Small weld on cylinder sleeve

[cgraham]

My contractor friend proposes to cut off a damaged fitting and welding on another to the sleeve of the cylinder controlling bucket curl on a compace backhoe. He has offered to do it as he has a well-equipped shop and is very competent. The cylinder will be removed, and so, drained.

I know that standard practice is to disassemble a cylinder before welding on it, and cleaning before and after.

He says there is no need to disassemble the cylinder for this weld. Just extending the cylinder will pull all the internals away from the work area. That raises a question about cleaning. He is not concerned that any metal particles of significant size will fall into the cylinder (using a rotary cutter).

So what is the reason for cleaning BEFORE welding? Is it fear of baking oil on the cylinder? I'm thinking that the mass of metal will dissipate heat from the relatively small weld, and thus this may not be a problem.

Thanks for views on this overall approach.

Charlie

 

[BTDT]

I'd say let him do it. It's already broke, worse case scenario, you will have to buy a new cylinder.

 

[Willl]

Ditto what BT said, although a small flush job with hyd fluid afterwards wouldn't hurt.

Are you going to replace the hose end also ?

 

[Willl]

So what is the reason for cleaning BEFORE welding?

To get a good weld.

 

[Bill Barrett]

purge with nitrogen will stop oxidation when welding.

 

[mechanic]

Anytime you do a weld it always a good idea to clean the metal as best as you to can to keep impurities out of the weld, which will cause pin holes and make a weld weak.

 

[BarryinMN]

I had an old TLB stabilizer cylinder spring a leak. $750 cyl & all day R&R project.

Blacksmiths shop fixed it in 10 minutes only needed to pull a hose off to prevent heating motion.

Your friend is correct on all points. Let him work his magic.

Rattle can touchup paint if you need pretty & back to work!

 

[cgraham]

Thanks for all the hints and encouragement. Will clean up the weld area with mineral spirits, allow the residue to evaporate off, weld and replace hose end if any sign of damage.

Barry in MN: nice to hear of your success on a similar project.

Sounds like I will be good to go. Scheduled for Saturday.

Charlie

 

[sandman2234]

Mineral spirits, although a lot better idea than gasoline is still a petroleum base and will leave residue. Maybe wipe that off with a linkfree rag soaked with alcohol (not jim beam) or some other cleaner that doesn't leave a residue. The weld will probably burn off the residue, but it is just a precaution.
I might consider laying the cylinder on a bag of ice where the seal is sitting just to keep any heat from drying it out or damaging it. Keep the seal and wipers as far away from the weld as possible. Drop a magnet in the hole to catch any stray particles before flushing well with hydraulic fluid.
Have you ever watched metal from the other side while someone is welding on it? You will have some contaminates, but hopefully not enough to matter.
David from jax

 

[john_bud]

Use brake cleaner to degrease. That's what it is made to do. Fast evaporation and no residue.

jb