Loading ...
Sorry, an error occurred while loading the content.

Re: Silver solder or just lead free solder?

Expand Messages
  • andyrud3
    ... Andy
    Message 1 of 7 , Mar 28, 2011
    • 0 Attachment
      --- In new_distillers@yahoogroups.com, o1bigtenor <o1bigtenor@...> wrote:
      >
      > On Sun, Mar 27, 2011 at 3:53 AM, geoff burrows <jeffrey.burrows@...>wrote:
      >
      > Great information from everybody! I plan on using copper pop rivets every 1 inch and then soldering the lap joints together.

      Andy




      > >
      > > Hi Andy,
      > >
      > > As long as you do a good job pop riveting, the sheet joins will be
      > > strong enough.
      > >
      >
      > You MAY have enough strength in the connections. Pop rivets are quite good
      > but their consistency level is not that good for anything that would be
      > considered a pressure vessel. Anything that contains a pressure greater than
      > 15 psi is by definition a pressure vessel and MUST be built to
      > specifications written for pressure vessels. Now if you have something where
      > there are NO restrictions to atmosphere then you can build it any way you
      > want. (You can build it any way you want even if it is for over 15 psi but
      > then if there are problems a massive shelf of books (ASME code is about 6
      > feet of binders of information) will hit you and it will hurt!) This comment
      > was written this way because there was absolutely no guidance on what
      > constitutes a ´good´ joint. This topic is not one that can easily be
      > addressed in a brief note either. There are many many books written on the
      > topic.
      >
      >
      > > All you are doing with the lead free solder is sealing any leaks where your
      > > ethanol/steam vapour might escape.
      > >
      >
      > If you are doing an open to atmosphere system why would you want the work of
      > doing both?
      >
      >
      > > Yes the soft lead free solder will give it a bit more rigidity if used
      > > in conjunction with the pop riveting. But solder on its own just butt
      > > joining copper is not really strong enough. On the other hand a bent over
      > > copper seam, pop riveted and soldered is as strong as you're going to get
      > > with copper sheet
      > >
      >
      > Well - - if you are doing a pop riveted joint you definitely DON´T have a
      > butt joint you have a lap joint even for your welding.
      >
      >
      > > Also don't forget if you are hammering or working your copper sheet a
      > > lot, it will work harden and will snap so to soften the copper again heat it
      > > bright red (that's called annealing) and let it cool it will soften
      > > nicely and be more malleable. To clean the copper again I used to use a
      > > mild pickling solution like at this link http://tinyurl.com/2gxer4y
      > >
      >
      > If you use any kind of solution to remove the annealing heat effected zone
      > then you need to very carefully clean the solution off of the material too
      > or you will be trapping corrosion and corrosives IN your lap joint - - a
      > really bad idea and that will cause failure. It might be just easier to use
      > some kind of abrasive pad (scotch-brite has at least 5 or 6 levels of
      > hardness/abrasiveness available).
      >
      > I am a licensed and ticketed pressure welder and I am a tinkerer so I am
      > trying to insert some care from BOTH sides of the equation!!
      >
      > Darald
      >
    • geoff burrows
      Hi Andy and Darald, (my comments are in line in blue) I totally agree with you about pressurized vessels and wouldn t even think of anything other than welded
      Message 2 of 7 , Mar 29, 2011
      • 0 Attachment

        Hi Andy and Darald, (my comments are in line in blue)

             I totally agree with you about pressurized vessels and wouldn’t even think of anything other than welded vessels for pressurized containers


        > Great information from
        everybody! I plan on using copper pop rivets every 1 inch and then soldering the lap joints together.

