Electronics in mineral oil ?????? - Page 1
Forum section: electronics / beginners

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 12:32:23 pm
content: Hello today i watched this videoand my question is ... would the thing just short and get damaged??? all the electronic parts are submerged in liquid...

author: Fsck
author_rank: Super Contributor
timestamp: May 26, 2013, 12:49:50 pm
content: it's non conductive-ish (not too significant)

author: plesa
author_rank: Frequent Contributor
timestamp: May 26, 2013, 12:55:16 pm
content: It will probably damage the unsealed components, mainly capacitors.

author: Balaur
author_rank: Unknown
timestamp: May 26, 2013, 12:57:58 pm
content: Quote from: ChrisGreece52 on May 26, 2013, 12:32:23 pmGeia sou,I don't comment on the PC in mineral oil stuff (bad idea for a variety of reasons). I'm just concentrating on this particular comment.Come on, you are a student, right? Why do you suppose that all liquids are automatically conductive?Have you heard about such thing as the resistivity? Go search for the resistivity of air - 1.3e16 to 3.3e16 ohm-metersHow much is the resistivity of mineral oil you ask? - around 1e11 - 5e10 ohm-meters which is OK with regard to that application.Have you not thought about doing a quick search on google before asking this question in the forum AND leaving a comment on Youtube.Excerpts from Wikipedia:QuoteApparently,  today's Greeks ask ignorant questions on Internet.PS: I love your country, I'm spending most of my summer vacations there.

author: firewalker
author_rank: Super Contributor
timestamp: May 26, 2013, 12:58:23 pm
content: And the fans will be struggling to move the liquid.Alexander.

author: eKretz
author_rank: Frequent Contributor
timestamp: May 26, 2013, 01:16:28 pm
content: Well, for all the nay-saying, if you go to the website, you can see that the initial computer was run submerged for over 3 years with no failures. They have since made a few more, and have had no problems with them. I'm not sure I would want something so bulky and mess-prone on my desk, but I wouldn't be afraid of reliability.

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 01:29:39 pm
content: It'd better run for longer than 3 years before the word "reliable" ever goes anywhere near it. Sure, it's reliableenoughfor the sort of person who would even bother with that (probably, it will be replaced/upgraded much sooner than 3 years anyway), but that doesn't make it truly reliable. I know I wouldn't touch it with a barge pole.

author: SeanB
author_rank: Super Contributor
timestamp: May 26, 2013, 01:31:43 pm
content: The hard drives might not like it......

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: May 26, 2013, 01:35:55 pm
content: Although the temperature will probably never get high enough to ignite it, the stuff is flammable:http://books.google.com/books?id=82ogYcG8kuAC&dq=mineral%20oil%20insulation&pg=SA8-PA6#v=onepage&q&f=falsehttp://en.wikipedia.org/wiki/Flash_pointhttp://www.sciencelab.com/msds.php?msdsId=9927364I don't think I would leave anything immersed in mineral oil unsupervised, oil fires spread easily.

author: Dave
author_rank: Super Contributor
timestamp: May 26, 2013, 01:38:10 pm
content: Often, liquid insulators are used, because they offer a far higher resistivity than just thin air. A good example would be power distribution transformers. They are fully submerged in oil, which provides both cooling and insulation.However, transformer oil is not suited for diy projects, like custom PCs, as it is highly toxic.So remember, if it is a liquid, it doesn't necessarily conduct electricity well.

