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clausont · 18-07-2007, 06:59

The boat that we just purchased had sat in the water and apparently had a pretty good crop of livestock on the bottom before it was hauled. When we got it, the bottom had been cleaned well with the exception of the prop and shaft which still has a significant encrustation of barnacles on it. My question is:
What is the best (safest for the prop and shaft) way to clean this debris? am assuming that pressure washing it when it was hauled did not remove it.
Oh, yes - I should mention that this is the first real boat project I am doing so I will have alot of questions.
Thanks in advance

svHyLyte · 18-07-2007, 07:25

Getting the large shells off isn't much of a problem. Give them a dose of WD-40, wait a few minutes until it soaks in and then have at it with a dull scraper. Geting the cement plates off that will be left once the shells are gone can be more difficult. I found that wrapping the shaft and strut with some cheese cloth and then thoroughly soaking it with an acid based stain remover such as Wink--or a 10% solution of Muriatic acid--would soften the plates enough to allow them to be removed, again with a dull scraper. It taks some patience however as the acid solution needs time to work.

Good luck!

s/v HyLyte

Vasco · 18-07-2007, 08:34

At the boatyard where I store my boat they clean the props with a grinder fitted with one of those 3M polishing wheels.

seafox · 18-07-2007, 15:20

I use a power drill with a brass attachment. Takes about 10 mins.

Roy M · 18-07-2007, 16:29

I just got out of the boatyard. During my stay I applied a product called PropSpeed, a two part process that results in a silicone coating on the shaft and prop. Several boats in the yard had been using it, so I got to see what two years of service amounts to. I was so impressed I decide to coat my Martec Mark 3 folding prop. The kit comes in various sizes, the smallest being 200 ml, which is about three or four times as much as I needed. Shop around for the best price.

clausont · 18-07-2007, 19:16

Ok - This weekend I will get it done. Thanks for all of the answers and I will look into the PropSpeed.

seafox · 18-07-2007, 20:58

Lots of people in NZ are using it now. Here you cannot buy it direct and have to pay for the application.
From what I have seen in the hardstand it works quite well.

cooper · 19-07-2007, 01:29

I use a semi sharp chisel and then just polish up with fine wet,wet and dry. The prop gets a further very fine polish, heated with a hot air gun and then soaked in lanolin, then finaly buffed off. This works quite well as long as the water tempreture is not excessive. Lanolin products have been used as an antifoul by some comercial operations but l havent seen thier results first hand.

clausont · 19-07-2007, 04:37

Interesting thought about the lanolin. I have never heard of this before. I can see where the water temp would be critical with that. With the cold water here in the PNW, that would probably not be a factor. The polishing seems like it would be a good idea.
Here is a pic of the prop and shaft:
http://www.cruisersforum.com/gallery/showimage.php?i=3511&c=2

cooper · 20-07-2007, 00:06

Hi clausont
if that is a pic of the prop before it has been cleaned then you have no problems !! In the warmer weather in the lakes here props can be so fouled as to be basicly useless in under two months. The boat goes no where and you get a kind of wirl pool effect just at the transom. It is amazing with a small two blade like yours (same as what is on my 30 footer except mine sort of folds) how much differance it makes when the prop is nice and clean..

clausont · 20-07-2007, 12:58

I have not yet done anything to the prop. This is my starting point so it is good to hear that it is no big deal. I know that it would be very inefficient the way it is. Probably still move the boat some the way it is, but not too well.
What would be used for antifouling on the prop if they get as fouled as you mention up there?
Thanks,

Tim

cooper · 20-07-2007, 22:39

A hard non ablative anti foul is usually used on props, but because I cant bring myself to buy a whole tin to use a couple of paintbrush fulls l dont do it. I have once in the past been lucky enough to have hauled out at the same time as a power boater, who was anti fouling too. I swapped him a stubby for a splash of his antifoul. I still ended up having to dive on the prop towards the end of the season, but it was not as bad. If my prop gets any reasonable amount of crap on it, it drops me back to 1 knot !! The slightest sea and l loses steerage and go backwards. Many years ago I used to hate diving under the boat (fear of the unknown) but now as long as I am warm , I love it.

clausont · 22-07-2007, 06:02

Thanks Cooper. I had been wondering that. I am sure thereare kinds of antifouling that one would NOT want to use, but I was not sure.
One of my first jobs is to strip the bottom, add an epoxy barrier coat and (I think) Petit Trinidad (or similar) bottom paint.
Any thoughts on this?