Black Oxide on Bolts

[69fourspd]

Not sure if anyone has a good method for getting bolts to appear factory with a black oxide coating.  I have tried the eastwood blackening solution and it looks good for about 30 minutes until it starts rusting.  I know it states to coat with a clear, but that defeats the purpose as a scratch in the clear will create a rust spot.  I know this sounds a little amateur, but I am getting a pretty good result from heating the bolts very hot and submersing in old black motor oil. This should definitely not be done with a structural bolt, as it may weaken them.  Not sure if the carbon bonds, but it makes them pretty scratch proof.  I tested both eastwoods solution against the motor oil dip and put both in a container with water(not submersed but high humidity). The motor oil dipped bolt looks to be unchanged.  The picture shows the oil dipped bolt on the right vs. eastwood on the left.  Both were blasted and cleaned.  I dipped the bolt on the right twice after heating until a grayish color with a propane torch.  Any thoughts or better results with other methods? I would love to get the look without paint and an expensive coating process.  Thanks.

[Ghoste]

The one on the right obviously looks much better.  Are the black oxide kits that expensive?

[69fourspd]

The one on the right was dipped in oil which seems much better than the black oxide solution from Eastwood.  They aren't very expensive, I just find that the parts rust still. If Anyone has a good black oxide kit which seals the bolts so they dont rust I am all ears.

[bobfist]

Hi, i have been using Westwood but always clearcoated the paret with satin finish.
Now im using a Swedish solution called smedjans, its a solution that oxide the bolts as well.
See my website för more info and pic

[Kangerman]

You could try getting some cold bluing from a gun store. There are a lot of different manufacturers. I've never used them, but the Eastwood stuff sounds like similar stuff.

[Dmichels]

I have worked in the firearms industry for about 20 years All the cold black ox dips are about the same The cold blue for guns fall into the same group You can get OK results with proper post treatment On guns I use some light oil to keep away the rust. All hot black ox (what Chrysler used) and gun blue are all about the same.  Guns turn blue because you polish the metal first. Most industrial black ox places have about a $70 min lot charge. They do this in bulk and you may loose some parts. Not a great option, Try to find a friendly gunsmith to dunk your pre cleaned (sand blasted) parts in there blue tank. OR if you are big time Buy the blueing salts yourself from Brownells and do it yourself. Caldweld plating (sp) may have something as well
Dave

[69fourspd]

Sounds good guys.  I know a guy who does gun restoration work and will give him a call.  Not looking to break the bank on coating bolts, but it doesnt sound like it would cost much to bring a bag of creaned hardware and dip. 

Thanks,
Matt

[Ghoste]

You say "if you are big time" in regard to the bluing salts, is it safe to guess from that then that it is fairly expensive chemical and associated hardware to buy.

[Dmichels]

It could cost you a few hundred dollars depending on how much you fab yourself

[Chatt69chgr]

I use the gun blueing method.  I chuck the bolts up in the vise using popsickle sticks to keep from marring them and use a 4-inch wire brush from Harbor Freight on my drill to do the cleanup work.  I then use laquer thinner to get all of the oil off and when dry, use a q-tip dipped in gun blueing rubbing the blueing liquid on.  Sometime the bolts, washers, nuts take the blueing very well.  Other times it doesn't work as good.  You can keep adding it blueing up to a point.  Then you wash the parts off in water and use some 0000 steel wool to lightly polish the item.  Next, blow dry immediately with compressed air and immediately oil.  They look pretty good when done.  Lots better than the rusted piece I started with.  The cost is low and it's something you can do yourself. 

[cdr]

Not sure if anyone has a good method for getting bolts to appear factory with a black oxide coating.  I have tried the eastwood blackening solution and it looks good for about 30 minutes until it starts rusting.  I know it states to coat with a clear, but that defeats the purpose as a scratch in the clear will create a rust spot.  I know this sounds a little amateur, but I am getting a pretty good result from heating the bolts very hot and submersing in old black motor oil. This should definitely not be done with a structural bolt, as it may weaken them.  Not sure if the carbon bonds, but it makes them pretty scratch proof.  I tested both eastwoods solution against the motor oil dip and put both in a container with water(not submersed but high humidity). The motor oil dipped bolt looks to be unchanged.  The picture shows the oil dipped bolt on the right vs. eastwood on the left.  Both were blasted and cleaned.  I dipped the bolt on the right twice after heating until a grayish color with a propane torch.  Any thoughts or better results with other methods? I would love to get the look without paint and an expensive coating process.  Thanks.

i like the way you are doing with old oil

[bill440rt]

I've used the Eastwood kit quite extensively in the past. I stick the bolts in a piece of cardboard & put them in a bead blaster, that way I can blast many bolts at once. Nuts are strung on a wire coathanger, same deal.
Blow them off with compressed air. Dip them in a degreaser, then rinse, then the blackening solution. When they come out, I blow them off with more compressed air & give them a shot of clear.
They've stayed looking nice for many years, as good as or better than black/gray phosphate bolts that were left alone.

[Silver R/T]

I would use epoxy underneath black oxide coating

[bill440rt]

I would use epoxy underneath black oxide coating

Bolts must be bare steel for it to work. Can't do it over primer.

[Dmichels]

If you have a sand blaster you can do a phosphate finish at home VERY easy You can get a gray to black finish on hardware. Get some manganeese phosphate solution from Brownells. Follow thier instructions All you need is a stainless pot and a heat source.
Dave

[bill440rt]

Yep! Did that on a gas grill a few times. Had to use a stainless pan. Kinda makes a stink, but the parts turn out great! 

[Ghoste]

Brownells seem to offer a few things of interest in the vintage car hobby.

http://www.brownells.com/.aspx/cid=11234/k=/t=P/s_o=New+Products+(Descending)/Products/Metal-Prep-Coloring

[mopar4don]

So lets say I want to do some fender bolts that will end up getting painted.
Will this process work for bolts that get painted?

[green69rt]

https://www.youtube.com/watch?v=7vTn6l5h67A&feature=youtu.be

[mopar4don]

Unless I missed something in the video, nothing is said about painting the bolts

[ODZKing]

I simply paint them with trim black. Not quite satin but not gloss. Close enough.

[mopar4don]

So I can paint them.
Hmm I really didn't it would work. Seeing how you soak them in WD-40 or oil.

[odcics2]

Anyone use Ospho to coat the bolts black, like the OEM finish?

[Mopar John]

In my case the restoration shop sought out nice original hardware then did a fine bead blast to retain sharp details.
Then they did their own phosphate type coating that looks like the original finish.
MJ

[maxwellwedge]

I tumble them first....makes bead blasting (if still required to get them clean) a lot quicker to get them in nice shape before sending them to the platers.
Chrysler used very little black oxide.....GM sure did. Chrysler used zinc phosphate plating in their specs for a lot of the fasteners. Also silver (clear) and gold zinc and silver and gold cad.
There are so many more "correct" bolts available now.....head markings, plating etc. than there were 10+ years ago. I used to hunt for clean, unrusted hardware....so much more available now.

[odcics2]

When is Black not black!


"Black Oxide versus Black Phosphate. ... A. David - Yes, black oxide can be used as a rust retardant, but it is not as effective as black phosphate. The black zinc phosphate acts sacrificially to protect the steel, whereas the black oxide will rely on the after-finish for corrosion protection."

As stated above, Chrysler used black phosphate.  My bellhousing to engine, trans to bellhousing, oil pan, clutch pressure plate, trans crossmember, and the torsion bar anchor on the pass side are a few of the places my car has them.