Welding of ports onto Hydraulic cylinder tube

[Hobby Shop]

Is it possible to push a tapered ring or ball bearing into the bore to straighten it out after welding?

On a much smaller scale this has saved my ass a few times.

 

[tonymor]

Hi Everyone.
So forgive me ahead of time for asking about welding procedures. I'm a general machinist operating manual machines. Don't have a lot of experience welding and our welder isn't really open to any ideas I have. Somewhat justified with what I know on welding.
Here's my situation.
We build cylinders for a machine we build. It's a large haybale stacker. Diameters of 2 1/2" - 5 1/2" cylinder tubes.. All 1/4" pre-honed tubing. Distortion of the tube being the issue when welding the port on. We have no engineers here. Just some guys with creative thinking....
Procedure has been to run a tig weld and then follow with a mig weld. The weld is anywhere from a 1 1/2" - 2 1/4" back from the front of the tube. The tube distorts approximately +.015 at the port and of course goes about a -.012 90 degrees to the port. It was recommended to me to carefully squeeze the tube back to a more round diameter in the press. I've had pretty good success at this. Generally get it within .002 -.004 round. But always have to use a flapper wheel heavily to clean up the tight spot at the port area. I've got a batch of approximately 100 cylinders to do. I'd rather not have to do this. I recommended going to just one weld. Well.... he says I'm trying to reinvent the wheel... So after some fussing he says he'll try it... But only with a tig weld. I don't know why he doesn't want to mig it. He's using 3/32" tungsten but says he thinks he should go 3/16". I'm thinking geez..... Aren't you going to be pouring in a bunch of heat with that size??? The whole idea from me is to get a good strong weld without putting so much heat into the part and distorting it... So again... I'm not a welder. But looking to you guys for tips that I can somehow get this guy to accept and try. My philosophy on life, and work.... is always be teachable. There's always someone with more experience and skill that you can learn from. My pops taught me this. I was an automotive machinist for 23 years and have now been a general machinist for 18years. I'm still learning... Thanks for any help.

We manufacture hydraulic cylinders. Welding ports on prehoned tubing similar to you. Some of the parts we make with bigger ports and thinner tubes we do squeeze back round. You can make a slug to go inside the tube to use as a stop to make it more repeatable. Bit of trial and error to decide how much undersize to make the slug.
Minimum heat required to get a good weld in a single pass is a good way to go. We weld everything . 030" mig. On 1/4" tubing we manage distortion well enough we don't even worry about pressing back round and certainly don't flapwheel the ID.

 

[Maintenance guy]

I've had similar issues in my off road fab work with uniball cup distortion and not pressing in properly. What I've had good luck with is putting a brass slug in the cup and weld with it in there and it keeps everything nice and round. Drilled and tapped in the center so you can get a slide hammer to pop it out of needed. Not sure if this info is useful for hydraulic cylinders but maybe an idea

 

[Mr. Atoz]

Counter bore your cylinder enough to get the piston past the warpage.

 

[david n]

You can make a slug to go inside the tube to use as a stop to make it more repeatable. Bit of trial and error to decide how much undersize to make the slug.

I was thinkin the same thing..........squish bottoming out on an undersized slug(stop)............... rinse and repeat..................

 

[Fredster]

Is it possible to push a tapered ring or ball bearing into the bore to straighten it out after welding?

On a much smaller scale this has saved my ass a few times.

It's a good idea..... I would just be concerned damaging the finish since it's pre honed material. I could make one out of aluminium....

 

[Fredster]

I want to thank everyone for their suggestions. Some good input here...Iv'e talked with our welder. Still being a stubborn son of a gun.......But we're going to start with no TIG weld and try dual shield and .... hard wire. Apparently he was already using dual shield after his TIG weld.....Pretty sure he's been using .035 wire but suggesting he also try .030. At that point I'll break out the dial bore gauge and see where we stand with our distortion. I really think going to one weld can help us out. Thanks again. I'll let you know how it all goes. Any other input is welcome

 

[Mr. Atoz]

I am wondering what the talk about MIG and Tig is. Every one of the cylinders we make have ports welded on using wire. And we make hundreds every week. Using a robot.

 

[Fredster]

Counter bore your cylinder enough to get the piston past the warpage.

I've done this on some. It works. But I still have to blend the area where it meats the hone surface . Trying to avoid the extra set up and time...

 

[eKretz]

If you have that many to do and he is being that stubborn, perhaps you should have him do several as a trial so you can directly show him which way is best. If you present it correctly, you can probably make him think it's his idea, and congratulate him...

You might be able to tell that I've found this technique useful from time to time.

 

[Fredster]

If you have that many to do and he is being that stubborn, perhaps you should have him do several as a trial so you can directly show him which way is best. If you present it correctly, you can probably make him think it's his idea, and congratulate him...

You might be able to tell that I've found this technique useful from time to time.

You nailed it!!! That's what were doing. A little R & D... He did calm down after a few days and we were able to discuss it. If it all works out, he will probably think it was his idea. And.....look at the time we're saving...

 

[Overland]

I noticed a few recommendations for dual shield MIG.
What would be the benefit of dual shield wire over solid wire please ?
Bob