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 01:42:35 pm
content: Quote from: Dave on May 26, 2013, 01:38:10 pmFor what it's worth, pure water has a conductivity of about 5-6 uS/m.Edit: Fixed typo.

author: SeanB
author_rank: Super Contributor
timestamp: May 26, 2013, 01:54:55 pm
content: Transformer oil is normally a very pure Napthenic oil, with pretty much no additives or impurities, as these actually reduce the resistivity of the bulk oil. Basically it is pretty much inert, and is meant to be that way. It does need a desiccator pack for high voltage use though as it is very slightly hygroscopic and condensed water accumulates at the bottom of the tank until it degrades the insulation. It is less toxic than any other oil, just from the lack of heavy metal additives. If it has been used with arc and other contamination however it can be very toxic, not from the oil but from the byproducts from arc damping and metal compounds in it and reactive breakdown short chains. Filter it, remove the acid and basic chains with a water scrub and ion exchange media and you get it close to new again and can reuse it in the same transformers.

author: firewalker
author_rank: Super Contributor
timestamp: May 26, 2013, 02:00:50 pm
content: Quote from: c4757p on May 26, 2013, 01:42:35 pmI believe it's uS/m for pure water. 5~6 mS/m would be drinking water.Alexander.

author: mariush
author_rank: Super Contributor
timestamp: May 26, 2013, 02:08:04 pm
content: I believe Tom's Hardware tried to do one submerged system and they found out they had to sort of epoxy (it was a long time ago, maybe they used silicon or something else) the insides of the cpu socket and the underside of the cpu socket and underside of vrm section...due to the closeness of traces and uninsulated solder points and high currents they got electric arcs and dead motherboards.Could have been from impurities in the oil or distilled water they used but anyway...Ah here we go, found the article... it was regular cooking oil :http://www.tomshardware.com/reviews/strip-fans,1203.html... pictures show acrylic coating and silicone cans.Pugent Systems does submerged systems and their faq says they don't have this issue:http://www.pugetsystems.com/submerged.phpbut i guess they use high quality oil, not cooking oil.

author: Dave
author_rank: Super Contributor
timestamp: May 26, 2013, 02:10:00 pm
content: SeanB, I just researched transformer oils a bit and you are right, the new oils don't really pose a health threat. Old transformers (before 1979) used polychlorinated biphenyls and that stuff was toxic. I must have picked up this out-dated information from somewhere and it stuck. Oops.

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 02:10:32 pm
content: Yeah, I'd say if the oil iscausingconductivity you're using the wrong oil...

author: madires
author_rank: Super Contributor
timestamp: May 26, 2013, 02:22:59 pm
content: Quote from: Dave on May 26, 2013, 02:10:00 pmNewer stuff also uses silicone oil and other synthetic oils. Those take more heat and expand less than mineral oil.

author: electronupdate
author_rank: Regular Contributor
timestamp: May 26, 2013, 02:42:48 pm
content: A timely question, here is a good commerical example of liquid cooling. It's a LED light bulb that I just finished tearing down. The vendor claims silicone based oil as the liquid:The review of the bulb is this video:

author: ResR
author_rank: Regular Contributor
timestamp: May 26, 2013, 03:08:57 pm
content: I used discarded car oil and submerged a flip-flop flashing led circuit into that as an experiment and I didn't find any difference in operation (only visibility was reduced due to stuff floating in oil). If that didn't cause any significant problems so pure mineral oil can be used theoretically as long it is clear. Of course HDD-s didn't like to operate in oil because it has much bigger friction than air.

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 03:15:11 pm
content: Discarded motor oil? Submerge something with higher impedance or tighter impedance tolerance than a little LED flasher and see what happens. The stuff's loaded with metallic debris...

author: mariush
author_rank: Super Contributor
timestamp: May 26, 2013, 03:23:46 pm
content: In theory you can use a hdd in oil ... just add a pipe/hose of some sort over the vent hole so that air can get into that vent hole and balance the pressure inside.The motor shouldn't have a problem spinning as it's somewhat completely inside the metal.

