|Topic Review (Newest First)|
|09-17-2010 10:28 AM|
Shawn - not off topic but applicable to the discussion.
Maine Sail was probably correct because with a 'rough surface' such as what you get when you apply bottom paint solely with a roller, the roughness promotes a large boundary layer - a regime where there is 'very little velocity' quite close to the hull when the hull is moving. Smooth surfaces have 'smaller' boundary layers thus have higher 'water flow' quite close to the hull. Although Ive never made any boundary layer measurements versus surface roughness ... I will offer that my 'smooth as a baby's ass' bottoms stay MUCH cleaner than when I only used a paint roller.
|09-17-2010 09:37 AM|
|T37Chef||Not to go to far off topic ...but a while back Mainsail had posted something I never knew, many ablatives (such as CSC I believe) do NOT begin the wear until about 7 knots of continued use? I know I don't sail 7 knots + as an average speed. Switched to Petitt SR 40 this spring, pulled the boat last week, about 5 months in the water...the hull had very little slime, didn't even need to be pressure washed really. Also, for several seasons now I have used Petitt Zinc Barnacle Barrie coat with much success...not this time. The shaft was covered in barnacles. The only thing different then years past is I now have a SS shaft vs the bronze I had prior???|
|09-16-2010 09:18 PM|
Only time/labor intensive on the initial coating .... economical, easy and fast for reapplication because you wind up using much less paint.
With ablatives most folks apply too much after successive years, then it very labor intensive to 'repair' all those damn 'flake-offs'. Pay me now, pay me later - your choice. ;-)
|09-16-2010 07:34 PM|
Originally Posted by RichH View Post
|09-15-2010 11:30 AM|
... other considerations:
Dont use a 'paint roller' to apply bottom paint, especially ablatives !!!!!!!!!!!!
Ablatives seem to last longer and more easily 'release' growth if they are 'as smooth as a baby's ass' .... a 'racing bottom' type surface.
You dont have to "sand" the bottom to get close to a racing bottom finish:
Apply the first coat of paint with a foam roller to the hull, let the paint 'cure' but not to 'hard cure'. Take a large polyethylene trowel (yellow WEST SYSTEM trowels work well) and with light pressure and with the trowell held a very shallow angle ---- KNOCK OFF all the 'tops of the hills' / teeny bumps caused by the roller and let the paint FULLY DRY. Then, with roller and trowel in hand, roll on a thin coat in narrow sections ... the boat will look like a zebra where you apply 'new' paint ... and quickly use the trowel to force the new paint into the remaining 'valleys' using the 'tops of the previously flattened 'hill tops' created before. Keep applying in this way until all the valleys are filled .... and the paint is now SMOOTH. Such will take several days to attain and does have a high 'learning curve' so you dont 'disturb' the freshly filled valleys. The trowel has to be constantly cleaned with thinner.
When the ablative is SMOOTH, any slime seems to 'peel' away in 'sheets' when I get up near hull speed ... and of course the boat is 'faster' due to the slick surface, etc. Ive found that I dont have to apply 'much' ablative in succeeding seasons --- just fill in the 'eroded' valleys, etc. with the paint and a trowel.
Its easy to build up a 'thickness' of ablative ... and thick ablative seemingly doesnt have much 'strength' and will eventually generate HUGE FLAKES from the hull. Thin smoothed-out / "faired" applications of ablatives dont seem to have this 'problem'. In this manner I use 50% less paint in the succeeding seasons. Ive just started using Micron Extra ... but the above 'smooth bottom' has worked well for decades of Micron CSC application.
