Copper rivets and washers.

[Ratty]

Ok, at last..the promised pics (see this thread) of my little (big) copper washer/rivet project! I gave up on the idea of filling the little holes in the copper ballcock with rivets and soldered them instead.
One of the offending holes..

A pair of holes prepared for solder..

Soldered..

and patinated to blend in..

Then I had to make a large washer to reduce the hole which the fixing bolt came through, the bolt was temporarily held inside the ball with a short length of flattened copper pipe. In order that the steel bolt didn't contact the copper it has a rubber grommet fitted..

To make the washer, first I cut a piece of copper pipe;

Flattened it, screwed to a block (so I didn't slice any more of my fingers when drilling!).

The hole saw was used initially to mark the copper before drilling the centre hole;

then I replaced the hole saw to complete the cut;

Voila! One 55mm copper washer.

 

[Ratty]

To curve the washer so that it followed the contour of the ballcock, I got myself a little toolkit together..1 x coach bolt, 1 x rubber grommet/bush thingy, 1 x iron ring a little larger than the washer, 1 x anvil and 1 x lump hammer..

Copper washer is placed on the iron ring, rubber bush placed on top;

Head of coach bolt positioned inside bush;

..and firmly tapped with the hammer;

One nicely curved washer;

Checked for fit;

Drilled and riveted in place (yes I bought some...several...thousand...2500 to be exact in 3 different sizes..should keep me quiet for a while).

The rusty washer and copper pipe is just to temporarily hold the bolt in place, (to prevent me losing it inside the now in inaccessible ballcock) and to keep the copper washer in postion.
Once riveted, the copper pipe was removed and the bolt fixed through the cast steel base. There is a thick rubber washer between the ballcock and the base to prevent the two metals contacting;

With a nice solid stand, I can now finish the sculpture...pics later.

 

[Drains]

Why are you concerned about the two metals touching Rats? Got something against batteries?

 

[steve202]

Will it charge up or something? Surely not!?

Nice work by the way Ratty.

 

[drivewasher]

Why didn't you solder the copper washer to the copper ballcock?
I used to cut a hole in copper water cylinders and solder a threaded ring in the hole to fit an imersion heater element.

Will the rubber washer be to prevent dissimilar metals corrosion by electrilosis?


AND how did you get the copper tube so flat after splitting it open?

 

[Ratty]

Why didn't you solder the copper washer to the copper ballcock?
I used to cut a hole in copper water cylinders and solder a threaded ring in the hole to fit an imersion heater element.

Will the rubber washer be to prevent dissimilar metals corrosion by electrilosis?


AND how did you get the copper tube so flat after splitting it open?

I didn't solder it partly because sculpturally I like the appearance of rivets - even tho' you barely see them - I like the physicality of 'fixings' as opposed to 'glues'. Soldering in a threaded brass ring to take a bolt could have worked but the ballcock is very thin copper and it really needed that reinforcement.
Yes, the idea of preventing dissimilar metals touching is to avoid any possible corrosion. Tbh I'm not too sure whether I get a bit over paranoid about this (I'd welcome input from any chemically minded members) but I do get a perverse satisfaction from finding solutions (even if the problems only exists in my overactive imagination ). I do know that if you hang a picture with a brass wire on a steel hook the electrolytic action between the metals will cause the brass to corrode and break...and something about sacrificial diodes in central heating tanks...my knowledge is hazy to say the least . The thick rubber washer between the ballcock and the stand actually has a dual function as it means the ballcock sits tight and snug against the steel with no wobbles or distortion.

The copper tube I flattened was only a few inches long and I simply opened it up a bit and squeezed it in the vice like so;

 

[drivewasher]

Thanks Ratty, now I get it. Dissimilar metals used to be a problem on landrover hinges, the pillar was ally and the hinges steel with the salt water in winter the ally pillars used to "dissapear"
Also the load rating and manufacturers plate on hgv trailers is pressed alli and you can often see where the ali rivets and the edges of the plate appear to have bee "eaten" caused by dissimilar metals and the salt water acting as an electrolite where they are fixed to steel chassis rails.

