Trying to repair a centrifugal pump

Hi everyone,

I want to repair my small 1hp centrifugal pump which has a crack and stopped being about to pump water from our dam.

It’s a very cheap cast iron bodied pump. The body cracked, possibly because it’s a very cheap and low quality pump. Anyways, the crack might have been caused also by the frosty weather (-1C min) and frozen water.

This little pump was great, strong enough for my applications. Shame it failed, just after 4 months 🥺.

I’m adding some photos so you can have an idea what our looks like.

I want to repair it until I sort a new and better pump (maybe stainless steel this time).

I’m thinking to apply some silicone around the affected area. Not sure which type of silicone or even if would work.

Anyway with plumbing experience who might be able to suggest some approaches? Also regarding a better suited pump than this one?

Thank you very much!!!

Hey Gabriel! My impression is that it is repairable. If it were my pump, I would certainly try.

I don't know that silicone would be strong enough, or bond well enough. Something like JB Weld might do the job though, if you prep the surfaces well. If you can clamp the outer surfaces somehow, the repair might last longer.

A master welder could possibly weld this (yes, welding a casting is possible). Or, it could be brazed.

I can't speak with authority, but it seems odd that that a casting would crack so perfectly. It's like separately cast parts were joined together somehow. But this is speculation. Hmm.

Hi Douglas,

Thank you for the suggestions.

I think this pump might have come defective to start with. The supplier is obviously saying it’s something else, nothing to do with the pump construction. As I can’t prove anything, as it was an online purchase and because of the lower cost of it I think I’ll be left with at as it is.

It’s good you think it’s ok trying fixing it. I’ll have a look on the product you suggested to see if I find it here in Australia.

Thank you!

Volute seals in pumps have been repaired by packing raw cotton coated with wax or expoxy into the cracks. Sometimes low tech gets the job done!

[quote=Douglas Something like JB Weld might do the job though, if you prep the surfaces well. If you can clamp the outer surfaces somehow, the repair might last longer.


I found the JB Weld product here. I’ll give it a go.

The good thing is if I manage to prepare the surfaces well and apply the product I can reassemble the pump and its bolts will work a bit like the clamp you suggested I think. 🤞

Thank you again.

I would try to make a groove along the crack  with a tungsten bit in a Dremel or a grinder with thin cutting wheel and fill with something like jb weld. but there are some super strong metal sealing epoxies from places like mscdirect.com and Grainger but some are quite expensive and probably not worth the expense on a 200 dollar pump. but something common like jb weld and the epoxies at auto repair parts stores and Walmart home depot and Lowes is easy to find and very strong. the slow drying epoxies tend to be stronger than the 5 minute stuff.

First things first.
Under Australian law, warranties must apply .
Check first and then hammer them if its under warranty, also contact the ACCC, to have the company listed.

I have given up with on line pump sales and I go to the Green and red Hardware, I have found they never dispute warranty claims if they are reasonable.
Some other photos to see where the break is within the whole pump would be good.

I am very familiar with Tassy, and if you are leaving this type of pump outside in winter freezing may be the reason!
What part of the `kingdom are you in?