Hot Dip Galvanizing: Difference between revisions
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*Hot-dip galvanizing design - MIG is good for weldments prior to hot dip, must be low Si - [http://www.duncangalvanizing.com/hot-dip-galvanizing-design]. Info on welding galvanized steel | *Hot-dip galvanizing design - MIG is good for weldments prior to hot dip, must be low Si - [http://www.duncangalvanizing.com/hot-dip-galvanizing-design]. Info on welding galvanized steel | ||
*Steels for tanks - [https://www.steeltank.com/Portals/0/Pressure%20Vessels/Development%20of%20Steels%20and%20Their%20Uses.pdf] | *Steels for tanks - [https://www.steeltank.com/Portals/0/Pressure%20Vessels/Development%20of%20Steels%20and%20Their%20Uses.pdf] | ||
*'''Materials''' - 'In the "old days" the common material was fire box steel. Some years ago "Max Ten" was specified which means the alloying agents in the steel would add up to no more than 0.10%. Today modern kettle makers know what can and cannot be used to make a galvanizing kettle. Certainly silicon, aluminum, and phosphorus contents in the steel must be VERY LOW. Also one MUST use the correct welding rod or else the welds will be "eaten up" by the zinc. In addition only the side walls can be heated (NEVER THE BOTTOM). Also the a horizontal stripe 6 inches high at the top of the walls and a horizontal stripe 12 inches at the bottom of the kettle are insulated and (NEVER HEATED). The maximum heat throughput through the walls is 10,000 BTU/sq.ft. on the heat zone of the side walls.'. '''Boilerplate steel.''' Firebox steel. '''Low Carbon Steel'''. | *'''Materials''' - 'In the "old days" the common material was fire box steel. Some years ago "Max Ten" was specified which means the alloying agents in the steel would add up to no more than 0.10%. Today modern kettle makers know what can and cannot be used to make a galvanizing kettle. Certainly silicon, aluminum, and phosphorus contents in the steel must be VERY LOW. Also one MUST use the correct welding rod or else the welds will be "eaten up" by the zinc. In addition only the side walls can be heated (NEVER THE BOTTOM). Also the a horizontal stripe 6 inches high at the top of the walls and a horizontal stripe 12 inches at the bottom of the kettle are insulated and (NEVER HEATED). The maximum heat throughput through the walls is 10,000 BTU/sq.ft. on the heat zone of the side walls.'. '''Boilerplate steel.''' Firebox steel. '''Low Carbon Steel'''. In the same article, Dr. Thomas H. Cook | ||
Galvanizing Consultant - Hot Springs, South Dakota, USA says that kettles are not for DIY. | |||
*Materials engineered for use in galvanizing operations - the specific property required is? Low in C and Si. It is flange or firebox quality steel. Boilerplate steel. [https://www.finishing.com/153/77.shtml] | *Materials engineered for use in galvanizing operations - the specific property required is? Low in C and Si. It is flange or firebox quality steel. Boilerplate steel. [https://www.finishing.com/153/77.shtml] | ||
*Sulfuric acid eats steel, but sulfuric acis is stored in steel tanks. Here is more about corrosion rates - a study - [https://www.osti.gov/etdeweb/servlets/purl/21319914#:~:text=Corrosion%20of%20carbon%20steel%20in%20sulfuric%20acid,as%20shown%20in%20reaction%201.] | *Sulfuric acid eats steel, but sulfuric acis is stored in steel tanks. Here is more about corrosion rates - a study - [https://www.osti.gov/etdeweb/servlets/purl/21319914#:~:text=Corrosion%20of%20carbon%20steel%20in%20sulfuric%20acid,as%20shown%20in%20reaction%201.] | ||
Revision as of 23:33, 11 February 2021
About
- Kettles - copper causes premature kettle failure.
- Kettle manufacturer - [1]
- Wikipedia - [2]
- Zinc Ammonium Chloride - used as flux - [3]. Zaclon in Ohio makes it. [4]
- Coating thickness for 1/4" and above steel is 85 microns minimum. [5]
- Kettle inspections - tests wall thickness - apparently for wear and complete loss of metal. Wall thickness is measured ultrasonically in situ o a working kettle with molten metal. [6]
- Melting zinc - you can even melt on stovetop, here is a tiny wad of zinc melted into a mini-ingot [7]
- Hot-dip galvanizing design - MIG is good for weldments prior to hot dip, must be low Si - [8]. Info on welding galvanized steel
- Steels for tanks - [9]
- Materials - 'In the "old days" the common material was fire box steel. Some years ago "Max Ten" was specified which means the alloying agents in the steel would add up to no more than 0.10%. Today modern kettle makers know what can and cannot be used to make a galvanizing kettle. Certainly silicon, aluminum, and phosphorus contents in the steel must be VERY LOW. Also one MUST use the correct welding rod or else the welds will be "eaten up" by the zinc. In addition only the side walls can be heated (NEVER THE BOTTOM). Also the a horizontal stripe 6 inches high at the top of the walls and a horizontal stripe 12 inches at the bottom of the kettle are insulated and (NEVER HEATED). The maximum heat throughput through the walls is 10,000 BTU/sq.ft. on the heat zone of the side walls.'. Boilerplate steel. Firebox steel. Low Carbon Steel. In the same article, Dr. Thomas H. Cook
Galvanizing Consultant - Hot Springs, South Dakota, USA says that kettles are not for DIY.
- Materials engineered for use in galvanizing operations - the specific property required is? Low in C and Si. It is flange or firebox quality steel. Boilerplate steel. [10]
- Sulfuric acid eats steel, but sulfuric acis is stored in steel tanks. Here is more about corrosion rates - a study - [11]
- Sulfuric acid does not eat polyethylene - [12]
Process
From [13]
Howto
- Sand blast
- Base bath - 10 minutes min
- Base bath - 7 minutes min
- Flux - ammonium
- Actual dip - 3.5 minutes (until base metal reaches melt temp of 835F)
- Water - trapped water explodes, and is dangerous, so first dip is dangerous and venting must be assured.
- Zinc - 2400 lb blocks are the feedstock for hot dip baths. This is only 0.1 cubic meter - or 4 cubic feet.
https://www.aisc.org/globalassets/modern-steel/archives/2014/08/2014v08_galvanizing.pdf
More about surface preparation: [14]
Sourcing
- Acid -
- Base - KOH pr NaOH for grease - [15], NaOH doesn't require hot water.
- Ammonium chloride - $2/lb [16]
Zinc Ingots
See Zinc#Sourcing
- [17]
- Carter Alloys, 2" zinc balls [18]
- ACI - [19]
- Ney - [20]
- Industrial Metal Supply - [21]. Do they have ingot?
- Victory - [22]
- Milward - [23]
- Umicore - [24]
- Belmont Brooklyn - [25]
- AEM says zinc - [26]
- Ingots on Thomas Register - [27]
- Zinc Ingot on Thomas Register - [28]
- Zinc on Thomas Register - [29]