author: SeanB
author_rank: Super Contributor
timestamp: May 26, 2013, 05:41:01 pm
content: Quote from: madires on May 26, 2013, 02:22:59 pmPCB based oils were used for high heat dissipation and low capacitance, as they are non polar molecules and have a higher boiling point than the Napthetic mineral oils. They also are carcinogens, and were very commonly used as a plasticiser in PVC until the 1980's, if you have old PVC which is exuding a sweet smelling liquid which is green where it contacted copper this is PCB oil. They are also very resistant to arcing and do not break down easily chemically, which is why they were used. Unfortunately they are around still in older equipment, as the transformers only had oil changes, with a flush of solvent ( R11, R12, R141b most commonly) to get most of the loose oil out, the remainder being well adsorbed into the insulation. Still in a lot of buildings as well, you take it out with the asbestos if you need to change, as it is very expensive to rip out all wiring and steel conduit from concrete. The funny thing is in transformers the extra insulating properties were unused, as they are conservatively designed and the original coolant they are designed for is the straight mineral oil.If you can seal the case of the computer then you can use high molecular mass gases for cooling, like refrigerants and other gases that are liquid or boiling at close to STP. The original Cray used R11 as a coolant as it boils at 23C at 1Atm pressure, and is easy to work with. Too bad you can only buy it in the USA and China.

author: marcel.j
author_rank: Newbie
timestamp: May 26, 2013, 08:42:25 pm
content: Hi all,I placed my Computer in mineral Oil and it is now already running for Two years. I am using an SSD because an HDD won’t work for long. The only Problem I have is cooling the whole thing! You can use normal Fans but because of the higher density of Oil they will break a lot faster.All The BestMarcel

author: M. András
author_rank: Super Contributor
timestamp: May 26, 2013, 08:43:42 pm
content: why put the hdd in the oil too? its fine in the free air too

author: Falcon69
author_rank: Super Contributor
timestamp: May 26, 2013, 08:52:08 pm
content: Guys, this is nothing new. People have been doing stuff like this for years. You don't even need fans if you submerge the system in mineral oil or distilled water. Water is better because the viscosity is less and can flow easier. All you need to do is develop a system that circulates the H20 and send it through external radiators that are cooled by fans.It must be distilled water. Distilled water is non-conductive, but the water from your faucet has minerals in it which makes it conductive.

author: marcel.j
author_rank: Newbie
timestamp: May 26, 2013, 09:13:36 pm
content: mineral oil is better because of the Temperature and the Radiator is useless without movement of the Fluid.-> Fans

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 09:18:05 pm
content: Quote from: Falcon69 on May 26, 2013, 08:52:08 pmI would be nervous something would dissolve in it and it would become conductive. I'd hate to add an entire rather large class of chemicals to the list of things that destroy my computer if they fall in...

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:43:24 pm
content: Quote from: Balaur on May 26, 2013, 12:57:58 pmThanks for your kind wordsi am a student indeed but not all liquids are conductive... i also did a research about that and i found out that it is conductive from yahoo answers (I know not the best place for answers but ...)

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:44:59 pm
content: Quote from: firewalker on May 26, 2013, 12:58:23 pmBut if it is not conductive as some of the replies suggest then you could remove the fan .....

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:48:36 pm
content: Quote from: 4to20Milliamps on May 26, 2013, 01:35:55 pmThanks for the info that would be the last possible thing i would imagine but ... if someone thinks that this would be a good way to overclock their CPU and keep its temperature down that would be explosively () wrong ....

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:51:13 pm
content: Quote from: Dave on May 26, 2013, 01:38:10 pmYeah but even the idea of puting your PSU under any liquid is a bit weird

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:53:34 pm
content: Quote from: firewalker on May 26, 2013, 02:00:50 pmWikipedia ApprovesQuotehttp://en.wikipedia.org/wiki/Conductivity_(electrolytic)

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 10:59:32 pm
content: Quote from: mariush on May 26, 2013, 02:08:04 pmWell i got to admit that it looks cool but isnt this a bit risky for you , your house and your Hardware of course? if anyone tries to overclock the CPU it might ge thot enough to ignite the oil .... but still i am not sure about it ... the tomshardware site suggest coocking oil .... (which i think is highly conductive) and the other site suggest the use of mineral oil..... also i found this site (recommended at the bottom of the toms hardware site)http://www.tomshardware.com/news/Server-Cooling-Hardware-mineral-oil,17348.html

