Repairing A Crack In A Cast Bronze Mounting Flange

[BlowingOldBoots]

Hi Folks,
I have this engine driven pump on the boat and I noticed that one of the holes on the mounting flange has a crack running along the top. On the bottom picture you can see the crack at the base of the web where the web merges with the flange. The crack is only the width of the web, it's not the line that extends circumferentially around the hole; that's an indent from the washer. It extends down the edge by a few millimetres

The pump is an old Jabsco and I believe that the body is a cast bronze. Does anyone know who could repair the crack in Central Scotland? I think it can be repaired with a bronze solder process after the crack is ground out, using pre heat and post heat. I read that during cooling the repair has to be peened frequently to remove stress.

When I come to remount the pump it simply butts up against a steel flange on the engine. What would you recommend I could do to attempt to isolate some engine vibration from the pump; a hard rubber or plastic gasket with some resilience? The pump is driven off the flywheel by a belt drive which is quite tight.

Your advice and thoughts on the matter would be appreciated.

Thanks,

BlowingOldBoots

[wully]

What does it pump?

[BlowingOldBoots]

It's an engine driven bilge pump and was referred to as a "salvage pump" in the blurb that came with the boat. It could be used for anything reasonable service: deck washing, small fire pump.

Jabsco Model 6590-200, 1 1/4" ports about 35gpm: -

http://www.jabscoshop.com/spare-parts/d ... e=6590-200

[wully]

Unless I was heading off up to the ice I doubt I'd bother repairing it... My last boatie had a big engine driven freezer compressor that was a bit shoogly and since I was mainly sailing in the utter hemhoroids I decided I could live without it.

Then again having no ice for yer gin isn't such a hardship as sinking but can you be sure the pump suction will stay clear if you did have to use it?

[BlowingOldBoots]

...... but can you be sure the pump suction will stay clear if you did have to use it?

I have a manual bilge pump as well. The end of the suction hose cant actually be reached as it goes through a tube in the drip tray under the engine. That part of the bilge is behind the water tanks so its vey inaccessible. When removing the suction hose I had to give it a sharp tug and something came off the end, probably a strum box. Its impossible to reach into the hole.

There is no rush to instal it. I will be repositioning the inlet hose and maybe, maybe, putting a deck outlet in as I have a spare inlet seacock. We shall see, plenty of other stuff to do.

[sahona]

Would brazing be a solution? And a looser belt probably won't do any harm.

[Aja]

Can't help with the braising part but I recommend you talk to Wm Johnston in Thornliebank on the south side of Glasgow http://www.williamjohnston.co.uk/ what they don't know about gaskets.....

Regards

Donald

[BlowingOldBoots]

Would brazing be a solution? And a looser belt probably won't do any harm.

The brazing bit I am not sure about, it came from a search of the web on how to repair cracked bronze. The belt tension may not be the issue, as I don't use it much. The pump sits on a bracket mounted on the starboard side of the engine mounting flange. Its out on a limb, is quite heavy, so its exposed to a lot of bending moment as the engine vibrates away.

Thanks for the replies so far. I will contact West of Scotland Engineering when I get home as they do all sorts of stuff and William Johnston's too.

I was hoping some old, wizened, cantankerous ex ship builder or forge master may know a trick or two.

[wully]

old, wizened, cantankerous .

If that was all you were looking for on here you'd be fine...

[Arghiro]

Chewing gum?

[BlowingOldBoots]

Chewing gum?

No thanks, I brushed my teeth.