Anodizing Outdrives

sms986

Petty Officer 1st Class
Joined
Sep 18, 2017
Messages
267
Has anyone ever done this/had it done?

I see this being much more beneficial than powder coating. "Paint" is not on top of the aluminum, it's in the outermost layer of it. Also better for corrosion protection.

Don't know if the outdrive parts are anodized before painting from the factory?

Anyway, I'm gearing up to anodize my outdrive parts. I have a 93% sulfuric acid dip tank that I'm dipping each part in for about 3 hours each (cold dip). Checking thread holes and thicknesses here and there before and after. Picture is the dipped bellhousing. I'm trying to avoid a hard caustic dipping for gunk removal.

Unfortunately, I can't do much about the pitting, unless anyone has any ideas?

For anodizing, my procedure is to cold dip in 50% caustic for 2 minutes to get off any residual oil, then hot DI spray, followed by a 73% nitric acid dip to remove surface metal impurities. and anther quick hot DI spray.

Anodizing in a 20% sulfuric acid solution with a lead cathode. 12V @2A.

Last is to boil in DI with dye for an hour.

Has anyone done something similar who can give some pointers?
 

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Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
67,444
Ayuh,.... Never seen it, never tried it, 'n doubt the benefit, but will be watchin',.....
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
24,785
I used to be involved with anodizing of aluminum / magnesium.-----Precision parts ( aircraft guidance components ) some bores had to be made O/S so that after treatment they were ( per drawing specs ) again.----Terminal voltage on the rectifier was set with an alarm , to make sure parts were in spec after treatment !-----So careful if you decide to proceed.------Look into having it powder coated.------Cost me $75 to have an Evinrude lightning gearcase powder coated.-----Money well spent and hope it stands up to 75 MPH in fresh water.
 

sms986

Petty Officer 1st Class
Joined
Sep 18, 2017
Messages
267
Eh, I have all of the chemicals needed for anodizing. Lead cost me $25 for 10#. Only cost is the lead and dye. Have a DI system set up at the house for work. More for learning than anything else. If it works out, I think it will be pretty cool. If not, after all the money spent to restore the boat I won't shed a tear if I have to replace some parts..

If I can't get this to work, I'll powder coat them. Have everything to do that too (except the gun), including an extra oven in the basement for knocking out cylinder sleeves.
 
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