        Andy

        > >
        > > Hi Andy,
        > >
        > > As long as you do a good job pop riveting, the sheet joins
        will be
        > > strong enough.
        > >
        >
        > You MAY have
        enough strength in the connections. Pop rivets are quite good
        > but their
        consistency level is not that good for anything that would be
        > considered
        a pressure vessel. Anything that contains a pressure greater than
        > 15 psi
        is by definition a pressure vessel and MUST be built to
        > specifications
        written for pressure vessels.  Our stills are NOT pressurized vessels so this information although good and very note worthy has no relevance to our hobby stills except to making good welded joints.  Now if you have something where
        >
        there are NO restrictions to atmosphere then you can build it any way you
        > want.  
        style="COLOR: #4f81bd; mso-themecolor: accent1">Exactly if you look at, and fully understand our hobby stills, it is blatantly obvious they are open with no restrictions to the atmosphere.As has been pointed out time and time again by more  experienced people than me  (You can build it any way you want even if it is for over 15 psi but
        > then if there are problems a massive shelf
        of books (ASME code is about 6
        > feet of binders of information) will hit
        you and it will hurt!)  I’ve seen a caged split rim lorry tyres (I think they are illegal now) explode and that is a spectacular sight and we only got it to 40psi so I understand what a large volume of air pressure can do This comment
        > was written this way because there
        was absolutely no guidance on what
        > constitutes a ´good´ joint. This
        topic is not one that can easily be
        > addressed in a brief note either.
        There are many books written on the
        > topic.
        >
        >
        > > All you are doing with the lead free solder is sealing any leaks where
        your
        > > ethanol/steam vapour might escape.
        > >
        >
        > If you are doing an open to atmosphere system why would you want the
        work of
        > doing both?
        style="COLOR: #4f81bd; mso-themecolor: accent1">  The shape and construction of some of our hobby stills, need a certain amount of integral strength hence the pop rivets (not everyone has access to a welder or can weld hence the work around).  The lead free solder is to stop our precious ethanol from escaping from our still before we get it condensed
        > > Yes the soft lead free solder will give it a bit
        more rigidity if used
        > > in conjunction with the pop riveting.
        style="COLOR: #4f81bd; mso-themecolor: accent1"> Pop rivets by their very nature are basically a swivel point waiting to happen if not used correctly and to a well thought out plan.  The lead free solder helps any would be racking of joined parts and sealing the system.  But solder on its own just butt
        > > joining copper is not
        really strong enough.  I would never advocate a soft solder butt joint hence the following statement.  On the other hand a bent over
        > > copper seam, pop riveted and soldered is as strong as you're
        going to get
        > > with copper sheet.
        style="mso-spacerun: yes">  I’ve planned, re-roofed (to very high building code specification I might add) and worked on a  copper domed roof in Cheetam Hill Hospital in  Manchester.  So I know how to cut join and work with copper sheet sizes and their expansion co-efficients etc.
        > >
        >
        > Well - - if you are doing a pop riveted joint you
        definitely DON´T have a
        > butt joint you have a lap joint even for your
        welding.  I know read previous comment
        >
        >
        > > Also don't forget if you are
        hammering or working your copper sheet a
        > > lot, it will work harden
        and will snap so to soften the copper again heat it
        > > bright red
        (that's called annealing) and let it cool it will soften
        > > nicely and
        be more malleable. To clean the copper again I used to use a
        > > mild
        pickling solution like at this link http://tinyurl.com/2gxer4y   I cleaned all my copper projects in the flat cut sheet format (it's easy this way) and cleaned everything in lots of warm soapy water then bent joined and assembled them.  Its  called common sense but you are probably correct not everyone has common sense you can’t buy it that's for sure and scaring pads are probably the way to go if you are unsure.  
        > >
        >
        > If
        you use any kind of solution to remove the annealing heat effected zone
        >
        then you need to very carefully clean the solution off of the material too
        > or you will be trapping corrosion and corrosives IN your lap joint -
        - a
        > really bad idea and that will cause failure.
        style="COLOR: #4f81bd; mso-themecolor: accent1">Not an issue  if you clean properly as in the previous comment.  

        Geoff

         

        It might be just easier to use

        > some kind of abrasive pad (scotch-brite has at least 5 or 6 levels
        of
        > hardness/abrasiveness available).
        >
        > I am a licensed
        and ticketed pressure welder and I am a tinkerer so I am
        > trying to
        insert some care from BOTH sides of the equation!!  > Darald

      Your message has been successfully submitted and would be delivered to recipients shortly.