SK-7 ... Rough surface? ... :-o

[Susquehannock]

Hi all...need some input please.
How many here have recently bought a Thermalright SK-7?

A friend and I both recently bought one from BestByte.net
and they have quite a rough surface. You could file your
fingernails on these machine marks. Really!:mad:

Started a thread about this over at AMDMB.com (http://www.amdforums.com/showthread.php?s=&threadid=216118) and, unfortunately, it
seems many others have received their SK-7only to find the
same machine marks.

[Royal Oaks]

Hmm, mine wasn't terrific, but I would not call it rough. Do you know where the others have ordered from??? I got mine from www.svc.com and the thing had an above average finish, not great. Do you by any chance have a pic??? If so, post that sucker on here and I will try and dig up and old one tomorrow after my exam. Ill catch up with this thread later to see, but I will try and show you a pic of my sink.

[felix88]

my old SK6 had some machine marks on the bottom, nothing major though. you could always fix it with a little lapping.

[Royal Oaks]

Alright I got an old picture for you. For some reason I don't have a pic of the SK-7 finish when I first bought it. Here it is though after a few months use....

[Susquehannock]

ThanX for image the Royal Oaks.

My SK-7 didn't look anything close to that. It wasn't even close!
Not only did it have machine grooves, but the surface wasn't
even close to being smooth enough to reflect light.:(

Unfortunately I lapped my heatsink last week. Try as I might I
just couldn't get a good image of the surface. So ....
I gave up and went to the shop to grab some sandpaper,
a piece of window glass, and a bucket of water.;)

It took over an hour to finish. Had to start off with 220 grit to get
the machine marks out. Once that was completed I concentrated on smooting. After various steps up in grit (cleaning between changes of course)
the surface began to shine. Now it has a 2000 grit finish that
looks like a copper mirror.:)

However, some say this is a waste of time. They assert that the
Xtremely smooth surface does not allow the TC (Thermal Compound)
to flow into the tiny pockets.
Not sure I agree with that yet though.


Which brings up the thread I started over at
AMDMB.com (http://www.amdforums.com/showthread.php?s=&postid=1757784#post1757784)
right when I got the sink in the mail. There has been some very
interesting discussion over there about heatsink lapping
and why a perfectly smooth surface is not always a good thing.
If you are into heatsink lapping it is certainly worth a look.

[OPTPrime]

2000 grit IMO is overkill, all you need is 400-600-800 ten minutes per grit and you should have a more than decent finish and great performing H/S

[felix88]

even if it looks like a mirror finish, it's probably still got some grooves and indentations.

think about how smooth the die of a Tbred chip looks, and then take a look at some of these zoomed pics:

http://www.xtremesystems.org/forums/showthread.php?s=&threadid=12278

[Susquehannock]

Originally posted by OPTPrime
2000 grit IMO is overkill, all you need is 400-600-800 ten minutes per grit and you should have a more than decent finish and great performing H/S


True, the 2000 grit finish is kind of an overkill. But it was
fun to see how shiny I could get the surface. 10 minutes per grit
is fine for the course stuff. But a really good polish job takes time.

It turned out pretty good IMHO.

[felix88]

thats pretty impressive. i really need to lap my 8045, maybe thats something i can do tomorrow.

[BrainStorm]

Here's a pic of my SK-7 after a little lapping. It looks worse than it feels, but it was somewhat rough when I got it. I really need to lap it some more, but I'm not sure I've got the patience :p

[Susquehannock]

Wow! That looks just like mine did.

Those cutter marks and the dish in the middle, exactly the same.

What do you think, is that surface intentional or a quality control oversight?:confused:

[antipop]

Originally posted by Susquehannock
True, the 2000 grit finish is kind of an overkill. But it was
fun to see how shiny I could get the surface. 10 minutes per grit
is fine for the course stuff. But a really good polish job takes time.

It turned out pretty good IMHO. Nice job, i lapped my maze3 but i had only 600 available, it took some time and the job is decent but it's not near a mirror like surface. I need to buy some of grit paper

[felix88]

Originally posted by Susquehannock
Wow! That looks just like mine did.

Those cutter marks and the dish in the middle, exactly the same.

What do you think, is that surface intentional or a quality control oversight?:confused:

maybe thats just the marks that the milling machine leaves? i'd think Thermalright would do a better job than that.

oh well, at least lapping isn't too hard.

[Susquehannock]

Originally posted by felix88
maybe thats just the marks that the milling machine leaves? i'd think Thermalright would do a better job than that.

oh well, at least lapping isn't too hard.


Yes, they are milling machine marks ... each little semi-circular
line is made by one of the cutters.

IMhO ...
That is NOT a specialy designed finish that Thermalright
came up with. It's a result of bad quality control.
The four punch marks were made after the surface was
milled so I'd say that somebody keyed the CNC production
machine incorrectly and the surface lapping step was omitted.


Like you said, lapping is easy enough though.
Good luck:D

[antipop]

Originally posted by Susquehannock
That is NOT a specialy designed finish that Thermalright
came up with. It's a result of bad quality control. Thermalright has always had good finished product, i hope it's only a minor mistake in the process that went undetected

[BrainStorm]

Originally posted by antipop
Thermalright has always had good finished product, i hope it's only a minor mistake in the process that went undetected

Actually, I've had a couple of ThermalRight HSs (An SLK-800 [see below] and the SK-7 above) lately come with a pretty crappy surface. Not sure why.

