How to derust without risk of hydrogen embrittlement?

[LucasDK]

Hi,

I need to derust a few small parts from a mechanical fuel injection pump. The parts comprise springs, hardened parts, high strength steel. With what method can they be derusted without the risk of hydrogen embrittlement?

Lucas

 

[Donald]

Hi,

I need to derust a few small parts from a mechanical fuel injection pump. The parts comprise springs, hardened parts, high strength steel. With what method can they be derusted without the risk of hydrogen embrittlement?

Lucas

Ultrasonic?

Maybe Trav will answer. He probably knows.

 

[Trav]

Hi,

I need to derust a few small parts from a mechanical fuel injection pump. The parts comprise springs, hardened parts, high strength steel. With what method can they be derusted without the risk of hydrogen embrittlement?

Lucas

Do you have a picture of the rusted parts.

 

[tnt_motorsports]

@LucasDK a picture or two would help. What makes you concerned about hydrogen embrittlement? Typically with fasteners when you change the coating and introduce heat to cure the coating is when I have seen HE introduced.

I would try some WD40 and some agitation to see if you can get rust off. An ultrasonic cleaner also works well.

Just my $0.02

 

[LucasDK]

Do you have a picture of the rusted parts.

I have not tried to clean them manually yet. These are precision machined parts and it really needs a gentle mechanical removal if any.

Lucas

 

[RDMgr]

Electrolysis followed by four or five hours in a 300°F oven to drive out any hydrogen atoms followed by fine wire brushing or light abrasive pad.

 

[kschachn]

I have not tried to clean them manually yet. These are precision machined parts and it really needs a gentle mechanical removal if any.

Lucas

Plus if those are high-strength parts they are already compromised.

 

[tnt_motorsports]

I have not tried to clean them manually yet. These are precision machined parts and it really needs a gentle mechanical removal if any.

Lucas

I’d use some motor oil and scotch brite to clean that up. Wash them with some brake cleaner after to clean them and coat with RP if you don’t reassemble and use the pump right away.

Just my $0.02

 

[LucasDK]

I’d use some motor oil and scotch brite to clean that up. Wash them with some brake cleaner after to clean them and coat with RP if you don’t reassemble and use the pump right away.

Just my $0.02

What is RP?

 

[tnt_motorsports]

What is RP?

rust preventative or rust preserver. An oil coating or such to keep the parts from rusting again.

Just my $0.02

 

[spasm3]

Walnut shell blasting ?

 

[Trav]

+1 Walnut shell or plastic media blasting.

 

[LucasDK]

Thanks for all your replies. There was a much easier solution. I removed the "rust" with ethanol based on a post in a different forum.
Background: The pump has been resting on a shelf for 3 years and the rust coloration is actually degraded bio diesel (in Europe there is 7% bio diesel at the pump) which has gummed up over the years and turned into a sticky, brown substance. Apparently this gummed up bio diesel is not dissolved by acetone and gasoline (however I did not try), but is easily dissolved by ethanol. The dissolving is not 100% but needs a little mechanical help from a small brush.