Lee PrecisionReloading EverythingLoad DataInline Fabrication
Snyders JerkyRotoMetals2WidenersMidSouth Shooters Supply
Titan Reloading Repackbox
Results 1 to 13 of 13

Thread: eutectic solder

  1. #1
    Boolit Master
    Join Date
    May 2013
    Posts
    3,625

    eutectic solder

    ive got a couple big oversize rolls of this stuff like 5lb rolls, supposedly its for soldering stainless steel like commercial kitchen stuff.
    I saw something today that said it was a form of babbit and it doesn't turn grey like regular lead tin solder.
    its very old stuff and I have no idea
    doers anyone know about eutectic solder?

  2. #2
    Moderator


    Winger Ed.'s Avatar
    Join Date
    May 2007
    Location
    Just outside Gun Barrel City, Texas
    Posts
    9,809
    You struck Gold on that stuff.

    It's 63% Tin and 37% Lead. Some variations of it has other goodies in it and up to 2% Silver.
    It has good flow, higher strength and is used in some high end applications for electronics.

    Stainless Steel is usually TIG welded with Stainless Steel rods.
    Last edited by Winger Ed.; 02-07-2022 at 07:17 PM.
    In school: We learn lessons, and are given tests.
    In life: We are given tests, and learn lessons.


    OK People. Enough of this idle chit-chat.
    This ain't your Grandma's sewing circle.
    EVERYONE!
    Back to your oars. The Captain wants to waterski.

  3. #3
    Boolit Master
    Join Date
    Feb 2007
    Location
    South Western NC
    Posts
    3,820
    Eutectic refers to the lowest temperature a given soft metal alloy will melt.

    By itself, pure lead melts at one temp, tin, antimony, silver, zinc, etc., melt at other temps. But, mixed together, the lowest melting temp (the eutectic point) of any alloy will be a bit lower than the melting temp of any one of the metals in the mix. The modest eutectic heat difference of some precise solder alloys can be important in some kinds of electrical soldering.

    I don't KNOW but I doubt the eutectic point of any lead alloy will make much difference in casting bullets.

  4. #4
    Moderator Emeritus


    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    15,914
    Specifically, "the words eutectic solder describe a solder alloy that melts and freezes at one single temperature."

    https://fctsolder.com/eutectic-solder/
    ~~~~~~~~~~~~~~
    “If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
    ― The Dalai Lama, Seattle Times, May 2001

  5. #5
    Boolit Buddy
    Join Date
    Mar 2012
    Location
    Alberta
    Posts
    270
    Does it have a label or any markings on it?

    Knowing that it is a eutectic composition doesn't mean much if we don't know what alloy system it is. If it's an old solder and the weight feels right I suppose we can assume it is lead-tin, in which case the eutectic is 62SN-38Pb. But it could be a trinary eutectic (three metals) or another mix, such as lead-bismuth.
    ---------------------------------------------------------------------------
    --BattleRife

  6. #6
    Boolit Master
    Join Date
    Feb 2021
    Posts
    1,039
    Solder for SS on McMaster-Carr is 45% tin, 54% lead, and 1% silver… makes me think silver is required to solder stainless steel.

  7. #7
    Boolit Master



    Echo's Avatar
    Join Date
    May 2008
    Location
    Tucson AZ
    Posts
    4,603
    Eutectic solder (60-40, actually 63-37), when it melts, goes directly to a liquid state - from solid to liquid, with no plastic state in between. ALL electrical work should include eutectic solder. As an ex-missile man, I remember a test where an SM-62 Snark missile crashed on launch. Investigation shed to cause to be a 'Cold' solder joint. That is where the soldering took place with a non-eutectic solder, and the solderer did NOT get the joint hot enough to actually melt the solder! They just got it soft enough to fill the space, and left it at that. And cars bodies (way back!) used to have welding joints smoothed over with 30-70 solder. It could be heated up to the plastic state, prior to the liquidus state, and used like mud to cover up and smooth out the surface.
    Echo
    USAF Ret
    DPS, 2600
    NRA Benefactor
    O&U
    One of the most endearing sights in the world is the vision of a naked good-looking woman leaving the bedroom to make breakfast. Bolivar Shagnasty (I believe that Lazarus Long also said it, but I can't find any record of it.)

