Cast Iron
- Thread starter Hilmar
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uh oh, what happened, hopefully not major.
the answer's yes, but i lack the experience to tell you how. tried it once unsuccessfully, I think i was chicken to put enough heat into it. its more difficult than steel or brass because of the graphite iirc
the answer's yes, but i lack the experience to tell you how. tried it once unsuccessfully, I think i was chicken to put enough heat into it. its more difficult than steel or brass because of the graphite iirc
Powder keg
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I've brazed cast with great results. Just make sure it's clean! You also have to get it hot enough. I used that brazing rod with the flux on it.
Wes
Wes
B
Bogstandard
Guest
Hilmar,
There is a large difference between brazing and silver soldering.
I will assume you are referring to silver soldering, and yes it can fairly easily be done.
Silver solder will not bridge large gaps. So if you are 'filling' a hole, it has to have a plug, preferably of parent metal, but something like free cutting mild steel can be used. A tapped hole with a loose fitting screwed plug is ideal, otherwise a plug with about 0.002" clearance. The silver solder, thru capillary action will bond the plug into the hole.
Both parts, because of the high carbon content in cast iron will have to be both mechanically and chemically cleaned just prior to the joint being made. A good high temp flux such as Tenacity 4a will help the process as it has a good cleaning action, and can withstand the higher temperatures and time that are associated with bringing castings up to temperature.
Let the casting cool down naturally, do not be tempted to quench. The sudden shock of quenching can both damage the casting and the joint.
If it is a smallish casting, say a cylinder, this work can usually be done with a plumbers type gas torch. Any larger and a secondary background heat source might be required, another blowtorch with a second pair of helping hands.
For brazing or bronze welding, a slightly different technique is required, and higher temperatures, and does really require an oxy/acet. set to do properly.
All that has most probably put you off for life, but if done correctly, is no different to normal silver soldering.
John
There is a large difference between brazing and silver soldering.
I will assume you are referring to silver soldering, and yes it can fairly easily be done.
Silver solder will not bridge large gaps. So if you are 'filling' a hole, it has to have a plug, preferably of parent metal, but something like free cutting mild steel can be used. A tapped hole with a loose fitting screwed plug is ideal, otherwise a plug with about 0.002" clearance. The silver solder, thru capillary action will bond the plug into the hole.
Both parts, because of the high carbon content in cast iron will have to be both mechanically and chemically cleaned just prior to the joint being made. A good high temp flux such as Tenacity 4a will help the process as it has a good cleaning action, and can withstand the higher temperatures and time that are associated with bringing castings up to temperature.
Let the casting cool down naturally, do not be tempted to quench. The sudden shock of quenching can both damage the casting and the joint.
If it is a smallish casting, say a cylinder, this work can usually be done with a plumbers type gas torch. Any larger and a secondary background heat source might be required, another blowtorch with a second pair of helping hands.
For brazing or bronze welding, a slightly different technique is required, and higher temperatures, and does really require an oxy/acet. set to do properly.
All that has most probably put you off for life, but if done correctly, is no different to normal silver soldering.
John
rake60
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Cast Iron can be repaired by either Silver Solder or Welding.
These video links are from Muggy Weld's web site for examples of both methods.
Silver Solder repair on Cast Iron
http://www.muggyweld.com/videos/ssclip4300.wmv
Welding Cast Iron
http://www.muggyweld.com/videos/cast3300.wmv
Rick
These video links are from Muggy Weld's web site for examples of both methods.
Silver Solder repair on Cast Iron
http://www.muggyweld.com/videos/ssclip4300.wmv
Welding Cast Iron
http://www.muggyweld.com/videos/cast3300.wmv
Rick
Bernd
Well-Known Member
Hey Rick,
Nice link. You just gave me another tool in my tool box of handy items. The hot rod boys use aluminum quite a bit. I know none of them know how to solder. That's bascially what the video's show.
The welding rod for aluminum kind of makes aluminum tig welding obsolete and cheaper. ;D
Bernd
Nice link. You just gave me another tool in my tool box of handy items. The hot rod boys use aluminum quite a bit. I know none of them know how to solder. That's bascially what the video's show.
The welding rod for aluminum kind of makes aluminum tig welding obsolete and cheaper. ;D
Bernd
B
Bogstandard
Guest
Rick,
What he is calling silver soldering, is most probably a version of bronze welding.
