Cleaning prop shafts and props

[Piers]

I've seen brick cleaner being used to dissolve the barnacles and similar from shafts and props.

But doesn't brick cleaner contain hydrochloric acid, so does it attack the metal? My shafts are stainless and the prop is bronze.

Please forgive the qn - I'm no chemist!

 

[ccscott49]

My shafts are bronze and props are bronze, I use hydrochloric acid on mine and never have any problems, after the acid has dissolved the barnacles and any lime type scale, its nuetralised anyway. Although they are thoroughly washed after treatment.

 

[longjohnsilver]

Hi Piers, my reply would be exactly the same as Colin's, no problems at all.

 

[tomhenson]

Same, the boat I used to work on used the hydrochloric acid and was fine.

Tom

 

[DAKA]

+1

Brick cleaner also contains a metal protector.

(if you ask the yard lads there is usually 5 l in the brick cupboard at the top of the slip, I'm sure they would be happy for you to try a splash as long as you replace it, be careful, its nasty in your eyes, wear goggles and have water on standby.)

 

[peterandjeanette]

Hi Piers

The hydrochloric acid will dissolve the chromic oxide (what makes stainless - stainless ! ) on the stainless metal, but this will oxidise again immediately so no problem there.

You would have to leave bronze in concentrated hydrochloric acid for a very long time before there was any effect - so again no problem.

As said before be sure to wear PPE - personal protective equipment.

Good luck

Peter

 

[Deleted User YDKXO]

Another vote for hydrochloric acid. Its used extensively in Med boat yards to clean props/sterngear and applied with a paint brush. As pandj say, definitely wear thick rubber gloves and eye protection when handling the stuff

 

[bammylovechops]

Is it ok to use on aluminium props as well???? Brick cleaner that is.

 

[MapisM]

My shafts are stainless and the prop is bronze.

Neither would worry me, but I'd rather take care of bushings.
Try to avoid contact with them, and/or rinse them immediately.

 

[Piers]

Brilliant. Thank so much for the info. Brick cleaner it is!

I'll get plenty of 5L canisters so I don't run out, and the PPE recommended.

Thank you.

Piers

 

[OceanRipples]

Brilliant. Thank so much for the info. Brick cleaner it is!

I'll get plenty of 5L canisters so I don't run out, and the PPE recommended.

Thank you.

Piers

Hi Piers,

considering a similar course of action and I just wondered if this worked for you?

Thanks!
Mark

 

[Greg2]

Hi Piers,

considering a similar course of action and I just wondered if this worked for you?

Thanks!
Mark

That’s a bit spooky - I did a search only yesterday on this topic and came across this thread.

Last time I did the shafts and props on a previous boat I think I used oxalic acid because it doesn’t harm the metals involved. It did the job but I also polished with an angle grinder with appropriate discs.

 

[Plum]

I've seen brick cleaner being used to dissolve the barnacles and similar from shafts and props.

But doesn't brick cleaner contain hydrochloric acid, so does it attack the metal? My shafts are stainless and the prop is bronze.

Please forgive the qn - I'm no chemist!

I have been using hydrochloric acid brick cleaner Bostik Concentrated Mortar & Brick Cleaner 5L on my bronze prop and stainless shaft for 6 years, 3 times per year. No problems at all. If you have an anode on your shaft or prop take it off first. Scrape off as much weed and or barnacles first and let the prop dry. I place a metal tray/dish (it's an old baking tray) under the prop. Pour 1/3rd of a litre of acid into the tray then use a 50mm paint brush to apply the acid to the prop and shaft continuously reapplying as it runs back into the tray untill you are back to smooth bare metal. If the barnacles are bad you may need to replace the acid with fresh but mostly 1/3 litre is enough. Dispose of used acid sensibility. Hose everything down with lots of water. Finish with 350 grit, or finer, abrasive by hand to ensure a very smooth surface. Wear goggles and have the hose ready in case you get some on your skin and you start to feel it.