The sacraficial piece you refer to would be a "Sacrificial Annode"
I think they are screwed on boats that go in seawater as my sons power boat has 2 screwed on the back below the water line, they get changed periodicaly, the theory is the annode dissolves thereby saving the expensive alli engine/gearbox

 

[Ratty]

All interesting stuff dw, so I'm not inventing it all then Funnily I googled sacrificial diode after I posted and got quite a few hits (147,000 ) and have just done the same for annode and got similar stuff (but only 387 hits) so my next search has to be wot's an annode and wot's a diode (cos I have absolutely no idea). Maybe tomorrow.

...then I thought it might be easier to look them both up in the dictionary (I'll let you know when I work out what it says ) but did discover..no such word as annode (google thinks there is) so took out an 'n' and got 271,000 hits. Bit of reading then

 

[Drains]

You'd get more hits for anode if you spelt it right, I imagine.

The process of disolution (is that right?) is Galvanic Action. I have a table of metals and their relative nobility somewhere. Zinc, magnesium and aluminium are used on boats - Zinc for seawater, aluminium for sea/river/brackish, and magnesium for fresh.
Table here
(notice where the "active" stainlesses are - they rot! That's why they have to be cleaned after welding....
Lack of anodes leads to pitting in steeel, and de-zinctification in brass, especially the cheap "yellow" brass your picture hooks are made of Rats.

As for copper and steel, I don't think i'd worry myself too much, especially if the piece is inside, as the presence of an electrolyte makes a huge difference. Outside of course you have the rain, sometimes with the odd chemical washed through it. And regardless, your attention to detail can't be faulted Rats - better be safe than sorry. I'm glad you value your work enough to think it's worth preserving

If you really want to be fancy Rats, you could include some little aluminium sacrificial anodes on your pieces, just for fun and professionalism. And a packet of spares for the client, hidden in a secret compartment.

 

[cobminor]

Ratty,

An annode is simply a terminal on the positive side of an electrical circuit, the negative is a Cathode.

 

[lexi]

Ratty,

An annode is simply a terminal on the positive side of an electrical circuit, the negative is a Cathode.

So ........Is a Cathode Tube a guy who watches too much telly..........


Alex

 

[Ratty]

Thanks for all the useful info Si, I shall print out the table and pin it to my workshop wall - then I'll know what I can use with what.
Actually I said brass picture wire not brass hooks, the incident of a picture falling off the wall (not mine) was where the brass wire was hung on a steel screw.

As for copper and steel, I don't think i'd worry myself too much, especially if the piece is inside, as the presence of an electrolyte makes a huge difference.

Not according to your table (if I understand it right), it says

For normal environments, such as storage in warehouses or non-temperature and humidity controlled environments. Typically there should not be more than 0.25 V difference in the "Anodic Index"

According to the index, copper is 0.35 and steel 0.85, a difference of 0.50. It might take a while but seems like some galvanic action would take place.
I just remembered this morning, a recent conversation about electrolytic reaction. We have been looking in to changing all our crappy plastic guttering and downpipes for galvanised steel, a company called Lindab do one- 'Aluzinc' - that is 80% aluminium coated and looks stunning. Sadly we were told we couldn't use it as we have lead valleys and they would cause corrosion. I want to argue it but think I will over-ruled (and looking at the table I can see why). We are waiting to see a rep about using their suggested alternative, colour coated. Ok I suppose, the original cast iron guttering was a reddish brown to match the window frames and they will colour match to your spec. I presume they are epoxy powder coated both inside and out, what I want to know is why can't they coat the insides of the galv. stuff to make it corrosion resistant? or is there something we can coat the lead with to stop leaching?
Anybody know of another system that might work with lead valleys?

 

[Lippyp]

All of our gutters are wooden (yep, I was surprised too but it seems the norm up here in barm cake land) with lead let in over the joints and cast iron downpipes.

 

[lexi]

There are cast aluminium gutters.........Alumask with coloured finish. Some people powder coat galvanised railings with success. Not a great fan of PC. Is the cost of replacing lead valleys out of the question with zinc. Patination oil can help with leaching on lead but it may still react with your galvanised material.

