brass black

[harlequin]

new to this brass black product but just tried it and it is very good and works instantly. Not cheap (£14) but worth it in the long run

[DelF]

I agree. It's the simplest, quickest and best blackening solution I've tried.

 

Derek

[fnick]

Can't compare to other products but it is easy and quick to use. Gets my vote!

 

Nick

[BETAQDAVE]

    I also use the product I find that it's easy to use.  You simply soak the parts until you get the desired finish, set on paper towel to soak up the excess, and let thoroughly dry over night.  Unlike paint, it adds very little thickness to the parts.  That's something quite important with very small parts!

[Maury S]

Make sure you dip the parts in a bath of baking soda + water to neutralize the reaction.

Maury

[Wahka_est]

Hi

 

Does it only work on brass or on other cast fitting also?

[mtaylor]

4 hours ago, Wahka_est said:

Hi

 

Does it only work on brass or on other cast fitting also?

The label says "brass, copper, or bronze".   Personally I've not tried it on copper or bronze.  Maybe some others have.

[BETAQDAVE]

I do have one question that is not addressed on the label.  How does one dispose of the used product?

[Duanelaker]

5 hours ago, BETAQDAVE said:

I do have one question that is not addressed on the label.  How does one dispose of the used product?

 The SDS on website for Casey birchwood Brass black 

 

 Waste Disposal:
Review current local, state and federal laws, codes, statutes and regulations to determine current status and appropriate disposal method for the ingredients listed in Section 2. Any disposal practice must be in compliance with local, state, and federal laws and regulations. Contact the appropriate agency for specific information. Treatment, transport, storage and disposal of hazardous waste must be provided by a licensed facility or waste hauler.

Edited March 12, 2020 by Duanelaker

[bolin]

On 3/7/2020 at 6:04 AM, mtaylor said:

The label says "brass, copper, or bronze".   Personally I've not tried it on copper or bronze.  Maybe some others have.

I have used it on both brass and copper, but not bronze. The effect is about the same on either. The metal will turn black within a minute or so.

[James H]

I'm using this to black my brass:

 

https://www.uschivdr.com/shopping-categories/shop-chemicals/

 

€16.50 for 250ml.

[DaveBaxt]

Hello guys.What a coincidence I just ordered some of this the other day and just received this yesterday and have only just noticed this post. I have started fitting some blocks to the cannons and have already used some brass rings and copper eye pins. my question is can this stuff be added to parts which have already be fitted. I don,t mean the rigging just one or to places using a cotton bud stick. Would there be any staining to surrounding areas? Best regards Dave

Edited February 6, 2021 by DaveBaxt

[bartley]

On 3/12/2020 at 8:24 AM, BETAQDAVE said:

I do have one question that is not addressed on the label.  How does one dispose of the used product?

Dave,

 

I have dealt with this disposal issue here.  If you search my thread you should find it more on this.

 

As I have mentioned also here the Birchwood Casey product is a little different from the other brands in that it contains both Selenous acid and Molybdate so it reacts with both copper and zinc- both of which are in brass.  So it reacts a bit more quickly and probably forms a deeper black.  Also it will react with any alloy containing either of these metals

 

John

Edited February 9, 2021 by bartley

[shipman]

Do these products have a shelf life?

Also, what proportions for the baking soda/water pickling solution?

Thanks.

[bartley]

OK shipman,

 

Shelf life of the blackening agent should be indefinite if you keep the lid on.  Pickling solution:  make it up about 8:1 of the water to solid.   Note: add the solid (sodium hydrogen sulfate) to the water not the other way round.  The soda water: it doesn't really matter;  I add the bicarbonate to the water until there is a little left undissolved.  This is called a "saturated solution".

 

John

Edited February 9, 2021 by bartley

[shipman]

Thank you, John. I'll be trying this with a bit more confidence 😎

[bartley]

Shipman,

 

A couple of extra tips:

A clean surface is the key.  You obviously know about pickling but don't overdo this step.  Pickling is etching the surface of your brass so 10 min at 60 C is usually enough.  Don't handle with your fingers now.  So, into your soda bath to neutralise the acid, rinse under the tap, drain and into the blackening reagent. Don't immerse your items into the bottle of reagent.  Put a small amount into another vessel which you can seal so you keep the original solution uncontaminated.  Neat Birchwood Casey reacts pretty fast (10 sec) so to give a bit more control I dilute this decanted solution 1:1 with water.  Then you can probably immerse your items for about 30 sec, into the soda bath, wash and allow to dry.  You will need to experiment with the time a bit - too short and blackening will be incomplete, too long and you will get "flakey" layers on top of the original.  These flakey layers rub off easily.  By the way the black stuff which rubs off is selenium which is toxic so wear gloves when you are cleaning up the surface.