Silver solder works on a capillary action, as does brazing, but at a higher temperature. Brazing being a much stronger medium.
Bronze welding is similar to gas welding but instead of melting the parent metal, a groove is cut and a filler rod and flux are used to build up the area, usually by a series of passes. It was the standard method of repairing cast iron if you didn't have the guts to weld it.
Gas welding of cast iron is in fact a fairly easy technique, once mastered it doesn't cause any problems. The parent metal is usually ground out as he shows, but then the gas torch is brought in and a pool of parent metal is started, the cast iron filler rod is then stirred into the molten pool, which is like sticky treacle, and the area built up by moving the deepening pool along the pre ground slot. Very good results can be achieved by as he suggests, bringing the parent metal up to temperature first, and at the end let it cool down naturally to prevent shock stresses forming.
Because of the 'supposed' difficulty of welding or hot metal joining of cast iron, a small industry started, that used precision drilled wedges to 'stitch' and pull cracks together. As far as I know this method is still in use today to carry out crack repairs on large cast iron castings where it would be difficult to pre heat such a large block of metal.
How do I know all this useless information?
Two years before I finished in the RAF, they paid for me to go on a part time (my own time, three, 3 hour sessions per week) two year, practical and theory course, on gas and arc welding, with the emphasis on gas.
I silver soldered up more model loco boilers belonging to the local model engineering club than I care to remember, all paid for by the government. But I did end up with some very nice university qualifications, and a fall back trade if needed.
John
What he is calling silver soldering, is most probably a version of bronze welding.
Silver solder works on a capillary action, as does brazing, but at a higher temperature. Brazing being a much stronger medium.
Bronze welding is similar to gas welding but instead of melting the parent metal, a groove is cut and a filler rod and flux are used to build up the area, usually by a series of passes. It was the standard method of repairing cast iron if you didn't have the guts to weld it.
Gas welding of cast iron is in fact a fairly easy technique, once mastered it doesn't cause any problems. The parent metal is usually ground out as he shows, but then the gas torch is brought in and a pool of parent metal is started, the cast iron filler rod is then stirred into the molten pool, which is like sticky treacle, and the area built up by moving the deepening pool along the pre ground slot. Very good results can be achieved by as he suggests, bringing the parent metal up to temperature first, and at the end let it cool down naturally to prevent shock stresses forming.
Because of the 'supposed' difficulty of welding or hot metal joining of cast iron, a small industry started, that used precision drilled wedges to 'stitch' and pull cracks together. As far as I know this method is still in use today to carry out crack repairs on large cast iron castings where it would be difficult to pre heat such a large block of metal.
How do I know all this useless information?
Two years before I finished in the RAF, they paid for me to go on a part time (my own time, three, 3 hour sessions per week) two year, practical and theory course, on gas and arc welding, with the emphasis on gas.
I silver soldered up more model loco boilers belonging to the local model engineering club than I care to remember, all paid for by the government. But I did end up with some very nice university qualifications, and a fall back trade if needed.
John
Just wanted to say here that I have a 1920s Stanley wood plane, that was my granddads ,I dropped it about 20 years ago and it broke in two!, a friend silver soldered it and reground the sole, it's been dropped a couple of times since (these things happen!)I can't say how much I've used that plane, I have several others but the blade in this one is made of a much better quality steel and doesn't loose it's edge, I still use it today!
Giles
Giles
rake60
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I AM NOT capable of welding cast iron.
Thankfully, we have a few men at your shop who are.
I HAVE machined weld repaired cast iron.
It is usually very hard and quite difficult to hold a size in.
When it's done you can see every bead pass in the finished
fits.
I have also machined cast iron that was accidentally welded
with a steel rod or wire. That STINKS! It's like trying to
machine glass.
That is a situation for the artificial diamond inserts.
The CBN (Carbon Boron Nitrate)
Those inserts are expensive and the welders who make that mistake
rarely do it twice in there career.
Rick
Thankfully, we have a few men at your shop who are.
I HAVE machined weld repaired cast iron.
It is usually very hard and quite difficult to hold a size in.
When it's done you can see every bead pass in the finished
fits.
I have also machined cast iron that was accidentally welded
with a steel rod or wire. That STINKS! It's like trying to
machine glass.