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 11:00:56 pm
content: Quote from: ChrisGreece52 on May 26, 2013, 10:59:32 pmThat would be onehellof a hot CPU.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:07:55 pm
content: Quote from: electronupdate on May 26, 2013, 02:42:48 pmThanks for the videos very educational and as you said a great exampleyou got a subscriber

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:10:06 pm
content: Quote from: c4757p on May 26, 2013, 03:15:11 pmSo he was lucky enough not to get a short even with pieces of metal floating around the circuit

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:13:33 pm
content: Quote from: marcel.j on May 26, 2013, 08:42:25 pmCould you use watercooling method??? would a simple pump like the ones used in a pc do the job??? it would just need to pump some amount of liquid out of the pc and there you would have a fan cooling the liquid down .....

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:18:07 pm
content: Quote from: Falcon69 on May 26, 2013, 08:52:08 pmWell i did not know these things .... and frankly i thought it was a new technique

author: Monkeh
author_rank: Super Contributor
timestamp: May 26, 2013, 11:23:25 pm
content: Quote from: ChrisGreece52 on May 26, 2013, 10:51:13 pmNo, it's really not. Liquid cooling (in various forms, submerged and otherwise) has been used in high power and high voltage electrics and electronics for longer than you've been around. Longer than most if not all people on this forum have been around..

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:26:40 pm
content: Quote from: c4757p on May 26, 2013, 09:18:05 pmRight for example NOTHING WITH SALT on the pcbut lets be real if the volume of the "case" is 50 liters ( just a random number but pretty close to what the real thing would be) and the components take about 10 liters from that volume we have 40 liters of distiled water ... if 10 grams of salt fall in this we havep = 0.01 / 40 (from wikipediahttp://en.wikipedia.org/wiki/Concentration)the result is 0.00025 grams / liter which is not that great but i have no idea how to calculate if that would be conductive.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:27:38 pm
content: Quote from: c4757p on May 26, 2013, 11:00:56 pmYeah not only because of the overclock but because of the bad heat dissipation of mineral oil.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 26, 2013, 11:28:47 pm
content: Quote from: Monkeh on May 26, 2013, 11:23:25 pmI had no idea but still the mineral oil that would be used for the submersion would have poor heat dissipation .

author: Monkeh
author_rank: Super Contributor
timestamp: May 26, 2013, 11:32:16 pm
content: Quote from: ChrisGreece52 on May 26, 2013, 11:28:47 pmIt has better thermal conductivity than air (not to mention the added thermal mass) and greater electrical insulation than air. It's a pretty logical choice and you'll find it anywhere you look at the combination of high power and high voltage.

author: c4757p
author_rank: Super Contributor
timestamp: May 26, 2013, 11:56:44 pm
content: Quote from: ChrisGreece52 on May 26, 2013, 11:26:40 pmWell, I was curious and tried to do the calculation myself, when it occurred to me: uS/m? Why is it siemens per meter? The conductance shoulddecreasewith distance, so shouldn't it be ohms per meter or siemens*meters? What am I missing here?

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 12:16:24 am
content: Quote from: c4757p on May 26, 2013, 11:56:44 pmConsider a cube of sideL, with electrical contacts on two opposite faces. The conductance increases with the cross-sectional area and decreases with the distance between faces. Thus:(conductance) = (conductivity) xL2/LSubstituting units of measure, we have:S = S/m x m2/ m

author: c4757p
author_rank: Super Contributor
timestamp: May 27, 2013, 12:27:15 am
content: Yes, that makes perfect sense. Stupid me was picturing a line between the two points, not a volume. Thank you.

