Posted by Steve Fay on April 10, 1999 at 10:06:05:
In Reply to: Re: Welding and Cutting posted by Smitty on April 10, 1999 at 08:27:26:
Hi Smitty,
Lets run over a few things...To weld cast iron
you must know what type of cast it is..there are
4: White cast (considered unweldable)
Gray cast
Malleable
Nodular or Ductile cast iron
Gray, Malleable and Nodular are all weldable...
now first off as with any weld you have to prep
the surface, it must be clean. You can use a wire
brush I usually use a knotted brush on a 4.5"
grinder...You can use an acid solution also..
just make sure it is clean. Make sure the piece you
are attaching is clean as well. Next check the fit;
once you know where that is mark the edges with
a chalk pen. Along each chalk mark grind a bevel
about an 1/8" deep...Grind the edge of the plate
about 30*
Ok now your preped...
Next is the pre-heat you will need to heat the weld
area about 400*-600* F How will know when it is
ready? Easy!! go to your welding supply house and get
a heat stick...It is a marker pen that will melt at
a desired temp...get one that melts at 600* F
while your there you will need to get nickel alloy
electrodes...such as ENi-CI or ENiFe-CI get the rods
in 1/8 " ....ok back to the project...Clamp the bracket
in place..
You will have to pre-heat the area with a torch
you have to keep the heat level there through out
the process...once the temp stick mark melts you
are ready to weld...set your machine to 125 amps..
this is not an arbitrary selection...anytime you
SMAW (Shield Metal Arc Weld)["stick"] take the
diameter of the weld rod and change it to a decimal
multiply that by 1000 and you have your amp setting
This will get you in the right area..I know the buzz
box doesn't have a fine tune selector so..go the
125 amps..no more than 135 ...If your box is only
ac your all set..If it is a combo...set it up
DCRP the Electrode is positive....
Once you have made the weld....wire brush the beads
then take a ball pien hammer and using the pien
hit the beads....this stress relieves the weld
last but not least you must let the weld cool
gradually....You can use sand...fire bricks
an asbestoes blanket..or any combination....
Good luck with the Project..let me know how it goes
Steve...<:-)