That is a situation for the artificial diamond inserts.
The CBN (Carbon Boron Nitrate)
Those inserts are expensive and the welders who make that mistake
rarely do it twice in there career.
Rick
doubleboost
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Hi
I have welded a fair amount of cast iron i use a tig torch and pure nickle filler rod it is easy enough to weld the problem is stoppong it from cracking.
We pre heat either a gas ring and a cutting torch if it is a large item (cylinder block) it is allowed to cool on the gas ring very slowly, grinding is the only way i can machine the finished weld
John
I have welded a fair amount of cast iron i use a tig torch and pure nickle filler rod it is easy enough to weld the problem is stoppong it from cracking.
We pre heat either a gas ring and a cutting torch if it is a large item (cylinder block) it is allowed to cool on the gas ring very slowly, grinding is the only way i can machine the finished weld
John
Hi Mcgyver.
I have to check things out again. The dimension between the Cylinders, the base and the crankshaft don't ad up. Some thing is not OK in that department.
The mountings on the cylinder and the base are OK The Crankshaft and the base are OK also but the center dim. of the low pressure cylinder and the crank shaft don't match up. On the cylinder the dim. are OK . I will check again see where things got off!
As replacement parts, the cylinder is 69 GB pounds and the base is 44 GB #
Hilmar
I have to check things out again. The dimension between the Cylinders, the base and the crankshaft don't ad up. Some thing is not OK in that department.
The mountings on the cylinder and the base are OK The Crankshaft and the base are OK also but the center dim. of the low pressure cylinder and the crank shaft don't match up. On the cylinder the dim. are OK . I will check again see where things got off!
As replacement parts, the cylinder is 69 GB pounds and the base is 44 GB #
Hilmar
I hope its a simple thing.
The Stuart castings are magnificent, the drawings are terrible imo - it would be easy to make a mistake. they don't have errors or anything, they are professional in that sense, but just made hard to read. This is an engine with a lot of parts, and it came with two 11x17 sheets with everything crammed onto them - and they never ever give a dimension if its conceivable possible that you could figure it out on your own. Compare those miserable plans to the full size, beautifully drawn and dimensioned plans Ted McJannet (sp?) did for my hit miss engine and I realize how much better it is to have a kind draftsman.
I hope you don't need to buy a casting.....worse news though we be if it wasn't available. I thought they stopped production of the triple? i guess they still have some stock, but wouldn't that be a kicker to wreck the main cylinder block and not be able to get a replacement the glass may be half full on that account!
The Stuart castings are magnificent, the drawings are terrible imo - it would be easy to make a mistake. they don't have errors or anything, they are professional in that sense, but just made hard to read. This is an engine with a lot of parts, and it came with two 11x17 sheets with everything crammed onto them - and they never ever give a dimension if its conceivable possible that you could figure it out on your own. Compare those miserable plans to the full size, beautifully drawn and dimensioned plans Ted McJannet (sp?) did for my hit miss engine and I realize how much better it is to have a kind draftsman.
I hope you don't need to buy a casting.....worse news though we be if it wasn't available. I thought they stopped production of the triple?
i guess they still have some stock, but wouldn't that be a kicker to wreck the main cylinder block and not be able to get a replacement the glass may be half full on that account!Mcgyver
Just got an E-Mail back from them.
When did you hear that the Triple is out?
Still have to find out where I went wrong but for that I have to make some more parts.
Have to fit the piston in the cylinder have a piston rod attached and do the measurement
to the shaft. Is it the cylinder, the base or the shaft.
The Casting I got in 1970 and by that time it may have been who knows how old !!!!
Hilmar
Just got an E-Mail back from them.
When did you hear that the Triple is out?
Still have to find out where I went wrong but for that I have to make some more parts.
Have to fit the piston in the cylinder have a piston rod attached and do the measurement
to the shaft. Is it the cylinder, the base or the shaft.
The Casting I got in 1970 and by that time it may have been who knows how old !!!!
Hilmar
B
Bogstandard
Guest
Hilmar,
Is it just the cylinder bores that are out or all the cover mounting holes as well, as it is a fairly easy job to sleeve and rebore in the correct position and you would hardly ever know it has been done. It would certainly be a lot cheaper than the $300 that Stuarts will charge you.
