Update on pump after a year. PROBLEM

[diverjon123]

Hi, I haven't been on tnet for a while and wow the app has gotten a lot better. A while back I found a iron bildge pump from 1864. Tnet members helped me get in touch with people that could help me and I greatly appreciate that. But another problem has now come to surface. After the pump was taken out of the electrolysis bath after sitting in it for a year, the pump was let dry and then was painted. Now a couple months after painting the artifact has started to crack severely and continue to widen as time goes on. I am very confused on why this is happening. Here are some pictures

On the last picture one can see these things I call rust bubbles. There are hard bubbles of watery rust when touched they "break". Not sure how those are formed but any help would be appreciated.
Thank you

 

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[Dr. Syn]

From your last picture and description, the pump wasn't dry, even though you thought it was. Moisture under the paint is a sure sign of that.
If this was cast iron, it's very porous, so even if it's dry to the touch on the outside it could easily hold moisture deep inside. Sealing in the moisture with paint might of let the moisture slowly rust the metal and work it's way out.

Kinda like why you season a cast iron skillet with oil, it provides a sorta non stick coating, and keeps it from rusting.

As to why it's cracking, if it's seeing a wide swing in temperatures, or freezing, the moisture would expand and possibly do this.

 

[diverjon123]

Thanks for the response. I did think that but I thought after a while the water would evaporate and leave the pump. I live in Florida so there is no freezing. I almost feel like as it is drying out it is shrinking and cracking. I would of course like to stop this cracking so if anyone has any ideas please let me know

 

[diverjon123]

Any other ideas?

 

[Jason in Enid]

You said that you "found" it, and had it restored. I would guess that the oxidation went much deeper and it was structurally weakened. All you are seeing is the natural progression that you tried to stop.

 

[Dr. Syn]

Well, to stop a crack, you can drill a small hole at the very end of the crack. Something like the crack is following the "grain" so to speak, and drilling the hole stops it. I've done it in metal, wood, and plastic with success.

Something else, how deep was this when you found it? Deep enough that maybe when you brought it up to the surface, any moisture/air in it expanded, and started the cracking unseen? Kinda like the Bends when you go too deep and come back up too fast.

 

[Dr. Syn]

Funny, this just reminded me of something. In painting something old, you often reduce the monetary value of it. Sure I can understand nice paint vs a piece of rusty metal but like in your case, the paint not only reduced it's value, but also caused irreversible damage.

But my story, way back when, my boss Russ had bought a pair of I'd guess you'd call them vessels, some type of pottery type containers, from Mel Fisher.
Paid something like 8 grand for them. Had them placed on either side of his front door on his McMansion. One day he comes home to find the wife had had the painters paint them cause she thought they looked grungy. He about lost it over that. They looked pretty, but she destroyed their value.

 

[hvacker]

You wrote that the pump sat in the electrolysis bath for a year? Was that a misprint?
What did you use for the bath solution?
It's hard not to make a connection from the electrolysis treatment to the cracks. Or that the cracks had been there and weren't noticed because of the rust.
Cast iron is often painted with no bad outcome. Cast iron can also have impurities that might have reacted in some way to the bath solution. Maybe sand blasting would have been a better method.
Being a water pump it might have been exposed to freezing in it's past, cracked, and wasn't noticed. Held together by rust.

 

[releventchair]

Baking it dry and sealing it from moisture after may slow the effects of decomposition.
It's integrity seems compromised by expansion.
While freezing has been nearly ruled out ,perhaps the electrolysis method added material rather than remove it.
Cast iron in a variety of types is a composition, often crystalline and one ingredient or more may have been displaced by another.

 

[Crappies-n-Coins]

The cracked paint could be making it appear much worse than it actually is, pics can be deceiving. The paint cracking on the side of the pump body may be paint only, not cast. I would remove the paint and see what the actual damage is.

Get a couple muffler clamps and put on (what appears to be) the discharge port, and have it brazed. Ditto (braze) on the mounting "ear".

 

[hvacker]

Cast iron if frozen cracks in a very predictable way.... Any way it can. Where ever the water settles it will freeze. With a pump, it's always expensive because there are lots of nooks and crannies.

I work with metal and because we were asked I'll say what I think.
The pump was already cracked but the rust covered it. The paint guys prepped it by sand blasting or whatever, painted it , and got paid. Did they say anything? Why... and not get paid??
Then the paint blistered because....Wrong paint more likely wrong prep and primer. The paint reveled the evidence. A cracked pump. Probably cracked for years. They could have Bondoed the thing and it would look great. But tell us one thing...was the price for the paint restore your best price? Think about this. I was a contractor and was never the lowest price.

Forget about needing to do things like dry out. Cast iron is slightly porous but not that a day in FLA wouldn't cure. If iron was that porous it would float.

Working with cast iron especially CI pipe fittings, I know what cracks it...Frozen water! Not paint.

 

[hvacker]

Cast iron if frozen cracks in a very predictable way.... Any way it can. Where ever the water settles it will freeze. With a pump, it's always expensive because there are lots of nooks and crannies.

I work with metal and because we were asked I'll say what I think.
The pump was already cracked but the rust covered it. The paint guys prepped it by sand blasting or whatever, painted it , and got paid. Did they say anything? Why... and not get paid??
Then the paint blistered because....Wrong paint more likely wrong prep and primer. The paint reveled the evidence. A cracked pump. Probably cracked for years. They could have Bondoed the thing and it would look great. But tell us one thing...was the price for the paint restore your best price? Think about this. I was a contractor and was never the lowest price.

Forget about needing to do things like dry out. Cast iron is slightly porous but not that a day in FLA wouldn't cure. If iron was that porous it would float.

Working with cast iron especially CI pipe fittings, I know what cracks it...Frozen water! Not paint.

 

[diverjon123]

Sorry everyone. I didn't really get into the full story. I found pump in a tropical climate where it doesn't not snow ever or even get below freezing. So cracking when could is not an option. Setting in electrolysis for a year was not a miss print or type. I had a huge bath of fresh water and some type of powder I can't remember but it was suggested to me by a wreck historian. He is here on tnet. After I found the pump I chiseled to take all stuff off of it the pump immediately started to rust. The electrolysis bath pulled all rust off and stabilized the pump from rusting when exposed to air. The water was changed regularly in the tub. After about a year I took pump and painted. Believe me there was no cracking at all in it. After painting the pump was fine for about a month then it started to crack and crack and it continues to crack and it is not the paint it is a full crack. So no contractors where hired to paint it or anything. I would just like to know how to stop this cracking. I'm not sure what the problem is.

 

[diverjon123]

Any ideas?

 

[hvacker]

Great mystery. I'd try to find out what the chemical was in the bath and take the research from there.
I've seen a lot of cracks in cast iron but it was always from freezing or being struck by something.

 

[hvacker]

Great mystery. I'd try to find out what the chemical was in the bath and take the research from there.
I've seen a lot of cracks in cast iron but it was always from freezing or being struck by something.

Here's a start...Cast Iron: Characteristics, Uses And Problems