Welder needed for tricky job.

[The Pastor]

What is the impeller made of? Is the impeller itself undamaged apart from the blades "falling off" (HTF did they "fall off" ? Do you mean they sheared off? ) Do you have the broken pieces of blade?

Imguessing just normal wear and tear, one would of came lose, and smashed the others off I assume.

I have 3 blades, I think thats all of them if, if not the others are in my cooling system somewhere......


It looks alot like mild steel. bit rusty. Impeller is fine, just blade less.

[Ixion]

If it's steel and you have all the bits any competant welder shoulld be able to braze them back on. I'd suggest brazing not welding , less likely to distort things, less clean up needed, and brazing should be quite strong enough for a low stress application (though if an expert disagrees, believe him)

[The Pastor]

If it's steel and you have all the bits any competant welder shoulld be able to braze them back on. I'd suggest brazing not welding , less likely to distort things, less clean up needed, and brazing should be quite strong enough for a low stress application (though if an expert disagrees, believe him)

Yeah, I had a go at brazing some nuts onto a mounting bracket and was thinking along those lines. The tricky bit would be in holding them while you heat it up - you can't rest the fins on the impeller without holding them on, might need 3 arms lol.

Please dont flame me for suggesting this

but how much force is acting on those fins? would soldering it work? Whats the worst thing that could happen, they would just fall off again....?

[Scouse]

Yo punks

The fins on my waterpump impella have fallen off, anyone here got a welder I can use, or (prefeably) can weld it up for me?


Ihave had basic welding (mig & tig) experiance but I cant afford to stuff it up.

Any help would be great.

See this is the sort of crap post I was talking about in the "MAYOR" thread go out and buy a new Impella next you will be asking who retreads motorcycle tyres

[Motu]

The blades are lost by cavitation or electrolisis.Go and see Muzza,he may be able to adapt another impellor to your shaft.

[Macktheknife]

Forget trying to solder them on, not nearly strong enough. Braze or weld but needs to be strong and accurate, if the angle is wrong then you wont get the desired result.

[Ixion]

Yeah, I had a go at brazing some nuts onto a mounting bracket and was thinking along those lines. The tricky bit would be in holding them while you heat it up - you can't rest the fins on the impeller without holding them on, might need 3 arms lol.

Please dont flame me for suggesting this

but how much force is acting on those fins? would soldering it work? Whats the worst thing that could happen, they would just fall off again....?

Doubt solder would work. Not strong enough, not heat resistant enough, and you'd have a heck of a job getting a good joint without oxy or propane kit (and if you've got that, y' can braze it).

Welders have all sorts of tricks they use with clamps wires etc to hold stuff in place, papier mache works too. Wander round to the nearest industrial area, look for jobbing wleders. Only worry I'd have would be what the balance of the unit would be like afterward, but you could always balance it staticly yourself with a little file.

[Ixion]

Worst case scenario you could even build new blades up by laying down a succession of layers of bronze, and then machining to shape.

I did this with an oil pump (gear type) that had lost a tooth (tooth lost, gone, not there to be reattached). It worked fine.

[MikeyG]

Talk some uni student into drawing it up in CAD and milling a new one out of billet.

Any eng students on the site?

[The Pastor]

See this is the sort of crap post I was talking about in the "MAYOR" thread go out and buy a new Impella next you will be asking who retreads motorcycle tyres

What the #$%^ do you know? shut the hell up.

Repair of water pump fins is a common job and its not going to kill anyone or damage anything.

Get some #$%%ing brains and go back home to your man and hope that he doesnt give you any more stiches. IF you cant help dont post you utter noob.

[The Pastor]

The blades are lost by cavitation or electrolisis.Go and see Muzza,he may be able to adapt another impellor to your shaft.

I don't understand what you mean by "The blades are lost by cavitation or electrolisis" Would you care to explain a bit more?

Forget trying to solder them on, not nearly strong enough. Braze or weld but needs to be strong and accurate, if the angle is wrong then you wont get the desired result.

Angle? A water pump is very simple, turning fins pump the water around, as long as they are in the right direction it should be ok? Sure it might not be as efficient as it was but it will still do its function and pump the water around. Or am I off the track here?

Doubt solder would work. Not strong enough, not heat resistant enough, and you'd have a heck of a job getting a good joint without oxy or propane kit (and if you've got that, y' can braze it).

