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Conference vicki::boats

Title:Powerboats
Notice:Introductions 2 /Classifieds 3 / '97 Ski Season 1267
Moderator:KWLITY::SUTER
Created:Thu May 12 1988
Last Modified:Wed Jun 04 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1275
Total number of notes:18109

399.0. "props, SS or aluminum?" by SEAVU::BOUSQUET () Tue Jun 06 1989 15:12

    Hi,
    
    Last weekend while idling around Wallum lake I found a pretty good size
    rock! The resulting damage was about 1 inch off my skeg and three bent
    blades on my factory aluminum prop (which has about 8 hours on it).
    I'll probably just file the skeg to give it a smooth edge. As far
    as the prop is concerned I'd like to buy a new one and have the
    damaged one sent out to be repaired and used for a backup. I priced
    replacement aluminum props as well as stainless steel ones. Can
    anyone explain the difference in performance and or gas mileage
    between the two? The price difference is significant. The boat is
    a 1989 wellcraft 18 foot with a 165 merc I/O. The current prop is
    a 21 pitch. I'm planning replacing it with the same. 
    
    Please be patient as I am very new to boating (about 8 hours)and also
    pretty new to this notes file. Thanks in advance for the information.
    
    AL
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399.1lots of propeller notesHPSCAD::WHITMANAcid rain burns my BASSTue Jun 06 1989 16:0218
Al,
	Welcome to the world of boating.  Why is it the rocks can pick out
the new guys so quickly???;-);-)

Anyway  a DIR/title=PROP  gives a list including notes

		42,
		46,
		254,
		263,
		322

  This is just a short list of BASE notes about propellers.  I'm sure a
directory of topics and replies (dir/title=prop *.*) would be much longer.  The
questions you ask are fairly well covered.  Look around in here a little bit
more, and if you still have questions, then fire away... 

Al
399.2CURIE::THACKERAYRay Thackeray MR03 DTN 297-5622Tue Jun 06 1989 22:593
    I don't know if you have a depthfinder, but one thing's for sure.
    
    Depthfinders are getting cheaper than propellers!!!
399.3What about my skeg?FINS::BOUSQUETWed Jun 07 1989 09:318
    I think your right Ray, $118 for a replacement aluminum and about
    $363 for an SS.
    
    Thanks Al for directing me to other notes with similar questions.
    One thing still bugs me though. Should I bother to have the skeg
    reworked? It looks like I lost between 1 1/2 to 2 inches off it.
    Will I lose any maneuverability at all? The skeg is also slightly
    bent.
399.4MAPS AND CHARTSTYCOBB::J_BORZUMATOWed Jun 07 1989 10:229
    THESE GUYS GAVE YOU SOME DAM GOOD ADVICE, MY DAM GOOD ADVICE TO
    YOU IS: IF YOUR IN FRESHWATER, GET SOME TOPOGRAPHY MAPS,
    OR ASK AROUND FOR LOCAL KNOWLEDGE. IF IN SALT GET THE CHARTS
    BEFORE YOU GO OUT REFER TO THEM AND STAY OUT OF THE 
    AREAS THAT ARE MARKED FOUL.
    
    CHARTS AND MAPS ARE DIRT CHEAP, GET IT./.....
    
    JIM
399.5CSSE32::APRILWinter WandererWed Jun 07 1989 10:2414
>    Thanks Al for directing me to other notes with similar questions.
>    One thing still bugs me though. Should I bother to have the skeg
>    reworked? It looks like I lost between 1 1/2 to 2 inches off it.
>    Will I lose any maneuverability at all? The skeg is also slightly
>    bent.

	You'll probably get conflicting stories about this but I can only
	tell you what I did.  I lost a couple of inches off my bottom skeg
	a few years ago.  I was told it would cost around $125 to fix it
	via a weld.  All I did was to file it down to take the roughness 
	off it and have used it that way ever since.  The boat 'pulls'
	slightly to the right but nothing major.

	Chuck
399.68 HOURS !!!!!MCIS2::LEEWed Jun 07 1989 13:039
    Hi Al, Well it didn't take you long to do damage to your boat, but
    I to damage my prop on my new boat also. You may have read my request
    in this file regarding prop damage, I got good advise. Sent the
    prop to H+H propeller in Salem.....Super job.....
    
