Question for nut and bolt gurus

[ryan-chevynova]

Hey all, so question in regards to nuts and bolts strength…

Recently I stripped down a car and threw the nuts and bolts into an ultrasonic cleaner. It got all the grease loose. Then I soaked for a few hours in full concentrate simple green, then scrubbed. Bolts came out great. Then I threw another batch in the simple green and forgot about it for 5 days. When I pulled them out they looked like this.



Caked on green powderish substance. I did also notice that I dropped some copper o rings in there along with it. I don’t know if the substance is simple green or oxidation from the copper?

I have taken a few of the bolts and sand blasted them, then dunked them in super blue. They look great again.



My questions are what do you think has happened and more importantly, have I jeopardized their tensile strength or rigidly at all? Some of these bolts are for the bellhousing, manifolds, cross members, etc.

Also, any other suggestion as to how to strip them down again would be much appreciate. Sandblasting and wire wheeling all of these won’t be fun.

 

[Indexmill]

Respectfully, this is not a question for a nut 'n bolt guru; we need a materials scientist.

 

[BrandonV]

No clue on the structural integrity of the bolts but Simple Green has tetrasodium glutamate diacetate in it with can act as a chelating agent. Might have reacted with the copper.

 

[no704]

I’d throw them in a tumbler like is used for cleaning brass when reloading.

 

[cgrutt]

I've heard Simple Green is not recommended for aluminum but quick Google search has some articles that suggest prolonged contact with all metals can accelerate corrosion process due to its aqueous-base and high alkalinity. Also some discussion about causing hydrogen embrittlement but that's above my pay grade. Effective as cleaner but shouldn't be left with prolonged contact and must be throughly rinsed.

 

[BrandonV]

I've heard Simple Green is not recommended for aluminum but quick Google search has some articles that suggest prolonged contact with all metals can accelerate corrosion process due to its aqueous-base and high alkalinity. Also some discussion about causing hydrogen embrittlement but that's above my pay grade. Effective as cleaner but shouldn't be left with prolonged contact and must be throughly rinsed.

I'm a big fan of the aerospace Simple Green which is approved by Boeing and Airbus for use on aluminum surfaces. Still wouldn't leave anything sitting in it for an extended period of time but it's far gentler.

Weirdly it's only a special order sort of thing but I'm pretty sure the purple Simple Green you can get Simple Green Pro HD, is the same formulation plus a fun purple dye. They advertise it as being, "Safe for Metals".

 

[ToolsRCool]

The corrosion may have been there the entire time, and was just uncovered from the grime. When wet, it my not show.

When I clean carburetors, they can sometimes look the same. I now follow it up with a soak in CLR, since today's ethanol absorbs water, and that moisture will leave minerals behind and can corrode aluminum, especially if un-plated. Simple Green and choke cleaner does not dissolve minerals.

To the above poster, I also use Extreme Simple Green Aircraft Cleaner when soaking carburetors in the ultrasonic tank.

 

[Tractorsellr]

What no704 said, put them in a tumbler with walnut media for 24 hours and they will look new.

 

[ryan-chevynova]

Sorry I was never alerted of everyone’s responses. I appreciate the feedback from you all. I would assume that integrity has not been compromised but the last thing I want is to put everything back together and stuff starts snapping. Fingers crossed that doesn’t happen. I will tumble and blue. Thanks yall!

 

[PFSard]

Might it be a good idea to contact the people who developed Simple Green and explain your conundrum before you spend any more time on this, especially re-use?

 

[Steve_P]

The threads look fine, and those are typically the first thing to be eaten off if it was in harmful chemicals. To test the strength, find a marked fastener, like class 8.8, and look up the torque spec for that size. Clean the threads with a wire wheel, etc. Buy a new nut that's a higher class/strength rating than the screw- class 12 if you can find one. Tighten the screw to spec, back off, 1.2X, back off, 1.4X... 1.5X... It should fail somewhere at about 1.8X the torque spec.

I can't imagine that simple green compromised the strength. I have accidentally left screws in a hot phosphate treatment too long (phone call and then forgot) and it will eat the threads away.

 

[Norcal]

I toss a little Dawn dish washing liquid in the parts cleaner but it is not recommended to leave then in for a long time, made that mistake with some greasy nut drivers.

 

[ryan-chevynova]

What no704 said, put them in a tumbler with walnut media for 24 hours and they will look new.

This is what I did and they look great now. Thank you for the advice and love the tumbler!

 

[ryan-chevynova]

I’d throw them in a tumbler like is used for cleaning brass when reloading.

Worked perfectly, thank you!

 

[ryan-chevynova]

So what are you guys doing for protecting the nuts and bolts moving forward. I always assumed “blueing” but reading black oxide might offer better rust protection? I’m open to any suggestions. Doesn't have to be black or blue.

Again this is for hot rod hardware and fasteners

 

[adsinnott1]

So what are you guys doing for protecting the nuts and bolts moving forward. I always assumed “blueing” but reading black oxide might offer better rust protection? I’m open to any suggestions. Doesn't have to be black or blue.

Again this is for hot rod hardware and fasteners

Find a local place that does zink plating. Take them a 5 gallon pail of nuts and bolts and you will have factory fresh hardware.

 

[ryan-chevynova]

I’d throw them in a tumbler like is used for cleaning brass when reloading.

Is there any way to “mirror” polish bolts in the tumbler?