Prop and shaft antifouling

[Roc]

Greetings to all....
What products do you put on your prop and shaft for antifouling?  How do you prime the metal?  Have you ever used Micron Trilux 33??

Thanks!
Roc-

[Ken Juul]

Last spring I put on a new prop that the manufacturer treated with a teflon laced laquer.  It seemed to work well because I didn't have to dive and scrape the prop all summer.  The true test will be when I see the prop when the boat is pulled in March.  VC17 and Liquid Speed are supposed to be the same type of teflon based laquer.  Should be available at West Marine.

Ron,can you supply any more details on your process? I won't be able to make the meeting and don't remember if the details were posted in the news letter.

[Roc]

What type of primer is recommended?? I have a stainless shaft and bronze prop.  I don't think antifouling paint can be put on bare metal??

Thanks,
Roc-

[Tom P, IMPULSE #233, '86]

Roc,

I've used "Underwater Metal Kit" by Pettit for approx 8 years with excellent results...

It comes in a red/white box, and has about a pint of each component (2 part), with the activator...I think it costs about $30 or $40 per box, but has enough contents to do approx 4 sailboats...Sometimes I've split it with a friend, or just kept it for next time...

At first it may seem like a painful process; have to mix 2 components for the first step, then mix 2 other components for the second step, and then repeat the last step (2 coats total)...But it really is easy, and if you time everything right, you can do it all and put on the bottom paint in less than 4 hours (without having to sand between coats)...

This stuff really does have excellent adhesion to the metal, and gives the bottom paint something to grip as well...I wouldn't use any other product...

I've bought it at West Marine, but could not find it on their web site...

Go here for more info:  http://www.pettitpaint.com/products2.asp?Productid=57&Catid=3&SubCatid=9

Tom

[Roc]

Tom,
Thanks for the tip.  What antifouling paint do you use over the Pettit underwater metal product??  With the spinning prop, I know it's hard to keep something on.

Thanks for your help.
Roc-

[Tom P, IMPULSE #233, '86]

Roc,

I've used several different antifouling paints with the Pettit Metal Kit...

About 8-9 years ago, I was using Pettit Trinidad (a modified epoxy)...A few years later, I switched to West Marine's CPP Ablative...The last two years, I used Interlux Micron Extra (ablative)...Two months ago, I sprayed the bottom with Interlux VC Offshore (hard vinyl)...

FYI, I'm on the lower Chesapeake Bay which has medium/high growth rate...And we use the boat approx 2-3 times a week, April-Dec; race every Wed night, and usually one or both weekend days racing/sailing...

Here's what I found; all the above bottom paints did well with the Pettit Metal Kit...After about 3 to 4 months of heavy use (3 outtings a week), the bottom paint on the prop will start to loose it's antifouling ability...May also start loosing small bits of paint on the outer edges of the prop...A month or two later (5-7 month mark), the prop paint will have little or no antifouling ability; the paint is still there, it just isn't doing it's job...It's my theory that the friction of the water on the prop "burns" the copper (and other antifoulants) from the paint, just leaving the paint...I had the same results with all the above bottom paints; maybe had slightly better luck with the ablatives (CPP and Micron)...

I quit using Trinidad because of paint build-up...Got tired of strippng all the epoxy off when the paint was no good; didn't want any old paint build up on the hull because sooner or later it will all have to come off...

I then switched to West's CPP (ablative); In my opinion the best bottom paint...The paint does a very good job of antifouling, and washes away (ie no paint build up), and is much easier to sand...And I beleive the directions say you could haul, pressure wash, and paint without sanding...I know a few people who have done it, but I prefer to do a little sanding to smooth the bottom out...

Two years ago switched to Micron Extra (ablative) thinking it may be better than the CPP...Wrong; Micron just costs a lot more, and I did not see any improvement in the paint...In fact, it went on very thick (even when thinned) and could not be "rolled and tipped" smooth like the CPP could...Several others I have talked to said they had the same application problems with the paint...And I honestly think the CPP did just as good a job with preventing bottom growth AND slime...Micron was just a waste of $$$...

Now I'm going for all out speed, and went with VC Offshore...Yea it's a pain; has to be cleaned every 2-3 weeks, but is VERY FAST....

If I was going back to "cruising" in my area (med/heavy growth), and wanted minimal hassle and great paint, I'd use the West CPP, and plan on having the bottom lightly scrubbed (in the water) after the first 4 months of the splash date, then every 2 months thereafter...Three good coats of paint should go a full two years in the water...

Hope this helps,
Tom

[Tom P, IMPULSE #233, '86]

To All,

For whatever it's worth...

I know of 3 people that had their props professionally copper plated by different companies (about $75-$100 each)...They all came back with different finishes; from highly polished, to very rough (like 60 grit sandpaper)...

The copper plating didn't seem to work any better than regular bottom paint...They maybe held off the growth for a month longer than bottom paint, but once growth started it seemed to get really bad in a short amount of time...

