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A good job we lifted!


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Hi All

Following out lift yesterdat at Brundall, which was only intended to be a weekend in the slings so I could fit a new depth transducer, we found we had some significant damage to all four props. This means we will now be out of the water for a fortnight, and dropping back in the weekend before Easter.

I got the transducer fitted no problem today, and then Col (HJII) very kindly agreed to come over and help me changing the oil in the outdrives, to show me how it's done. We weren't going to bother, but it was only when Ian (Senator) suggested it's be a good idea, it got me thinking a bit, even though I though the oil was done in July.

Upon draining the starboard leg, the oild was black, and had obviously not been changed for some time. There wasn't any emulsification to speak of, so at least that was good news. On draining the port leg, the oil was almost new! As both drives had been off in July and had new bellows fitted (which still look new), why on earth would they only change the oil in one leg???? :roll:

It also turned out all the anodes are zinc, and completely covered in oxidation and scale, rendering them useless. The ring anodes were also not doing much as the surface of the leg behind was painted! I have now ordered two sets of aluminium anodes from Aquafax, which I'll be fitting next week after I have rubbed down the mating surfaces to bare metal.

On the plus side, the legs do seem to be in good shape, so I'll just be giving them a quick wire-brush and a coat of the Volvo grey paint. The antifoul on the hull is also pretty good, as this was done last summer, but while it's out I'll give it another once over.

I can also report the oxalic acid and wallpaper paste certainly does the trick with the black streaks and genral grubiness! I didn't go for the woodchip finish as Jimbo suggested, but I'll take a photo of the nice floral print I went for instead :naughty:

My thanks to Col for giving up his time to help us, and now I've seen how it's done, next time I'll be fine. It does just go to show, though, that you should never assume that you are being told the truth about work that has been carried out! :?

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Hi Mark,

If the previous owner paid to have the bellows changed I can't see him saying just change the oil in the one leg either, so I would think he would be as surprised as you to find dirty oil in one side. Just shows the value of DIY, at least you know it's done.

My legs were on mineral oil and it took hours to get the stuff in, how long did it take you to get the synthetic stuff in and did you pour it in through the fill plug or pump it in from the bottom?

IMHO if you are going to use boats like yours on the Broads you can probably lift them every 3 years but if you are going to sea they need checking at least once a year, your props will probably give you a few more knots and save the cost of the lift and repair a few times over in fuel if you put a few sea miles in her, not to mention stopping the legs shaking themselves to pieces.

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My legs were on mineral oil and it took hours to get the stuff in, how long did it take you to get the synthetic stuff in and did you pour it in through the fill plug or pump it in from the bottom?

I got differing opinions on whether I should have mineral or synthetic. In the end I asked Brundall Marine Services to get me whatever they use in these drives, and ended up with semi-synthetic.

To be fair, it did take Col quite a while to get it in, but we used the filler hole with the legs raised as high as they would go.

One thing that did surprise, is that when lifting the legs, they go into "beach" range at 6 degrees and all the way up to 40 degrees, and in this range you can apparently run them at a max of 1000rpm. As soon as they go over 40, they stop lifting and the red LED on the gauge flashes, so I assume this is in the "trailer" position and is as high as they go. Are yours the same Ian?

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Mine go to 43 but they hit the rubber stop on the top of the transom shield at that. I take it yours do stop at 6 unless you press and hold the override button.

Fully up is the trailer position, it is so they don;t dig into the slipway when you pull it out on a trailer.

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No wire brushing on ali drives please ... as they can leave bits of ferrous material behind.
:o

I presume that having bits of Ferrous material in contact with an Aliminum leg would set up an electralitic erosion problem?

Is that also why Mark's boat has Aliminum props?

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You can have stainless props, but have to pay more attention to your anodes, ali props are normally used as they are light, cheap, and easy to repair. The major issue with leaving little bits of ferrous material is is not really any electrolysis they may cause themselves but simple corrosion. As they begin to oxidise they cause any protective layer you apply afterwards to blister and ruin the integrity of the layer allowing the bare ali exposure to electrolyte, in this case water so making electrolysis and erosion of the legs more likely, obviously the more saline the water is the worse it gets.

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No wire brushing on ali drives please Mr Bird. Production paper, Abrasive impregnated nylon brushes but no wire brushes as they can leave bits of ferrous material behind.

Thanks for the tip David. There are a few areas where exaclty what you describe has occured with small blisters below the paint, that when scratched off reveal bare ali below with a slight rust stain colour. I take it using a brass bristled brush (try saying that when you're p**sed!) would be okay?

Something else we noticed with our props, was that the forward prop is 3 bladed, with the aft prop haveing 4 blades. Col thought that was a bit unusual. Are anyone elses like that?

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Best not use metal of any sort Mark, unless made from the same alloy as the legs. Screwfix do a really useful set of brushes impregnated with abrasive quite cheaply, Perry and I tried some on our props last year and they were most effective.

http://www.screwfix.com/prods/23273/Abrasives/Brushes/For-Drills/Wolfcraft-Nylon-Brush-Set-3Pc

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Thanks for the tip David. There are a few areas where exaclty what you describe has occured with small blisters below the paint, that when scratched off reveal bare ali below with a slight rust stain colour. I take it using a brass bristled brush (try saying that when you're p**sed!) would be okay?

Something else we noticed with our props, was that the forward prop is 3 bladed, with the aft prop haveing 4 blades. Col thought that was a bit unusual. Are anyone elses like that?

Hi Mark My Petrol Sealine had three and three but the diesel boats have a four and three blade prop to dispense the extra torque from the diesel engine.

Jonathan :Stinky

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Yay, props delivered back today from Steel Developments :dance . Now that a pretty good service I reckon, considering I only posted them last Monday! I'll be refitting them later this week once I have antifouled the outdrives, and then booked the lift back into the water for Friday.

Of course, that means that this weekend is probably going to result in some totally unsuitable behaviour over Breydon as a bit of a shake-down before the Easter shenanigins!

Now, if only I could remember which way round the props went. I don't want to be doing 30kts in reverse!!!! :lol:

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Ah, I was up at Brundell today - should of remembered you had your boat lifted......

We went to Brian Wards to sort out the replacement helm panels in Walnut - should look really nice.

Had a walk along the boats in NYA - some lovely floating palaces there !!

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He's here tomorrow David, at 8am !!

Hopefully he'll be able to sort the problem !!

Mark, I put a note on the other thread, but if you're going to Breydon on Saturday and my engine is fixed, we'll meet you up there. We could have a bit of pre-photo taking prior to Easter !!

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That's a shame Luke, but I think the weather on Saturday is supposed to be a bit crap, so probably not ideal for a photo opp. I haven't decided if it'll be Sat or Sun yet, but Breydon will definately have the peace shattered on one day of the other!

Got the props back on today:

post-264-136713671642_thumb.jpg

The outdrives and trim tabs have new aluminium anodes on, and have been tarted up with a a spray of grey paint and then grey antifoul. The hull has had two coats of antifoul too. Just a few more minor jobs to sort including a bit of black Hammerite on the prop cones before the re-launch on Friday :dance

I've also changed the thermostats in the port engine to see if that cures to cool running problem we had (never got above 60 degrees), and didn't even lose and coolant!

Watch out Krakens, here we come!

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