Suggestions - Barnacle removal

[BobM]

Just hauled a few weeks ago and there are quite a few barnacles on the prop, shaft and between the rudder and the partial skeg.

Chemist that I am, I figured that a dab of phosphoric acid based Naval Jelly and a scraper should do for the ones in easy reach...any tips on how to get those on the curved surface skeg in front of the rudder?

It would be nice to get down to the boat today and set up my Fairclough boom tent...nice if it wasn't cold as hell out there today (20 degrees).

Thanks in advance for your exterminating tips!

BobM

 

[ITMaster]

Interesting Concept About Better Living Though Chemistry Bob

Why would you select Phosphoric over Nitric, Hydrochloric or Sulpheric for that matter? Or, even a con solution of Acetic since these guys are organic? My curiosity is getting the best of me about how one of these acids would be better for this application.

I like the idea of eatting the boogers up and watching em fizz away into a liquid blob under the boat.

Is environmental clean up an issue?

 

[Bob S]

Bob,

I got most of mine off with the pressure washer. I have one or two stubborn ones I think I can buff or sand off. I'd like advise on how to buff the prop?

 

[Mike B]

Just scrape them off. No chemicals required, just some elbow grease. Plus your grandchildren will thank you when they have clean water to drink. Just remember to wear gloves as they're like razor blades.
Mike

 

[BobM]

The naval jelly is just that, a jelly made for rust removal, so it will stick to the barnacles rather than just run off. The barnacles, which are probably calcium carbonate, should be pretty responsive to phosphoric acid. I could certainly use a stronger acid, I just don't have a form of it that isn't a liquid easily available.

The bottom was pressure washed, but for some reason they didn't do a good job or couldn't get these off. Probably the former. I could drag my pressure washer out and wash the hull at the same time I guess.

 

[Warren Milberg]

I've had really good luck using "On and Off" to clean the scum line on my boat and to get rid of few barnacles here and there. In my case, I've found that getting to the boat as soon as possible after haul-out is key or the hard growth turn into impossible growth quickly the longer you let it stay on the boat. I use a bendy putty knife to knock off any growth that the "On and Off" misses, particluarly on my shaft and prop. You may be able to do that on the forward edge of your rudder between it and the skeg. Or, another possibility would be to take a piece of bendable metal, like a hack saw blade, turn in upside down, and then work it up and down in the slot between rudder and skeg. Good luck.

 

[shemandr]

Like Warren and Mike I just scrape them off. A paint scrapper or putty knife, a stool to sit on and about 10 minutes of excercise usually does it. I haven't ever painted or treated the shaft or prop. I do clean the bottom regularly during the season including knocking off the barnacles with the same tool (And less back pain). Same for the bottom of the keel.

 

[RichH]

Muriatic (Hydrochloric) acid will dissolve the remnants of barnacles (after scraping .. the best way to remove). Commercial consumer products that will also work (but not as fast) on the 'remnants' are: "lime-Away" or any 'acid-type' toilet bowl cleaner. No problems with fighting off the eco-crazies; just use a plastic tarp and scatter a liberal amount of baking soda which will neutralize the acid drips.

You really dont want to use acids on bronze (Cu-Sn) as it will begin to extract the wee bit of zinc (always present for 'machinability') and thus weaken it over repeated applications of acid.

 

[Alan]

Isn't it a shame...

...that when people are concerned about the environment and minimizing their ecological impact, that some have to look at this responsibility as "the eco-crazies". It's about time that we ALL took responsibility.

 

[BobM]

My original question still hasn't been answered. I certainly understand that either mechanical or chemical persuasion is useful to remove barnacles. What I was looking for is, I guess, is there a particular tool people have used for getting in the slot between the convex leading edge of the rudder and the concave skeg surface. Do you bend a scraper a particular way? Let's refocus the thread on this please.

Regarding the environment. I took a doctoral level course in environmental physical chemistry. Once of the discussions was that individuals are a significant contributor to pollution. Yes we each only contribute a little bit , but the sum of the contributions is significant.

 

[sailingdog]

Plastic putty knife.

 

[Glenn17467]

Use a putty knife using gentle pressure and plenty of water to wash away. To remove remainder of barnicle, gently scrub with a plastic pad. Use the same procedure on the shaft and prop.

