Prop Strut casting – anyone have a place to purchase?

[Rob Osterman]

Hello,

After a recent endeavor with a crab pot, I’m looking at replacing my propeller strut. Upon pulling the strut, we found that it was beginning to show signs of de-zincification. There were a few pink splotches and pitting around the bottom

I was wondering if anyone knew of a company that had a Pearson strut casting on hand and could ship a new strut over. The outfit I’ve tried in Seattle are four weeks out and would need to create a one-off casting from my existing strut.

Thanks!

Rob

[Rob Osterman]

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   Cracked paint strut mount
   

[unabated]

When the marina in Deltaville lifted unabated by the prop shaft, they bent the strut also. I talked to the people in Seattle. I Thought it was going to cost around 1200 bucks for a newly casted one.   Ended up having a foundry in Baltimore straighten the one I had.  They did a great job and for only a few hundred bucks.  Have many miles on the boat since then and have been plenty pleased. 

Too bad the engine has to come out to do that job. Although that should only take 4-5 hours getting the beast out. 

Plus the re-installation / alignment is a PITA.  And the refairing work. 

Alan 

[Rob Osterman]

Hey Alan,

Thanks for the information. Fortunately, the strut isn’t bent — the filler above the strut needs to be re-done and the bolts replaced. I’m going to add an extra zinc to the strut bolts to hopefully slow any further corrosion on the strut.

I was able to pull the strut without pulling the engine. There were no difficulties getting to the strut bolts and pulling it off. Why did you need to remove the engine for your job?

Rob

[unabated]

Two reasons actually.  I felt around down there and decided there was no way I was getting them nuts off.  There are some differences in how the engine beds were laid so your maybe be different. 

Secondly and probably more important was an oil leak from the pan gasket. I got tired of throwing absorbent pads under there.  So when I got the engine out to do the strut I replace the pan gasket. 

  As it turns out when I got back from the Bahamas, the fuel tank started leaking and so the engine had to come out anyhow a second time to do the fuel tank.  At that time I had the front oil seal replaced which cleaned up the rest of the oil leaks that I had. that was the time that I found a couple of  pins worn through on my steering a quadrant. 

So all in all, I got pretty proficient at removing that engine and putting it back in by myself. Piece a cake. 

Alan 

[Rob Osterman]

Good point! It could be that the Yanmar I put in allows for a little more clearance to the strut bolts. Either way, it’s a major pain of a project!

I’m thinking of reinforcing the strut and adding another two bolts. Sorry to hear about your strut endeavor — did you notice any corrosion when you had the strut out?

[cstewart]

Rob:
I have had two encounters with the strut, and both turned out with less cost than I thought. On my old Pearson 323 I lost my strut to galvanic corrosion and when I could not find a way to get a new bronze cast, I had a local (Gulf Shores, AL) machine shop make one of SS. It was stronger and cost only about $600. This year, on the 424, on my return from Cuba, I had a boo-boo that bent the strut and the shaft. Fortunately I was able to get into Key West and when we pulled the boat we found the bronze strut had about a 13 degree bend in it. They were able to put it on a press and straighten it for about $300. However the shaft had two counter-bends in it, and it had to be replaced. That was all very expensive. I have wondered that if the strut had been stainless, it may not have bent but may have pulled the bolts out of the bottom, which would have changed the complexity of my problem. As it was, the boat was never at risk of sinking, but it does make you worry when the strut gets that kind of pressure.
Charlie Stewart
OneEighty #54

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[Chuck Ruble]

Rob, Buck Algonquin is the best source for a new strut. I don’t have the specifications for our strut. The easiest method would be to send them the old one. They’ll create a sand cast from it and make a new one if they don’t have it already available as a cast.

I would expect it should be between $500 and $900 for a new strut. You’ll need a new cutless.

It’s possible the bonding wire to the fixture had a corroded terminal causing higher resistance on the circuit. I see this sometimes when we see halo’s around thru-hulls too. I’m not sure why these and props get pink faster than a thru-hull. I’d guess the metallurgy is different as it has more of itself to support vs a compact fixture like a mushroom.

