Trim Tabs - Orkney Pilothouse 20

[MelJones]

Morning gentlemen

 

Having now got a bit more sea time with the Orkney, I am definitely keen to fit some trim tabs (Dogfish Dave confirmed something I'd been thinking already - thank you).  We have a definite list to port which is of course more noticeable in a seaway and she currently rides very much with her nose in the air.  

 

Has anyone got a recommendation of a local supplier/fitter?  Purbeck Marine are on my list already, but welcome other suggestions.

 

Thanks.

 

Mel.

[Tarlach.]

How about self levelling tabs such as the ones in the photo, find them on eBay, different sizes for boat and engine size. Easy to fit yourself as no wires needed !!

Neil

 

 

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[Rob]

I have these, as so others in the club. They are great except designed for freshwater in the US! So, when the rams rust (they will) replace with stainless ones. I have done this and so far so good.

 

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[Brian]

I would go for Bennett Trim Tabs, had them on my previous boat and they were brilliant. Also very good after sales service.

I've got Nauticus Smart Tabs on present boat. The rams rusted through after about 3 years, when I contacted Nauticus they said they thought 3 years was good.

[MelJones]

Thanks guys.  I did look at these on another boat that we thought about buying, but they didn't look particularly strong to me.

 

I also prefer the adjustability of hydraulic ones.  The Orkney is quite weight-sensitive and I'd prefer to be able to trim this out when necessary.

[Brian]

There a few local suppliers for Bennett's

Marinautic at Cobbs Quay.

Magic Marine at Broadstone (where I got mine).

Saltwater Solutions at Parkstone Bay Marina.

[MelJones]

Thanks Brian.  I'm waiting on a quote from Marinautic and will give the others a buzz too.  

 

Not sure that I fancy getting out the drill myself for these, although it doesn't look too bad a job and I may yet be pushed into it.  Purbeck Marine suggested a figure of around £800-1000 for two days labour on it though (which I thought was steep on top of the £500+ parts) although in fairness, that was just off the cuff and they may yet call back with a reduced figure.  

[2006holmwood]

Have you thought about electric trim tabs so much easier to fit.

[Coddy]

If  you fancy electric trim tabs try these people for Lectrotab

 

HyproMarine
Mount Pleasant Lane
Lymington Hampshire SO41 8LS
Phone: +44 1590 681445
Fax: +44 1590 681446
info@hypromarine.co.uk
www.hypromarine.com

 

A good article is here about all different trim tabs and how to install

https://www.westmarine.com/WestAdvisor/Selecting-and-Installing-Trim-Tabs

 

Dave

[Brian]

I fitted mine myself, not difficult.

[MelJones]

Have you thought about electric trim tabs so much easier to fit.

Thanks - keep seeing/hearing things that suggest they are more likely to fail than hydraulic though.

[MelJones]

I fitted mine myself, not difficult.

 

Been watching YouTube videos of fitting them, and I agree, doesn't look hard.  Just need to take a look at the boat to see that the pipework can run through easily (think it will) and might do it myself.  

[gonorn]

I have just installed a set of smart tabs on an explorer elite, force 4 where as cheap as buying online if you go down that route.

Simple to install and made a noticable difference to bow rise. However I dont have a list to adjust for, I've read many different views on the tabs and in the end decided to just have a go, Some of the forums can get a bit heated over the auto tab vs manual tab.

[Brian]

Mike

I've got two stickers for you, I'll bring them to the meeting tomorrow

[gonorn]

Thanks Brian ill see you tonight.

[MelJones]

Update - I've ordered a set of M120 Bennett trim tabs from PH Marine up Reading way.  I was put in touch with them by the very helpful guys at Marine Components who explained that they were restricted to selling direct from the door and at RRP by their agreement with their distributors.  As I wanted them delivered they put me in touch with Peter who offered me a very competitve price and has arranged for them to be delivered tomorrow.

 

What was also interesting today is that I called Orkney for their recommendations on sizing of the trim tabs.  They said that they did not recommend fitting trim tabs in anything other than the PH20 inboard version and larger boats.  Apparently the slamming and nose high attitude is by design.  They were very helpful and offered a different perspective, but I can't say that I found that they had any convincing arguments against trim tabs.  If you take their argument to its conclusion, you either live with the slamming/nose high profile or you significantly reduce speed.  As for listing, you have to live with it.