As far as lapping goes, I can never seem to get it completely flat. I usually end up with the edges being somewhat rounded. What's the cure for that? Just going slower? More water for lubrication?

Susquehannock, very nice lapping and polish job!

[Susquehannock]

Wow, that surface looks terrible BrainStorm.
It looks worse than my SK-7 did. Sorry to see that.:(

Someone has to send a letter to Thermalright and
ask about this problem.

When I build my gaming rig later this Summer I intend
to get either an SLK-800 or 900. If the surface is that
bad it's going right back to the vendor. Lapping a $20
heatsink is fine. But if I am going to pay $45-50 for one
it had better be right!


As far as keeping the corners from rounding....just be very
careful to keep the sink flat. The CPU core sits near the
middle. So a few rounded edges likely won't hurt anyway.;)

And always, ALWAYS use water. To get the polished surface you
see above, I had to thoroughly clean the paper of particles
every few passes once I got above 1000 grit.

To be honest, if that were my SLK-800 I'd be sending it back.
And a letter would be going out to Thermalright as well.


Good luck BrainStorm .:D

[BrainStorm]

That one already went back because the fins were way off of perpendicular to the base. The one I got in return was certainly better as far as both the base and the fins go, although quite honestly it didn't really seem to make any difference to the cooling.

[zakelwe]

I received an SLK900U the other day and that had similar machine marks on them. To be honest I think they look worse than they are, but you'd think that they would get rid of them just for appearance sake. Their heatsinks are not cheap after all!

I once polished the bottom of an old SK6 just to make it look pretty. I finally got down to using t-cut on it, which seemed very good at making it like a mirror. I eventually used an angle grinder to cut it in half to fit to a Rage 128 Pro for the vpu and the memory.

Regards

Andy

[Susquehannock]

Seems that many Thermalright buyers are getting heatsinks
with bad finish recently.
And some have the fins soldered on crooked too.



___________________________________________
edit:


See my other thread over at AMDmb.com. - LYNK - (http://www.amdforums.com/showthread.php?s=&threadid=216118&highlight=sk7+rough)

[antipop]

Originally posted by Susquehannock
Seems that many Thermalright buyers are getting heatsinks
with bad finish recently.
And some have the fins soldered on crooked too. That's really bad for their rep! Too bad there heatsink are the best available

[TerroH8er]

My SLK-800 had the same marks on them. I would think that Thermalright might want to finish them a little better so their heatsink recieves some better reviews, although I doubt they would be dumb enough to send a reviewer an unfinished heatsink.

[Susquehannock]

Yeah, imagine a reviewer saying: "This heatsink makes a nice fingernail file." :hehe:


Even the new SLK-900 have the machine marks.
Here's an image that someone posted here last week. The semi-circular
marks are clearly visible in the AS3.

[antipop]

I doubt that proves something, i mean you don't get the exact printing of the base of the hsf on the core, the guy here put too much as3 and when he removed the hsf, it was a bit like glue

[saaya]

well it prooves that theres something wrong with the guy at their milling machine :p

id say either drugs or incompetence. i bet the quality guy (assuming they have one) thinks it doesnt really matter if they shine like a mirror or they dont.

[Susquehannock]

Originally posted by antipop
I doubt that proves something, i mean you don't get the exact printing of the base of the hsf on the core, the guy here put too much as3 and when he removed the hsf, it was a bit like glue


yeah, way too much Silver.:rolleyes:

Look at the core. The machine marks are plain as day.
Just like a footprint in thick Silver mud! :hehe:

Looks exactly like machine marks ... if it's not the machine
marks on the bottom of the sink that made those semi-circular
lines, then somebody spent a lot of time making them look
EXACTLY like the machine marks that's on the bottom of many,
many ThermalRight heatsinks over the last few months.:p


In fact, they look exactly like the marks when we changed the CPU
in my bud's board a couple weeks back. He didn't have any
sandpaper when we put the 2500 on, so we left it as is
and made sure there was ample Shin Etsu compound to take up
the gap created by the dished surface on the bottom of the heatsink.

But when we took off the SK-7 to change over to the 1800 dLt3c,
we saw exactly what you see in the image above.
Well, portions of the Shin Etsu stuck to the heatsink. But from
what was left on the core you could clearly see machine
marks just as you see in the image above.


And what about the heatsinks with the fins soldered on crooked?
That's not to be overlooked either.
Don't get me wrong. ThermalRight makes some great
products. It just seems they are having a bit of trouble with
quality control.
It will be rectified shortly, if not already. Otherwise they
jeopardize ruining their illustrious reputation.

[Tettejaak]

Originally posted by felix88
thats pretty impressive. i really need to lap my 8045, maybe thats something i can do tomorrow.

Let us know the results please!:) I would like to lap mine if it does take effect.

[sandman]

my slk-90 wasn't smooth, but it wasn't too bad.

I lapped it up to 800grit.

[dioSRL]

also my slk900 had some machine marks on it. With some lapping (400-800-1200-1500), also for the cpu(to full copper) and I had a RISE in temps like 2C :)