author: amyk
author_rank: Super Contributor
timestamp: May 27, 2013, 05:56:52 am
content: Some more examples of oil (and water) for insulation:http://en.wikipedia.org/wiki/File:Z-machine480.jpghttp://youtu.be/Q4ffx5eX39E

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 08:45:59 am
content: Quote from: c4757p on May 26, 2013, 11:56:44 pmIn this case i think i miss something and i am getting confusedill give it a reaserach when i find the time.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 08:47:29 am
content: Quote from: IanB on May 27, 2013, 12:16:24 amThank you but personally i did not got a thingi am not familiar with conductivity calculations i only searched a bit yesterday

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 08:51:23 am
content: Quote from: amyk on May 27, 2013, 05:56:52 amAnd logicaly for creating X rays the you need high voltage transformer so in both cases the oil was used as an insulator .... my whole life is a lie

author: JackOfVA
author_rank: Unknown
timestamp: May 27, 2013, 11:06:32 am
content: As far as human safety of mineral oil goes, you will find it stocked at drugstores in a grade suitable for human consumption. (It's a laxative.)Mineral Oil has a flash point of 170C (335F), and a boiling point of 310C (590F) A typical transformer oil (Conoco/Phillips 76 Transformer Oi) has a flash point not much different > 293°F / > 145°C. As I understand it, neither are classified flammable under the relevant US classification scheme because the flash point exceeds 100C/212F.According to Conoco 76 Transformer Oil MSDS, you can drink it as well: "Ingestion (Swallowing): No harmful effects expected from ingestion."Although mineral oil may not be as good as transformer oil for heat conductivity, it's still quite usable as a coolant. Heathkit made, starting in the 1960's, a high power 50 ohm transmitter load, the "Cantenna" consisting of a carborundum resistor mounted on the lid of a 1 gallon paint can. The purchaser assembled the kit and locally procured a gallon of either mineral oil or transformer oil to fill the can.http://www.repeater-builder.com/test-equipment/heath/hn-31-cantenna.pdfHeath's time versus dissipation plot below shows the difference between mineral oil and transformer oil. Over a long enough time, no difference, but a considerable short term difference.Higher quality dummy loads, such as those manufactured by Bird Electronics, use silicon-based oil as I understand it. Not sure whether that was the case in the 1950's though.I have a Cantenna that's 45 years old, still has its original fill of mineral oil. Not the worlds best dummy load, but certainly adequate for many tasks.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 12:21:20 pm
content: Quote from: JackOfVA on May 27, 2013, 11:06:32 amOh ok then

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2013, 04:23:19 pm
content: My Kenwood Dummy load lost part of the oil fill from years of cycling. Topped it up ( was still factory sealed, losses are from weeping past the PL259 plug seals) with around 200ml of silicone oil and it works well again without gurgling.

author: ddavidebor
author_rank: Super Contributor
timestamp: May 27, 2013, 04:27:57 pm
content: One of the old cray supercomputer was liquid cooled with the fluid in direct contact with the ic and the board.I suppose 3M still made that fluid

author: kfitch42
author_rank: Frequent Contributor
timestamp: May 27, 2013, 05:06:05 pm
content: http://en.wikipedia.org/wiki/Fluorinert

author: G7PSK
author_rank: Super Contributor
timestamp: May 27, 2013, 05:28:47 pm
content: Transformer oil does not burn very well, I had a 25 liter drum to top up a welding transformer years ago. Just recently I lit a bonfire that was a bit damp so I looked around for some wast oil which is what I would normally use but could not find any so I tried the remains of the transformer oil, it would not burn even when mixed with some petrol and diesel once the petrol burned off it left the transformer oil.

