Welder in Tomball or NW Houston area

[Oscar]

Would Hastelloy-W or -X be of any use for you? or Perhaps Inconel 625?

Nickel Filler Rod

Inconel 625

Haynes Hastelloy-W

Haynes Hastelloy-X

[beertracker]

Here are some photos of my Pontiac CI head. Last question is this a job for spray welding and if so how much do you think it would cost?

The surrounding area is thin.

[Ironman]

Spray would probably work. Is this hole available from outside the head, or is this the result of port and polish? Can you access the backside.
If it is accessible from the outside, you may even be able to use a carbon block inside and braze the hole and the surrounding area.

[beertracker]

Originally Posted by Ironman

Spray would probably work. Is this hole available from outside the head, or is this the result of port and polish? Can you access the backside.
If it is accessible from the outside, you may even be able to use a carbon block inside and braze the hole and the surrounding area.

Yes, the hole is available from outside the head & I can access the backside. I was porting with a carbide cutter inside the port when the cut through occured.

I have taken the head to several welders and they told me since the surrounding material is thin the hole will open larger when they apply heat. I don't know if these welders use spray or not.

I can try to find a spray welder and see what he says otherwise buy another set of heads. Another set of heads is $300 compared to the cost ? of a spray repair. bt

[Ironman]

Originally Posted by beertracker

I have taken the head to several welders and they told me since the surrounding material is thin the hole will open larger when they apply heat.

That's why I suggested brazing. Brass melts at a medium red heat about 720C degrees, I think. It is ideal for casting repair. Spray welding is used for crankshaft buildup etc.
If you set up a neutral flame, and use a carbon block for backing, you should have no problem filling the hole with brass. There is not enough heat to cause warping of the head, and you can also purchase low temp brazing alloys. Lo-temp rods are always called silver or phos-copper rods.
One I always keep on hand is the Bernzo-Matic rods sold in hardware stores as silver brazing rod. They are blue flux coated, quite low temp, and could be used to braze a steel patch over the hole. One thing about silver is it has capillary action and flows into cracks, but you made that by grinding so there should be none.

If you heat and wet the casting area with silver, and wet the patch material, then put them together, add heat and silver brazing rod, it will be done. And a lesson learned.

[beertracker]

QUOTE
That's why I suggested brazing. Brass melts at a medium red heat about 720C degrees, I think. It is ideal for casting repair. Spray welding is used for crankshaft buildup etc. If you set up a neutral flame, and use a carbon block for backing, you should have no problem filling the hole with brass. There is not enough heat to cause warping of the head, and you can also purchase low temp brazing alloys. Lo-temp rods are always called silver or phos-copper rods.

One I always keep on hand is the Bernzo-Matic rods sold in hardware stores as silver brazing rod. They are blue flux coated, quite low temp, and could be used to braze a steel patch over the hole. One thing about silver is it has capillary action and flows into cracks, but you made that by grinding so there should be none.

If you heat and wet the casting area with silver, and wet the patch material, then put them together, add heat and silver brazing rod, it will be done. And a lesson learned.
END QUOTE

Ironman:

Good ideas, I really like the last one about using a Bernzomatic silver brazing rod and a steel patch. Is this the Bernzomatic silver rod you mentioned?

http://www.bernzomatic.com/product/n...-welding-rods/ working temperature 915° C to 926.6° C

You mentioned "brass melts at a medium red heat about 720C degrees, I think." I found a online reference showing yellow brass melting at 930C. I don't know if this is significant or not. http://www.engineeringtoolbox.com/me...als-d_860.html

Will 930C be low enough to prevent warping of the head?

The only factor I don't know is the temperature of the exhaust gas as it exits the port. Obviously it must be below the melting point of the silver brazing rod and cast iron is a good dissipator of heat.

Thanks,
BT

[Ironman]

Originally Posted by beertracker

QUOTE
That's why I suggested brazing. Brass melts at a medium red heat about 720C degrees, I think. It is ideal for casting repair. Spray welding is used for crankshaft buildup etc. If you set up a neutral flame, and use a carbon block for backing, you should have no problem filling the hole with brass. There is not enough heat to cause warping of the head, and you can also purchase low temp brazing alloys. Lo-temp rods are always called silver or phos-copper rods.

One I always keep on hand is the Bernzo-Matic rods sold in hardware stores as silver brazing rod. They are blue flux coated, quite low temp, and could be used to braze a steel patch over the hole. One thing about silver is it has capillary action and flows into cracks, but you made that by grinding so there should be none.

If you heat and wet the casting area with silver, and wet the patch material, then put them together, add heat and silver brazing rod, it will be done. And a lesson learned.
END QUOTE

Ironman:

Good ideas, I really like the last one about using a Bernzomatic silver brazing rod and a steel patch. Is this the Bernzomatic silver rod you mentioned?

http://www.bernzomatic.com/product/n...-welding-rods/ working temperature 915° C to 926.6° C

You mentioned "brass melts at a medium red heat about 720C degrees, I think." I found a online reference showing yellow brass melting at 930C. I don't know if this is significant or not. http://www.engineeringtoolbox.com/me...als-d_860.html

Will 930C be low enough to prevent warping of the head?

The only factor I don't know is the temperature of the exhaust gas as it exits the port. Obviously it must be below the melting point of the silver brazing rod and cast iron is a good dissipator of heat.

Thanks,
BT

That is the rod I was referring to
I have seen broken exhaust manifolds repaired with brazing, and that worked but would be a bastard to do as the exhaust cooks and permeates the manifold and it is strange enough to weld a exhaust with Ni-rod, never mind brazing.

I honestly think you are worrying too much on this. I probably have the temp wrong for brass, I have that number stuck in my head from reading about lo-temp brazing.
I would say fuck it and grab a torch and do it. What do you have to lose at this point?

Another option. If you have any skill with welding cast, I would weld a steel patch over the hole back about 1/4" from the hole, using the cold stitch and peen method. Then give your wife the credit card and when she is gone shopping put the head in the oven and heat it to 250 deg.
Take it out and flip it over and use N-Rod to fill in the 1/4" gap from the steel patch to the surface of the port interior where you carved it through....maybe a bit more and then smooth it off. Cover it in cat litter and let it cool for a day.