Compressor Blade Blending

[Patrick McHugh]

I just got done blending the first stage compressor blades on a PT-6/28 turboprop engine at work today. By blending I literally mean I sanded down the rough areas, nicks and scratched the compressor had after sucking in bugs, dirt and dust over the years.


714 horsepower!

I used Crocus cloth taped to a gloved finger and went one blade at a time.

I got to thinking, my compressor on my Turbo looks pretty nasty, like it ingested something or ran without a filter for a little while. It's still serviceable, but it's got to be losing performance from the disturbed airflow.

Has anyone ever blended their blades?

[Brad D.]

I found this in an industrial diesel generator rebuild manual

Burnish or polish out minor surface damage using silicon carbide abrasive cloth for aluminum parts and crocus cloth for steel parts; clean before reassembling with cleaning solvent

Remember your compressor wheel is aluminum and the turbine wheel is a steel alloy, many times inconel or mar-m.

[altus22]

I may be too cautious, but shouldn't you have the wheels rebalanced after doing this?

[johnnye23]

I think using the same technique you will be fine Patrick. I have had to cut off corners of blades and GE CF-6 blades . The maintenance manual gives the allowable repair limits. If the blade is unrepairable we replace them in pairs using the same moment weight and install them 180 degrees apart.

[Patrick McHugh]

Very cool! I am going to do this, i'll be i'm losing a bit of performance.