HVAC-Talk: Heating, Air & Refrigeration Discussion banner
Cancel
Create thread New Forums

Coroded Compressor Suction Line

Jump to Latest
21 - 40 of 43 Posts
Discussion starter · #22 ·
fridg said:
This is from using flux on a steel to copper connection , when using flux you should always clean your flux off & paint the brazed section to stop the air reacting with it. As you know 2 dissimilar metals & a liquid can create an electrolytic solution like a capacitor.

We always painted this type of weld in our manufacturing plant for this very reason to stop pitting.
Click to expand...
This is how Manitowoc brazed in the compressor at the factory.
 
Discussion starter · #23 ·
fridg said:
This is from using flux on a steel to copper connection , when using flux you should always clean your flux off & paint the brazed section to stop the air reacting with it. As you know 2 dissimilar metals & a liquid can create an electrolytic solution like a capacitor.

We always painted this type of weld in our manufacturing plant for this very reason to stop pitting.
Click to expand...
What do you think? Should I try to braze a layer of StaySilv 45 over the entire area, or should I cut out the are affected and try to braze a new line closer to the compressor housing?

Thank you.
 
#28 ·
AEA 4440... :)
 
Save
Like Like
#31 ·
Here's a Q30
Not many out there
They only made one smaller....... Q20 for over seas

Check out the tilted forward angle on the evap to help harvest

Image
 
Save
Like Like
#32 ·
I am not sure if this applies to critically charged units or not, Residential split manufacturers say if you have an oil leak not to add any oil to a system unless you are up to your ankles in it.
 
Save
Like Like
#34 ·
rioan28 said:
What do you think? Should I try to braze a layer of StaySilv 45 over the entire area, or should I cut out the are affected and try to braze a new line closer to the compressor housing?

Thank you.
Click to expand...
I would be cleaning all the pits out with a wire brush & emerytape , hitting the weld with flux & 15% silver solder , cleaning all the flux off & painting the braze.
 
Save
Like Like
#36 ·
Sorry I should have stated 45% silver solder , not the 15%.
And don't be sparingly on the flux , put plenty of that on the pipe & on your solder while brazing. Sorry for any confusion.
 
Save
Like Like
#37 ·
That stub is steel - it was originally plated with copper to allow soldering to a copper tube. But in this case the plating is gone and the steel is badly corroded.

Silphos will not flow to steel.

45% silver and the appropriate white flux will flow to steel - but of course the plastic-range of 45% is somewhat narrower than Silphos. <g>

And the 45% will require all the pits to be shiny-metal CLEAN.

I think I would try CLEANING it to PERFECTLY CLEAN and then using J/B Weld to coat the line. What would be even cooler would be to slice a piece of copper into two half lengthwise and then bonding that two-piece 'sleeve' over the pitted area with J/B Weld. Clamp the two pieces together over the repaired / sleeved area overnight.

PHM
-------



rioan28 said:
Hello all,
I am new to the hvac world and would like an opinion on how you might solve this problem.
I have a customer with an Manitowoc QM30A ice machine who lost all its refrigerant through a pinhole in the corroded suction line right at the compressor.
The compressor still works so I was thinking about trying to braze on top of that pinhole to cover it up and also braze all around but I don't know if the brazing with Stay-Silv 15 will stick to that corroded surface. I have use a brush to clean it as much as possible.
The other option would be to cut the compressor's suction line closer to the base, where I still have good metal and braze in a new line there, but not sure how to that would affect the compressor.
I have included two pictures showing the problem.

Any advice would be greatly appreciated.

Thank you,
Rob
Click to expand...
 
Save
Like Like
#39 ·
The reason for not using phosphorus bearing braze rod with steel is that it forms a brittle compound with iron. 45% does not use phosphorus. 15% contains a lot of phosphorus hence SilFos.
 
#40 ·
I believe Manitowoc uses 55%
They even send a piece out with replacement compressors. This is strait up corrosion because of the freeze thaw pattern on this cap tube machine and the insulation was butted right up to the compressor shell. The area stays wet all the time when it's not frozen ;)
 
Save
Like Like
21 - 40 of 43 Posts
You have insufficient privileges to reply here.
About this Discussion
42 Replies
17 Participants
Last post:
fridg
HVAC-Talk: Heating, Air & Refrigeration Discussion
posts
5M
members
275K
Since
2000
The #1 HVACR Community
Full Forum Listing
Explore Our Forums
AOP Residential HVAC/Refrigeration(Beenthere Zone) General Discussion Tech to Tech Chat - Residential Controls Refrigeration & Ice Making