Runnning warm on water?

[SilentDeath]

perspex is same as acrylic?I wouldnt use below 10mm as if it cracks (which the first acrylic blocks were known to do) you will end up with water everywhere.
Main cause of cracking was when tapping or screwing in barbs, mainly brass ones...

Ive got a 12mm thick, largeish sheet of white polyethylene here if any one wants a bit. This stuff doesnt crack atall and is water resistant. only problem is its not clear, and the surface is textured so you might want to lap it but you dont have too..

Ive spoke to the machinist thats probably going to cnc me some blocks, price is £40 each inc materials + four hours worth of milling, as two of you are machinists here, is that good? My design is great (IMO ) and I think I can sell them.

[GAteKeeper]

I agree with you SD - my english in that last post was sh1t. I meant to say that i didnt trust the perspex (a brand name of acrylic) to work as a hold down plate as well, which is what my design requires.

As to a price, not got much experience but £40 doesnt sound too bad. Four hours probably wont give you a good finish - might have to lap it your self but its not hard.

GAteKeeper

[madocks]

Main cause of cracking was when tapping or screwing in barbs, mainly brass ones...

I think the main cause of people breaking their perspex was lack of knowledge with regards to tapping;

The average person does not appreciate that to tap a 1/2 inch hole, that you will need to pre-drill approx 11.2mm (not a common size for the average DIY'ers tool box).

They will also find problem when they tap to 1/2 inch thread, as BSP threads are classed as "specialist" and not many people have them. Specially in todays metric era.

You must ebsure that you are tapping to the same pitch as the thread on the barb. EG: BSP, whitworth, NFS etc

Also when tapping it is vital that for every full turn clockwise on the tap, that you counteract with half a turn anti-clockwise to get rid of the little bits of plastic which clogs up the tap and causing cracks.

Also its worth noting that a set of taps has 3, one to rough out the thread, one to semi finish and one to finish it up nicely. I believe some people have actualy tried using the barbs as a tap.

My cover is made from perspex, I have no cracks and have presure tested it to 95PSI. Also it doesnt leak

[madocks]

Ive spoke to the machinist thats probably going to cnc me some blocks, price is £40 each inc materials + four hours worth of milling, as two of you are machinists here, is that good? My design is great (IMO ) and I think I can sell them.

Ummm, it depends, if youve gone to a cnc machinist who is a private company and is willing to create the program for you and knock them off through his business, 40 aint bad at all

However, if its a chap in work, or a friend thats doing it for you on the fiddle, 40 is cheaky. The milling on my water block took about 6 hours, that was by hand. If i had the option of a cnc mill, i reckon i could knock one of in under an hour. Sure lapping has to be done yourself, but you cant expect a mirror finish from a millng machine.

Perhaps haggle and get a north bridge out of him for the 40 quid too, then sell them on.

Gonna show us your design?

Any discount for the writing of the program? Ill do it for you if he lets you have it cheaper.

[madocks]

Then use some brasso to get it up to a bright sheen.
GAteKeeper

Is brasso a common lapping practice or something which you have done?

I wasnt sure about the properties of brasso, and know that some polishes also acts as a surface layer for scratches etc. I avoided using brasso in case it created a surface layer that would affect the heat transfer.

[SilentDeath]

Yes hes done the program (and changed it about 10 times becuase of my new ideas and is giving the materials for free (included in the £40). Hes lapping it to 1200 grit, tapping the holes, and providing oring seal and screws to fix it.
Ill pm you a pic of the prototype block, the final ones will be quite different though.

I think brasso creates a surface layer. I think instead you can use citrus acid (from a lemon) with salt. Cant remember the ingredients but it was something like that.

[GAteKeeper]

I use cherry coke to remove the crap brasso leaves behind as well as any finger prints and mild oxidation. Works better than you would have thought!

As to drilling and tapping perspex I have done it before - was going to make a bayres by hand but changed my mind about a res. Its not the tapping its the taper on the male fittings (part of the design of BSP) that causes the cracks, not that my first block had any that were caused by the fittings, they were all from the glue. I am more concerned with the stress that bolting the block down to the mobo will cause arround the holes, leading to catastrofic failure.
As you say you have to have the right taps & drills (11.8 for 1/4" BSP and 13.something for 3/8" BSP) I have 2 seconds and a bottom tap, seconds are ok as long as you can go all the way though the hole with the tap, otherwise you need to finish with a bottom tap.

