# Brass pop up sprinklers may not be all brass



## ericc (Aug 3, 2020)

Quite a while ago, I noticed that one of my sprinklers was leaking.  It was one of those classic brass ones that us older folk think are high quality.  I removed it and took a look, although not such a good look, as I discovered later.  The stem leading to the nozzle had corroded away, leading to loss of the gasket surface.  This caused the leak.  This is a fatal failure, and I put it into a coffee can just in case I ever got a ceramic crucible so I could cast it into something useful.

Fast forward a couple of years, and I noticed that my kitchen sink faucet sprung a leak.  It was only about a year old, but it was a generic and probably not meant to be repaired.  I decided to strip it for brass.  It became obvious that most of the metal in the faucet was not brass.  Anything that did not touch flowing water was some kind of zinc alloy, probably zamak.  The flange, escutcheon, body, handle were all zamak.  They showed corrosion.  Only the valve cartridge nut, sealing plate, and the hose fittings were brass.  About 5 oz. of brass out of a several pound faucet.  I looked at the Internet, and I saw a scrapper video that said that faucets were only worth 0.40 per pound instead of 1.30 per pound for scrap brass, since they were made of less and less brass.

This encouraged me to look back at the failed sprinkler.  It was obviously solid brass, but brass doesn't corrode like that.  The scrapper video suggested I use a file to tell what is brass and what is zamak.  It turns out, under a thin brass plating, most of the sprinkler is zamak.  And, both stem and body are quite corroded, to the point of failure.  The only brass piece is the nozzle, which must be brass, else it would fail pretty quickly.  Doing a web search on this only turned up one interesting hit.  A web page said that brass pop-up sprinklers were considered the pinnacle of quality only up to the 1970's after which they were superseded by plastic ones, due to longevity issues.  But it didn't tell the reason.  So, brass sprinklers may be made of mostly zinc alloy.  That may explain a failure I saw in a foundry class using scrap plumbing fittings as stock.  Lots of fumes and poor yield. So, make sure you check everything with a file before you throw it into that crucible.


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## RJSakowski (Aug 4, 2020)

I'm surprised that a manufacturer would plate brass over pot metal..  That is clearly IMO a deceptive practice.  I have seen lots of decorative items advertised as brass when in fact they are brass plated over steel.  The same for use of nickel.  But at least the claim could be made that it is for decorative purposes.

To add another issue to the mix, thanks to RoHS, and more recently to California Prop. 65, lead has been removed from brass.   At least in some cases , this makes the brass more susceptible to a condition known as "zinc rot" where the zinc is dissolved out of the brass, leaving a porous structure and, in the case of plumbing fittings, a leaking plumbing fitting.

Seven years ago, I replaced the pressure tank on our home water system.  Not wanting to deal with corrosion issues, I used brass exclusively for the fittings, including the long tank tee which fits under the tank.  About two years in, I noticed a wet spot and a drop of water every 45 seconds.  The tank sits on a pedestal surrounded by a drainage gutter, so the leak was more an annoyance than a threat.  Some research indicated that this is a fairly common problem with some brass fittings, particularly this one as it os machined from sand cast brass and has fairly thin (<1/16") walls in some areas.  I ordered a replacement fitting for standby.   The leak is up to about one drop in five seconds now and at some point I will have to replace the fitting.  

This not a trivial task as the tank holds 85 gallons of water and is in an awkward corner with my lathe on one side and my drill press on the other.  Fortunately, the tank has a 5/8" socket on top.   I had the presence of mind to make a threaded eye bolt for the tank and install a sky hook in the floor joists above so I can lift the tank with my come-along.  I also added couplings to the plumbing allowing for easy breaking of the system.  

Since I have a replacement part, I will use it and hope that the repair outlives me or at least takes me to a point where I no longer care about such trivialities.  That's on good thing about advanced age; a thirty year warrantee is a lifetime warrantee for me.


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## aliva (Aug 4, 2020)

Unless is says it's solid brass, it's plated. Go with 316L stainless fittings there not all that expensive, but will last for ever


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