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Heatsink Strip & Refinish Experiment.

Old 11-16-2019, 09:08 AM
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1QwkSport2.5r
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Default Heatsink Strip & Refinish Experiment.







This is the original older style heatsink from my Novarossi Legend 28-8RT in my Losi LST2. It suffered some road rash from a ridiculous wheelie endo. This heatsink has the cutouts on the side and was the blue color. The modern heads are round and smooth without the cutouts, AND itís PURPLE! I had ordered a new heatsink from Nova Direct, but they didnít tell me it was purple. The picture on their website was of the blue one, which is what I expected to get. I really donít like purple.

So I decided to do something way off the wall with the blue head with road rash. Sand out the road rash, strip all of the anodizing, and polish the crap out of it to look like itís chromed. This is what it looks like post-anodize stripping. I also am going to sand the dimpled as-case texture off and smooth it out. On a physics level, this will remove some surface area for cooling, but I donít anticipate much. This engine never runs warmer than 240F as it is, so Iím not worried.
Old 11-16-2019, 09:15 AM
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To strip the anodizing, I used a bath of drain cleaner. I forget the brand, but it came in a thick ziploc bag. It was a mix of sodium hydroxide (Lye) and potassium hydroxide. I wore rubber gloves - a MUST to do this part. Pour a little drain cleaner on and scrub with a toothbrush QUICKLY. The aluminum gets hot as the dickens real FAST. Scrub, rinse with water to cool off and repeat until the anodizing is gone. After you rinse the last time when your satisfied with the stripping, the aluminum will get a black oxide film on the surface. A quick scrub with Bar Keepers Friend kitchen cleanser removes the oxide layer. Rinse really well and dry. BKF is the only cleanser that works the best because it has oxalic acid in it. This is the key. Other cleansers may work, but will take longer.

Now I’ll sand the cast surfaces between fins and the cutouts to remove the factory CNC machine marks. with 220 grit abrasive and follow with finer grits until I can run a polishing wheel over the surfaces I want polished.
Old 11-19-2019, 12:54 PM
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looks good! very curious to see the final product!
Old 11-28-2019, 06:50 AM
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I’ve been working on it when I can find spare time. I have all of the casting texture sanded out between all of the fins. I need to custom make some polishing and ultra fine sanding discs for between the fins. Once I can do that, I can move on to the polishing part.
Old 12-24-2019, 10:39 AM
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I still have a little fine polishing to do, but this is where Iím at with it. Iím not polishing between the fins as that would interfere with its ability to cool properly. The top and outside edges of the fins are all in doing as well as a little cleanup down the bore.

Old 12-26-2019, 08:43 AM
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looks really good! don't blind yourself when the suns out lol. i am really curious if there would be any change between yours and stock and how much change in temps you would experience. would be pretty hard to compare but would be interesting!
Old 12-26-2019, 04:38 PM
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Originally Posted by D3MON View Post
looks really good! don't blind yourself when the suns out lol. i am really curious if there would be any change between yours and stock and how much change in temps you would experience. would be pretty hard to compare but would be interesting!
I think the the cooling properties should be very similar. With the anodizing gone on the whole head, I think that should balance the sanding out of the casting marks. But given the scratch pattern between the fins, it should be no different or even better than OEM.



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