Folding prop blades - slightly pinkish but still satisfying ring.......replace?

[West Coast]

Hi all,

I have a 3 blade VP folding prop, probably around 15 seasons old. It is a bit pitted, but not been getting any worse over time. However, using a wire brush to clean it, I have noticed the surface is a 50/50 mix of shiny bright brassy finish and a pinkish shade.

However, when struck with a hammer, I get a really good satisfying ring from each of the blades.

Could the pinkish areas be surface only? Or am I fooling myself, and get a replacement?

 

[Billjratt]

Bet mine's older and pinker than yours! It's just beginning to get to the stage where it doesn't ring as true as I think it should. However it was recently sent to be assessed or repaired and came back with a clean bill of health, so I must assume the professionals are happy for it to be used.
I hope this doesn't affect your opinion of getting 'lectrics on our pontoon! (We are neighbours for those who I have confused)

 

[West Coast]

No change in the electrics!

Where did you get your prop assessed? Glasgow somewhere?

 

[rob2]

The blades on a folder are pretty heavy lumps and can afford to lose a bit off the surface. Although the deterioration of the surface may make them slightly less efficient, they are unlikely to shatter, unlike the thinner section blades on a fixed propellor. The mechanism whereby the zinc is lost from the matrix acts mainly on the surface so I'm not surprised it was passed as fit for purpose.

Rob.

 

[West Coast]

The blades on a folder are pretty heavy lumps and can afford to lose a bit off the surface. Although the deterioration of the surface may make them slightly less efficient, they are unlikely to shatter, unlike the thinner section blades on a fixed propellor. The mechanism whereby the zinc is lost from the matrix acts mainly on the surface so I'm not surprised it was passed as fit for purpose.

Rob.

Thanks, that's helpful. You are right that the blades are chunky. So, the fact that I can see pinkish (ie dezincified?) areas, this is likely surface phenomenon only, and beneath the surface is likely ok?

 

[Tranona]

Dezincification is perhaps more common in the gears aand where the pins run in the bronze hub, so may be a good idea to check that area as well.

 

[West Coast]

Dezincification is perhaps more common in the gears aand where the pins run in the bronze hub, so may be a good idea to check that area as well.

Right enough, there is a higher proportion of seemingly dezincified surfaces in these areas. Ho, hum

 

[vyv_cox]

Thanks, that's helpful. You are right that the blades are chunky. So, the fact that I can see pinkish (ie dezincified?) areas, this is likely surface phenomenon only, and beneath the surface is likely ok?

Abrade the pinkish areas with a fine file or 180 grade wet and dry. There is a good chance that the DZ is only on the surface. If it looks pink at a depth of more than 1 mm I would budget for a replacement at the end of the season.

 

[Slowtack]

I have the same discoloration but on only one of the three blades. Any ideas why this might be?

 

[West Coast]

Abrade the pinkish areas with a fine file or 180 grade wet and dry. There is a good chance that the DZ is only on the surface. If it looks pink at a depth of more than 1 mm I would budget for a replacement at the end of the season.

Thanks Vyv, but that's my worry, having wire brushed and then sanded them in the way you suggest, the pinkish colour remains.

 

[West Coast]

I have the same discoloration but on only one of the three blades. Any ideas why this might be?

Afraid no, all 3 of my blades show the same shades of pink