I’m not a galvanic corrosion expert. I clean up after the incidents and do the best to keep if from happening again by looking for issues that could be the source of the problem.

The photo is probably the worst case I’ve ever seen. Both drives suffered the same fate.

Chuck

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[Rob Osterman]

Thanks, Chuck! That’s a scary picture. My strut doesn’t look nearly that bad!

Charlie — that’s a huge bend!!

[Discoverie]

Back on the strut replacement question. I have a friend who is chief engineer at a foundry.  I think they still do prototyping work. If we had a model, I could send it to him and ask if he could cast a replacement. If that worked out, there would still be the machining work, but that should be an easier nut to crack. 

Anyone know where we can get a strut not in the boat? 

tkx,

rb 

[theller85]

do not… and i mean seriously do not do this. The cost to produce a mold and produce a replacement is insane compared to the cost of making the part individually. Perhaps your friend will do it for free, but your burning up a very very big favor. 

Perhaps your friend is willing to do it for you, but a mold could be 10k+. 

Remember, the invest cast has to be cut out of big damn block steel, so your spending all your time machining a big ass block of steel when you could be machining your parts. You normally have to make a high number of parts before recovering your costs, even with prototype molds.

I would suggest you model a new strut (how ever you like it) and have it cut from stainless. 

I have access to a 3 axis CNC and the proper modelng software. 

Tom

[Discoverie]

It’s not a mold. It’s a pattern that’s used in sand casting. But it is true that cutting a die would be expensive. If you have a foundry, sand casting bronze can be reasonable. Machining is another kettle of fish. 

Bob just reminded me there was a guy in Rhode Island that casts bronze. It’s possible that he might know where a strut (or pattern) can be found. Or better yet a place to machine a casting. 

Roger

A former foundry worker 🙂

[john stevenson]

I think the guy would does a lot of casting in bronze is here: http://www.bristolbronze.com/

I used him a long time ago to replace the aluminum hinges on the locker hatches (http://www.svsarah.com/Sarah/ewUpgradeDeckRig.htm#Cockpit).  However, I'm not sure he does anything larger than those small fittings.  If the same guy still runs that shop and you call him you will be a long time getting off the phone.  He likes to talk to sailors.

Regards,
John Stevenson
http://www.svsarah.com
Sarah's Blog

[Rob Osterman]

Chuck,

Thanks for the lead – I contacted Buck Algonquin and they recommended I contact Prue Foundry.

I spoke to a very nice man at Prue Foundry who indicated he made a number of original parts for Pearson and that the strut I currently have was most likely made by him. He has all the tooling for the strut and is making a new one for me.

I referred him to the site for an introduction — it seems like Prue is the place to go for replacement struts!

[Rob Osterman]

You can contact him at baprue@comcast.net or via phone 508-776-3285.

[Discoverie]

yes that’s the guy! Roger Winiarski at Bristol Bronze. I bought a bronze ID plate a while ago from him. Bob Fine also mentioned him. So I rang Roger up and told him about the situation. A rather detailed story followed, here’s the short course.

1) the guy that cast the orginal struts for Pearson (not Roger) sometimes used questionable metal  (“he’d go to the junk yard, buy copper and use that in the melt”)

2) he can definitely do struts, he did a large one for a power boat recently.

3) for our size boats, the cost could be about one boat unit ($1K) for the first one and includes machining and cutlass bearing. Additional ones would be less.

5) he would need a strut to make a pattern from. If it was in pretty good shape, the cost would be less (needs to use it to make the pattern, more prep more cost)

tkx,

rb

[Chuck Ruble]

Rob, glad the information helped you out. Very kind of you to share the information you acquired.

Chuck

[theller85]

a couple years of polymer engineering drifting into my vocab.

Glad the original foundary was found. Wonderful find. Perhaps the shop will make a few extra pieces on the setup and hold them for future sale.

[Rob Osterman]

The new strut came in and it looks fantastic. When I compared it to the old strut, you could really see the bend caused by the line wrap.

The yard is reinstalling the strut today and is adding an additional layer of fiberglass reinforcement over the potting area. We were debating whether to add two additional bolt holes to the strut mount but decided with an external fiberglass reinforcement.

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