 

I love Orkney boats, but I don't love those issues so I am only too happy to try to improve on it.  Let's hope this does the trick.

 

The other interesting thing is of the three Poole companies I called to supply/fit trim tabs for me on Monday, none of them have called me back yet (it's Thursday).  One (Marinautic) did say that they were going on holiday today and would try to get back to me before then, so I can understand them not responding, but no idea where the others are.  Must have too much work to be bothered by me!  

 

Hope to fit the tabs this weekend.  If you happen to see me working on Sirona at Cobbs (she is on a workstand next to the fuel pontoon) do pop by to say hello.

[Tarlach.]

I was told by Parker boats that the 660 pilothouse does not need trim tabs also, but due to the offset wheel house "Tarlach" does list slightly to port. I'm considering some myself. Do tell how you get on !

 

 

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[Rob]

I was told by Parker boats that the 660 pilothouse does not need trim tabs also, but due to the offset wheel house "Tarlach" does list slightly to port. I'm considering some myself. Do tell how you get on !

 

 

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Sounds like you two should go halves as only need one each?

[MelJones]

Having bit the bullet and spent a small fortune on two metal places and a bit of wiring, I thought I better get to fitting them.  Saturday was the day.  Thought this very rough run through might help others who think about doing it themselves.  It is easily within the capabilities of anyone who can drill a straight hole of the right size and make a few basic electrical connections.  

 

I opted for the M120 trim tabs from Bennett.  My feeling was that the hydraulic system was likely to be more reliable than electrical ones, although some do speak highly of them.  I also didn't like the principle of the Volvo system, as it is simply adding drag, not downward force which is what I was looking for.  Any trim tab will increase drag in any case, so the more I could do to minimize fuel wastage, the better.

 

There are lots of videos on YouTube (including the ones on Bennett's own website, so I am not going to take you step by step as an idiots guide, but you might learn something else - especially for PH20 owners.  

 

Outside of the boat:

 

So, this is Sirona

And this is the space I have to play around in:

First, as ever, measure twice, cut (or drill) once.  The backing plates for the tabs are used as the guide.  

Pass screws through the outer plate, binding the trim tab to the backing plate and boat.  

This is one of the most important tools that you can have for getting the fitting right

The point is that when you fit the tabs, they are initially in the "all-up" position.  Accordingly, the whole of the plate needs to be negative as viewed against the line of the hull.  That is to say, not pushing down on the boat at all when in use and lifted up.  Instead of messing around trying to measure this (5/8") negative lift, I got the idea of making this template from a YouTube video.  It also means you can make both sides identical.

Using the supplied templates to drill accurate holes.  It was slightly annoying having to convert imperial drill bit sizes to metric, but it helps if you write the correct size on at least one of the templates or next to the imperial on the instructions.

I had opted for the (more expensive, grrr.) EIC control unit which shows the amount of trim that you have in real time.  This meant there had to be an extra hole for the sensor wire (grey).  As this is all completely covered by the upper mount, this together with copious amounts of silicone (inside and out) offers reassurance that drilling all these holes in your boat isn't too much of a problem.

Screw everything together, apply epoxy to the underwater screws (only 8 of them and quite small reassuringly) and lots of marine grade silicone above the waterline and the outside of the boat is finished.  This only took me about an hour and half and I was going slowly to ensure accuracy.

 

Inside the boat coming next.

 

[MelJones]

Inside the boat:

 

This was a different story, simply due to the difficulty of passing cables and pipes though inaccessible parts of the boat.  Ignoring time to go to Screwfix to get some fibreglass rods for fishing cables back and forth, this next stage took me around 3 hours.

 

With the hydraulic pipes (black) and sensor wires (grey) now inside the boat (thankfully above the waterline and not impeded by anything inside the hull) it was time to pass them through to where I wanted to site the HCU (hydraulic control unit, or pump).  Having examined all sorts of options for passing them behind, under, through and bits that would not require any cutting or drilling of the boat, I opted to drill two 10mm holes as the lesser of evils.  The alternative would have been to cut a large hole in the splashwell to grant access to there and then fill it with a screw-on cover.  I didn't fancy that if it could be avoided as two 10mm holes with silicone filler in this position will pose a far lower risk of water entering the hull than a gurt bit fitting on the stern and exposed to the weather.

