Reconstructed totally wasted exhaust adapter

Album link showing the process I took.
https://goo.gl/photos/9enZHLqh9tCwRjDe7

From this


to this


Doing it myself saved more than half the cost. Finding 2.5 inch pipe cheap is not easy.
Hampton Rubber had a 6 inch pipe nipple for $12 and the square key stock of one foot for $3.

Years ago, I had a machine shop make 2 of these from steel for $75 each.
My engines use four of these.
I started engine and heard a loud noise. Not much except rust holding this together. Whacking with hammer showed how thin the cast iron had become.

2.5 inch diameter steel pipe joined to cast iron flange.
Hub end formed from 5/16 square key stock.
Brazed with silicon bronze rod inside and outside.
Bimetal hole 3 inch cut the flange to inset the pipe to provide greater surface area for brazing.

I used Permatex gasket maker high temp rated to 700*F for the gasketing, and also skim coated inside of the exhaust surface. I found it holds up protecting the metal from rusting.

This repaired piece is thicker than OEM and with the silicon bronze brazed surface, will outlast me.
If exhaust makers bronze coated their iron, then these parts would never rust away.

Beautiful bronzsmith's work and great teaching skills, there is no need to buy and sometimes is not even for sale.

North Baltic sea said:

Beautiful bronzsmith's work and great teaching skills, there is no need to buy and sometimes is not even for sale.

Click to expand...

Thanks very much, this took me a few days to make.
You definitely can't buy this part anymore, Palmer closed back in the late 1970's.
This part fits between the water cooled exhaust manifold and the riser. The riser is clamped onto the round hub, other end bolts to exhaust manifold.
It won't get excessively hot enough to weaken the bronze.
The riser and exhaust manifold are FWC.

I modified the Barr riser #20.0000 to include it into the closed cooling circuit.
I brazed on a bronze pipe to the riser's end and plugged its outflow, redirected the cooling flow out through a core plug.

That bronze pipe since 2000 is like brand new, hot salt water and exhaust gas has caused no damage.

Back when I bought the boat, and had to get 4 new risers for $1000, I thought up the way to make them last. Been 16 years now working in salt water and no problems with them.

When I see GREAT posts like the OP's, I get that "gees, I really want to purchase a welding unit." Yes, I know he brazed his assembly but a welding unit would still be nice. The only problem is I have the same feelings about purchasing a backhoe. I KNOW I will use each at least once.....

Brazing on cast iron is very successful way to join cast to steel. Got to make sure the cast is really clean metal. I had some cast areas inside on the flange that refused to accept braze even though it looked clean. So I soaked part in white vinegar and scrubbed with a toothbrush till it was real clean, then the braze wet the cast. Other thing to do is grind with stones in drill, or use a grinder. And a SS brush works great too. Lowes has SS brushes in their weld section.

And you can once cast is wetted out with braze, pile on more thicker layers of braze to build up strength.
The weld shops tell me the white flux coated brazing rods are silicon bronze, or at least bronze, they are not brass.

We took a 4 hour boat ride and it worked without falling off. So I am happy.

You have a right to be happy after your fine example of craftsmanship with bronze and cast iron!