Cast iron pot repair

[lordnelson]

Hi, I did a quick search on the metal works forum and couldn't find anything relating to my question, so can anyone help me with the repair of an old cast iron pot. It has holes in the base up to 10 mm in diameter but the rest of it is in good nick. Is there any hope for this pot or will it be an ornament from now on?
Thanks

[.RC.]

I would ornament it and get another one...reason being i doubt any fix would be successful with the constant hot/cold cycling when in use will eventually cause any weld repair to fail...

[Grahame Collins]

Hi and welcome to the forum.
There are potentially many members with the experience to help but they can't with out knowing any details which may affect the outcome.
More information is needed to accurately give an opinion of any value.

What is the pot size and shape ?
Are the holes from rust/corrosion or are they drilled ?
Do you hope to be able to cook in the pot ?
Do you wish to have the repair remain invisible?

All of those factors can have an effect on how a repair could be carried out.

Arc welding is difficult, but would be the best way of an almost invisible
Expect to pay $100 plus for a pkt of suitable electrodes.The downside is without a skilled operator the repair will likely crack.

Brazing is a way to fill the whole with minimal risk of cracking.

In short the type of repair depends on the result you want.

Grahame

[kraits]

yeah, what grahame said but, if you do give it a go yourself with the stick and don't do the necessary preheating you can expect to see a bigger problem then a hole and that is a crack from the shock,

here's one for you grahame, if its around 3/8 thick on the base would you recommend peening after each run? personally i would, or on something such as a pot base and only been comparitivly thin would this enduce cracking (not suggesting a sledge hammer to peen with either)

i welded up a fire place grate for a mate from an old victorian home (victorian era) thing must have been 110 years old if not older and the quality of cast was rather ordinary, when preping the Vs in the grate pre preheating i noticed heaps of tiny impurities though the cast, what could only be described as slag or even dross inclusions, was a bugger to weld and to maintain the temp on something like a grate . so the other question is how old would you say this pot is? and like grahame said a small tube of cast craft is around the $100 mark so might be better off just buying a new one.

[matthew_g]

Just to throw it out there, Has anyone used the 1kg pack of Cast Iron rods from Supercheap Auto for $12.00....
I have and I can only report a mixed result depending on the job..Definantly need to peen in every weld with them or it will crack instantly..
Matt

[kraits]

didn't know super cheap sold them (generally get what you pay for) but, the other option would be weld all's.

[matthew_g]

Never thought of weld all's it could possiably be an option for other cast repairs, But I don't think they would do for a pot..?????
I just thought I would throw it out there that there are some cheap cast rod avaliable, But yes you are correct in saying that you DO get what you pay for.

Although in saying that, Peening in each pass is a small price to pay if you want to save $90.00 odd bucks...
Matt

[RayG]

Hi All,

Just in case some might have missed it, or be tempted to try arc welding cast iron without the appropriate pre-heating.

Have a read of this Cast Iron Welding (http://www.locknstitch.com/CastIronWelding.htm)

Just as an aside, I was at a local foundry recently, Furphy's who used to make cast iron camp ovens, pots and really nice cast iron frying pans and such, they still sell it, but nowadays it's all imported from China, and the foundry is closed down.

Regards
Ray

[azzrock]

i used incolly rods to repair some cast iron once. not shore if it was a good choice. i just someone suggested welds alls and i didn't have any

[Sawmaster]

constant hot/cold cycling when in use will eventually cause any weld repair to fail... Damn!?


So, over time, the welds are likely to fail?

http://img42.imageshack.us/img42/1209/castiron.jpg (http://img42.imageshack.us/i/castiron.jpg/)

Yes and I am sorry to say they will and sooner rather than latter.

Specifically the welding in the photo. Deposited steel weld metal is not even a close match for cast iron. The cooling/contraction rates are way different from one another. Steel has an elasticity that cast iron is nearly the opposite.

If you "must" use an electrode try nickel based as it stretches a bit better.

Finally they weld as deposited has an inbuilt stress point that certainly will have cracking in it already. The weld toes must blend in to the parent metal to avoid notch cracking points.
Sorry but the successful welding of cast iron has some very definite "rules"and those welds broke most of them.I am surprised they are still attached.

