Oil packs

mb2 · Post by **mb2** » Fri Dec 22, 2006 8:49 am

OK, so gel packs (with enclosures) are a great thing. but everyone is scared they're going to destroy their hard drive, and few of us have comprehensive backups of all that really important data (not to mention time spent installing/configuring).

i read on one of the posts about someone thinking of making their own gel packs.. So, wouldn't it be a lot better if u could make them with oil? (ie, the stuff that u see PCs immersed in). sure, immersion in the oil would surely kill a HDD, but a little hole/splash on the circuit board wouldn't.. making it IMO a lot safer.

So, how would u go about making ur own (strong-ish) packs

quietfreek · Post by **quietfreek** » Fri Dec 22, 2006 10:40 am

personally i would make shure the gel was thick enough so that even if the was a rupture it would nt spill out.

Agar gelly used for bacterial cultures would be perfect. if you filled the bag whilst it was hot and then you could set it to the shape required to fit to your HDD and even if the bag did tear your biggest concern would be fungal / bacterial growth, perhaps some bleach / detol in there wouold fix that

jaganath · Post by **jaganath** » Fri Dec 22, 2006 11:31 am

sure, immersion in the oil would surely kill a HDD, but a little hole/splash on the circuit board wouldn't.. making it IMO a lot safer.

The stuff in gel packs (ethylene/propylene glycol?) shouldn't harm the hard drive either, afaik.

BillTodd · Post by **BillTodd** » Fri Dec 22, 2006 4:24 pm

jaganath wrote:
sure, immersion in the oil would surely kill a HDD, but a little hole/splash on the circuit board wouldn't.. making it IMO a lot safer.
The stuff in gel packs (ethylene/propylene glycol?) shouldn't harm the hard drive either, afaik.

I believe they're mainly water (hence the heat capacity) thickened with methyl-cellulose, which makes them slightly caustic.

The oil idea is ok , but you'd have to find packaging that wouldn't be broken down by the lighter hydrocarbons in the oil.

I quite like the idea of casting the drive in jelly

There is an entire pc embedded in a gel on the www.epiacenter.com web site.

disphenoidal · Post by **disphenoidal** » Sat Dec 23, 2006 9:19 pm

quietfreek wrote: Agar gelly used for bacterial cultures would be perfect. if you filled the bag whilst it was hot and then you could set it to the shape required to fit to your HDD and even if the bag did tear your biggest concern would be fungal / bacterial growth, perhaps some bleach / detol in there wouold fix that

That would be really cool. Do you know where I can get my hands on some of that? Although I imagine you wouldn't know of a US distributor. How much does it normally cost?

proc · Post by **proc** » Sun Dec 24, 2006 3:42 am

I was thinking of a substitute for gel packs too.
The problems I see with oil are two:
1) it could probably break the plastic bag as noted by BillTodd
2) when heated oils expands a lot compared to standard gel packs

I was thinking of doing some experiments with silicon grease or zinc or copper based greases (they are used in cars and motorcycles). They should have nice thermal properties even if they can not beat water solutions on this field, but they should be safer than water and oil too (at least I hope so).

I have two raptor 36gb that are on a shelf because they are definitively too noisy and its a pity not to be able to use them, so when I'll have some grease to experiment with I'll report back for the SPCR community.

alleycat · Post by **alleycat** » Sun Dec 24, 2006 5:51 am

BillTodd wrote: I quite like the idea of casting the drive in jelly

That could be worth a try! I don't know what the properties of candle gel are, though.

pyogenes · Post by **pyogenes** » Sun Dec 24, 2006 1:28 pm

quietfreek wrote:personally i would make shure the gel was thick enough so that even if the was a rupture it would nt spill out.

Agar gelly used for bacterial cultures would be perfect. if you filled the bag whilst it was hot and then you could set it to the shape required to fit to your HDD and even if the bag did tear your biggest concern would be fungal / bacterial growth, perhaps some bleach / detol in there wouold fix that

Agar has great thermal properties. It melts at about 85C but solidifies around 35-40C so it's relatively easy to work with. A few pointers since I worked witht he stuf quite a bit (my degree was in microbiology)

Microbe growth shouldn't be a problem - agar is difficult to break down for most bacteria which is why it is used instead of gelatin in microbiology. Still, there are simple precautionary measures that can be taken.

bacterial growth is very easy to prevent - just dissolve a lot of salt into the agar before you use it (add salt until no more dissolves - perfectly okay if it crystallizes afterwards). Very few bacteria can survive extremely high salt concentrations and they aren't gong to be found around the house unless you have raw sea salts. And if those start growing, they aren't much to worry about - they don't cause diseases and if you're lucky they'll form some bright colors. (for those that care, those are technically not bacteria - it's archeabacteria)

Mix in some athlete's foot powder to prevent growth of mold.

Agar is available in grocery stores, but read the packaging, sometimes it's really just gelatin

ronrem · Post by **ronrem** » Sat Dec 30, 2006 5:19 am

Isn't part of the deal with gel that it has good heat transfer? In effect is both heatsink and cushion.

BillTodd · Post by **BillTodd** » Sat Dec 30, 2006 5:43 am

Isn't part of the deal with gel that it has good heat transfer

Not 'good', but considerably better than still air.