    How do you like your boat.......
    
    Dave
    
399.7Rub it in!FINS::BOUSQUETWed Jun 07 1989 14:4116
    Hi Dave,
    
        I can't tell you how I felt when I heard that sickening "crunch
    crunch". It broke my heart! I still haven't gotten over it!
    
        I will have the damaged prop reworked and used as a spare. It's
    cheaper than buying new. Hopefully two props will be all I ever
    need.
    
        Other than the prop damage the boat has been super. It's quiet,
    handles well, is very well put together (except for the skeg) and
    reasonably fast at about 46-47 mph.
    
        Thanks for the advice.
    
    AL
399.8Repaired prop is fineTHOTH::BONETTIThu Jun 08 1989 11:093
    I had my prop repaired at H&H in Salem last year. They did a great
    job. Prop is like new and it only took less than a week even sending
    it to them through UPS. I think that it cost me around $65.00.
399.9Count your blessings?BMT::SAPIENZAKnowledge applied is wisdom gained.Fri Jun 09 1989 16:2416
    
       Look at the bright side.
    
       A few months ago I read an article (either Offshore or Soundings,
    can't remember) about a gentleman that was travelling somewhere along
    up north at night (on his maiden voyage as well!) and proceeded to
    take the boat right over a small waterfall (about 25' elevation I think
    it was).
    
       If I remember correctly, there were a number of cracks in the hull
    as well as prop damage, etc. The gentleman insisted that "any damn fool
    can drive a boat."
    
    
    Frank
    
399.10A Waterfall!TIDES::BOUSQUETMon Jun 12 1989 10:147
    A waterfall.  I guess it wasn't that bad after all!
    
    Thanks everybody for the input. I had the skeg repaired for $100.00.
    The prop is being reworked for $60.00. I also bought a factory
    replacement aluminum wheel. Thought maybe I could use a spare.
    
    Al B. 
399.11Another source of infoNRADM::WILSONIt doesn't get any better than thisWed Jul 19 1989 13:387
    
    The August issue of Trailer Boats Magazine has a lengthy
    article on props.  I just received my copy in the mail
    yesterday so I haven't read the whole thing yet, but it 
    looks interesting.              
    
    Rick W.
399.12Size: SS vs. Alum.HAZEL::YELINEKWITHIN 10Tue Nov 07 1989 09:5633
>    I am kinda leaning towards buying a 15x17 stainless myself. If I do I 
>    will have have a 15x17 aluminum that is like new to trade in (or sell to
>    someine in this conference).

    My Grady White 204C (20 footer) has a YAMAHA Stainless Steel prop
    which came standard with the 150 hp engine. The Yamaha accessories
    catalog provided all kinds of data for proper prop selection. The
    dealer indicated to me that the 'nearest' equivalent (in performance
    taking into account my type of boat) spare Aluminum Prop. would(must) 
    differ in size in order to come close to matching the performance 
    characteristics of the stainless steel one. This change probably
    takes into account the additional 'Flex' characteristic of the Alum. vs. SS.
    
    ...The specs are as follows...
    
                  Material: SS      
->                    Size: 15.25 X 15 (stock on 150hp Yamaha)
       Gross (Boat) Weight: 2750 - 4400 Lbs.
             Length (Boat): 21 - 26 ft.
               Speed Range: 32 - 40 miles/hr.
                    Part #: 6G5-45970-01-98
                      -------------
                  Material: Aluminum
->                    Size: 14.5 X 17 
       Gross (Boat) Weight: 2950 - 5000 Lbs.
             Length (Boat): 22 - 28 ft.
               Speed Range: 28 - 36 miles/hr.
                    Part #: 6G5-45947-00-EL

The point I'm attempting to make is that the Alum. prop. (for a given size) 
is not equivalent to the SS prop in the same size. 
    
  /MArk
399.13SS vs Al or Pitch vs diam ?ULTRA::BURGESSNauti nineties readyTue Nov 07 1989 11:1911
re                 <<< Note 399.12 by HAZEL::YELINEK "WITHIN 10" >>>
>                            -< Size: SS vs. Alum. >-

	This looks like a pitch/diameter trade off to me, i.e. you may 
find there is less difference due to stainless vs alumin than there is 
due to pitch.  I'll dig out my Michigan wheel prop selection book & 
check.

