Hello everyone!
I'm new to this site and have one MAJOR question to be answered by the pros! Actually I know the answer, but having a difficult time explaining it to our weld shop.
First, let me give you some background of myself. I'm a Hydraulic Specialist with over 18 years experiance in troubleshooting, design and repair of hydraulic and pnuematic systems and components. About two years ago, I was hired at a "job shop" (Hamilton Machine Company) to start up their hydraulic division.
Everything has gone fairly smooth until now. I quoted fabricating a new 10 inch bore by 9 1/2 feet cylinder with 3/4 inch wall and a welded trunnion mount near mid cylinder. Material is 1026 D.O.M. prehoned tubing. Our lead welder is fully certified in all aspects and is extremely knowledgable. I "ASSUMED" he new how to do it with minimal distortion to the precisioned honed inside diameter. WRONG!!! It shrunk .047" one way and opened .018" the other and created a taper! Way to much to rehone or bore out. Now I have a $4500 P.O.S.!
He said he did it "by the book" and heated the barrel to about 600 degrees. He tied it in with something and used 7018 as filler.That is absolutely the wrong technique. I'm not a certified welder, but do weld some. I worked at a premier hydraulic corporation for a long time and we never preheated bores for weld. thier technique is to "chill" the entire bore. This means to fill the bore with ice and cap off ends to retain ice while the outside diameter is being welded. Remember this weld is not pressurized. It simply holds the trunnion to the barrel. After our issue we had a "talk". I said next time we don't preheat, ice the bore, and only put about 3 passes of mig on each side of trunnion. This basicly led to me not 'knowing what the f...k I'm talking about and full of sh*t!".
So, my questions are these: any of you ever done this before or heard of it? Where can I find this technique documented so I can make a copy or download it?
Your help is greatly appreciated!
Thanks,
Mark
- weldin mike 27
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Weldmonger
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Posts:
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Joined:Fri Apr 01, 2011 10:59 pm
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Location:Australia; Victoria
Hey there,
This seems to be one of these "tricks" of the trade that is used on a very specific basis. You say you have done it before, so you know it works.
Although trying to explain it to someone uninitiated will meet with b.s meters going off every time. Finding it written down will probably be hard because it goes against every rule of welding most of us are taught, eg: ice = quenching, and quenching and welding aren't always the best bed fellows.
But then again no one will EVER be able to write down all the little tricks that get us through every day.
If you KNOW it works then show people rather than telling them.
Sorry for all the rambling
Mick.
This seems to be one of these "tricks" of the trade that is used on a very specific basis. You say you have done it before, so you know it works.
Although trying to explain it to someone uninitiated will meet with b.s meters going off every time. Finding it written down will probably be hard because it goes against every rule of welding most of us are taught, eg: ice = quenching, and quenching and welding aren't always the best bed fellows.
But then again no one will EVER be able to write down all the little tricks that get us through every day.
If you KNOW it works then show people rather than telling them.
Sorry for all the rambling
Mick.
diversifabber
- diversifabber
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New Member
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Posts:
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Joined:Sun Mar 04, 2012 2:26 pm
Hey everyone,
I am new to this site, but have been welding and building stuff for a long time. I was doing some research online for a project and read this post with great interest. I need to weld a trunnion mount to a hydraulic cylinder barrel midway and want to control shrinkage and distortion as much as possible. I too thought preheating would probably be the way to go. This chilling technique is quite a different concept and is counter to obtaining a good weld, but if it works I am certainly willing to try it. This is an EXPENSIVE cylinder to replace, and I don't want to mess it up. More input and info would be greatly appreciated. So, Mark, did you make a believer out of the welding foreman?
I am new to this site, but have been welding and building stuff for a long time. I was doing some research online for a project and read this post with great interest. I need to weld a trunnion mount to a hydraulic cylinder barrel midway and want to control shrinkage and distortion as much as possible. I too thought preheating would probably be the way to go. This chilling technique is quite a different concept and is counter to obtaining a good weld, but if it works I am certainly willing to try it. This is an EXPENSIVE cylinder to replace, and I don't want to mess it up. More input and info would be greatly appreciated. So, Mark, did you make a believer out of the welding foreman?