Wato wato all, back to the making of the Britannia silver bowl.
I feel somewhat of a fraud, talking about the thickened edge here as the completed bowl was not a complete success, having not gone entirely to plan. Annealing is a topic I will cover in another post, suffice to say at this stage over, or under annealing causes problems. In this case, near the end of raising the rim cracked. This meant I had to cut off my, hard fought for and carefully made thickened edge. Oh well, at least it wasn’t a complete disaster, I am still happy with the end result. I will explain in detail later in this process.
Quick re cap, the peening process moved material from the centre of the disc towards the edge. Calking pushes the edge down compressing the edge in on itself thickening the edge in the process.
Just as the raising process work hardens and will crack the silver if overworked, so only a single overlapping blow is desirable, or wise, at each and every calking stage for the same reason.
With the bowl to be resting on a sandbag for support, a soft faced cross peen hammer, I used a modified raising hammer, is bought down confidently, striking the edge. Accuracy is very important, each blow ideally overlaps slightly to lead into the next blow. The hammer must be square on, if not sharp ding or undulations will develop leading to uneven distribution of the silver. This will cause problems further down the raising process as the sides will become uneven, worse, it may encourage cracking due to the added stress caused by the gathering of a forceful blow on a very small ‘ding’. It may not develop into a crack until further along, you may not even be able to find a cause when it happens.
A thing I have learnt working with this slow process is that, you may well be able to cover up a misplaced blow, even forget you made it, the silver wont!!!!
Sooner or later something will happen, I will show uneven raising examples another time. The message I wish to convey this time is, take your time, don’t just hit it, measure and control your hammerblows. If you don’t, and hit it willy nilly, it will come back to haunt you later.
I found, as Christopher Lawerence showed on his demonstration, I had much more control and more feeling by holding the sandbag on my lap the whole time. Same rules as raising, move the disc, not the hammer, concentrating on keeping the hammer blows consistent and square to the edge. The picture shows one of my raising hammers that I softened, rounded off to reduce the chance of catching the edge of the silver with a sharp edge, as seen on the opposite side of the hammer showing the original as it came factory finished.
Knocking off removes the burr that is created by calking process. The beauty of this is that material is saved by re compressing it back into the rim rather than, as you would be forgiven for naturally doing, removing the burr with a scraper or file.
As can be imagined this is a delicate process, too hard and you will remove all of the work hammering the rim back on itself, too little force and the burr remains causing problems further along. This is done on a flat plate, hammering from the inside on a steel flat plate in the early stages. Later it becomes impossible to get a hammer in as the opening reduces in size. The picture of the copper one shows the knocking off process done on a mandrell. The hammer used is a collet, of domed faced planishing hammer.
Remember the pickling process is your friend. Every time you strike the silver it will stand out as a shining mark that clearly stands out from the pickled matt finish. No excuse for overworking as you can see where you have been, again don’t just hit it, measure your blows and make sure you are as consistent as possible.
After each round of sinking, then raising, calking process is applied until the end of the raising process, or when the desired thickness is reached, whichever comes first.
Hope you can follow this, please let me know if I’m not clear on something and I will add to this.
Thats all for now, raising proper starts next time, untill then. All my very best wishes.
everyone cocks up with annealing now and then, esp with larger items as sometimes you just can’t see the whole thing at once.
I was taughts to raise and then trim the edge, but the thickened edge techniques looks do-able so I might try it(Obviously not with the two vessels I have in prgress at the mo as they’re nearly done). For me I think it’s sucess will depend upon how much strength is needed to hold the vessel still, as if its much more than is needed simply to hold it on the stake whilst you hammer I may well fail – wrist strength is an issue for women(I can’t raise without a wrist brace or my girly wrists suffer horribly)
Thank you for that, quite true I think my reluctance to get the silver too hot made me overcautious. I will cover in another post my solution and a great tip with a sharpie marker, helping to determine when the correct temperature is reached.
I wanted to use this technique for two reasons, first aesthetic, I was focusing on the thin edges of my copper bowls and thinking they needed a thickened edge to go with the chased/raised decoration, I thought they lacked depth, visual weight to match the pattern if you will.
I have a real thing about not adding elements, soldering on a rim would be an easy, faster option. My fascination with the techniques I rave about on this blog all involve ‘growing’ forms and patterns from a single sheet of metal. I have nothing against soldering, I just love the idea that from a flat sheet alone all this is possible. It’s a schoolboy like fascination with the process that makes me feel like a cheat if I solder elements on. I hope I get over it as I’m making a rod for my back!
Secondly I read about past masters, most of these skilled makers were more practiced than pretty much any modern maker can aspire to. As it was a conventional job, piecework being prevalent, also being penalised for waste. They honed their skills to the point that they could achieve completed forms with the minimum of trimming. As I understand it calking and peening came about due to increases in metal prices. Back then, as now, image was a great substitute for substance, makers coming up with this strategy to give the appearance of greater weight, without the increased cost.
I feel I was being a little ambitious for this bowl, being as it is the first silver bowl I have attempted. I have had great success with copper ones, copper being a very different animal than Britannia silver, as I discovered to my cost.
Don’t you think this is one of the great things about our craft, you never stop being surprised or learning new experiences that take you in directions you probably would never have though of without going through these processes.
Just a thought about your wrist strength, do you use a heavier hammer towards the rim? I do, I find this helps with consistency as the extra weight allows me to ‘throw’ the hammer at it without having to grip the shaft tightly and use more physical strength rather than the hammer weight.
If your holding hand is weak, forgive me if I am telling you something you know already, have you tried to reduce your angle, raising a smaller amount on each course, reducing the bounce, just a thought.
Thank you very much for replying to my post, it means a lot, comments like yours make it all worthwhile. Very best wishes.
I’ve seen how quickly men raise compared to me – I already do it pretty slowly, as long as i wear a brace ( as much to keep the joint warm as for support) I’m ok.
I kind of like the idea of the integral edge becuase it sounds easier – I always find adding rims quite fiddly as its hard to get a clean join over a large area like the rim of a cup. I must admit I never use copper for trials, I just jump right in and get on with it becuase I find copper is such a different beast to work with than silver – it probably helped that silver was a LOT cheaper when I first started playing with it
I wish I could use silver all the time. This one was a grant I was given, a 20cm by 20cm 0.9mm sheet was £400.00!!!! Ooh err eh. You are so right though copper is an entirely different animal. I like the way you can patinate it though, so with that and the cost it will be more copper until I sell more jewellery to fund it, or better still I get a commission, always hope I guess. I look forward to seeing your new creations, very best wishes.