My once tidy battery locker because a snakes' orgy of wires, pipes and tools.

But, with a small amount of cursing, fibreglass splinters and more cursing, I managed to regain control and get everything where it needed to be.  The HCU/pump was easy to fit, but harder to fill with ATF fluid.  I'd recommend a very small funnel (which I didn't have) or lots of paper towels (which I thankfully did have).

Then it was simply a case of running the big blue control wire to the helm, having cut out a convenient space in which to mount the switch.  This would have been slightly less troubling had I have been sure that it was going to be long enough.  When I ordered, I didn't think to specify a length, so what I got was only just long enough.  Do bear this in mind.

This particular switch requires both a standard positive connection but also a positive connection from the engine key.  This is so that when you switch off your engine, the tabs are automatically told to lift up.  This was a key feature for me to avoid any damage by the dry stack fork lift if I forget to lift them manually before leaving the boat.  I took the regular +ive connection from the feed to the switch panel and the engine-switched +ive connection from the rev counter's positive feed.

 

This is now my helm position, with the trim tab switches in clear view and easy to tweak as you look at the bows of the boat.  I thought about mounting them lower, but this would have meant having to look back and forth when you really want to be concentrating on what effect your use of the tabs is having on your trim.

All done, and I had her put back in the water for a quick sea trial.  Everything worked brilliantly, although I did find that in pushing the pipes/cables up into the battery locker I had mixed up which was port and which was starboard.  The sensors were correct though, so 50% right!  Back at the pontoon, I quickly swapped the pipes around on the HCU and everything was working as it should.

And how did it perform?  Remarkable.  Firstly, a disclaimer - with only me on board, and less weight at the stern in particular (no kids, wife, fishing tackle etc) then the trim was always going to be better.  However, it was very obvious that the trim tabs had a huge effect on the boat's trim when applied.  Being a big enough fellow, my weight alone in the helm's seat does tilt the boat slightly to starboard.  The tabs easily corrected this.  Equally, I could drop the bow to an acceptable level very easily.  I'm now looking forward to trying it out fully loaded, but I have high expectations based on what I've seen so far.

 

As ever, doing one job on a boat shows up others that you need to do.  In this case, I need to fit an extended auxiliary engine mount so that the leg does not foul the trim tab.  I also need to fit a different stern ladder for the same reason. I expected these.

 

However, I had not expected to find that my four-way battery control switch is either not working or has been wired up badly.  It seems that there is constant power to the 12v system even when in the "off" position and that the other settings don't work as they should.  That might explain why my VHF keeps telling me there is low 12v power when the domestic battery has 12.9v.  Ah well, another job for another day.

 

Hope that has been interesting for people considering doing the same type of thing.  

[great white]

Well done looks like a good job achieved with minimum fuss.

I am sure that they will work well on a fully loaded trip.

 

A lot of the Motor Boats in the Marina at work fit anodes to the tabs and antifoul them [the tabs not the anodes] otherwise it is amazing how quickly they foul up.

[Rob]

Drystack i belive charlie - though anodes are still a good idea!

R

[MelJones]

Yes, we're dry stacked, but I should have added that fitting anodes is another job on the list. 

 

As for antifouling - many people complain that it rubs straight off trim tabs, but a light coating of epoxy first should do the trick.  I'm not going down this route until such time as she is likely to spend more than a week in the water at any one time. 

[Mal Thomas]

Mel, has the trim tab had any intefering effect on the transom transducers, ie turbulence when scanning the bottom with sonar.

[MelJones]

No, not so far as I've noticed so far.  I've got a new Axiom display but didn't spend any time playing with it specifically - most of the time I had the Axiom set to the chart display and the smaller Garmin 555 set to sounder.  Didn't notice any problems with either though and I did have the high chirp and realvision settings running on the Axiom for a while.  

 

I think the design of the M120 with the downward flared edges should produce less water disturbance than conventional flat tabs.  The Garmin's transducer is closer to the tabs than the Raymarine one, so if there was an issue I think I probably would have seen it on that first.