Prop treatment Med - Update

Hurricane

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Most on here will know that we've tried everything on our stern gear.
Our part of Spain has some very aggressive marine growth so we have all being trying to find a solution.

On JW, we have come "full circle"
We now do nothing.
Well - not nothing - we just don't apply any coatings.

Salesmen and enthusiastic boaters will often come up with new ideas.
But after a season in the water they all fail.
The big problem that a coatings manufacturer has to overcome is making his paint actually stick to our props.
The power that we dissipate through the water takes any paint coating off - nothing sticks.
Once someone can come up with something that sticks, they can then concentrate on finding a suitable antifoul but until then, they shouldn't waste their time developing the antifoul bit.

Now, the big problem with ALL coatings is that some of it DOES actually stick.
And the bits that stick can then be a huge problem to remove prior to re-coating a year later.

So, our solutions is - "don't put anything on" so the it is easy to remove when you DO need to get rid of it.

Over the last 4 years, we have been perfecting our technique of removing barnacle encrusted stern gear.
And this year we have confirmed the process.

In Spain,in the supermarkets we buy a product called "Agua Fuerte" which is a Hydrochloric Acid (I think - I never did Chemistry as school).
This acid "eats" anything containing calcium - barnacles etc.
We have been using it ever since the marina opened but we have only recently understood the best technique.
In the past, we just sprayed it on and the washed it off after a few minutes.
But the trick seems to be to keep the acid moving - thus keeping it active.
So, using quite a small amount of this acid (in an old plastic ice cream tub) and a 2" paint brush, we dip the brush in the acid and apply it to the underwater metalwork (props etc).
We continue agitating the acid using the paintbrush (describing small circles) seems to keep the acid activated and (just like magic) the barnacles disappear. In fact, it is like using a powerful grinder - as you rub, the barnacles disappear.
I've also enhanced the process a little by using a long loo brush.
You have to be careful, the acid is nasty stuff - you wouldn't want to get it in your eyes and any that gets into skin cuts can be very painful.
I wear eye/face protection and rubber gloves.

Using this technique this year, I was able to clean all the barnacles of the stern gear whilst the rest of the boat was being pressure washed. See here - note this pic taken after about 40 mins (me on my own).

DSC07282_Small_zps5vtxwb9t.jpg


The props in the above pic had nothing other than the above process carried out - only gentle rubbing with a paint/loo brush dipped in acid.

So, to make it even easier in subsequent years, I've been polishing the props.
No paint and highly polished surfaces make it really easy to clean - especially using the Spanish "Agua Fuerte".

Last year, I used some cheap felt pads attached to an angle grinder and metal polish blocks.
This year I did the same but with a small addition.
After mechanically polishing with the felt angle grinder, I finished by hand polishing.
I didn't have any metal polish available so I tries some "A Glaze" prep.
This is the pink stuff that looks like Windowlene.
And it really made a difference.
See here

DSC07299_Small_zpsokodu5vv.jpg


DSC07300_Small_zpsbb4zcs3o.jpg


So, maybe I'm the first person to use A Glaze on my props.
Well, actually it isn't A Glaze - just the A Glaze Prep.
And having thought of it in hindsight, maybe I should have tried finishing the job off with the actual A Glaze itself.
I could have kicked myself - I should have done it to see what happens - maybe I'' try the actual A Glaze as well next year.
 
Wow, impressive result M, you would struggle to find more shiny u/w gear even at a boat show....! :encouragement:

Just a small warning on this:
I wear eye/face protection and rubber gloves.
Not sure about what exactly this "nasty stuff" is made of, but with most of these acids also the vapours can be toxic - and sometimes, without any bad smell, which is obviously even worse, because you don't notice. It should all be clearly stated on the label, anyway.

Also, I would check if it's aggressive with rubber. I'm thinking of the inner part of the shaft bushings, of course.
 
Yup, hydrochloric acid removes barnacles easily. It is normal practice in boat yards in France to pay €100 extra for "acid wash" when they lift and scrub the boat, and it makes the props as you show them there.

Aglaze prep - the pink stuff - is a fine cutting compound so it should polish the metal nicely

None of this stops the barnacles coming back though! Propspeed is the only successful thing I've found for that, but it's so expensive you might as well lift the boat or pay a diver
 
Yup, hydrochloric acid removes barnacles easily. It is normal practice in boat yards in France to pay €100 extra for "acid wash" when they lift and scrub the boat, and it makes the props as you show them there.