  8. #8
    Boolit Grand Master

    gwpercle's Avatar
    Join Date
    Sep 2011
    Location
    Baton Rouge, Louisiana
    Posts
    9,341
    Quote Originally Posted by JonB_in_Glencoe View Post
    Specifically, "the words eutectic solder describe a solder alloy that melts and freezes at one single temperature."

    https://fctsolder.com/eutectic-solder/
    JonB ... I need to see some explaining ...
    How can something ...melt and freeze ... at one single temperature .
    And I'm not a graduate of MIT ... just an old Louisiana Swamp Rat ... keep keep this esplanation simple .
    Gary
    Certified Cajun
    Proud Member of The Basket of Deplorables
    " Let's Go Brandon !"

  9. #9
    Boolit Grand Master popper's Avatar
    Join Date
    Jun 2011
    Posts
    10,597
    That is the meaning of eutectic. generally for a binary lead/tin alloy, at the proper ratio liquid goes to solid phase. Above/below the alloy forms various combinations of liquid and solid until it all solidifies. Real 'cold' solder joints are due to the metals not getting hot enough to combine with the melted solder.
    Click image for larger version. 

Name:	Phase_Diagrams_Image_003.png 
Views:	18 
Size:	204.4 KB 
ID:	296902
    Whatever!

  10. #10
    Moderator Emeritus


    JonB_in_Glencoe's Avatar
    Join Date
    Mar 2010
    Location
    Land of 10,000 Lakes
    Posts
    15,914
    Quote Originally Posted by gwpercle View Post
    JonB ... I need to see some explaining ...
    How can something ...melt and freeze ... at one single temperature .
    And I'm not a graduate of MIT ... just an old Louisiana Swamp Rat ... keep keep this esplanation simple .
    Gary
    The melting point and freezing point describe the same transition of matter. In this case from liquid to solid (freezing) or equivalently, from solid to liquid (melting). When the melting point equals the freezing point. This "point" is the temperature at which the solid and liquid forms of the molecule, are in equilibrium.

    FYI, the meaning of equilibrium is, a state in which opposing forces or influences are balanced.
    ~~~~~~~~~~~~~~
    “If someone has a gun and is trying to kill you, it would be reasonable to shoot back with your own gun.”
    ― The Dalai Lama, Seattle Times, May 2001

  11. #11
    Boolit Master
    Join Date
    Dec 2018
    Location
    Capital Region NY
    Posts
    681
    Linotype is also a Eutectic, thats why you don't want to let it solidify in your pot. It goes from solid to liquid in one shot, usually with a squirt to the heavens.

  12. #12
    Boolit Buddy
    Join Date
    Mar 2012
    Location
    Alberta
    Posts
    270
    Quote Originally Posted by gwpercle View Post
    JonB ... I need to see some explaining ...
    How can something ...melt and freeze ... at one single temperature .
    And I'm not a graduate of MIT ... just an old Louisiana Swamp Rat ... keep keep this esplanation simple .
    Gary
    Many substances melt and solidify at one temperature, the most common example being water.

    Water at 0°C (32°F) can be entirely solid, entirely liquid, or a mix of the two.

    If you have a bucket of water as a liquid, taking energy out of the water can lower the temperature to the freezing point. Then, if a little more energy leaves the bucket, some of the liquid turns to ice. As more energy leaves the bucket, more of the water turns from liquid to solid, but the temperature doesn't change. It is always 0C/32F.

    Eventually all of the water will freeze, then if more energy is removed from the bucket, the temperature of the ice starts to drop again.

    This is why ice water is such an important reference point. If you have a stable mix of solid ice and liquid water, the temperature must be 0C/32F, it is the only temperature at which that mixed state can exist. Many pure metals are used for similar temperature references at higher temps.

    Non-eutectic alloys have what are called mushy stages, where they are a mix of solid and liquid over a range of temperatures.
    ---------------------------------------------------------------------------
    --BattleRife

  13. #13
    Boolit Grand Master
    bangerjim's Avatar
    Join Date
    Apr 2013
    Location
    out of here, wandering somewhere in the SW.
    Posts
    10,164
    All 316/416SST joining I have ever done is with a TIG welder. I guess they sell SN/Pb solders for the purpose, but the strength sure is not there!

    Sort of like those Aluminum soldering rods the sell at flea markets.............what a joke! They always demo them by soldering a pop can together! The stuff is worthless for real life structural jointing.

    I would treat those rolls of solder you have as what they REALLY are - - 45%Sn + Pb. Good for adding that 2% Sn to your melt - if needed.

    I sure would not trust mud-dauber hand soldering to the SST joints I have done.

    And do not get lost in the weeds about "eutectic metals". Nothing special at all.

    banger

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check