Any of you guys have suggestions/experiences of repairing a small weeping crack in a cast iron cylinder head?
Been welded already but chasing the weld.

JB Weld Iron putty, etc,?

Intake or exhaust port???

If its external, loc-n-stich pins work great, I have used them on many a block and head.

I've had several heads and blocks cracks repair using that method, that to me is the best method out their

It’s a Hemi. Internal crack at the top of the ledge between a spark plug and a stand boss.

under the valve cover is still exterrnal to me. Into water? loc-n-stich is still the right fix. lets see it.

I was made aware of stitching over 50 years ago.

I was asking for suggestions using epoxy, etc.

Thanks.

What was it welded with?

A shop that does a fair amount of head repair did it, not really sure.

Depends on the skill of the welder doing the repair. I seldom see cast iron welding hold up unless the part is preheated and cooled down in an oven. On a cylinder head that will mean disassembly and regrinding the seats as they may move during the heating process. Cracks that have to hold water should be drilled at the end of the cracks and then welded. If you don't preheat and say, try to use just a nickel rod very poor success rate.

The 1968 to 1970 ("916" or are they "906" castings # ?) BB heads are horrible about freeze cracking under the center two exhaust ports
Stitch and lock has worked great on repairing several that I have had fixed

Since it's been welded already and leaking through the weld, I think some sort of epoxy is your only option.
I don't know what to suggest b/c I've had zero luck w/ welded cast iron holding water.

Is this a coolant passage leak ? If so, where are you trying to apply the epoxy ? internal or external of the cooling circuit ? anyway, I'd search for a 3M product, JB weld epoxy probably isn't the best. good luck though.

Have you thought about trying head gasket sealer ?
Blue Devil sealer works. I found it lasts 4-6 months of daily use.
You pour it in with engine cold, start and idle for 50 mins. Done
I kept a car going for a couple of years with it.

BlueDevil's Head Gasket Sealer is a permanent seal that can repair and seal leaks in cracked heads, warped heads, blown head gaskets, heater cores, and freeze plugs. It's compatible with diesel and gasoline engines and can bond to aluminum, cast, alloy, metal, or plastic. It's safe to use and won't clog or harm your engine because it doesn't contain any solid or particulate matter.