Lost Speed

walruz · 24 July 2007, 00:16

I seem to have lost 10 kts off my performance. I have a rebuilt 91 2 st Yammy which was doing 36 kts but when I went for WOT the other day it would only deliver 26 kts. Some is down to weed as the boat is moored on a drying out mooring but I do not believe weed will take 10 kts off. (I last acid sprayed it about a month ago).

Any ideas and suggeestion are greatfully appreciated.

Thank you all

Ian

codprawn · 24 July 2007, 00:30

Depends on the fouling but you can easily lose 10kts or more!!!

wetterthebetter · 26 July 2007, 01:02

We’ve just taken the stuff off the bottom of ours.. barnacles, slime, weed, things that were unidentifiable and the boat is flying again! So set to work.. it costs nothing except hard graft.

Hugh Jardon · 26 July 2007, 01:11

they guy who bought our last boat could not get his gin palace on the plane when it was covered in weed, it appears it can make quite a difference, i have never experienced it as always keep mine on the trailer

Stoo · 26 July 2007, 03:22

Are you still getting the same revs at WOT? That would tell you if it's a hull crud problem or an engine problem...

Is your prop in good shape? I just had mine tunes and had a few dings fixed... gained about 3 or 4 knots just from that bit...

Is your Missus accounted for? She's not dragging behind with her foot through a mooring line or anything is she?

walruz · 26 July 2007, 17:02

Quote:

Originally Posted by Stoo

Are you still getting the same revs at WOT? That would tell you if it's a hull crud problem or an engine problem...

Is your prop in good shape? I just had mine tunes and had a few dings fixed... gained about 3 or 4 knots just from that bit...

Is your Missus accounted for? She's not dragging behind with her foot through a mooring line or anything is she?

I don't have a rev counter (it's on the futures list but with a baby due in Nov the future is a long way away) but engine noise is very similar. Prop was new in the winter and has not touch a rock (YET).

I do spray the bottom every month or two but with the weather recently this has been problematic.

Thanks for all the suggestions.

Has anyone antifouled a moored 5.4 SR. what did you find?.

Ian

walruz · 31 July 2007, 14:54

Ok guys.

I feel like an idiot now. Finally tides and work let me get on the beach to properly check the state of the weed growth

it was horrific. Took 2 containers of acid to wash it off (nice stuff to work with - make sure you wear old clothes). Took her out a hey presto almost all my lost speed returned.

So anyone with a moored boat not antifouled heed my warning and check the weed growth more often.

Unfortunately on the way bak in I developed fuel probs so I now have to work out if I have a blockage somewhere, water in the fuel (have a filter on BUT) or pump problems. Ah the joys of owning a boat

.

Happy ribbing
Ian

codprawn · 31 July 2007, 15:32

What acid are you using? Does it dissolve the barancles?

walruz · 31 July 2007, 21:08

Quote:

Originally Posted by codprawn

What acid are you using? Does it dissolve the barancles?

Never had any barnacles to try it on but it does keep the steps clear on the local quay so probably would do the job. It's a concentrated hydrochloric acid - be very careful when using. You can get it on your skin if you wash off within 15 minutes or so but longer would probably burn you.

Regards
Ian

Tim M · 31 July 2007, 21:40

Acid ey. Not heard of that one before. I spent about an hour and a half with a friend cleaning barnacles and slime off my hull this afternoon. Not something I wish to continue doing on a monthly basis. I'm either going to anti foul or put some other magic formula on when I take it out next month.

How easily does the nasty stuff come off with acid then? Is there any scrubbing required or just a rinse?

BigFella · 31 July 2007, 22:13

Muriatic acid (which is a dilute form of hydrochloric acid) is used for cleaning/descaling brickwork as it dissolves lime and calcium.... works on barnacles too especially if you kock the caps off them with a scraper first

Just beware 'tis not nice stuff so all the usual safety precautions are a must..............

codprawn · 31 July 2007, 23:04

Guessed it would be HCL - I tried to buy some but all my local chemical comapnies have a minimum order of £100 - any ideas where I can buy say 25l of the stuff???