Aglaze prep - the pink stuff - is a fine cutting compound so it should polish the metal nicely

None of this stops the barnacles coming back though! Propspeed is the only successful thing I've found for that, but it's so expensive you might as well lift the boat or pay a diver

At the prices here for lift and scrub, it is a "no brainer" - we even get a free lift/scrub each year within our service charge.
 
Yup, hydrochloric acid removes barnacles easily.
Doh! I read the OP quickly, and didn't notice when Hurricane mentioned that this is the actual content of the "nasty stuff".
Not too bad then, particularly when diluted, as surely is in bottles meant for public sale.
 
Doh! I read the OP quickly, and didn't notice when Hurricane mentioned that this is the actual content of the "nasty stuff".
Not too bad then, particularly when diluted, as surely is in bottles meant for public sale.
actually MM it is very concentrated, at least as my boatyard uses it ( probably bought commercially). It makes your eyes really hurt if you go anywhere near and the smell is strong. In France you can buy much more conc acid retail than you can in uk, but the boatyard stuff is probably commercial supply.

My boat will be lifted oow in ten days. I'll read the bottle and report back
 
actually MM it is very concentrated, at least as my boatyard uses it ( probably bought commercially). It makes your eyes really hurt if you go anywhere near and the smell is strong. In France you can buy much more conc acid retail than you can in uk, but the boatyard stuff is probably commercial supply.

My boat will be lifted oow in ten days. I'll read the bottle and report back

I still have a bottle of the stuff we buy from our local Spanish supermarket.
I'll take a pic of the label and post.
I always keep some in my lockup - comes in handy for lots of things.
I don't know kf anything as strong that is as generally available in the UK - nearest being brick cleaner from builders yards but, in my experience, that product seems weaker.
 
Our boat yard in La Rague has a parts shop as well as an engine shed ( where I see anecdotally what keeps busting /being overhauled )
They sell HCl in litre bottles about €5 or less .
We have been copying everybody else as Hurricane says ,just agitate with a brush and wear suitable PPE .
"De norm" seems to be just leave em plain metal .

I can just about reach with a snorkel and paint scrapper every 6-52 in the season ,and have a mini dive kit if I can be bothered phaff ing / recgarching the bottle afterwards etc .
So we just accept it as a boat chore .

Having said that it's over powered anyhow and growth seems only to knock a knot or two off .
Interestingly if I go for a sustained blat - long speedy run then have a look after a lay up ----ie fouled props
It's the hub area that brasses up real shiney ,not the tips of the blades -which spin faster ? -props ,yup a "black art "

The only caution I would say is --Ithink it's important to give em a really good rince off with water .
Otherwise there may I stress may be a tendency for the acid to etch the metal surface -destroying any natural shine and making future adhesion by "critters"etc easier .
But we are talking @ microscopic level and once done ,it's etched -maybe a bit of wax polish ? Kinda offsets this ?
Trouble is once etched its irreversible - but we are talking microscopic -then agian that's what we are up agianst -
Microscopic adhesion of algae that "critters" then feed on
 
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Here is what I learned with giving anti-fouling to running gear.

If you make Velox the trick is this. 1) Apply primer as soon as you can the more it stays the better [if staying a month on before AF is better then 2 weeks] 2) give anti-fouling just a couple of days before launching (Do not do as on the instructions)
Propspeed apply as instructed and works best but cost twice if not trice to Velox.
 
That's superb Mike, and is the condition I have decided (after my admittedly only 1st go at coastal prop cleaning this spring after years on the Thames) that I want to get my stern gear to be in. I tried various things when boat was out the water and sort of worked out that as highly polished as possible and a chemical clean and refinement/repolish whenever out was probably going to be my best route. What you've posted, with such great results, is good proof that that's the way forward for me.

I did try a few UK brick cleaners on the props and rudders and then ended up getting the very best results from Starbrite Hull Bottom Cleaner. I suspect, but don't know with any certainty, that it might be stronger than the generally available builders cleaning acids, or that it might be a mix of Hydrochloric and another acid giving it more "fizzing" cleaning action. It comes with a spray but I soon worked out like you that paint brush and agitation method worked best, and wasted least liquid. Would be interesting to know what the composition is of the one you use out there.

