composite props

dolf

Recruit
Joined
May 2, 2010
Messages
2
have a sea ray sport 185 4.3 190hp 14.25 x 23p 3 blade aluminum thinking of switching to piranah composite anybody tried these? any info would be great thanks
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: composite props

IMHO - composite = emergency spare use only.

What are you actually trying to accomplish with a prop change, there are many alternatives.
 
Joined
Apr 29, 2010
Messages
27
Re: composite props

IMHO I wont be running with Aluminum or SS any longer. I bumped a rock last week while in reverse going maybe 0.5mph with 4 people in the boat and it pretty much destroyed the entire outdrive. If I had a composite, the blades would have shattered and not caused any damage at all. I'd rather put $20 per blade (4 blades for propulse, 3 for pirahna) into my boat a couple times a year than $1200 for a new outdrive every year.

I was at a new unfamilar dock so I trimmed all the way up and put it in reverse, and off we went. Then we came back, dropped off 2 people (had 6 in boat originally). Same spot, same everything. I trimmed the motor up, put it in reverse and BANG. The boat stopped dead in its tracks, engine died, and we sat there. So I got up, looked over the back of the boat, and sure enough, I could see the prop sitting on TOP of a rock. It was slanted upwards so the boat drove right into it and then up and got stuck because we werent going very fast, I had just put it in revers about 2 secs earlier. So I trimmed the motor up to get it off the rock and it didnt trim but maybe half inch. It didnt seem like much damage, the prop was just bent a little so I took off and we had a good day the rest of the day but I did notice it pulled to the left a little.

So then the next week I had the prop repaired, and off to the lake we went. Cool right? 50 bux to repair the prop whata bargain right? WRONG. What NONE of us saw (boat guy included) was that the cast metal piece thingie mababoie that holds the trim arms to the boat were cracked all to hell from the collision the previous week. So, this time when we put the boat in the water after the outdrive had been bouncing around on the dirt road, we were doomed. We got out to the lake, put in, took off (no more pull to the left, it was the prop doing that) and opened it up and not 10 mins into the trek, we heard a load POP. I slowed down to see what it was and as we slowed down I heard a *thump* which was the outdrive hitting the transom because it was now busted loose. I looked over the edge and I was like........ uhhhhhhhhhhhh why are the 2 trim arms flappin in the wind. So we turned around, headed back with a nice rooster tail following us (the arms were flappin all over the place causing a tail). Put the boat in the trailer and now we're pretty much out for the season because I cant afford $1200 to fix it.

Took it back to the repair guy and he then noticed that there were cracks in the cast metal piece thing and told us that it was probably from the previous weeks collision.

Short story. NEVER gonna buy another metal prop ever again. I could give to ****s if the prop breaks. I never want to have that happen ever again. The real bummer is that I had already ordered a pirahna prop and 3 sets of different pitch blades because I was afraid something like this might happen. If I had the composites, I woulda been out 1 day rather that out for the whole season. If I had the composites on that day, I woulda hit that rock and shattered probably all of the blades but the boat would not have gotten stuck ontop of the rock and it woulda just floated right over it and not caused any damage to the tilt ears that got cracked. As far as the pro's/con's for composites that I've read, most people who are against them are against them because they break at the slightest nick of a hard object. Well, this is one case where I'd give anything to have had a composite prop. Who cares if they break easily. Thats what they were designed to do anyways.

BTW, I had ordered the pirahna because propulse doesnt have a 3 blade set. I prefer 3 blades over 4 blades. I dont haul skiers. I just putt around the lake and maybe troll fish some.
 

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: composite props

NKOB - composite prop would not have saved your drive in that case. If the drive impacted a rock hard enough to fracture the ram mounts, you could have had a half thawed frozen jello prop on there, it wouldn't have matered.

A soft prop protects the drives internals and the coupler - to a certain degree. Metal props offer that kind of protection by having a sacrificial hub, the advantage of the breakaway hub - you can usually limp home at idle speed as is, and do the prop swap later without going swimming.

FWIW - I have never had a metal prop just decintegrate and leave me dead in the water. Had a composite do just that. After a long conversation with the manufacturer (they said it was not possible for that to happen) they agreed to "look" at the prop and then make a determination on replacement. I have an 18' boat that is 2600lbs and powered by a 4.3, way under the maxes for that prop, and I knew that I hadn't hit anything, but I was suprised when, 6 days later I recieved a new prop and a letter stating that due to a manufacturing defect........not indicative of the material.......replacement should provide years of trouble free service....etc. I didn't trust it, so it went on ebay NIB.

To be fair though, my dad has been running a composite since '01-'02 without an issue, but he has a pontoon with much less power.
 
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