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Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 8:20 am
by Watermole+
SkimmingTheCream wrote: Sun Jul 23, 2017 7:43 pm Very nice Watermole :Hat:
Was the original made in a mould rather than machined ?
Trevor
Yes Trevor, by looking at the old original, I would say that they were definitely cast in moulds.

I have just learnt that copper may be toxic to fish so will make some more from brass (which does contain copper but as an alloy).

wm+

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 8:32 am
by Swythyn Troutbeck
Very nice indeed WM. Lovely.

Troutbeck :Hat:

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 10:00 am
by Nobby
They look so nice in the copper though. Could they be set in resin? Anybody any experience of resin moulding?

http://www.mbfg.co.uk/casting-resins.html


I have some imitation flowers around the house, with the flower set in resin in a glass to look as though it were mere water.

The world is full of new toys these days......and I want them all! I wonder if one could cast those Match Aerial arbour sections you once made, Leszek?

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 10:01 am
by Nobby
double post, sorry. The site is 'hanging' badly today.

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 10:07 am
by Snape
Utterly beautiful WM+. :Hat:
Don't worry about copper metal being toxic, it's not. Copper compounds are toxic but the metal is so unreactive with water there won't be a problem, just as we don't suffer poisoning from water passing through copper water pipes. Same applies to lead and mercury - the metals are not toxic. Vapours and compounds are a different matter. :Scared: Remember that brass is 60% copper so it is still there. Stick with copper... :Happy:

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 10:33 am
by Dave Burr
Nobby wrote: Mon Jul 24, 2017 10:00 am They look so nice in the copper though. Could they be set in resin? Anybody any experience of resin moulding?

http://www.mbfg.co.uk/casting-resins.html


I have some imitation flowers around the house, with the flower set in resin in a glass to look as though it were mere water.

The world is full of new toys these days......and I want them all! I wonder if one could cast those Match Aerial arbour sections you once made, Leszek?
Encasing objects in resin is quite straight forward Nobby. To do a plummet you'd need to pour a small amount as a base, let it set then put the plummet on top and fill the container. No 'join' is visible. I did my son's dead scorpion once but, because it hadn't quite dried, some body fluids coloured the resin yellow.... but it was still a cool paper weight. I'm certain that many fishing objects would look attractive if preserved in resin.

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 12:15 pm
by Nobby
Apologies, then if copper isn't toxic in the aquatic environment...I read that it was when I kept tropical fish years ago. A search on Google suggest that it is, but it's a subject I have no understanding of.

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 3:24 pm
by Fredline
They are way too good to drop into water.

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 4:04 pm
by Barbulus
Excellent WM+; a truly delightful idea to take a simple functional item and change it into a thing of beauty. I imagine they come with a suitable label advising both fish and people not to swallow them......

Re: A small but weighty matter..

Posted: Mon Jul 24, 2017 9:43 pm
by Snape
Nobby wrote: Mon Jul 24, 2017 12:15 pm Apologies, then if copper isn't toxic in the aquatic environment...I read that it was when I kept tropical fish years ago. A search on Google suggest that it is, but it's a subject I have no understanding of.

The problem with the toxicity issue is that references to copper, lead etc being toxic refer to their ions (as compounds) not the metals themselves as the metal cannot interact with biological systems. If you ingested lumps of lead, copper or even drank mercury they would just pass through you as they are not affected by gastric juices so do not react and are not absorbed (lots of cases of toddlers swallowing copper coins).
Lead is pretty unreactive but over a long period of time could react slightly in the aquatic environment (hence banning lead water pipes), copper is less reactive and does not react with water (hence being used for water pipes etc) and mercury is less reactive still (hence being used in amalgam filings). These are all classed as heavy metals and once in compound form, their ions are highly toxic to all living things although toxicity is about dosage and not the actual substance. Everything is toxic at a high enough dosage...
The dosages to kill 50% of average men (assuming we are similar to rats!) are
Caffeine: around 170 cups of coffee.
Salt: about 1/2 lb
Ethanol: just over a pint of 40% spirits, 20 pints of beer.
Citric acid: 15,000 oranges.
Sugar: 5lbs.
Water: 15 pints
These would all need to be consumed rapidly before any is excreted.

I definitely think WM+ should go ahead and stick to copper plummets....