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Prop Question
Posted: March 21st, 2019, 8:38 pm
by fleck05
I have two blades damaged on a 4 blade 23" prop. The tips curled under and some sections broke off. The damage is all less than 1/2" from the ends. The boat yard said to replace it and the prop guy couldn't do anything. We just finished a list of fixes, so adding another $2000 for a prop hurts. Question: I know props are engineered to match, but if I file edges down smooth making two of the blades less than 1/2" shorter, will the problem be minor or major? I run between 5-7 knots, so if it's a matter of not moving as much water some extra rpm's aren't a big deal. But if it would result in some kind of vibration or wiggle that could cause other damage then obviously it's not worth it. Thank you.
Re: Prop Question
Posted: March 21st, 2019, 10:53 pm
by bud37
Is the boat on land now, if so look around for a used prop......I don't think I would want to have vibrations heading back up the shaft to the trans etc. What did you hit ?....5-7 knots is around 1500 rpm, even something very small will show up at that rpm. If it were me I would park it till it could be fixed properly, check that prop for corrosion failure as well......just my opinion......good luck with it.
Re: Prop Question
Posted: March 22nd, 2019, 8:13 am
by km1125
Get a better prop guy.
I have the same boat ('83 3607). Several years ago I ran through some mud and damaged both props. One was badly curled down about 1/2", but the other wasn't much better. The prop shop was able to get the prop back to original specs and matching the other prop. I had had both props scanned and adjusted a few years before that, so I had really good "before" specs. They were able to return the props to those specs, and it cost me $733.10 (but I also got a $183.27 discount for being a repeat customer, as it was the same shop that did the original tune-up).
In the meantime, I used a set of spares I had purchased from a local guy. They were slightly smaller but since I don't cruise at WOT, it didn't matter much. I put the original set back on over the following winter. My spares cost $300. Deals are out there if you're patient and flexible with the specs. I've already used them twice and it's great to just haul the boat, put the spares on and drop it back in and then have the rest of the season to get the mains repaired and ready to put back on in the off season.
I would definitely not file them down. You could easily end up with an imbalance situation, with either weight, pitch or diameter that will cause vibrations. If the edge is not survivable, and good prop shop could cut the diameter of both props down by the equivalent amount.
EDIT - I went back and looked and they did take 1/2" off my props. They were originally 22" diameter and now they are 21.5". Mine are originally 22x22 props. You have 23"? What engines and reduction gear do you have?
Re: Prop Question
Posted: March 22nd, 2019, 11:37 am
by fleck05
“Is the boat on land now, if so look around for a used prop......”
It is on land now and for 7-10 more days. I am looking for a used prop, but am always impressed by the years of experience in the responses here... this was just for me to get some additional info from outside local opinions.
I’m in Key West right now and it seems like used props would be easy to find, but this is essentially a small town so there aren’t a lot of resources. I’m also searching online. If I were closer to Tampa I’d go to that large boat part pulling place, but cost of transport there would not be worth it.
If anyone knows of a used 22-23 inch prop for the starboard side with a 23 D pitch for a 1 3/8” driveline I’m interested... text me at 619-753-1285
Re: Prop Question
Posted: March 22nd, 2019, 11:56 am
by fleck05
“I would definitely not file them down. You could easily end up with an imbalance situation, with either weight, pitch or diameter that will cause vibrations. If the edge is not survivable, and good prop shop could cut the diameter of both props down by the equivalent amount.
EDIT - I went back and looked and they did take 1/2" off my props. They were originally 22" diameter and now they are 21.5". Mine are originally 22x22 props. You have 23"? What engines and reduction gear do you have?”
Ah, that makes total sense, and the fact you did the same thing with a Carver 3607 is even better. Yes, they are 23” props, and the boatyard found a set of less expensive prop at 22” they said would work ($1500). We have TAMD 60 Diesel engines by Volvo Penta. (As a side note I’ve been impressed with the performance of the engines, but any part with the name Volvo Penta is 2-3X more expensive... something I’m sure is old news to all of you, lol.)
So far I’m only dealing with the local boatyard, very nice people, just looking for ideas and input from this group full of people who have “been there, done that,” for some opinions from people not trying to sell me something. I’m going to have a talk with a prop shop. Thank you.
Re: Prop Question
Posted: March 22nd, 2019, 12:18 pm
by waybomb
Take a look at ebay! Set up a search and have ebay automatically send an alert when a new auction comes up.
And then send yours out for repair, or get another set on ebay if cheaper.
I bought spare props for my 4207, 3697, and stainless cleavers for Plain Vanilla.
All of them way cheaper for each set than even one new prop from a prop shop.
Re: Prop Question
Posted: March 22nd, 2019, 12:48 pm
by fleck05
“Take a look at ebay! Set up a search and have ebay automatically send an alert when a new auction comes up.”
I’ve been searching eBay, but yes - an alarm is the way to go. In fact I’ll keep it on from now on, too. If a deal pops up on a prop it’s always handy to have a backup.
Re: Prop Question
Posted: March 22nd, 2019, 12:49 pm
by bud37
Geez, I honestly thought there would have been lots of used props around given the last few years....I see you have diesels. Well hang in there, something will show up, its a nice spot to be trapped in heh.
Re: Prop Question
Posted: March 23rd, 2019, 3:11 pm
by fleck05
Conclusion:
Had a prop guy in business with 20 years and good reputation in the Keys come by... I asked if the prop is good for anything and (after explaining why in detail) the bottom line is it's good for yard art, that's about it. I couldn't find many 23" props, and none for 1 3/8" driveline. We're biting the bullet and getting a match set of smaller props - they're a little less expensive and after reading nightmare stories of bent driveline repairs and strut problems, a good set of props are probably the right investment. We are going to sell our good 23" port side prop and a 23" spare port side that came with the boat to help offset the cost (damaged prop was starboard side, didn't have a spare for that one). Thanks for the input.
Re: Prop Question
Posted: March 23rd, 2019, 9:26 pm
by tomschauer
Why smaller props? Why not get a single starboard prop to match your good port prop?
Usually the larger diameter, the better the "bite". Someone can correct me, but I would rather have a larger diameter and less pitch for better bite and efficiency.