When it does fall off check the notch areas id by the black arrow and the failure path will start from that point.

Grahame

[lordnelson]

Hi and welcome to the forum.
There are potentially many members with the experience to help but they can't with out knowing any details which may affect the outcome.
More information is needed to accurately give an opinion of any value.

What is the pot size and shape ?
Are the holes from rust/corrosion or are they drilled ?
Do you hope to be able to cook in the pot ?
Do you wish to have the repair remain invisible?

All of those factors can have an effect on how a repair could be carried out.

Arc welding is difficult, but would be the best way of an almost invisible
Expect to pay $100 plus for a pkt of suitable electrodes.The downside is without a skilled operator the repair will likely crack.

Brazing is a way to fill the whole with minimal risk of cracking.

In short the type of repair depends on the result you want.

Grahame

Thanks Grahame, I'll try to answer your questions as best I can.
I've since learned this is an old water fountain, not a pot as such. I have attached photos to show the pot shape, and size is roughly 30 cm diameter.
I'm looking to restore it but not necessarily use it over a fire or heat.
The holes are from corrosion. The base is shown and is in pretty bad shape. Internally the base is pretty badly pitted as well.
What's the best way to fill in the holes. I'm not fussed whether or not the repair is visible or not.
Thanks for all the helpful replies so far.

[4-6-4]

Dear Nelson, The pot looks like an outer cast iron vessel used in the old days for heating glue in the wood working industry. There should be an inner pot which held the animal glue and water was in the vessel you have The water was heated to keep the glue useable. This is why the base has corroded. While we are talking about welding iron I once welded a cast iron frame on a Vertical Miehlie printing press. The method used was to fasten the frame rigidly to a flat plate after having preped the areas to be welded and proceed to gas weld the required areas letting it cool before cleaning it up. The gas technique lets the weld flow slowly and is not as violent as the arc. Disadvantages are the availability of flux and rods. I would turn it into a flower pot and unless you have some rellies you do not like the cooking angle is out. A further note my dear old grannie when she was married about the turn of the century did all her cooking in cast iron camp ovens of various sizes ove an open fire. Oh the wonders of modern technology 4-6-4

[Metalman]

Hello Nelson, as a left field concept, you could machine away the base completely and shrink fit a new disc of cast iron in its place. The interference would have to be minimal as cast iron is not good in tension but after a few heating and cooling cycles I would expect it to be water tight.
Mm.

[Grahame Collins]

Hi Nelson,
I can think of a couple of ways of approaching this.


Braze the holes up if its going to end up as an ornament.it will hold water but I would not heat it up over and over-as per RC's comments
or
If you want to get it back to as close to original as possible cut the entire base out and replace it with a piece of weldable cast iron. I'm thinking about a BBQ plate as an economical donor insert.


The preps would have to be possibly plasma cut and then ground.

This will require oxy acetylene brazing /welding skills.

Grahame

[Chas]

As you are not planning to heat the pot, have you considered using fibre-glass resin inside the base to seal the holes? There are a couple of brands sold in auto supply stores for patching car bodies which might be suitable, cost $15-$20 for a 500g can. One I have used successfully is K&H Kahrglass, but there are others. If you need the pot for drinking water rather than as an ornament, you will neet to ensure there are no toxicity issues with the resin.

Chas.

[Vernonv]

"Knead It" steel. (http://www.selleys.com.au/putty/epoxy/knead-it-steel)

[kraits]

great idea Vernon, cook ya taucker on selly's kneed it. i recon you would be better of plugging it up with asbestos, anyone fancy been poisoned today?

[Vernonv]

Maybe you should actually read his posts before shooting off your mouth Kraits. He specifically says "I'm looking to restore it but not necessarily use it over a fire or heat."

Maybe he could plug it with your foot, once you remove it from your mouth. :doh::roll:

[kraits]

im in the process of removing it, thanks Vernon:doh:

[Sawmaster]

Yes and I am sorry to say they will and sooner rather than latter.

Thanks for the time and effort you put into your reply Grahame, but tell me, how did you get into my post? Are you a moderator?

Replaced the cast-iron lugs with steel ones. Catastrophe avoided.

Cheers
Graeme.