John
Is it just the cylinder bores that are out or all the cover mounting holes as well, as it is a fairly easy job to sleeve and rebore in the correct position and you would hardly ever know it has been done. It would certainly be a lot cheaper than the $300 that Stuarts will charge you.
John
Hi John,
That is the problem, all is done on the thing.
If You look at the other thread
But thanks for the Tip. That would be a easey fix
I am thinking of all kinds of things. We will see.
I think Sh....t happens to all of us some times.
Hilmar
That is the problem, all is done on the thing.
If You look at the other thread
You see in what state it is in.
But thanks for the Tip. That would be a easey fix
I am thinking of all kinds of things. We will see.
I think Sh....t happens to all of us some times.
Hilmar
B
Bogstandard
Guest
Hilmar,
You are perfectly right in the saying of s##t happens, it takes a certain kind of person to admit their mistakes publicly, and you are such a one, we can all learn from other peoples mistakes.
To get back to your little problem.
Now I have had a look at the cylinder, it looks like there is not much 'meat' left to play about with on the cylinder walls, even a sleeve might not do it.
To me, because you have gone so far, I would just carry on as you would have done if it was correct, and make no allowance anywhere else for the cylinders being offset, except for the fittings that go into the cylinder, top caps and crosshead guides should be made to fit the cylinders as though they were in the right place, as long as the screw holes don't break out or interfere with any porting.
As long as the base is correct, it would just mean that the cylinders are offset.
Not having the plans available to look at, it just might mean all you have to do is modify the bottom of the crosshead support, to take into account the changed geometry of the con rod swing, either by shortening slightly or putting a deeper countersink into the end, or a combination of both, to allow the con rod to swing without touching anywhere. Look at your crosshead guide drawing, and see if there is enough meat on the end to remove say 3/32" off the end and if you could get a slightly larger countersink in there. It might not run as perfectly as it should, because of the offset putting the geometry between the crank and the crosshead out slightly. But if you do try it, and it works OK, you will save yourself a load of cash, and you will end up with a unique engine with offset cylinders, a good selling point.
On the other hand, it just might mean I am talking thru my a##e, and there are too many items involved to go down that route. Without seeing the plans, and using basic knowledge of steam engines, this is the conclusion I came to.
I know it is of no consolation to you, but you can now see why I always mark things out, even though not needed, and make a machining schedule. Just a quick check before you put cutter to metal will tell you if major mistakes are going to happen.
I am not saying do it as I say, just consider it, it might mean a way around your problem, the choice in this case is totally yours.
John
You are perfectly right in the saying of s##t happens, it takes a certain kind of person to admit their mistakes publicly, and you are such a one, we can all learn from other peoples mistakes.
To get back to your little problem.
Now I have had a look at the cylinder, it looks like there is not much 'meat' left to play about with on the cylinder walls, even a sleeve might not do it.
To me, because you have gone so far, I would just carry on as you would have done if it was correct, and make no allowance anywhere else for the cylinders being offset, except for the fittings that go into the cylinder, top caps and crosshead guides should be made to fit the cylinders as though they were in the right place, as long as the screw holes don't break out or interfere with any porting.
As long as the base is correct, it would just mean that the cylinders are offset.
Not having the plans available to look at, it just might mean all you have to do is modify the bottom of the crosshead support, to take into account the changed geometry of the con rod swing, either by shortening slightly or putting a deeper countersink into the end, or a combination of both, to allow the con rod to swing without touching anywhere. Look at your crosshead guide drawing, and see if there is enough meat on the end to remove say 3/32" off the end and if you could get a slightly larger countersink in there. It might not run as perfectly as it should, because of the offset putting the geometry between the crank and the crosshead out slightly. But if you do try it, and it works OK, you will save yourself a load of cash, and you will end up with a unique engine with offset cylinders, a good selling point.
On the other hand, it just might mean I am talking thru my a##e, and there are too many items involved to go down that route. Without seeing the plans, and using basic knowledge of steam engines, this is the conclusion I came to.
I know it is of no consolation to you, but you can now see why I always mark things out, even though not needed, and make a machining schedule. Just a quick check before you put cutter to metal will tell you if major mistakes are going to happen.
I am not saying do it as I say, just consider it, it might mean a way around your problem, the choice in this case is totally yours.
John
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