BTW - I do have a contrasting 'signal' color coat under the 'working' coat to indicate when I have to build back to proper paint thickness.
hope this helps.
|09-15-2010 11:01 AM|
Originally Posted by aa3jy View Post
1. It unnecessarily and prematurely wears away the paint
2. The paint particles that have been scrubbed do no good in the environment
Im located on the Upper Eastern Shore of the Chesapeake. I used to use Micron CSC .... recently the water condition there became sooooooooo foul (turbidity that you can 'walk on') that Micron CSC no longer gives protection - if the boat isnt used every FEW DAYS a thick slime would form on the hull; and, the barnacles apparently 'anchor' themselves first in the slime to gain a foothold, and then eventually attach directly to the Micron CSC. The result is that Thousands of Barnacles were attaching to the hull (mostly 2-3ft. down from the waterline, down deeper on the Prop/Rudder, etc. - probably due to the electrolytic action of the running gear zincs).
Since Slime seems to be 'new' cause of enhanced hull fouling, Ive changed to Micron Extra (anti slime coating) which seems to be 95% effective in keeping the slime off the boat bottom; less slime has promoted NO barnacles.
With all ablatives you MUST 'move' the boat or keep it in an area where the water is MOVING - go sailing often .... OR when slime does begin to build, simply go out and anchor, take along a large rubber 'squeegee' (& affixed to an 8 ft. long pole) used for cleaning WINDOWS. From your dinghy you easily 'squeegee' off any accumulated slime, doesnt disturb the ablative paint hardly at all (very little 'red' in the water when you 'squeegee') ... and then go sailing.
In the Carolinas where slime & 'slime + barnacles' seem to be an especially bad problem, Ive noted that many boats are now using an ablative only 2-3ft. down from the waterline and then using a hard bottom pant below that. Many seem to be using Teflon loaded hard paints such as Baltoplate or VC17.
As regards the 'usual' prop barnacle fouling, Ive been using Petit Zinc Rich Barnacle Barrier with moderate success. Ive also noticed for quite a long time that boats that have lost their zincs do not have barnacle problems on their props - probably due to the electrolytic action between the prop metals and the seawater. Im going to experiment with NO prop zinc (on a huge Max-Prop) and rudder shafting, etc. ..... and when in my slip, etc., simply 'hang' a 'guppy zinc' over the side but electrically connected to the boats bonding system .... so I get full anode protection, keep the barnacles away from the prop, etc. - you have to make sure that the propshaft is somehow electrically connected to the boats bonding system to do this properly.
I have a 'high suspicion' that barnacle infestation STARTS with attachment to the prop/shaft and then the barnacles 'propagate' to the rest of the hull from that 'vector source'; and, if I minimize the barnacle attachment to the prop, etc.; then, the rest of the hull wont see much if any 'infestation'.
hope this helps.
|09-15-2010 10:19 AM|
Originally Posted by blt2ski View Post
|09-15-2010 10:15 AM|
It may be different as you say. Some marina's are going overboard, others to as strict a minimum as possible. One can in my case, take a diver "outside" the marina, and have them dive the boat, no issues to my knowledge. Not sure how legal...........
If you go to 48° North - The Sailing Magazine and look at back issues in editorials and some letters to editor, and an aricle or two, you will see the letter bomb issues I am talking about, not sure if equal to back east and the op's issue or not. Nov 09 to about march 10 have items on it.
|09-15-2010 09:40 AM|
The difference between your situation and the OP's is that in Maryland, there are no state-wide restrictions on in-water hull cleaning. But since back east, boatyards and marinas are typically one and the same (as opposed to California, where by law they must be separate legal entities) this particular marina is apparently choosing to use its recent inclusion in the Clean Marina Program to ban in-water hull cleaning for its tenants (even though this is not what the Clean Marina Program advocates) and force them to take advantage of that marina/yard's haulout facilities for hull cleaning.
I would be interested in seeing any documentation regarding the situation in your area, though.
|09-15-2010 09:28 AM|
You clean it, hope you do not get caught, and get kicked out of the marina, or haul it, and have it pressure washed. My marina will not even let you wet sand your hull after painting if you want a wet 600 grit smoothness. Some still do. But if you see what hoops you have to go thru..........I'll see if I can find some info on the local jurisdiction that sent out a few letter bombs last fall.
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