Shafts and Props Question

[Jackman]

Guys,

She's all ready for the water, I put in this coming weekend. I have one question, though, that's bugging me. The first year I had the boat I cleaned the shafts and repainted them since they were painted before. Didn't ask any questions, just did it. Now that I have them cleaned up, shiney and the props are shining because they were just scanned ect, I am wondering about paint. I was thining that since the props and ruinning gear are part of the bonding system, why should they be painted? Wouldn't you want as much conduction as possible to maximize the effectiveness of the bonding system? WOuldn't painting the gear reduce the boats ability to dissapate a stray current?

Just curious, I'm not an electrician. What do you guys do?

Thanks,

Jack

 

[lisaann]

try wiping the shafts and props down with stp oil additive seems to work well
mark

 

[Passages]

Don't paint props. I was at Hale Propeller here in CT a while back and the owner showed me a FUBAR prop with a lot of galvanic erosion. Said it was due to a combination of paint on prop a inadequate cathodic protection.

If you run your boat on regular basis, criters will not have an opportunity to take hold on props & shafts.

 

[Nonchalant1]

Only reason to paint em is for anti-fouling for marine growth. It depends on where you are and how often you run it. Interesting articles in last 2 months of Passage Maker magazine about painting and anti-fouling running gear.

 

[Passages]

Resurrecting an old thread since I now have a similar situation to Jackman.

Spent a good chunk of time chiseling critters off my shafts, props & rudders. Then rotary wire brushed everything nice & shiny.

I know you NEVER PAINT PROPS, but why not the shafts? There was a good amount of critter residue this year (as opposed to last year where there was little to none - go figure), and I would like to avoid that chore next year. So why can't I hit the shafts with a coat of metal prep primer and 2 coats of ablative?

I did a survey in the shed today, out of 12 boats, 4 had paint on the running gear. What do you think?

 

[Genesis]

I paint running gear and have painted props before as well.

The only issue with the props is that the paint won't stay on 'em. I've never had a problem painting struts, shafts and rudders - I consider it part of the bottom job - it makes a BIG difference.

 

[Capten]

Marine growth on the shafts is a big problem for us and a serious performance robber. We've never been able to keep paint on the shafts though and usually just leave the metal bare and plan on diving once a month to clear them. The PropSpeed treatment we used this past year did stay on the shafts and did keep growth and barnacles form adhering to the shafts. I would recommend it.

We have never painted props on any of our boats (partly due to fishing superstitions) but have not had any real issues with marine growth on them. If I did have problems on the wheels I think I would use the PropSpeed. It's expensive but I am now a believer.

 

[Genesis]

I've never had trouble keeping paint on the shafts. The key is proper primer.

This year I'm trying a primer and Trilux - I've used brushed paint before, this is sprayed. We'll see how I like it.

On props the paint definitely works but keeping it on is a problem. We get a LOT of growth on the wheels and even very, very small amounts of it cause major performance disruptions. Its almost impossible to get them truly clean diving the boat; you can scrape but you have to get it ALL off and getting back to the original smooth surface is not easy.

A potentially huge issue with running gear is the struts. If you get hard growth on the struts near the cutless bearings it can interrupt water flow through the bearing - this will quickly lead to overheating and bearing failure and you're then dealing with pulling that apart next time you're hauled - and that is NOT a fun job.

 

[REBrueckner]

Galvanic corrosion on quality underwater gear is not caused by anti fouling paints. Inadequate (galvanic) corrosion protection and stray (electrolysis) currents , of course, and poor alloys (crevice corrosion and the like), yes, again. If you use your boat a lot, especially during the active marine organism reproductive season, it's not likely you need to paint your props. But if your boat sits week after week and is only used occasionally on weekends, you'll have to paint them or clean them underwater water. The only other alternative is one of the sonic protection systems which emits low frequency vibrations and dislodges new marine critters.

 

[Capten]

We've tried a few primers in the past on the shafts but still can't get paint to stick for long. Maybe it's us!

The PropSpeed however sticks like glue to the shafts. I hear it locks onto the props very well also.

Here is a photo of our shafts once the 2 part PropSpeed was applied last spring. Took 2 of us about 25mins to do both shafts once they were clean and prepped. Notice the golden color.

 

[jim rosenthal]

A few years ago I tried the Interlux treatment on my shafts; brushed to bare metal, Zinc Chromate primer, 5 coats of Interprotect. Didn't stay on worth a damn. Now I have the yard wirebrush them and then I spray on outdrive paint, which works as well as anything and is cheap and easy. And try to run the boat at least weekly. And pay a diver to clean them off. There doesn't seem an easy answer to this. Nimrod, was your boat in the Bay for last year or at the shore? If you were in the Bay and felt that PropSpeed held up, I might try it....

 

[Capten]

A few years ago I tried the Interlux treatment on my shafts; brushed to bare metal, Zinc Chromate primer, 5 coats of Interprotect. Didn't stay on worth a damn. Now I have the yard wirebrush them and then I spray on outdrive paint, which works as well as anything and is cheap and easy. And try to run the boat at least weekly. And pay a diver to clean them off. There doesn't seem an easy answer to this. Nimrod, was your boat in the Bay for last year or at the shore? If you were in the Bay and felt that PropSpeed held up, I might try it....

Jim,

We tried the Interlux a few years back with the same poor results.

Re PropSpeed: We applied it over at Jabins in early May and stayed at BBM until early July when we left for Sunset Marina. We did not run the boat much during that time while we prepped for our summer at the ocean. No growth at all observed during my pre-departure dive.

We stayed in Ocean City until early October. Again no growth on shafts although we were using the boat quite a bit. We did a quick haul out in early December at Jabins to change zincs (the water was too cold and I was too lazy to dive and do it) and again there were no barnacles on the shafts and the PropSpeed still looked like the photo I posted previously. There were some large barnacles on the prop nuts and in the engine sea strainers. The boat had practically no use during that 2 month period back at BBM - only one lunch trip to Crab Claw.

All in all I would say that the stuff works. We will not be hauling to paint this year so it will be interesting to see how the PropSpeed holds up/works after an extended period. As I mentioned previously, BBM Service Dept is now offering the PropSpeed. Not that I would have them do it. I think we bought ours from a distributor in Baltimore.

 

[Traveler 45C]

The only other alternative is one of the sonic protection systems which emits low frequency vibrations and dislodges new marine critters.

Sonic Protection Systems? I'd like to hear more about those...

 

[doc g]

Pettit Barnacle Barrier is good and stays on well . Works good in the bay. It is in a spray can. Mine was done in June '05 . Still there and no growth as of October when I last dove on it.