Blade thickness

[ROADHOG]

I have a set of 30 labbed Bravo's and I'm curious as to the blade thickness on the edge. I measured the edge of the blade and it measured about 40 to 45 K for thickness would this be classified as a thinned blade or is that about normal for a labbed prop? Edge is sharper but not razor sharp in comparison to my 28 labbed Bravo's.

[bbladesprops]

That's my kind of question.

Where do I begin?

Who did the work?

There are tolerances to work with. That explains the differences between propellers, 30's-28's. The #'s are considered proprietary in my opinion. Extreme leading edges are not a location that is measured "specifically" on certain recipes. If you move your mic. in .025 you will more than likely see a large increase in thickness. Some people/shops like to make the leading edges razor sharp. We believe there is a time and place for certain thickness curves. Pleasure boating isn't the time for a knife edge. Tight radius yes, knife edge no. More likelihood of stress risers creating cracks.



I would be more than happy to discuss this in depth with you if you want to give us a call.

Thank you.

[ROADHOG]

Bret,
Props where labbed at Mercury, 30's were done about 4 year ago and 28's were done about 3 years ago. 30's were done for a 35 Nordic with power and 28's were done for 358 Sonic with 500 EFI's.

Why I'm asking is because I have 2 sets of 30 labbed and 1 set of 28's. I'm upgrading my 358 with the 30's, last year I turned my 28's 5200 rpm this year with some minor motor work I now can turn my standard Labbed 30's 5400 rpm's.

My other set of 30's I beleive to be a standard labbed finish nothing fancy. The 30's I'm inquiring about have been changed several times by Mercury. I called Mercury today to give them the numbers on the Hub to try and determine what the last modifications were. They never called me back I will call them again Tuesday and hope they will be good enough to look up the info.

[throttleup]

The trailing edge is not necessarily an indication of the blade thickness. When we measure blade thickness is done at several different radii and about an inch or so in from the leading or trailing edge. There are times when it is advantageous to thin the trailing edge area depending on the application.

Every time the prop is worked it can only get thinner. It's possible to overwork a prop. At a certain point a prop just gets too thin to be worked any more.

The best thing to do with your props is to run them and see how they run. Then go from there. As long as diameter or blade area has not been removed from the props a prop can be matched to another.

It's common for customers to send in a half dozen props all of the same pitch but with different histories. Then we inspect all of them and come up with a pair of the best two props.

Blade thickness should vary from one lab set of props to another depending on the application. When the props are lab finished many factors should be taken into account which determine how the prop is worked.

Matt

[bbladesprops]

Hello,

I was at Merc Racing during that time frame. Please give us a call and I'm sure I can answer your questions concerning the rework and serial #'s.