I wouldnt mind seeing your design SD.

I need to get arround to knocking up a webby with my 3 designs on it.

GAteKeeper

[TeePee]

Is cherry coke better than vanilla coke? I've always used vanilla myself but will I get lower temperatures with cherry? What about diet?

[turkster]

I wouldnt use diet, you dont want to end up with a slimming block
You could use ammonia, thats used by jewellers to clean up copper.

Why not use polycarbonate for the top if you want to use plastic? Its virtually industructable although a bit more expensive than perspex. Anyway I dont quite see the point of using plastic apart from the fact that it is transparent.

[Shogun]

.
Anyway I dont quite see the point of using plastic apart from the fact that it is transparent.

Exactly, then you also have to worry about sealing it properly, where as with a full copper block you can just solder it shut.

[SilentDeath]

Soldering is the worst way to seal a block. It takes longer, cant be taken apart easly for cleaning and worst of all makes the insides all oxidised.
When you heat up copper, it oxidises about 1000x quicker than in normal air and then once its sealed theres no easy way to get the insides clean. You can use acid but its still better to aviod soldering.
My first two blocks are soldered btw

An o-ring is best imo as it gives a good seal and wont cause problems. You dont have to worry about the seal, it will work every time.

Ive also tryed using silicone sealant, it worked ok, no leaks.
Ive even tested with bluetack and that worked VERY well probably as well as sillicone.

Another reson for plastic is its MUCH quicker to machine, copper takes a while to do 12mm holes, where as polyethylene you can do it instantly.

Plastic is also a LOT cheaper. Copper costs loads, brass costs more...
Alu is not suitable for waterblock tops becuase of corrosion (even if anodised) and then cant be soldered anyway...

Polycarb is the best transparent plastic that I know of for waterblocks but there are far better plastics that are not transparent. LD polyethylene is one of the best imo.

[GAteKeeper]

O-rings are the best IMHO esp. if you can machine a proper grove for it to go in and use 4+ cap screws to clamp the top on properly.

I wouldnt solder it as as SD says it oxidises something cronic plus there realy isnt a need with the low pressures of water systems. BTW I have pressure tested hydrylic pipes for aircraft for a living using water and compressed air the seals were O-rings and they were tested up to 8000PSI ('bout 590BAR) and they sealed fine - was interesting when they went!

Personally I am going with a copper top and an o-ring -my last design used a peice of o-ring string super glued together. I havent found plastic cheeper than copper, I pay ~£5/kg for my copper (I think based on some quick in head arithmatic).

GAteKeeper

[turkster]

Yeah I'm using a thin (only 2mm) top with one hole at each corner. The barbs, just 1/2 inch copper pipe are soldered onto this with silver solder and the whole lot stuck and screwed down with all weather sealant. It has never leaked a drop and was quick and easy to make. Only problem is that it is a bit fragile.

I wouldnt solder it because it would be difficult to clean and of course impossible to open as Silent says. Saying that i've never opened my block in its 6 month life although I should probably check it out considering my system has a mixture of copper and alu in it . But my temps are fine so I couldnt be bothered

[GAteKeeper]

I wouldnt solder it because it would be difficult to clean and of course impossible to open as Silent says. Saying that i've never opened my block in its 6 month life although I should probably check it out considering my system has a mixture of copper and alu in it . But my temps are fine so I couldnt be bothered

You want to see what 3 weeks of Alu,Copper and de-ionised water do:



I was just testing and was planning to run for a couple of days while I modded my ATI 9600XT to take a GPU block but it didnt fit.

I had to spend a few hours cleaning it and re-testing the system with the 33% anti-freeze mix i am running now. My next block will be an all copper thing.

GAteKeeper

[turkster]

Hmm looks nasty. I wouldnt be surprised if mine was a lot worse than that because i used plain tap water, havent opened it for 6 months and have never chnaged the water . There's laziness for you .
I have an alu block with copper top with a copper pipe rad. The strange thing is that my temps are fine, in fact very impressive for a system with only a passive rad

[madocks]

Hmm looks nasty. I wouldnt be surprised if mine was a lot worse than that because i used plain tap water, havent opened it for 6 months and have never chnaged the water . There's laziness for you .
I have an alu block with copper top with a copper pipe rad. The strange thing is that my temps are fine, in fact very impressive for a system with only a passive rad

OMG, get some anti freeze or tapsafe in there