Brazing cast iron

I have a set of fully ported 452 heads and they were epoxied on the side of the ports. One of the pieces of epoxy was loose so I carefully ground it off. Would it be better to braze these shut or re epoxy them?

ONLY if you know how to braze cast iron, you could make scrap out of them fast.

There is a tig rod out, that doesn't require a preheat and is supposed to work really well. I'll see if I can find the name of the filler material.

Silicon/bronze. I would still suggest preheat but it works very well.
Doug

You can use silicon bronze, but I'd use EZ Weld tig filler rod.

You can buy it here

EZ Weld tig wire

That ez tig filler seems interesting, I'd assume it's better than just the flux coated brass rods?

Well the flux coated brass rods are only for oxy/acety welding.

I'd much rather use a gas lens, with a 12 pyrex cup. That way you can get the tungsten in the port, be able to see, and have plenty gas coverage.

Great setup for tight places.

So that rod has to be used in conjunction with a tig welder? Good thing I know someone that has one

Yes it's for tig welding. Without shielding gas it's not going to work properly.

Ok, well thanks! That gives me some hope, I hate to see these ol heads go to waste, someone definitely put some money into the porting, pushrod area has been tubed as well, I just don't trust the epoxy, especially if I go e85

Regular er70s you could use with a torch, but with a custom blend, I'd ask the manufacturer.

Well for 27 bucks that ez wire may just be worth a try

I vote for the epoxy. Splash zone seems to work for most... I would not weld them. Too many successful applications of epoxy in heads to chance welding it up...

I Had a crack in the bowl in one of my well ported 452 heads. I took it to an a very good old guy at the welding shop to try and braze it. He could not get it to seal up. On a side note, If you can't get it fixed I have a ported 452 I would sell cheap.

If all you want to do is fill a void then epoxy is a safe method. If you need to repair a crack then it has to be welded. Brazing doesn't cut it. In "the old days" you would arc weld it with ni-rod. I know nothing about tigging cast iron but if I were doing it I'd want to pre-heat the whole head. Bob Glidden used to use a pizza oven. I think a good size gas bar-b-que would work just fine.