Propeller Painting Input

[scenarioL113]

I have brand new virgin props. I would like some input on painting them and anti-fouling paint.

I have some extra interlux interprotect 2000e that I was thinking about priming them with and then painting them with antfouling paint. I have tried many different things over the years but nothing I ever did stood out as "The Way".

I have done trilux, outdrive paint, barnicale barrier, regular bottom paint etc...

I read up that the interprotect 2000e allows the bottom paint to be more effective on the bronze props but IDK if it will be a waste of time. The interprtect is 2-part and will need a number of coats.

What you guys think?

[Tony Meola]

Frank

For our boating season up here in the NEXT, I have had good results using the Petit zinc spray. It seems to hold up well on the props.

[Carl]

Lots of work, many steps and expensive. Prop Speed works and holds up well. Buddy of mine used and he went from yearly growth to nothing.


Guys in the Club have been using the Zinc Spray from Pettit with good results at $30 a can @ 93% zinc.

Other guys have one up-ped them with HomeDepot Cold Galvanize Zinc Spray at $6.58 a can @ 93% zinc.

Both claim similar results.



Me, I'm found of using the boat enough to keep the running gear clean...but once inawhile if I hit the shaft and wheels enough with the roller when painting bottom, I'll continue to paint the antifoul over the gear...which never last IF I use the boat.

The idea of putting barrier paint on wheels with a coating of antifoul over makes me cringe. Nice new clean, slippery, balanced and tuned blades with globs of paint on top. Now if using ablative paint that wears away...I'd expect lots of wear on spinning items and a rudder behind the wheels. Maybe hard paint then...If it sticks then you have to grind off yearly or it builds up.

[Charlie J]

ive never painted my wheels or shafts
i did paint my rudders
in the spring i would just use a 3 m pad on a drill
and remove the crap that the power wash missed in the fall
prop speed is great i understand but expensive
if you use the boat weekly you shouldnt have any problems

[Amberjack]

I had marine growth until the boat moved from a nearshore (shallow, slow, warmer water) berth to a far end berth with deep, faster moving, cooler water. And I started running at higher speeds. There hasn't been a growth problem on my uncoated undercarriage since.

[ccroke13]

I did a little experiment. One year I did the Home Depot cold galv spray on the shafts and props. I put 100 hours on the boat that season and when I hauled out there where barnacles and growth all over them. Last year I cleaned up the shafts and props and used nothing. Put 93 hours on her and the running gear was nice and clean and even better after the power washing. This year I’m going to do the same as last and hope to have another 100 hour season.

[Tooeez]

When I was up north I would paint the shafts and wheels with the bottom paint--end of the season there was no paint, and few barnacles. When I moved south the bottom paint did nothing--within weeks the props were covered. I then used the Petit spray, which kept things clean for about 9 months before it wore too thin. Last haul the yard applied the Petit from a can with a brush--much thicker coating which seems to be working much longer.
I think what helps a lot is every few weeks I go to the local sandbar, anchor up in about 4 feet and get under the boat with a leather palm workglove. I run my hand over the shafts and props, and I can feel the tiny developing barnacles pop right off. I don't know if the zinc is supposed to keep them from growing, but it seems to me that it is hard for them to stick to.
For what it is worth, when I was considering what to use one of the yard guys whispered in my ear that the propspeed doesn't last worth a damm.

[beachbum]

Another shout out for propspeed. It's expensive but it works.

I'll try to dig out a photo of a Sunseeker 92 on shafts that we put propspeed on, came out a year later very clean. Repeated yearly for 5 years.

We also tried it on Arnesons under the advice of propspeed themselves and it lasted about a month before there was no visible evidence of it!

[beachbum]

That was beginning of April, Propspeed had been applied a year before. The boat was moved twice since mid-September i.e. twice in the previous 7 months. Shafts spun every other week whilst on the berth, boat was down on cruising speed about 1.5 knots.

Water temp during summer around 23-25 deg celsius, down to about 12 during winter.

[scenarioL113]

I went with Petit Prop Coat. We will see how it goes. Thanks to all who gave their .02 I like hearing all the different ideas

[Snipe]

Prop speed!! Here it is on the 100ft Hatteras I run in the summer.

[Carl]

Them there are some mightly purdy wheels!

[scenarioL113]

Prop speed!! Here it is on the 100ft Hatteras I run in the summer.

I honestly thought those were the props you were putting behind those 370's

[Snipe]

Frank I honestly don’t know what’s going to work on my boat I am going to have to experiment a little bit! I spoke with Bob H he has been very helpful! Put the port motor in today to get some final shaft measurements.

[scenarioL113]

Frank I honestly don’t know what’s going to work on my boat I am going to have to experiment a little bit! I spoke with Bob H he has been very helpful! Put the port motor in today to get some final shaft measurements.

I would prob take an inch of prop/pitch off of whatever the prop shop says is good. Unless the prop shop knows that you want to make your rated RPM PLUS 100 minimum. You want to make that RPM EASILY. You want to make that WOT RPM the same way you make your cruise RPM.

You have big HP and if underprop a bit you will have happy engines. No other way to prop it IMHO

[Snipe]

Thanks frank I will def be propping on the light side to make rpms plus. I talked to jimmy G and he told me his prop size and pitch so I have a starting point i know he has 380’s but i think the power curve is close. Between him and Bob H I have a starting point also combed through the internet and this sight for other 31’s with 370’s but not sure if they made shaft angle and engine modifications. I have a couple good prop guys to work with.

[JH_B28]

Thanks frank I will def be propping on the light side to make rpms plus. I talked to jimmy G and he told me his prop size and pitch so I have a starting point i know he has 380’s but i think the power curve is close. Between him and Bob H I have a starting point also combed through the internet and this sight for other 31’s with 370’s but not sure if they made shaft angle and engine modifications. I have a couple good prop guys to work with.

Hi Snipe,

Our last 31 we sold had 370's with shaft angle reduced to 12 deg. We ran Michigan DJX 3 blade 21x24 full cup. Cruising at 2400rpm we were seeing 28kts and top end was about 34kts. This was full diesel and water. There was another 31 here in PR with our same set-up but running Michigan Dyna jets and they saw 37 kts top end. Boat was built lighter than ours.

Hope this helps.

Regards,

Jorge

[Dug]

I paint my rudders but not my props. I do not get enough hours on the boat overall and end up with little bitty barnacles. I looked into propspeed this past fall and it was SERIOUS money. Even the yard didn’t think it was worth it.. So, I applied nothing. Maybe next year I’ll remember I have some of that spray that they stopped producing like a decade ago but of course worked well!

Dug

[Snipe]

Thanks Jorge I have a set of Michigan hytorque 21x24 that I bought from a friend was going to have my prop guy play with these a little bit. I plan on buying a brand new set of acme 3 blades as well.