Great update and many thanks for posting it.

Andy
 
Here is what I learned with giving anti-fouling to running gear.

If you make Velox the trick is this. 1) Apply primer as soon as you can the more it stays the better [if staying a month on before AF is better then 2 weeks] 2) give anti-fouling just a couple of days before launching (Do not do as on the instructions)
Propspeed apply as instructed and works best but cost twice if not trice to Velox.

Nop - tried that on our first season - I think it was on our trip to Malta - the Velox just didn't stick.
There is a huge amount of energy being released by the props on a planing boat.
I challenge ANYONE to find a coating that sticks to bronze under those conditions.
 
That's superb Mike, and is the condition I have decided (after my admittedly only 1st go at coastal prop cleaning this spring after years on the Thames) that I want to get my stern gear to be in. I tried various things when boat was out the water and sort of worked out that as highly polished as possible and a chemical clean and refinement/repolish whenever out was probably going to be my best route. What you've posted, with such great results, is good proof that that's the way forward for me.

I did try a few UK brick cleaners on the props and rudders and then ended up getting the very best results from Starbrite Hull Bottom Cleaner. I suspect, but don't know with any certainty, that it might be stronger than the generally available builders cleaning acids, or that it might be a mix of Hydrochloric and another acid giving it more "fizzing" cleaning action. It comes with a spray but I soon worked out like you that paint brush and agitation method worked best, and wasted least liquid. Would be interesting to know what the composition is of the one you use out there.

Great update and many thanks for posting it.

Andy


To make it easier the next time that I clean the props etc, I polish using these felt disks - they come with the polishing compound - looks like a Mars Bar (never tried eating one though!!)

http://www.ebay.co.uk/itm/ANGLE-GRI...inium-Brass-/110989899499?hash=item19d78376eb

I use a cheap B&Q angle grinder with an M14 shaft/thread.
In fact, I have two grinders on the go - "Wax On" - "Wax Off" approach.
Messy job - use eye and face protection.
Then some stockinette and the A Glaze pink polish finished by hand.

Just thought those links above might be helpful.
 
Nop - tried that on our first season - I think it was on our trip to Malta - the Velox just didn't stick.
There is a huge amount of energy being released by the props on a planing boat.
I challenge ANYONE to find a coating that sticks to bronze under those conditions.

It worked a on friends Sunseeker 46. Prop speed has worked on a Pershing 37 with shafts and Cats 355hp top speed 36-39 knots, and some other boats.
 
Yup, hydrochloric acid removes barnacles easily. It is normal practice in boat yards in France to pay €100 extra for "acid wash" when they lift and scrub the boat, and it makes the props as you show them there.
Yup, La Rague was using hydrochloric acid on the props of my Targa 48 back in 2003. Its ironic that we haven't moved on in 13yrs by way of finding an effective method of keeping sterngear clean in the Med. I've tried Propspeed as well but as you say it was an expensive treatment and within a few weeks the coating was beginning to peel off so as far as I'm concerned it was an expensive waste of money. Apart from paying a diver, the only solution I've found so far is to move to a cleaner part of the Med. Sterngear fouling is definitely much worse in the SoF and Baldricks than it is in Croatia or Sardinia. I would have my sterngear cleaned 3 or 4 times a season in Palma but in Carloforte there was hardly any fouling after a whole season in the water
 
Really impressed with the results even though the waters are slightly colder this time of year - what was the duration between the last lift/scrub/polish and this one???

Last lift and scrub, John, was Oct last year.
Maybe you misunderstood the pic taken during the pressure washing.
That pic was taken AFTER I had done the Agua Fuerte treatment (whilst Cisco was still pressure washing the rest of the boat)
 
Come on then Mike lets have the images before the scrub.....!

As I recall, many moons ago, we used to buy 32% inhibited hydrochloric acid to de-scale water cooled condensers to cooling towers, serving water cooled chillers. I reckon its the same as the AF we buy in Spain. I use to buy it in bulk from Woburn Chemicals, Milton Keynes - I believe they are still trading. It was always good to have some in the garage, had to keep the kids away though.....!
 
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