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 05:44:34 pm
content: Quote from: G7PSK on May 27, 2013, 05:28:47 pmThis is because, against intuition, liquid does not burn. What actually burns when you set fire to petrol or alcohol is the vapor coming off the surface of the liquid. If you have a heavy oil like transformer oil there is so little vapor coming off the surface of the liquid that it cannot form a flammable mixture with the air and so it cannot make a flame.When it is desired to burn heavy oil there are two possibilities. One possibility is to pass the oil through a heating coil on the way to the burner so it has a much higher vapor pressure before reaching the flame. Another possibility is to atomize the oil into fine droplets before spraying it into the flame. This way the existing flame will heat up the droplets and evaporate them so they can burn. It is not uncommon to use both approaches at the same time--preheat the oil and then atomize it at the burner.

author: SeanB
author_rank: Super Contributor
timestamp: May 27, 2013, 05:57:41 pm
content: Jet fuel is pretty good at putting out fires, and to get it to burn takes a bit of work. Soak paper in it, have an unsoaked bit to act as a wick and light it. It takes a while to get hot enough to carry on vapourising on it's own heat, but when it does it burns really well. We used it as a firelighter, easy enough to tap the nearest aircraft fuel system water collector for a half litre to use. Another use was as a cleaner for PCB's, it removed a lot of gunk and then was easy to remove with alcohol, also an aircraft fluid.

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 08:39:25 pm
content: Yes, jet fuel is essentially kerosene, which is a petroleum distillate heavier than gasoline but lighter than fuel oil. Distilled petroleum spirits are a notably good solvent. They are the key component of those cleaning products like "Goof Off" or "Oops!" that you find here in America, and also the main component of "white spirit" or "clear mineral spirit" that is also a good cleaner.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 09:05:24 pm
content: Quote from: IanB on May 27, 2013, 08:39:25 pmI think with this question we will go far from the topic but then how it is used by airplanes

author: c4757p
author_rank: Super Contributor
timestamp: May 27, 2013, 09:10:44 pm
content: It's just hard to ignite. It burns quite well once it does ignite, though...

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 09:14:09 pm
content: Quote from: c4757p on May 27, 2013, 09:10:44 pmOh ok

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 09:14:18 pm
content: Quote from: ChrisGreece52 on May 27, 2013, 09:05:24 pmIt keeps the engines very clean, obviouslyI'm not sure of the nature of your question? Jet fuel is burned in jet engines to produce heat and ultimately thrust to make the plane move. Look up "jet engine" or "gas turbine" to get more information about how such engines work.Inside a jet engine there is a combustion chamber where the fuel is injected as a fine spray into the hot flame. The hot flame evaporates the fuel allowing it to mix with air and burn, continuing the process.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 09:18:52 pm
content: Quote from: IanB on May 27, 2013, 09:14:18 pmOHHHHH ok but your description reminded me the Thermal engines as we call them (free translation) the ones which i am taking exams on tomorow(if this name did not sounded familiar we are studying single particle gasses "perfect gases" and examining their use inside a machine we also study the Carnot machine* I KNOW THAT WAS OFF TOPIC*

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 09:31:27 pm
content: Quote from: ChrisGreece52 on May 27, 2013, 09:18:52 pmThe English translation would be heat engine. The Carnot cycle is a classic cycle studied in thermodynamics as it is represents the most efficient system possible for converting heat into work.There are many heat engine cycles possible. The jet engine or gas turbine uses the Brayton cycle, for example.

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 09:39:13 pm
content: Quote from: IanB on May 27, 2013, 09:31:27 pmNow That i mean to sayand thanks for your help with the translation and your skill to understand me

author: IanB
author_rank: Super Contributor
timestamp: May 27, 2013, 09:56:55 pm
content: Well good luck with your exams! Thermodynamics is a subject that gives many people a headache

author: ChrisGreece52
author_rank: Frequent Contributor
timestamp: May 27, 2013, 10:00:41 pm
content: Quote from: IanB on May 27, 2013, 09:56:55 pmWell it gave me one thats for sure i am still a bit defensive about this but ill do fineanyways goodnight and talk to you i got my answer to my oil PC question ill do a bit of reasearch on the combustion engines and ill be fineAnd thank you and all of the othe members that helped me with this