Polished -vs- Satin Finish: The Results...
 

Darin(Houston Propellor Servivce) and everyone, It was a beautiful weekend to test and the results are in!

A satin-finished prop, in this case, is FASTER.

History:
The Contest - http://pub47.ezboard.com/fteambajama...icID=122.topic

The First Test - http://pub47.ezboard.com/fteambajama...icID=137.topic

Pictures after Finishing - http://offshoreonly.com/forums/showt...threadid=48726


The test conditions for my original factory Mirage Plus 23P were:
Temperature: 82*F
Humidity: 80% Relative
Pressure: 29.90 In HG
Winds: Calm, 5-10knots
Tides: High, little movement
Load: 1/2 tank Fuel, 2 people
WOT MAX Speed: 65.4mph


The conditions yesterday with the satin-finished prop were:
Temperature: 84*F
Humidity: 80% Relative
Pressure: 30.00 In HG
Winds: Calm, 5-10knots
Tides: Incoming, Almost High, moderate movement
Load: 1/2 tank Fuel, The Same 2 people
WOT MAX Speed: 66.1mph


This time, I also made two runs(similar to the first time) to get an average to cancel out any wind or tide effects. The only difference is that I ran East-to-West and vice-versa because the tides were incoming(running north) and the wind was southerly(heading north).

I felt that with those two factors, the speeds would be innacurate if I ran north or south.

In any event, the speeds were identical this time, going both directions.

I would conclude, based on my speeds, slightly higher temps and an identical load, that a satin-finished prop is faster.

BajaDaze well done
 

you coun'dt have provided better testing results,Great Job!!!!!!!!! and very interesting.

Thanks very much :cool:

maybe the satin prop had a little more bite cutting down on the slip ratio??? sounds good anyway, hell my props are polished on my boat, guess this winter I will have to send them to houston prop

I think that is why Merc. doesn't polish the labbed props.

Thank's H2XMark,and yes it's a heck of alot easier to finish the props out satin,Instead of mirror polishing ,That takes away alot of time and energy,but they look nice either way!Satin is also cheaper as far as the cost. again good Job /Baja Daze!!!!!!!!!!!!

Darin/Houston Prop

Mine are in right now for satin finish. Should have them back on Wednesday. I will post results but I doubt my tests will be as controlled as BD's. All I know is my best GPS ever was 78.3. If I ever see anything better than that, I would have to say it was the satin.

Doesn't matter either way - but at least with the satin I won't have to worry about those ugly water spots on the props.

I guess all I need now is an acurate GPS. The GPS I have is 1-1.5mph slow at 70mph when compared to the speedos in my vehicles.

What motors are in your boat to go 78.3mph? I assume you have a 29 Outlaw.

HO's

Lookin' forward to the results. Happy testing. :)

Got the satin props back early. They look pretty menacing. If it ever stops raining I’ll get to try them.

No, but you will get rust spots.

Menacing
 

had to get the dictionary out on this one :rolleyes: (mean):D ;) Darin;)

Hey HOUSTONPROP,

I don’t know what dictionary you have but I looked up the word “menacing” in my dictionary and this is what showed up:

Dictionary(new version)
 

OH !!! YOU have the new version! !Yours is alot better :D keep up the good work someone has to do it./later Darin:D

LMAO!!! :D :D :D Webster's been doing his homework...

Finally got on the water. No earth-shattering test results in terms on polished vs. satin. I made one wide-open run and only saw 77.1 mph. Nowhere near my best of 78.3 mph. Could of had something to do with the fact that it was 92 degrees today vs. the 80 degree day when I saw the 78.3. It might be September before we see any 80 degree days. Also had a full tank of fuel.

How much difference in speed do you guys see when running with a full tank vs. say...1/4 tank? I'm way too chicken to run that low since I know how inaccurate boat fuel gauges are. I top off the tank each time I go out.

I did manage to get one picture today - you can never have too many boat pictures:

Then I would say that the speedo's in your vehicles are off a touch. GPS should be the more accurate instrument for checking speed. The speedo's in my two vehicles are about 2 mph different from eachother. My truck is almost dead nuts on with my gps, but I did have the speedo re-calibrated last year (new larger tires that the dealer put on it before I took possesion threw it way off and actually affected the computer and the tranny shift points....was a pain in the ass).

'Foul

I agree. Vehicle speedos are not real accurate. Tire size and inflation play such a big role. Nonetheless, I've tested that GPS against 3 different vehicles and it reads 1 - 1.5 slow in each verhicle. I'm still not buying a new GPS but if I ever have a chance to borrow a better one I will. The one I have is one of those cheapo $119.00 ones

29 Outlaw,
I have seen 2-4 mph between full and slightly less than 1/4, and a few hundred rpm. Figure a difference of maybe 800 lbs.

gps speed
 

LAST WE CHECKED OUR GPS SPEED IS WHEN WE STUCK THE SUCTION CUP ON THE (AIRPLANE WINDOW) , cruising AT 525 MPH .:D :rolleyes: Darin;)