BigFella · 01 August 2007, 06:22

I haven't used it for a long time. Try local builder's merchants (as it is used for brick cleaning and also is the stuff used by plumbers to descale your boiler

) or better still you can usually get it from Swimming Pool supplies outlets in reasonably small quantitites.

walruz · 01 August 2007, 17:37

Quote:

Originally Posted by Tim M

Acid ey. Not heard of that one before. I spent about an hour and a half with a friend cleaning barnacles and slime off my hull this afternoon. Not something I wish to continue doing on a monthly basis. I'm either going to anti foul or put some other magic formula on when I take it out next month.

How easily does the nasty stuff come off with acid then? Is there any scrubbing required or just a rinse?

Took me about 1/2 an hour or less to do the entire job on my own. Spray on leave about 5 - 10 mins and wipe off with a deck brush. Check you haven't missed any where and a quick second spray on those spots. No real elbow grease required. It takes off the green slime, brown slime and that black stuff which is usually a BUGG*R to shift. Just don't leave it on your tubes for long as I am not sure what the result would be. I always do mine when it is on the beach but the tide is on the way in.

Only other word is over time is will also eat away your spray gun but they are only £20 in B&Q.

Ian

Pete7 · 01 August 2007, 19:24

Quote:

Originally Posted by codprawn

Guessed it would be HCL - I tried to buy some but all my local chemical comapnies have a minimum order of £100 - any ideas where I can buy say 25l of the stuff???

The local Machine Mart in Portsmouth sells it in 5 litre containers. Can't remember the price but wasn't expensive.

Pete

waverunner · 01 August 2007, 19:30

Quote:

Originally Posted by walruz

Ok guys.

I feel like an idiot now. Finally tides and work let me get on the beach to properly check the state of the weed growth

it was horrific. Took 2 containers of acid to wash it off (nice stuff to work with - make sure you wear old clothes). Took her out a hey presto almost all my lost speed returned.

So anyone with a moored boat not antifouled heed my warning and check the weed growth more often.
Unfortunately on the way bak in I developed fuel probs so I now have to work out if I have a blockage somewhere, water in the fuel (have a filter on BUT) or pump problems. Ah the joys of owning a boat

.

Happy ribbing
Ian

I am surprised at the amount of people on this forum who keep their ribs on moorings but do not anti foul their hulls, surely they should understand the consequences will be loss of speed, combined with the inevitable job of cleaning off the hull.

codprawn · 01 August 2007, 22:10

Quote:

Originally Posted by Pete7

The local Machine Mart in Portsmouth sells it in 5 litre containers. Can't remember the price but wasn't expensive.

Pete

Didn't think to check them. There are "proper" marine barnacle removers but of course they are silly money!!!

codprawn · 01 August 2007, 22:12

Quote:

Originally Posted by walruz

Took me about 1/2 an hour or less to do the entire job on my own. Spray on leave about 5 - 10 mins and wipe off with a deck brush. Check you haven't missed any where and a quick second spray on those spots. No real elbow grease required. It takes off the green slime, brown slime and that black stuff which is usually a BUGG*R to shift. Just don't leave it on your tubes for long as I am not sure what the result would be. I always do mine when it is on the beach but the tide is on the way in.

Only other word is over time is will also eat away your spray gun but they are only £20 in B&Q.

Ian

Don't worry about the tubes - Hypalon is very acid resistant - they make gloves for the chemical industry out of the stuff!!!

Spottydog · 02 August 2007, 07:03

Quote:

Originally Posted by waverunner

I am surprised at the amount of people on this forum who keep their ribs on moorings but do not anti foul their hulls, surely they should understand the consequences will be loss of speed, combined with the inevitable job of cleaning off the hull.

I couldn't agree more!!

This lot refuse to antifoul, and yet will don protective clothing, gloves, masks etc and then lie on the ground in a muddy harbour, scraping the hull and spraying it with concentrated hydrochloric acid!!!

Tens of thousands of pounds worth of supposed "pride and joy"!

They are MAD!

But still, I suppose it give us yet another thread to listen to their crazy chemistry experiments.

walruz · 02 August 2007, 07:15

Quote:

Originally Posted by codprawn

Don't worry about the tubes - Hypalon is very acid resistant - they make gloves for the chemical industry out of the stuff!!!

Thanks codders.

That puts my mind at greater ease.

Ian