Welding Cast Iron Vice

[Tim]

I have one more question pretaining to welding cast iron.
I have a castiron vice that I fixed for a buddy of mine but while he was using it the welds broke. I did not Pre-Heat it and I just let it sit out in the open air while it was cooling off.
Here is what I would like to try.... I want to Tack weld it on my work table...Pre-heat it in my gas grill Then "If at all possible" weld it while it is in my gas grill then control the cooling by slowly turning down the heat.
Sounds good I suppose but I am worried about sparks flying and hitting the propane tank. How might I go about protecting the tank? Any Ideas?
I dont have a welding blanket.
Any Ideas?
Thanks
Tim

[Tim]

I pre-heated the vice in my gas grill and pulled it out and performed the welding. Now the vice is back in the grill and
Post heat is commencing.
One thing bothers though...I am thinking that I should have used a machinable rod becuasue they give and non machinable rods dont. Seems to me that a cast iron vice has to "Give a little" becasue of the torque applied to it.
Tim

[Roger]

Your grill probably doesn't have the mass , insulation or control for real slow cool down. Setting in container of wood ashes and covering with about 6" ashes is better. Pearlite from garden shop will also work. This process is much easier but probably too late to help.
Good luck.

[steelhanger]

New cast iron mulitple position vice 6" x 8" at sam's club $42.00. Why bother with the broken one?

[Tim]

Steelhanger:
Its the challange of actually fixing something and somthing to keep me busy while I am out of work. Cleaning house all day just doesnt cut it any more ;)
Tim

[Rocky D]

Are you sure it is cast iron, and not cast steel?? Grind test it. Sparks are red, cast iron, if they are yellow, cast steel, and pre and post heat will not be necessary.

[Tim]

Rocky D:
Boy do I feel dumb. The sparks are yellow. I am glad you pointed
that out to me. All this time I thought the vice was made of cast Iron and here it is made of cast steel.
To all that read my post...For me saying it was Cast Iron...Please forgive me.
Rocky...If I ever have to weld cast steel again...What type of rod would you recommend?
Thanks again Rocky D :)
Tim