Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

To paint or not to paint - Heatsink Question
To paint or not to paint - Heatsink Question
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 9th October 2018, 02:38 PM   #11
Soundhappy is offline Soundhappy  France
diyAudio Member
Soundhappy's Avatar
Join Date: Oct 2012
Location: Montpellier near Mediterranean Sea France
ShopBuilt - How to Anodize Aluminum!

Quality work
class A amplifiers with full range speakers
sings like angels in heaven
  Reply With Quote
Old 9th October 2018, 03:07 PM   #12
oreo382 is offline oreo382  Canada
diyAudio Member
Join Date: Jan 2013
Location: Winnipeg
Paint is better,just don't paint the area where the transistor/mosfet is mounted.
  Reply With Quote
Old 9th October 2018, 03:20 PM   #13
metalman is offline metalman  Canada
diyAudio Member
metalman's Avatar
Join Date: Jun 2003
Location: Victoria, BC, Canada
As a practicing professional materials engineer, let me weigh in.

From a purely thermal point of view, best option is to apply a thin coat of a matte black paint. Stay away from glossy finishes.

Heatsinks are overwhelmingly convective as far as heat transfer goes, so it won’t make a big difference, but a matte black paint will have a much higher emissivity than the “silver” aluminum for radiative transfer. A thin coat of paint will only create a negligible effect in terms of insulating against conductive heat transfer.

Darn career gets in the way of my audio addiction!
  Reply With Quote
Old 9th October 2018, 03:21 PM   #14
rookakoma is offline rookakoma  Hungary
diyAudio Member
rookakoma's Avatar
Join Date: Nov 2007
Location: Budapest
Under natural convection conditions, the performance of a heatsink with a black surface will be 6% to 8% better than that with a plain or bright surface. However, this differential disappears under forced air conditions.



Scott has right:
Heatsinks work more by convection than radiation so colour isn't such a large issue as surface area, orientation of fins and good air flow
F5 Turbo
  Reply With Quote
Old 9th October 2018, 03:58 PM   #15
alexberg is offline alexberg
diyAudio Member
alexberg's Avatar
Join Date: Oct 2009
Black body emits into a vaccum about 5.76W @ 100K per meter square. Having heatsink @ 330K it will change to 690 W. Be aware that finning does not help. Assuming two sides of 4" high 19" unit to be a total heatsink projection area we'll get 0.1 m^2 thus 69W. Emissivity of an anodized aluminum is quite good.
  Reply With Quote
Old 9th October 2018, 09:42 PM   #16
Bare is offline Bare  Canada
diyAudio Member
Join Date: Dec 2001
Location: vancouver
Nonsense. Paint the heat sinks .. thinly tho.. with flat black paint.
Ideally with parts still as rough textured castings
Heat dissipates faster as result, researched, documented and proven.. decades ago.
This from a misspent youth fielding Yamaha TZ Racers for the Yama factory.
Lotsa testings by industrious Yama Engineers revealed that the thin black paint was best for purpose.
IE; keeping reciprocating parts running at ~11,000 rpms with a Heat critical 0.008 " running clearance ..from seizing solid.. at 180 mph.
Myopic beliefs aside, this was a serious issue, long ago dealt with.
As for the critical temps of a couple of $$ Output device.. Really ??

Last edited by Bare; 9th October 2018 at 09:49 PM.
  Reply With Quote
Old 9th October 2018, 09:49 PM   #17
Btsd is offline Btsd  Australia
diyAudio Member
Join Date: Aug 2015
Location: Perth
I go with what look I want.
Bottom one (aleph J) black heatsinks with polished edges.
Second up (aleph mini) fully sandblasted heatsinks with polish edges.
Everything else I have built in the Aleph set is fully sandblasted.
Attached Images
File Type: jpg DSC05868 e.jpg (140.2 KB, 223 views)
  Reply With Quote
Old 9th October 2018, 10:28 PM   #18
res07njc is offline res07njc  United States
diyAudio Member
Join Date: May 2005
Location: Tampa Fla
It's true, that paint is an insulator. Electrical insulator!

I've had success mounting parts straight to the painted surface. In other words, no mica, just grease. One mans "loss", another's gain.

Providing the aluminum was prepped smooth and the active device has no particular burrs or sharpies. So far just TO-247 parts.

I've gone so far as the contemplate taping off natural aluminum just for the area where the mosfets are going to be mounted!
  Reply With Quote
Old 10th October 2018, 02:00 AM   #19
vdi_nenna is online now vdi_nenna  United States
diyAudio Member
vdi_nenna's Avatar
Join Date: Oct 2000
Location: PA, USA
To paint or not to paint - Heatsink Question Send a message via Yahoo to vdi_nenna
How to anodize without battery acid.
Acid vs non-acid process results look the same in photo.

Anodizing and dyeing aluminum without battery acid... - Observations
I build, therefore I am.
  Reply With Quote
Old 10th October 2018, 11:12 AM   #20
KatieandDad is offline KatieandDad  United Kingdom
diyAudio Member
KatieandDad's Avatar
Join Date: Nov 2011
Location: UK
Thank you guys. The heatsinks are already painted in matt black. I'll leave them alone.
  Reply With Quote


To paint or not to paint - Heatsink QuestionHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Rockford DSM Heatsink Paint permo Car Audio 6 13th April 2018 12:33 PM
Really OT question about paint Conrad Hoffman The Lounge 14 22nd January 2008 09:28 AM
quick question regarding paint sqlkev Multi-Way 2 3rd July 2007 03:21 AM
Paint steel chassis with the "aluminum paint" used on wire fence? vax9000 Tubes / Valves 2 23rd July 2006 02:14 AM
Chassis and heatsink thermal paint arnach Everything Else 4 1st December 2002 02:49 AM

New To Site? Need Help?

All times are GMT. The time now is 05:10 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio