Propeller balancing using a scrapper?

[Kez]

Years ago a machinist taught me how to use a scrapper for metal work. I did not think much about it until recently when I was trying to prep some old JG props that I bought many years ago, that perhaps a scrapper is a more effective tool than a file. The JG props have thick blades and it takes a lot of work to thin them. Scrapping does not leave deep gouges and will not clog a file. Has anyone tried this? I have not seen any scrapper smaller enough for our props. Perhaps I can grind a small file into a scrapper?

Thanks,

kez

 

[shoboat]

Kez,

3M grinding wheels are the best I have found.

2-Sfine work very well.

Filing or scrapping would take forever.

Mark Sholund

 

[Kez]

Kez,

3M grinding wheels are the best I have found.

2-Sfine work very well.

Filing or scrapping would take forever.

Mark Sholund

Mark,

I do not want to use a Dremel or a grinding wheel for two reasons. 1. I am concerned about generating fine particles. I wear a mask but still I am not set up to do the job. 2. Unlike you, I am not skilled enough to use a grind wheel. I can easily ruin a good prop by taking out too much material.

So I use hand tools to work my props but I think a scrapper will work better than a file.

Thanks,

kez

 

[John Beardslee]

Kez,

3M grinding wheels are the best I have found.

2-Sfine work very well.

Filing or scrapping would take forever.

Mark Sholund

Mark,

I do not want to use a Dremel or a grinding wheel for two reasons. 1. I am concerned about generating fine particles. I wear a mask but still I am not set up to do the job. 2. Unlike you, I am not skilled enough to use a grind wheel. I can easily ruin a good prop by taking out too much material.

So I use hand tools to work my props but I think a scrapper will work better than a file.

Thanks,

kez

Concern over small dust particles is all good. Especially with BeCu but unless my memory fails me Jim Gale (JG) never used BeCu as a material in his props, I think his were manganese bronze and most of the blades had lots of extra material and would take a lot of time to balance and sharpen. Maybe Jerry Dunlap can confirm if he sees this. I used a 1" X 42" belt sander with the spring tension on the belt reduced so the belt would conform to the curvature of the back side of the smaller blades. I think a metal scraper would take along time to remover enough material to balance and sharpen any prop. I've done my share of scrapping in metal working machines as well as a few props.

Thanks, John

 

[Kez]

Hi John,

I remember reading an article by Jim Gale in the 70's or early 80's in which he mentioned he used 2% Be in his props. 2% Be by weight is a lot. I noticed Dumas started offering JG props in the 90's. They probably used a different alloy since the color looked different than those I bought when JG was making them.

I never tried a belt sander but I used a Dremel with sanding disc before. If you let the sanding disc dwell too long in one spot, the prop is gone. I have since determined that I will stick with hand tools only or I pay the prop gurus for their service.

I just grind the tip of an old file into a scrapper but it does not work very well. What I learned from this exercise is that the scrapper takes too long to thin the blades but it works well to smooth the file marks. Better than a sandpaper in my opinion.

Thanks,

kez

 

[John Beardslee]

As they say: There is more than one way to remove the epidermis of the feline creature!

Thanks John

 

[Tom Foley]

Hi John,

I remember reading an article by Jim Gale in the 70's or early 80's in which he mentioned he used 2% Be in his props. 2% Be by weight is a lot. I noticed Dumas started offering JG props in the 90's. They probably used a different alloy since the color looked different than those I bought when JG was making them.

I never tried a belt sander but I used a Dremel with sanding disc before. If you let the sanding disc dwell too long in one spot, the prop is gone. I have since determined that I will stick with hand tools only or I pay the prop gurus for their service.

I just grind the tip of an old file into a scrapper but it does not work very well. What I learned from this exercise is that the scrapper takes too long to thin the blades but it works well to smooth the file marks. Better than a sandpaper in my opinion.

Thanks,

kez

I can send you a box of old props if you want to use power tools . You pay shipping I'll load you up !

 

[Kez]

Hi Tom,

That is very kind of you. Thanks very much. I will PM you.

kez