 

[Rich (P303)]

My original question still hasn't been answered. I certainly understand that either mechanical or chemical persuasion is useful to remove barnacles. What I was looking for is, I guess, is there a particular tool people have used for getting in the slot between the convex leading edge of the rudder and the concave skeg surface. Do you bend a scraper a particular way? Let's refocus the thread on this please.

Regarding the environment. I took a doctoral level course in environmental physical chemistry. Once of the discussions was that individuals are a significant contributor to pollution. Yes we each only contribute a little bit , but the sum of the contributions is significant.

Picky... Picky... Picky.

I haven't tried this... how about using a hack-saw blade... less the hack-saw. You should be able to conform to the surface. Could be tough on the hands to hang on to the blade. Maybe wrap some adhesive tape around the ends?

Don't forget about the barnacles in the sea-cocks!

 

[Ross]

This is probably a question for the chemists. I know that citric acid is very effective for removing calcium compounds. And I know that liquids don't stay on vertical surfaces without help. Would a starch based gel or paste saturated with citirc acid be a solution to keeping the acid in contact with the barnacles?

 

[BobM]

I am a chemist, albeit an analytical one (meaning that I test things rather than use with chemicals to make things). Naval jelly is a jelly containing phosphoric acid used for rust removal, which is why I thought it would potentially be useful. It is also widely available. I can buy it at every hardware store I can think of. However, it may not be all that useful. I found an article online where some scientists tried a host of acids and acidic mixtures and only found 1:1 Hydrochloric acid/water to be useful (<2 minutes for 40mL to dissolve a gram of barnacles). They tried a 40% solution of phosphoric acid and quit after an hour, as they saw no results (bubbling to indicate carbon dioxide was being emitted). However, it is very inexpensive (Naval Jelly), so it is worth a shot if I have trouble. I can apply some, have lunch at the club and then return. :-d

 

[RichH]

Re: Isn't it a shame...

Alan
The reply to your statement is that if people had real concern for the environment, they'd practice SPERM CONTROL. You cannot get more 'elemental' than that.

 

[RichH]

BobM
The best tool I have for barnacle removal in those places is a Swiss Army Knife that has a saw blade.
The Chemical composition of 'shells' is .95 Calcium Carbonate. The BEST (reactive) is always HCl which is easily neutralized (for a chemist). You can also use the inhibited boiler descaling compounds (RydLyme, Marsolve, etc.) with the same effect and with less enviro impact. For surface deposition removal that I DONT want to cut off, I simply soak a polypro (web or needle punched) towel with descaler apply as a 'poultice', cover with Saran to retard dehydration ... and simply wait a day. Thats what an old fashioned 'wet' chemist would do.

 

[dvideohd]

Mike....

After the gloves comment - I immediately had visions of grand kids saying..
"Thanks Grandpa... but what are we going to do with all these Holey Gloves...??"

I think it hard to balance all this "green stuff" sometimes...

Acid does not leave behind much residue... Multitool with the right blade, perhaps... (like Fein - or Dremel - or from Harbor Freight...)... My scraper works well in a small area... but for a whole keel or boat bottom - that's a question...

I wonder if a "marine planer" will do a good job on the "bottom" - next spring.

--jr

 

[BobM]

Rich. You are definitely on the mark on your ultimate solution to pollution control LOL. I like your saran wrap idea. The problem is that my boat is an hour away and it would be impossible to justify TWO trips to the boat in one weekend to my Wife. I am better off if I let her forget that it exists for the off season.

Thanks for the input from a "wet" chemist. I really don't want to encourage the non-initiated to play with 1:1 HCl/water. It certainly isn't something that should be taken lightly from a safety perspective.

 

[Mike B]

Jerry, LOL I'm sure the G Kids would get a kick out of them. Actually the gloves don't get that beat up. They just keep me from bleeding and possibly getting an infection. Another option I've seen used is a long handled, flat blade ice scraper. It basically looks like a garden hoe that's been flattened out. It'll scrape off large areas at a time. This isn't rocket science, a quick look around the garage or a hardware store is bound to find a tool that will work satisfactorily.
Mike