80 MNS restoration

[Blackdog]

Simple stupid float pin extraction

http://i955.photobucket.com/albums/a...bi240/Carb.jpg


Pondered how to extract float pin for a while. I didn't think the left post was a problem as far as seizure was concerned, so the right post was the problem, the one with the pin head. By using channel locks as shown all pressure was on the pin and the right post. Make sure the left jaw is just touching the part of the pin that extends out from the left post. After looking at picture I see I should have opened up channel locks so jaws were parallel. I suppose that if you were ham fisted and continued pressure after pin pops you could do some serious damage so be careful. I really don't think this is a problem, but I have to mention it.

[Blackdog]

Gas tank electolysis

Read the articles on gas tank electrolysis, thanks for the reference. In my youth I worked in a chrome shop for 6 months. It seems to me that the way they have it set up that the tent stake is the anode, giving off atoms of iron to the surrounding electrolyte, hence the reduction of the rod. This is the primary reaction going on here, any reaction with tank is purely incidental. The tank is what should being reduced, the tank should be the anode "positive charge" and the rod should be the cathode "negative charge". The electrolyte should be only a way of conveying atoms of iron from the tank to the rod, there should be no reduction of the rod it should in fact grow microscopically larger. I don't consider myself an expert in this field, can anybody correct me?

[3Phase]

Don't do it

The tank is what should being reduced, the tank should be the anode "positive charge" and the rod should be the cathode "negative charge".

You will wind up with a fuel tank made of thin, metallic, gauze under the paint that's full of holes and a nice, fat, healthy, wire.

The wire anode is positive, the tank as cathode is negative so metal transfers from wire to tank, not the other way around.

Finishing dot com FAQ


Regards,

Scott

[Blackdog]

Thanks 3Phase, yes if I left it on for 10 hours it would be toast, but what about 10 minutes? I remember that at the chrome shop we would clean parts by submerging it in hydrochloric acid with a charge with the part as the anode. It was very fast and aggressive. Incidentally when I worked there I was not the plater, I was the prep man, filling pits with copper, polishing, etc. But I did keep my eyes open. I am not trying to second guess you or say you are wrong, I know you are right. I am just trying to understand the principals involved. How does making the rod the anode remove the rust? I know it does, but why? And why wouldn't the method I described, carefully monitored for a short amount of time, clean the tank also? Here again I am not trying to be confrontive, I will NOT be using the method I describe, I just love playing with theory. Thanks for setting me straight.

[3Phase]

Electrolytic rust removal is lossless so no good metal is lost in the process. The idea is to safely clean the metal tank while converting as much of the rust as possible back into good metal without causing any harm to the tank, yourself, your neighbors or your neighborhood.

I'm not sure what you're not understanding here. The current flows from the positive anode to the negative cathode. The metal of the anode becomes electropositive and contributes positive cations to the electrolyte which then move toward the cathode.

If you hook the poles up the other way and make the tank the anode and the wire the cathode then the tank contributes its good metal. You can do it for ten seconds but there is no real point because for ten seconds you're moving good metal from the tank wall into the electrolyte. That's not what you want to do. Don't try to outthink the process with conventional flow vs. electron flow, just go with positive to negative or you'll drive yourself mad.


Yes, you can clean metal and remove rust faster with acids but, except for phosphoric acid, you lose good metal along with the rust. Acids are messy. Acids have to be handled and disposed of properly after use and acids cause hydrogen embrittlement of the metal. You really don't want a thin, brittle, tank filled with several gallons of gasoline sitting between your knees.

Phosphoric acid is different. Phosphoric acid dissolves rust quickly and attacks the good metal in the tank slowly. It leaves a bright finish with a thin, hard, iron phosphate coating on the metal that resists rust. It also causes hydrogen embrittlement so if you use it to finish a tank make sure you keep the soak time to the minimum amount of time necessary to remove the rust.


Regards,

Scott

[Blackdog]

Thanks

Thank you, now I understand. Sometimes the most obvious things are the hardest to see. Was not aware of the hydrogen embrittlement factor with acid, knew it happened with plating, but not acid.

[3Phase]

Thank you, now I understand. Sometimes the most obvious things are the hardest to see. Was not aware of the hydrogen embrittlement factor with acid, knew it happened with plating, but not acid.

Dog, electrolysis, even with an alkaline electrolyte instead of the usual acidic plating solution, will also cause some hydrogen embrittlement so the major benefit is removing the rust without removing the good metal from a thirty-year-old tank.

The welds, seams and crevices corrode and the walls weaken and develop pinholes until the tank isn't really a tank any more, it's just several pieces of metal held together by rust and paint. Remove the rust and ....

You'll have to rinse the loose rust and debris out of the tank then look carefully inside with a strong light and probe with a metal pick to see if the tank can be cleaned up and used or if you'd be better off getting another tank and painting it. I have seen some old tanks that turned out really well, my tank included, and I have seen some that were supposedly 'saved' that really shouldn't be used except on an unridden showpiece or put in a museum.


Use your best judgement and be careful.


Regards,

Scott

[latexeses]

Just in case.....

http://twinoak.altelco.net/~jacil/cl...ElecSetup.html

There used to be a link to the XS650 forum that had the long version but it is no longer I'm afraid.

Worked fantastic on a rusty standard tank of mine.

[Blackdog]

Parts cleaner

Using the same reaction, couldn't you make a parts cleaner? Either by wiring parts together and electrifying wire or a metal basket that is electrified. Also would it work on brass {carb parts, etc.}?

[Blackdog]

Parts cleaner

Also, wouldn't doing it in an old crock pot accelerate the reaction?

[Blackdog]

Also

Is there a limit on the amperage involved?

[3Phase]

Yes
Yes
Yes


http://preview.tinyurl.com/l7lzll




Regards,

Scott

[Blackdog]

Excellent, was that a yes on the brass too? There were 4 questions. I'll try to quit bugging you for a while here, Thanks again for all your help, I learned a lot.

[3Phase]

Dog, I've learned a bit more looking this stuff up and I honestly don't mean to come across in a stentorian manner.

These links are mostly concerned with conserving marine artifacts but there's some good theory and application:

Yes, you can clean brass
http://nautarch.tamu.edu/class/anth605/File12.htm

Galvanic cleaning
[/url]http://nautarch.tamu.edu/class/anth605/File10a.htm#GALVANIC[/url]


Regards,

Scott

[Blackdog]

Zinc

Okay, you've given me a lot of information to digest, which keeps me in a happy state. Haven't read all this stuff, but plan to. So another question: what would happen if you put a carb body in with just water and zapped it? The caustic solution with zinc would be violent, as you know.