Welders have all sorts of tricks they use with clamps wires etc to hold stuff in place, papier mache works too. Wander round to the nearest industrial area, look for jobbing wleders. Only worry I'd have would be what the balance of the unit would be like afterward, but you could always balance it staticly yourself with a little file.

Yeah I was thinking about that, I have a little flame thrower that runs off butane which would get the fins/impeller hot enough to braze it but where would I buy some braze sticks and the flux? I think I might be able to figure a way of holding them up.

[Scouse]

What the #$%^ do you know? shut the hell up.

Repair of water pump fins is a common job and its not going to kill anyone or damage anything.

Get some #$%%ing brains and go back home to your man and hope that he doesnt give you any more stiches. IF you cant help dont post you utter noob.

Ouch that wealy wealy hurwts especialy coming from you GAYLORD

[Ixion]

Keep it seemly folks.

Not every biker has the money to be able to face a large repair bill with equanimity.

And creative engineering is a time honoured Kiwi tradition. In this case, as noted, there is no element of danger or risk to others involved. Worst case, Mr Renegade Master wastes some time, it doesn't work, worst worst case he does some more damage to something. Best case, it works he saves a chunk of coin and learns some valuable new skills.

Myself, today, I'd buy the new part. If it was available. But 40 years ago, I'd have tried to save my money. Cos I didn't have much.

Also, not all of us run bikes where we can just go and buy new parts. Some of us HAVE to make from scratch.

And what's inherently wrong with retreads for bikes (if they were available) ? Not everyone on two wheels is a sprotsbiker blasting around at 300kph. For a scooter with a top speed of 50kph I can't see any objection to a retread tyre.

The biker community is a rich and varigated one. Enjoy the heterogeneity, don't rain on another biker's parade.

[Ixion]

I don't understand what you mean by "The blades are lost by cavitation or electrolisis" Would you care to explain a bit more?



Angle? A water pump is very simple, turning fins pump the water around, as long as they are in the right direction it should be ok? Sure it might not be as efficient as it was but it will still do its function and pump the water around. Or am I off the track here?



Yeah I was thinking about that, I have a little flame thrower that runs off butane which would get the fins/impeller hot enough to braze it but where would I buy some braze sticks and the flux? I think I might be able to figure a way of holding them up.

I'm out of my depth a bit here so anyone who knows better please correct me. But, FWIW, cavitation refers to a phenomonen that can occur when water flow in a system is restricted for some reason (either poor design or a semi blockage). The pump pumps water out faster than it can flow into the pump chamber. That creates a "cavity" in the fluid, and the pump is under no load. Then water flows back in, and hits the pump. That repeated "hammering" (it's the same sort of thing as water hammer, for you plumber types) , can cause quite significant damage. Electrolysis refers to damage by chemical action. "Stale" coolant can become electrically active . This cause an electrolysis process between disparate metals in the cooling system, which will weaken components. In very very crude terms, your coolant becomes acidic like battery acid and makes your cooling system components rust or rot.

Fin angle is quite important both to ensure decent flow, and also to prevent the dreaded cavitation , already referred to. But there should be enough evidence on the impeller to show the angle the blades were on

Doubt you'd get enough heat out of a butane torch. If you are serious about wanting to have a go, PM me and I'll lend you oxy gear, and some brazing rod. I won't offer to do it for you, cos I'm not very confident it will work.

[Motu]

I don't understand what you mean by "The blades are lost by cavitation or electrolisis" Would you care to explain a bit more?



Angle?

Electrolisis is when your coolant turns acidic,and the cooling system turns into a battery,transfering metal from here to there - impellor fins get ''eaten away''.Cavitation is when low pressure air pockets form on the blades,metal molecules are ''sucked off'' - this is what eats away outboard props.

Angle? - very important,it controls the speed of the coolant flow....and is designed to prevent cavitation.Get it wrong and your coolant will move either too fast,or too slow.

Go and see Muzza,he knows more about automotive water pumps than anyone in the country,he may be able to adapt something to your shaft.His prices are very reasonable - he has changed impellors for me for free,the last pump he did for me he did a hell of a lot of modifications on,and it cost less than a new pump with all new parts inside.

Where in Kaiwaka are you? Twas my town as a wee lad.