Brass? British Mortar

[Cannoneer]

This mortar was up for auction recently, and I was very tempted to bid on it, but I passed on it for one major concern that I had and I'd like some other members input on this. This is how the item was described: Solid brass, 15.6 lbs., 7.50'' long, 3 7/8'' OD, 3 3/8'' ID. The problem I have with it is it's color; I'm no metallurgist, but to me it just has the appearance of having to high a copper content, it looks like the same color as "red brass" plumbing pipe and joints. It sold for what I think is a very fair price, I've seen the same pattern and similar size mortar go for a lot more than this one did, but I'm glad I let it go, I wouldn't have felt safe firing it.

[KABAR2]

Its possible being unfinished it has taken on a patina, or depending on lighting I’ve seen

Items Photograph come out in odd colors.....  I had a photo of a Enfield sling swivel for the three band

rifle up for sale, when the buyer got it he questioned why it wasn’t brass like in the photo,

The lighting made it look a gold color even though it was iron. the auction house may not know the difference

between brass and bronze and the writter used "brass"........

The mortar I had years back had a reddish tint to it when I first got it this disappeared

When I polished it.

[cannonmn]

It is almost impossible to tell from the color, as has been said, from how much patina is on it, we don't know, we don't know what his camera or flash settings were when he took the pix, etc. etc.

We've had many discussions here about brass vs. bronze and one of the more technically knowledgeable members pulled up properties of either.  There are brass alloys that have higher tensile strength than some bronze alloys, and vice-versa.

I guess my point is that brass vs. bronze isn't really a simple issue, you have to know exactly what particular alloy you are dealing with, out of dozens if not hundreds of different mixes that are used for either alloy.

The old gunners settled on roughly 90/10 for "gunmetal" bronze, which the Brits always called brass.  Not only did tensile strength matter, but hardness, since a metal that was too soft would allow bouncing ball going down the bore to dent it too easily.

[dan610324]

for me it looks like an bronze mortar of a wintage produvtion.
no onr have talked to it furimg thr past time
aŽnd nobodu havr heared it bark eithe         
hed just sad tht not anyone had shoot it for an long timr

[Victor3]

for me it looks like an bronze mortar of a wintage produvtion.
no onr have talked to it furimg thr past time
aŽnd nobodu havr heared it bark eithe         
hed just sad tht not anyone had shoot it for an long timr

 Hvae you been tsetnig the pordcut of yuor aclohol sitll aigan, or is it jsut a porblem wtih yuor keyebaord?

[Double D]

Remember Dan's first languange is not english, and I believe most of his posts come through a translator program.

[cannonmn]

>most of his posts come through a translator program.

It looks like that particular post was translated through at least a 6-pack, believe me I know the feeling and the results.

[dan610324]

 

 sorry guys   

I never use any translation program
and doesnt drink beer

but I must admit that I dont even remember writing that message 

cant understand what language its written in

but ok I drink rum sometimes   

I promiss to not touch the keyboard when Ive been looking in the rum bottle again   

[Double D]

I tried to cover for you Dan.   

[dan610324]

no idea   
just to confess .
yes I was tired and hadnt my reading glasses on   

anyone believing me ??

[Ex 49'er]

What's not to believe. Your word is your oath and that's good enough for me.

[Victor3]

 Okay, back on-topic....

 About a year ago, what looked to be an identical one came up on ebay. The seller didn't answer my questions about diameters, powder chamber or casting quality, so I passed. What you've listed as the O/D & I/D would leave a wall thickness of 1/4". In an unknown quality of casting, I'd be afraid to fire something like that with much more than a light blank, regardless of the alloy. It may have been made as a decorative item (I notice there's no vent machined), so any porosity or other casting flaws might have been viewed as acceptable by the maker.

[Cannoneer]