Www.solocoastalsailing.co.uk

 

[Momac]

I have used Oxalic (Bar Keepers Friend Power Spray) but found Harpic Power Plus cheaper (maybe not so cheap these days ) and somewhat more effective applied with the help of a cheap paint brush and washed off with plenty of water and a cloth .
Brick acid is potentially okay but stronger still than Harpic . I haven't dared to try that yet but guess it can be diluted so could prove to be economical.

 

[Plum]

I have used Oxalic (Bar Keepers Friend Power Spray) but found Harpic Power Plus cheaper (maybe not so cheap these days ) and somewhat more effective applied with the help of a cheap paint brush and washed off with plenty of water and a cloth .
Brick acid is potentially okay but stronger still than Harpic . I haven't dared to try that yet but guess it can be diluted so could prove to be economical.

Harpic stuff says hydrochloric acid at 9% which is almost the same as the brick acid dilution at 10%. The harpic £1.90 for .75litre from Sainsbury's is thicker so does not run off so quick but the brick acid is cheaper £6.15 for 5 litres from Toolstation.

 

[Momac]

Harpic stuff says hydrochloric acid at 9% which is almost the same as the brick acid dilution at 10%. The harpic £1.90 for .75litre from Sainsbury's is thicker so does not run off so quick but the brick acid is cheaper £6.15 for 5 litres from Toolstation.

Harpic was a quid per bottle not so long ago !

 

[ChromeDome]

Is it ok to use on aluminium props as well???? Brick cleaner that is.

My bottle specifically states NOT to use on terrazzo floors, marble, aluminium and enamelled surfaces (without considering alloy or other variants).

Personally use various tools before acid.
My shafts are 40 mm so cut a bit of steel tube in two and use them to slide along the shafts. Amazingly fast..



Props (Nibral) are carefully done by drill w/ steel brushes, angle grinder w/ flap discs, paint remover disc..

Next season will be Hammerite Steel Primer and Velox Plus propeller antifouling as per shared experiences here..

 

[AndieMac]

…………Next season will be Hammerite Steel Primer and Velox Plus propeller antifouling as per shared experiences here..

What about your shafts?

I think I read somewhere, Hurricane, who seems to have tried and documented every hull and running gear anti-foul procedure, didn’t have much success with Velox? Appreciating of course his boat resides in a very high marine growth area.
Is your boat UK or Med?

 

[ChromeDome]

Boat is mainly in the Baltic with low (11 ‰ / brackish) salinity and with medium to high growth during the summer (boat on the hard during winter). Barnacles vary from year to year but wasn't too bad when boat came out a couple of weeks ago.. As always the growth decreases with the use of the boat but it gets a good high speed (20+ knots) run regularly in attempt to keep growth at bay and engines et al alive. When out the 30' hull took half an hour to clean with a high pressure washer using a rotor nozzle. For comparison, a mate's Princess 35 with hard traditional AF, that sat for some weeks due to TAMD41 cooling issues, took more than two hours.

Together with boating mates I've tried several solutions over the years - from nothing to dedicated products like waxes and car underbody protection to 2-part primer & antifouling. Displacement, semi and planing hulls involved, sterndrives and various length of shafts and rudders.

Some useless, some not too bad but none really good. Before this season year a sterndrive got the complicated and advanced treatment used for wind mills at sea (owner had access to that through a friend ). Tough stuff, but no convincing AF properties.
To add to my research, after having the hull dry-ice blasted, primed and thin-film AF applied also to shafs and props, it became clear that the GRP primer didn't stick well to metals. The chat about using a primer with etching properties made be decide on that followed by Velox, but their description of how the paint partially dissolves their primer made me more interested in the universal Hammerite (even less expensive), considering a possible later use of something different..

Going to apply before next season launch. The PTFE-based thin-film antifouling (does not work by means of active ingredients emitted into the water, but by means of a very smooth surface) lasts two seasons, so it'll be the shafts, props and rudders only.