Electrolytic rust removal

[berettafan]

http://thisoldshed.tripod.com/electrolysis.htm


Did this with a couple exhaust clamps and after 3hrs the results are unreal. Maybe 30 seconds with a brush after removing them from the solution.

[robmog]

erik,
it does work great..
beats hours with a wire wheel, not as fast as blasting.
but leaves a nice surface ready to plate.
one caution, the dreaded hydrogen embrittlement.
i did some spring retainers this way, and they snapped like dry twigs when compressed!
what power source are you using?

[berettafan]

Yes, did read about the hydrogen embrittlement thing; probably should've mentioned.

Power source is a battery charger set on 2amp trickle.

[berettafan]

Supposedly you can 'bake' your way out of the hydrogen embrittlement issue but i don't think i'd trust my life to such a solution.

[robmog]

i've done alot of research on the topic and am planning to post on my experience with home plating.
i live in the middle of nowhere, and don't have access to commercial plating services. plus i'm afraid they might lose the small bits!

[jameshtaylor]

So how is it done. + side to the part. Is the part grounded?
Sorry, I see the link you posted.

[real550A]

I used this method to "boil" out my rusty gas tank after an 18 year sleep. It cleaned it down to nice grey metal inside in about 20 hours. No rust since.

[MrJTP2001]

http://www3.telus.net/public/aschoep...lyticrust.html

[chris_seven]

Hydrogen Embrittlement, very difficult issue and a well known problem with electroplating.

The theory is that if hydrogen does diffuse into the steel during an electrolytic process then 'baking' the part for a few hours at around
250 degC resolves the problem and this is often carried out on non-critical parts.

I would worry that if plating/electrolytic conditions were bad enough to produce significant mounts of hydrogen and parts were embrittled recovery by baking wouldn't be a great idea.

In general any parts that have a moderate level of residual stress when they are embrittled are unlikely to be recovered by baking.

Any relatively high strength fasteners with a hardness of 40 HRC and above are unlikely to recover after baking.

I am fairly sure that plated aircraft Fasteners are always tested for the effects of hydrogen embrittlement and if they show this problem they would be rejected and not baked.

Low carbon steels with low residual stress would probably recover os they would be unlikely to be significanlty damaged my the micro-voids and cracks that can be caused by hydrogen.

I guess that the best way is to set the cell correctly to minimise surface hydrogen prouduction, at least for critical parts.

[H-viken]

I really prefer this method over using acids. Like most other things it has potential downsides, just need to be selective when to choose it.

/Johan