 

John

Edited March 10, 2021 by bartley

[bartley]

On 2/6/2021 at 7:16 PM, DaveBaxt said:

 my question is can this stuff be added to parts which have already be fitted. I don,t mean the rigging just one or to places using a cotton bud stick. Would there be any staining to surrounding areas? Best regards Dave

Dave,

 

My experience is that if it is bare wood there is usually some staining (depending on the timber and how long you leave it in contact). However, if the timber is painted there is no problem.  These bolt heads were blackened after installation.

 

 

John

Edited February 10, 2021 by bartley

[DaveBaxt]

5 hours ago, bartley said:

Dave,

 

My experience is that if it is bare wood there is usually some staining (depending on the timber and how long you leave it in contact). However, if the timber is painted there is no problem.  These bolt heads were blackened after installation.

 

 

John

John Thank you for your reply and sending that photo ( nice job by the way) That looks like its worked great on the painted area. Fortunately most of the areas I have done so far have been painted. I have started dipping all of my eye bolts and rings in Brass Black and it even works on the copper although takes a bit longer. I also found out that this stuff is pretty deadly on any tools that are not stainless steel. Shouldn't have used those pliers for lifting things out of the blacking solution.

[allanyed]

For blackening copper, liver of sulfur works very well and can be applied to parts that are already attached to the model without staining the wood.  See Ed Tosti's Young America clipper build log as he goes into some good detail on doing this.   I have not found it to  work on brass though.

Allan

Edited February 10, 2021 by allanyed

[shipman]

Hi Alen.

Liver of sulfur DOES have a shelf life.

I bought some, it was light pink. Put it in a drawer untouched for a year. By then it had turned clear, with 2 or 3 black specs floating around. And useless, hence my questions about shelf life.

[bartley]

Yes indeed, shipman, this is true.  Liver of sulfur is a complex mixture of sulfides and polysulfides. Over time in air these decompose to in active sulfates.  Shelf life may be less than a year,  Strangely it works well on copper but not very well on brass which is 60% copper.

 

John

[DaveBaxt]

6 hours ago, allanyed said:

For blackening copper, liver of sulfur works very well and can be applied to parts that are already attached to the model without staining the wood.  See Ed Tosti's Young America clipper build log as he goes into some good detail on doing this.   I have not found it to  work on brass though.

Allan

I think we discussed this earlier and I ordered some liver of sulfur then which is before I ordered the Brass black I think I will have to chase up ebay. Should have been here before now. Thanks again for your input.

[DaveBaxt]

6 hours ago, shipman said:

Hi Alen.

Liver of sulfur DOES have a shelf life.

I bought some, it was light pink. Put it in a drawer untouched for a year. By then it had turned clear, with 2 or 3 black specs floating around. And useless, hence my questions about shelf life.

Thanks shipman for letting us know about that. Interesting to know if that happens even when unopened.

[shipman]

And in the dark at stable temperature. I assume the active ingredient in suspension 'condensed' into the black flecks.

Any Chemists out there?

[bartley]

Shipman,

 

Oxygen is the culprit in the decomposition.  This may sound like a cop out but oxidation is one of the most difficult processes to understand so it is difficult to predict what the products are.  Firstly liver of sulfur is not a single chemical substance . It is a complex mixture.  amongst the products of decomposition are sulfates which colourless but also sulfur itself which will be insoluble.  In its pure state it is yellow but it tends to pick up impurities and and is often green or brown.  If the product has been used there will be copper and other metal present so they may attach to the sulfur. One of my chemistry professors used to say " a little bit of colour goes a long way".  Meaning you don't need much of an impurity attached to a pure substance for our eyes to observe the color as close to black.  So its difficult to say what the black flecks are but my guess is that its supfur eit some impurites attached.

 

John

Edited February 10, 2021 by bartley

[shipman]

Thank you for that, John.

As I stated, the bottle was unopened by me.

Perhaps the stuff was low grade rubbish.

[JohnU]

I'm using Brass Black to blacken my brass parts. Works great! I have one problem with it. The blackening comes off easily. This is especially a problem for flat shim stock. The blackening comes of in flakes when rubbed.

 

Is there some trick to making it bond to the metal?

 

John

[Roger Pellett]

After blackening, I spray mine with a light coat of Dulcote.

[bartley]

JohnU

 

If you read my posts on the chemistry if the process you will see that the selenium in the blackening agent does not "bond" to the brass but is physically trapped in little etched pits.  If the process is too fast or prolonged for too long then several layers build up and these rub off easily. You will probably get better results if you dilute the reagent at least 1:1 to slow the process down.

 

John

Edited March 8, 2021 by bartley