I know this first hand since I checked them out regularly when I cleaned my prop/bottom....

I would really like to know how well the zinc plating does, since I was told it's better than copper plating...But obviously not bad enough to pay the $$$ for it :-)

Tom

[Ray & Sandy Erps]

I was told that melting parafin wax to coat the prop has anti-fouling qualities.  It's something I've done at each haul out but don't have a baseline to compare it to as far as how long it keeps the barnacles off.  They eventually start to accumulate before the next haul out but I don't mind needing an excuse to go diving to scrape them off and change the zincs.

[bjmansfield]

Has anyone tried any of the anti-fouling paint made for outboard drives on their prop??

Jack

[bjmansfield]

Ron:

Re:  the primer

I agree completely.  Our local WMarine still has the Tempo brand outboard drive anti-fouling kit which has the primer and Anti-fouling paint.  

This is what I was wondering if anyone had used?

Also, on the copper plating on wooden ships of sail,  I think that was for stopping/repelling boring worms more than barnacles.

Jack

[Tom P, IMPULSE #233, '86]

Ron,

Like I said in my first post above...

I have always had excellent results by priming with Underwater Metal Kit by Pettit before applying the bottom paint; http://www.pettitpaint.com/products2.asp?Productid=57&Catid=3&SubCatid=9

It successfully stuck to my prop and shaft for 2 years (shaft and prop both bronze)...

I also had great results on my last boat which had a stainless shaft/bronze prop...

Tom

[Roc]

Jack,
That is what prompted me to ask this question.  I've used Tempo primer and antifouling paint that is for outdrives.  I've used this for several years.  The problem is that is comes off in sheets because it never sticks well.  I've even cleaned the prop and shaft with bronze wool and Mary Kate on & off, and it still doesn't stick.

One other question I have for everyone is if I put primer and paint on my prop, will it throw the balance out significantly enough??

Thanks,
Roc-

[Roc]

Ron,
Don't you think the epoxy primer in the underwater metal kit would put on a thick coating, that could throw the balance out?? (I don't know what the consistency of this stuff would be, thick or thin..) According to Tom, he uses WM CPP on his prop over the primer kit, I would think a thick coat of that CPP would compromise the balance??  Ablative paint needs to go on thick...Tom, any advice....

Ron, What type of paint would you prefer after using the primer kit?

Thanks for all the suggestions..

Roc-

[Tom P, IMPULSE #233, '86]

Roc,

I apply a pretty thick coat of primer and bottom paint to my shaft/strut/prop with a brush...And have a very hard time believing it has any significant effect on the prop balance...

I realize that prop balance is important, but I think a possible difference in paint thickness is definitely splitting hairs...

The very first step is to get the metal clean before the priming process...I usually use a stiff wire wheel and drill motor to get the surface clean; not highly polished clean, but bare metal clean...Then wipe everything down with acetone before painting, and I'm careful to not touch the area with your bare fingers (don't want oil from your skin on the metal)...

Next, I always tape off the area on the shaft for the zinc...It's much easier to tape it off and remove the tape while the paint is still wet, than to scrape the area later which will possibly cause the paint to chip...  

The first coat of the primer kit (a metal etchering process???) goes on VERY, VERY THIN; the directions say apply a thin, "translucent" coat, and they mean it---more is not better...The next coat is the actual grey epoxy primer, which the directions recommend 2 good coats...I usually put this on fairly heavy...

Once the last coat of epoxy primer reaches it's cure window for bottom paint (approx 2 hours???---I can't remember), I put a decent coat of bottom paint on everything...By applying the bottom paint within the epoxy primer overcoat window, you do not have to sand the primer (which will reduce the thickness), and I believe you also get a better bond between the two paints...

When I paint the hull (usually 3 coats when using CPP), I always add another coat to the running gear as well...Therefore, I may have a total of 5-6 coats of paint on the shaft/prop (2 coats grey primer, 3-4 coats bottom paint)...

Once again, I definitely think worrying about paint thickness and prop balance is splitting hairs...You are applying the same paint to ALL surfaces of the prop, in pretty much the same manner (in my case brush)...Therefore, it's not like you are painting ONLY one blade of the prop with 6 coats of paint; which might cause a balance problem...

By painting the whole prop, only the VERY SLIGHT difference of paint thickness on each blade will affect the balance, which I strongly believe is minimal...  

And it's not like our props are turning super high RPM's, like some motor boats...So prop balance is less crucial...  

Now, the last time I did this job I brushed on the primer, and sprayed the whole boat bottom (bottom paint)...The ONLY reason I did this was I wanted the smoothest finish possible on the entire hull (for speed), and not because of prop balance or any other issues...

If/when I change back to an ablative bottom paint, I will go back to my past practice of rolling/brushing everything, including the prop...

Just letting you guys know what works for me...

tp

[Roc]

Tom, THANKS for the info.  You've been very helpful!!!

Regards,
Roc-