	R


399.14More on my prop thoughtsLEVERS::SWEETCapt. Codfish...GW Fishing TeamTue Nov 07 1989 11:3412
    What I am thinking is this. I have a 15X16 stainless now. This 'feels'
    great comming out of the hole but I do not get as many MPH as I
    think I should for the RPM's at cuise. I have a 15x17 aluminum that
    gives beter MPH but has some vibration comming out of the hole and
    it general does not feel quite right. I am thinking the 15x17 stainless
    may give me the MPH and a better hole shot since it will not flex.
    The 460 ford block generates 335HP pushing 7000lbs which is alot a torque
     for the aluminum.
    
    Any comments?
    
    Bruce
399.15stresses and strains an' such stuff...ULTRA::BURGESSNauti nineties readyWed Nov 08 1989 13:0840
re                 <<< Note 399.12 by HAZEL::YELINEK "WITHIN 10" >>>
>                            -< Size: SS vs. Alum. >-
    
>                  Material: SS      
>->                    Size: 15.25 X 15 (stock on 150hp Yamaha)
>       Gross (Boat) Weight: 2750 - 4400 Lbs.
>             Length (Boat): 21 - 26 ft.
>               Speed Range: 32 - 40 miles/hr.
>                    Part #: 6G5-45970-01-98
                      -------------

	The closest I could find to this is 6G5-45970-00-98, but 
according to Michigan Wheel that is a 14.5 X 15 and is in the  "House 
boats and cruisers"  category.

>                  Material: Aluminum
>->                    Size: 14.5 X 17 
>       Gross (Boat) Weight: 2950 - 5000 Lbs.
>             Length (Boat): 22 - 28 ft.
>               Speed Range: 28 - 36 miles/hr.
>                    Part #: 6G5-45947-00-EL

	Michigan lists this number, also in the "House boats and 
cruisers" category, but closer to the  "21'-19'Bts - All Loads, Skis" 
group.  They claim this is more nearly equal to the  Yamaha
6G5-45978-01-98 though,,,,,  disclaimer; this is all under one 
grouping for the Yamaha 150, 175 and 200 '84 through current, also the 
V-6 special 84-85 and the PRO V and Excel 86 through current.

	errrr,,,,   FWIW, etc.

	Reg


PS:	I seem to remember that stress in a prop is some inverse 
function of (approx) the square of its diameter, but its only 
inversely proportional to the pitch, so.....  for as given HP and RPM 
a prop with a smaller diameter and a higher pitch will be less 
stressed.

399.16Howcum I can't get an SST prop through the mail?TOOK::SWISTJim Swist LKG2-2/T2 DTN 226-7102Thu Oct 11 1990 09:247
    Am I alone in wondering why the major discount mail-order marine
    suppliers never list any props in their catalogs (other than the
    "Comprop" low-performance spare)?  (Boat/US, Bliss, Overton's, etc).
    
    If I want to buy an SST prop do I have to go to the parts counter of
    a dealer and pay full retail price?  
    
399.17No way to retailTROA01::DPURDIEThu Jun 20 1991 18:435
    Does Michigan Wheel carry stainless props for a Johnson 150 V6
    outboard? The only listings I have seen are rather short and don't even
    list any props for this motor.
    I would like to find someone other than the dealer that has a selection
    of props for this motor since the dealer want $400 (canadian)z
399.18Ward's marine has them. Winthrop, Ma.SALEM::NORCROSS_WFri Jun 21 1991 09:153
    Ward Marine has a listing for Michigan Stainless "super prop" for the
    Johnson/Evinrude V6. All sizes are $269.25 (list for $359.00).
    Wayne
399.19Propeller EngineeringWXYZ::DEMBAFri Jun 21 1991 13:328
Also try Propeller Engineering. A couple of months ago he had
the best price going for Michigan props. He does repairs and
sales. 

	Propeller Engineering
	5 Fountain Street
	Springfield, Ma	 01108
	413-733-2297