Thanks for your comments; I had thought about what both of you have said about the reddish hue possibly being caused by an ambient color coming from another object being reflected on the metal of the mortar, but I looked long and hard at the photo and I finally decided (though I could be wrong) that was the color of the metal itself. I just finished putting red brass (made from plumbing connections) tyres on four trucks for a naval carriage I've been working on, and the color of this mortar echoes exactly the color of the tyres I just cut, sanded, and polished.
I'll say again, I'm certainly no expert on this subject, but this so called red patina that some say develops on bronze and/or brass I'll have to admit I've never witnessed. I've got a few brass barreled pieces and I have never seen oxidation cause a red tint on any of them, and I have many photos of ordnance, much of which are definately of guns made by historic bronze founders using the classic gun metal recipe of 90% copper and 10% tin, (along with some other trace elements and minute ammounts of other metals that different makers purposelly added to their alloys) and havent seen this color in them either. I have definitely seen the rich reddish-brown patina that will in time develop on bronze pieces but never this pink-red hue (like a new penny).
Yes, there have been some enjoyable past threads on the subject of discerning brass from bronze and also the suitability of these metals being used for making ordnance. The first part of the preceding sentence was covered by GG (I hope George doesn't mind if I paraphrase him) when he said he didn't think it was that easy a task to identify bronze as opposed to brass by simply eyeballing the metals and that he thought the only sure way was to have the metal tested. I agree a hundred percent with what he said on that topic.
There's no question that discussing modern alloys of bronze and/or brass is a complicated topic, there are alloys now being made that utelize equal amounts of tin and zinc and while this alloy is usually referred to as bronze it could just as easily be called brass.
From Spencer Tucker's "Arming the Fleet": "Bronze (ninety parts copper and ten tin) continued for some time to be the favorite metal for cannon, because it stood the shock of discharge better than iron and was easier to cast. (Increasing the proportion of tin hardened bronze but also made it more brittle; decreasing the amount of tin made the metal too soft for cannon and also more elastic.)" One doesn't have to be an expert to comprehend the meaning of that statement; with an alloy composed of the wrong ammount of metals things could quickly become hazardous to your health and well being.
I don't know, in the final analysis I suppose it was just some internal warning flag that popped up that made me hesitant to buy the mortar. In any event it's a done deal and it's gone, but I did get something else and when it arrives it will cheer me up.


Dan; you drink whatever you want to, whenever you feel like it, and damn the torpedoes, full speed ahead!

[Cannoneer]

Okay, back on-topic....

 About a year ago, what looked to be an identical one came up on ebay. The seller didn't answer my questions about diameters, powder chamber or casting quality, so I passed. What you've listed as the O/D & I/D would leave a wall thickness of 1/4". In an unknown quality of casting, I'd be afraid to fire something like that with much more than a light blank, regardless of the alloy. It may have been made as a decorative item (I notice there's no vent machined), so any porosity or other casting flaws might have been viewed as acceptable by the maker.

Victor,

 I sent two questions to this seller; one asking if the piece had a powder chamber and if it did what were the dimensions? The second asking if they knew what metals were used in casting it. Like you, I got no response, which in my opinion, is never a good sign. The wall may be a little thicker than .25'', I can't gauge the difference between the muzzle face and reduced diam. of the wall, but you're absolutely right, it's still TOO THIN. I'm posting another photo of a mortar that was on eBay around the time you're talking about, it looks real similar to me (except this one looks more like yellow brass), and you'll notice that someone bored down into the vent cup and then drilled the vent lower than the rim of the cup. The only reason I can come up with to do this is that it had to be done because the bottom of the powder chamber is below where the cup begins, and on the real mortars thats not the way the vent and cup were arranged. This also probably means there's not enough metal thickness in the breech area. Well as the saying goes: If it sounds too good to be true,then........., which may account for this item selling for $202.00, that's less than half of what a British Coehorn model of this size usually goes for on eBay.

[dan610324]

BUT IF YOU LOOK AT THE 4 PICTURES ON TOP  HERE YOU WILL NOTICE AN EXTREME DIFFERENCE IN COLOR BETWEEN THE PICTURES .

sorry forgot the capslock

the third picture have what I would say is an slightly oxidated bronze color .

number one and four looks almost like pure copper
number two somewhere there between

I still believe its all about the camera settings and light settings .
can vary much between different screens and screensettings also .
always difficult with colors on computers .

but of course its not possible to tell what alloy used
maybe none of the four photos show the actual color .

this is written by an sober man   
but not for long more 
its friday evening now 
but tonight it will just be an small rum with pepsi , and a few drops of lime and lots of ice .
ok , maybe 2 small , but no more 

[Victor3]

I still believe its all about the camera settings and light settings .
can vary much between different screens and screensettings also .
always difficult with colors on computers .

but of course its not possible to tell what alloy used
maybe none of the four photos show the actual color .

 I've at times edited a picture's contrast for auctions and got all kinds of questions from potential bidders about the color of an item. Hard to tell for me, being somewhat color-blind.

[/quote]
this is written by an sober man   
ok , maybe 2 small , but no more 
[/quote]

 I'll drink to that 

[Cannoneer]

Dan,

 Your comments about the photos are right on the money in my opinion. The first and last look like the tubes made out of copper, the third has a lot more reasonable appearance for brass or bronze. Now, as for attributing all these variations in color on the digi-cam's settings, all I can say is I'm no Ansel Adams, you could be right, but I'd also have to add that Ive got a lot of stored photos and I'm kind of curious why I can't find a lot that display the same problem with depicting a barrel's brass color in a basically accurate fashion. The truth in the end is I just don't know, but there are also some other issues about this mortar that make me feel pretty good about making the decision to pass on it.

As for the matter of a few rum drinks in an evening; who are we to argue with almost the entire medical research professions currently held opinion that now states it's good for our health?