Building the Ultrasonic Antifouling Kit from Jaycar

[sandman_bm]

ultrasonic antifouling

Well Rob and I have nailed together 5 of these wee beasties and they seem to be ticking and buzzing quite happily but not having a scope with storage is a bit of a pain, not being able to see the waveform.We went the pushing a length of string uphill route, farnells,maplins, china, germany for the parts, oh and to a particularly unhelpfull transducer company on the south coast, pcb,s made by robin.still waiting to hear from Percy Thrower and gardeners world for the optimum time to pot the transducers, with luck install next weekend

 

[Silent Lady]

A particularly unhelpfull transducer company on the south coast

Not very helpful are they . Suppose if you are the only company doing them you can please yourself what you do or don't do

Glued mine to the hull last week. Used some of Maplins thick epoxy which is supposed to stick metal to GRP. Cleaned a small area with glass paper applied the glue with some micro ballons and let it set . The bit on the mixing card was solid in 10 minutes and reasonably hard so I think I should have a good bond. Boat out a couple of weeks ago for a scrub so hopefully will have it working this weekend.

 

[Fr J Hackett]

Not very helpful are they . Suppose if you are the only company doing them you can please yourself what you do or don't do

Glued mine to the hull last week. Used some of Maplins thick epoxy which is supposed to stick metal to GRP. Cleaned a small area with glass paper applied the glue with some micro ballons and let it set . The bit on the mixing card was solid in 10 minutes and reasonably hard so I think I should have a good bond. Boat out a couple of weeks ago for a scrub so hopefully will have it working this weekend.

Not so sure that using micro-balloons in the epoxy to stick the transponder to the hull is a good idea, I think you are weakening the transmitted pulses by dint of absorbtion into the matrix of voids created by the micro-balloons. Better to just use the unthickened epoxy or pot directly onto the hull. Time will tell.

How much do you estimate the cost of building a unit in a) actual expenditure in £s b) man hours in sourcing and c) building etc.

 

[sandman_bm]

ultrasonic antifouling

I think the micro baloons will possibly weaken the amplitude of the signal, however excluding air unless using some sort of vacuum device is uncertain as well, I am stil minded to bond the transducer direct to the hull but have missgivings about using epoxy, aluminium is not the best metal to accept a glued joint due to it ability to oxidise in seconds after cleaning which gives a weak bond but is rigid,from experience the best jointing compound I have found is rubber modified cyanoacrilate but at 45 squids a squirt ???

 

[greenalien]

not having a scope with storage is a bit of a pain, not being able to see the waveform.

http://proto-pic.co.uk/products/DIGITAL-OSCILLOSCOPE-DIY-KIT.html

I have one of these, not any more difficult to build than the antifouling kit and very useful.

 

[trisailing1]

I think the micro baloons will possibly weaken the amplitude of the signal, however excluding air unless using some sort of vacuum device is uncertain as well, I am stil minded to bond the transducer direct to the hull but have missgivings about using epoxy, aluminium is not the best metal to accept a glued joint due to it ability to oxidise in seconds after cleaning which gives a weak bond but is rigid,from experience the best jointing compound I have found is rubber modified cyanoacrilate but at 45 squids a squirt ???

Yes ally is a tricky thing. I used the jb weld that stuff is tuff. My boat is of aluminium, sanded the area then cleaned with acetone attatched straight away.

 

[snooks]

Thanks to our battery charger going up in smoke a few weeks ago, I switched our ultrasonic off as we don't have shore power now.

Just two weeks has given Pixie a long (8-12 inch) beard of green slimy weed.

Some came off but she is notably sluggish, so the US anti foul has gone back on, with it set to switch off at 50% capacity for their own good.

Fingers crossed the wind charger can keep up for the time being.

