?

Guessing 1:1:1 of A:B:thermal paste.

Also what is good thermal paste to mix in. I have AS3, AS5, Silicone grease, and thermaltake tim.

Any help is appreciated.
 

Zap

Elite Member
Oct 13, 1999
22,377
7
81
You may need to experiment a bit since how much you mix in affects the permanence of the bond, as in you mix in more thermal paste and it becomes less permanent. I recall Arctic Silver used to have instructions with their AS Epoxy BITD and they said to just use the same thermal paste, in a 1:1 ratio with the epoxy already mixed. YMMV. I haven't been able to find the info that I remember, but the closest I've found is this:

Arctic Alumina Thermal Adhesive

Varying the ratio of the mix will not significantly affect the curing time, but may affect the strength of the final bond.

It doesn't say anything about that on the Arctic Silver thermal epoxy page.

I'd say to use Arctic Alumina thermal epoxy and a separate tube of Arctic Alumina. Mix the epoxy following directions, and then mix in a 1:2 to 1:1 ratio of Arctic Alumina to premixed epoxy. Then try it out. Note that from the time you start mixing, you only have about 3-4 minutes of time before it starts curing - need to have it all mixed up and on the heatsink and clamped together in that time.

Supposedly freezing components can cause epoxy to crack, so that may also be a way to remove stuff.
 

GalvanizedYankee

Diamond Member
Oct 27, 2003
6,986
0
0
OP/Zap, I tried AS Epoxy 70% to AS-5 30% on Intel fet sinks 1/4"sq. After setting over
a cool night, the sinks would dink off. So all got cleaned and AS Epoxy was used 100%.
If I were to do it again, the mix would be 80% to 20%. After setting over night the board
would be stressed to heat all up.

OP, can't you make a retention bracket for the VGA card's sink??

This is what we need. Anyone that can find it in the lower 48 gets :beer::beer::beer:

Shin-Etsu
1 component RTV
KE45W
Neutral Cure System


...Galvanized
 

Melectricus

Senior member
Feb 2, 2003
420
0
0
Thanks ZAP,
I did a little searching with some of your keywords :) and narrowed it down a little. Seems to be in the 1:1:1 to 1:1:2 range - nothing definite. I have a ton of the epoxy and tim laying around and a dead mobo to play with, maybe I'll head out to the garage and look for stuff to glue onto the chips and try a variation or two.

Edit: Yankee, it is for the ramsinks on a Zalman cooler. I'm pulling them off another card (held on by tape) the gpu is a physical retention bracket that I can use AS5 on. Maybe I'll try a proportion lower like you suggested as a baseline test 2:2:1
 

zagood

Diamond Member
Mar 28, 2005
4,102
0
71
Originally posted by: GalvanizedYankee
OP, can't you make a retention bracket for the VGA card's sink??

...Galvanized

Pretty sure he means to add ramsinks (since it's plural).

-z
 

Zap

Elite Member
Oct 13, 1999
22,377
7
81
AKA Frag Tape. Used some in the past with limited success. It holds okay if heatsink isn't too heavy and the contact surface is large.
 

TrevorRC

Senior member
Jan 8, 2006
989
0
0
Frag tape needs some time to cure, too, and it's a once-only thing...not quite as good as AS5, but not absolutely terrible, anyway.

In the case of copper though [your RAMsinks], I can see the problem. This is why it'd be better to go with aluminum or an Al/Cu mix... Aluminum is substantially lighter at a very low reduction in cooling capacity.

Looking into that stuff Galvanized.
--Trevor
 

Melectricus

Senior member
Feb 2, 2003
420
0
0
I don't have any frag tape laying around, and I have had mixed results anyway.

Well I did pull the old mobo out of the garage along with some fender washers and mixed up 6 batches of different combinations of thermal epoxy with artic ceramic and thermal grease. Kind of got carried away, we'll report back tomorrow how all 6 worked.
 

Zap

Elite Member
Oct 13, 1999
22,377
7
81
Your results should prove interesting one way or another. :thumbsup:
 

Melectricus

Senior member
Feb 2, 2003
420
0
0
First results from non-scientific tests A:B:TIM after 24 hours
White thermal grease:
1:1:2 Remained a paste
1:1:1 Harder paste
2:2:1 Like bad acrylic caulk

Artic ceramic
1:1:2 hardish paste
1:1:1 like acrylic caulk but pulled up way too easy
2:2:1 set pretty well but not strong enough

Suppose if I let them cure a few days it would be different. The thermal grease was a definite bust. 2:2:1 with ceramic may hold some promise with a light aluminum, but I would think it would need to be applied thicker than I would want to. I would definitely go to 3:3:1 with ceramic.

But hey what the hell, I'll try 3 mixes of AS5 tonight at the lower TIM ratios and see how it looks after 24hrs. Most people have AS5 around anyway.
 

Melectricus

Senior member
Feb 2, 2003
420
0
0
Could be we're mixing up: I think 4 to 1 is too much TIM using your terminology, I'm saying I think 6 to 1 is better, which is 3:3:1 in my terminology.

So you were right, the other ratios were wrong, but I think the ratio of yours that I used is also wrong - maybe. ;) Maybe Artic Silver 5 cures different, I'll let you know tomorrow.

I really didn't expect to fool around with this, curiosity got the better of me when I realized I had all this stuff laying around and didn't need to work on the VGA until the weekend :) I really do appreciate the input.
 

Melectricus

Senior member
Feb 2, 2003
420
0
0
If anyone is still interested, I did the artic silver 5 yesterday
2:2:1 set, came off with a twist of a plastic knife, not bad
3:3:1 set, came off harder probably best
4:4:1 set, brittle bond ( at this point it's hared to measure small quantities well) seemed like too low - after a longer cure I'd guess it would really hold.

So summary so far for different TIM mix:
1. Thermal grease seems to really mess up the epoxy set and makes it a hard paste, guess only a pinpont drop to a larger quantity of epoxy would work in a pinch.
2. Artic ceramic would work fine at 331 tho I didn't try there, dries like hard acrylic caulk. Maybe a longer cure it would be more solid.
3. AS5 dried more brittle but worked well at 221 or 331, I'd say either would work depending on the thickness of the film.

I'm done, If anyone asks the question, I'd first ask what they are mixing with epoxy then adjust accordingly. :beer: to all