If the valley gutters are skewed then you may be able to catch it in a hopper and separate it from main gutter. After all these years I still think the cast iron is the best. With better paints available they will last more than a lifetime. Thing is that the non standard sizes are now made as specials.........with a price tag to match.
Alex

 

[MrFluffy]

Paints/clear varnish remove the electrolyte from the equation , which removes the galvanic corrosion, as the mini battery can never form without electrolyte no matter how far apart on the galvanic table the materials are.
I took my ally downpipe off the gutter to use to make some exaust cans with and replaced it with some nice easy to care for plastic then painted it and only people I tell know, sometimes technological advances are good

 

[Ratty]

Thanks for the input lex, I was actually looking at cast aluminium earlier, (after googling wood gutters out of curiosity!) there seem to be quite a few different suppliers. I don't really want a coated finish as they never last as long, but the cast aluminium suppliers seem to imply the 'mill finish' is resistant to most corrosion except 'direct contact' - no mention of run-off. I also saw a few places selling copper guttering but could find no reference to corrosion re; lead so will have to ring and enquire (no prices there either so don't know how it compares). We did talk to a builder mate about replacing the lead valleys but it would be major & expensive and the same with trying to separate from the main gutters as it would mean having 3 downpipes at each valley (there are 5 valleys). I think cast ali might be the way to go, a bit more than the galv stuff but looks much more like the original cast and no fear of rusting. Having discovered there are alternatives I shall look into it further.

 

[Ratty]

I took my ally downpipe off the gutter to use to make some exaust cans with and replaced it with some nice easy to care for plastic then painted it and only people I tell know, sometimes technological advances are good

Not for us! I find it terrible stuff, looks awful and shrinks and expands all the time causing the joints to leak and fill with crap and you can't lean a ladder against it so getting to the roof (or even to clean the gutters) is a total pain. Painting? There is over 100 metres of guttering alone and 10 downpipes of 5.5 metres + all the brackets & other bits....you want the job?

 

[lexi]

Not for us! I find it terrible stuff, looks awful and shrinks and expands all the time causing the joints to leak and fill with crap and you can't lean a ladder against it so getting to the roof (or even to clean the gutters) is a total pain. Painting? There is over 100 metres of guttering alone and 10 downpipes of 5.5 metres + all the brackets & other bits....you want the job?

All True. On an old house of character pvc is a real no no. I fit them to customers more modest houses frequently .........after they have rejected the price of cast iron. They make a horrible sqeaking noise as the sun comes out and goes in.........that is how much they move. The other problem is that the systems get superceded by new joint designs etc.
Marley systems have changed four times in 20 yrs making each system obsolete.......the new parts will not fit properly into old.

When putting ladder against gutter you have to go up first under gutter and fit a piece of
4x2 to take weight of ladder............PITA. Still....Plastic is quick and cheap. That is what majority of peeps want. Funny thing is PVC Rainwater has went up 3 times in 12 month with metal not far behind.

Alex

 

[MrFluffy]

Ive never noticed the squeaking noise, and all ours are now plastic, gutters inclusive along with some 100mm plastic vents for the new fosse system as laid down in the building regs here. Theyre all just half round and come with seals that allow expansion so maybe thats why they don't creak, mix of manufacturers even. Joints seem to be holding 4 years in too. The only time I used to get nervous was when the workshop gutter filled with snow because of the weight, but Ive added more support after seeing it sag during heavy snowfall and Im happy again. Any material would have needed the extra mechanical support to deal with that loading...
Still at 200+ years old and being made of stone and cow poo, even a gutter and drainage system is a modern tardy tack on to the original. It originally would have had no gutters and be surrounded by a pebble drain but we already decided against being authentic and having mould growing up the interior walls. That was dealt with by the previous owner by using asbestos sheet in place of plasterboard, another common technique seen locally on older housing. Plastic is quick, cheap AND low maintenance, I have enough on my plate as it is without wasting time on extra stuff...
The rest of the guttering we replaced was galvanised tin, which did leak like a sieve because it had pinholed through in places like you'd expect...

You can get a type of steel that when it starts to rust, the outer layer seals up with the corrosion and no further corrosion can take place. Its the stuff they make some of the iron bridges out of in the states, to save the cost of painting. That'd make the ultimate gutters, painted, and when the paint breaks down the coating takes over...
http://en.wikipedia.org/wiki/Coreten

 

[Ratty]

Well I finally finished the copper ballcock sculpture so here's a couple of pics, photo's courtesy of Steve Russell, who's been here for two long days photographing my work.