 

[sandman_bm]

ultrasonic antifouling

[How much do you estimate the cost of building a unit in a) actual expenditure in £s b) man hours in sourcing and c) building etc.[/QUOTE]

Its hard to give a definative answer at the moment until its all fitted,but one can discount building unless you want to compare it to a commercial unit cost,sourcing and ordering items about 3 hours, building including winding coils and etching boards about 15 man hours,the major hiccup costwise is the transducer,ie shipping,import duty and the dreaded VAT.
If I was to build one or two units I would just buy the kit from Jaycar, far easier, more than that then it depends on your skills and how you value your time.its very hard to quantify a project like this which might well be a one off, we had problems finding the right fittings to pot the transducer in, I guess due to lack of skill at internet searching, but for me it would be no problem to machine the things up from plastic bar stock so there are lots of variables to take into account, the bottom line I think is if you want to build just for one boat buy the kit and swallow being turned over by the excise men

 

[Norman_E]

I think you could pot the transducer in one of these http://www.easy-irrigation.co.uk/back-thread-sizes-inch-p-575.html with one of these nuts http://www.colglo.co.uk/product.php?product=EF625.NUF0630&category=21851298155705670617

There are other makes and suppliers, and any big plumbing equipment supplier probably has them in stock.

 

[haydude]

Please don't do this - you can do permanent damage to your hearing.

I would also keep it well away from your testicles, unless you do not care about your capability to proliferate. It kills the staminal cells.

 

[SolentPhill]

Boat came out of water today and had a lot of barnacles on engines, the ultrasonic was only fitted 3 weeks ago so yes they could have attached since it went in early march.

 

[Norman_E]

"Barnacles on engines"??? Do you mean out-drive legs perchance? If so I have my doubts that ultrasonic anti-fouling units fitted to the hull will do much there as the legs are probably not connected to the hull acoustically, i.e. rubber mounted.
P.S. If you have outboard motors, can you tilt them up when the boat is left?

 

[SolentPhill]

"Barnacles on engines"??? Do you mean out-drive legs perchance? If so I have my doubts that ultrasonic anti-fouling units fitted to the hull will do much there as the legs are probably not connected to the hull acoustically, i.e. rubber mounted.
P.S. If you have outboard motors, can you tilt them up when the boat is left?

Yes sorry legs, but the unit is mounted on the inside on the transom between the legs/engines

You could actually hear the unit ticking from the outside

 

[snowleopard]

Use in mud

I am in the fortunate position that I am spending some of next winter in Melbourne and often visit the local Jaycar which is 5 mins down the road.

My mooring is half-tide with soft mud and I also have had no luck preventing growth. There are two problems: (a) the mud leaves a film on the surface on which organisms can grow isolated from the toxins. (b) sulphides in the mud seem to be reacting with copper and turning it to inert copper sulphide. The original Coppercoat applied some years ago is now black instead of green in the area in contact with the mud.

I would really like to hear the results of trials from anyone who regularly dries out in mud.

 

[Scotty_Tradewind]

Apologies if this off the track but it relates to Snowleopards question re: 'drying out in mud.' I reckon that doing so means that the cutlass bearing may 'take a hammering' due to the gritty particles in the mud. As my cutlass bearing went on my long keeler within two years when on a fairly shallow mooring (and a new propshaft was ideally required,). I fitted a water fed stern gland which then pushed out that water via the stern tube.( Not something that can be done with a 'p' bracket held cutlass bearing though.) It meant that as soon as the engine was started the cutlass bearing was flushed through and hopefully pushed out the sediment collected in the bearing before engaging gear.
The engines water intake filter also needs checking more regularly when being in a mud berth.

 

[SolentPhill]

Hate to add but walked past a boat this afternoon that had UA fitted a while ago and has been fairly clean, now there could be a problem but when I saw it today you couldn't see the legs for weed, it's one of those powerful ribs and there was also weed on the back tubes.

I will look into it a bit more as there could be a fault.

 

[Norman_E]

I wonder if it could work at all on the tubes of a rib? The Jaycar unit switches off if battery voltage falls to 11.5v. I think commercial ones may do the same so any system is dependant on the batteries being adequately charged at all times. Once a system is switched off and fouling starts, getting the system back on again will be unlikely to clear the fouling because it works by disrupting the start of the food chain.

 

[Didi]

Just a quick wrinkle I picked up from Goudgeon Bros book about using epoxy to bond metals - as oxidisation was mentioned above?

Apply unthickend epoxy to the metal surface to be bonded (after cleaning) then wire brush it while still wet - this removes any deposits and prevents further oxidisation.

Not done it yet but sounds good?

 

[iainbluk]

On whilst under way

What do the forumites feel about whether or not to have the UA on whilst sailing? Switching my 2 units off would save quite a bit of juice especially as I am planning a night passage in the next week or so?

 

[Fr J Hackett]

Probably not a problem but the current draw is not that excessive certainly not for a day.