Prop Speed on Sea Cocks

[Ardens2]

One of our sea cocks has frozen (probably from minimal maintenance)
Someone suggested painting Prop Speed inside the Sea cock. We asked the yard manager about it as our boat was pulled from the water today for the bottom paint. He had never heard of doing this. Anyone with any experience with it. We plan a November return to the warm Caribbean water where growth is a problem.

[tkeithlu]

It doesn't sound like a very good alternative to usual lubrication and regular exercise.

What kind of seacocks do you have? If they are tapered cylinders now is the time to take them out, lightly sand off the corrosion with very fine sandpaper, and grease them. If the stuck one is a ball valve, take the hose off, drip a little penetrating oil in, let sit, and tap with a mallet to get it going again.

[Ardens2]

We are trying to stop the growth on the sea cock as it enters the boat from the water side. That is where it was suggested to paint the prop speed, not inside the boat. We would still lubricate the sea cocks.

[Rucksta]

Propspeed works best when the coated item is moving most of the time.
It's advantage over antifoul is it's resistant to erosion at the tips due to high tip speed and cavitation.

A stationary prop (with Propspeed) will foul faster than an antifouled hull.

A hard anti fouling seems to work better than Propspeed in low flow areas like the inside of a through hull fitting.

Ablative antifouling requires water flow to slough off hence the preference for a hard paint in this area.

Additionally Propspeed relies on having a finish so smooth the critters can't get a bite on it.
Are you able to polish the inside of the through hull and apply a mirror finish?

[fstbttms]

Umm... try regular in-water hull cleaning. Just sayin'.

[Ardens2]

Rucksta,
That makes sense and thank you for the reply. We will go with the anti fouling.

[Nani Kai]

Originally Posted by fstbttms

Umm... try regular in-water hull cleaning. Just sayin'.

+1. Especially easy in the Caribbean.

[tkeithlu]

Quote "We are trying to stop the growth on the sea cock as it enters the boat from the water side. That is where it was suggested to paint the prop speed, not inside the boat. We would still lubricate the sea cocks."

Hmmm. I misunderstood the question. I apologize. You want to stop marine growth on the outside. Why not ordinary anti-fouling paint?

[tamicatana]

For cleaning of thruhulls awa saildrives I have found that a set of hookah cleaning brushes of appropriate lengths and diameter sizes work a treat

[MicHughV]

The last time I checked all my bronze seacocks...I noticed pitting on the tapered shaft and housing. Turns out, that even with seacock closed, it was leaking, 'cept I didn't know it.
I used grinding past on the tapered shaft inside the housing, but even after hours of labor, could not remove enough pitting to make a difference.
All the seacocks are electronically bonded internally, but I'm wondering if bottom paint on the outside flange may have contributed to the pitting.

Before applying any bottom paint of any kind, may be worth your while to remove the tapered shaft for a visual check.

[Manateeman]

Directly on top of your seacock, put a tee rather than an elbow. Short nipple and a cap. Tef-Gel in the cap threads.Now when you open the seacock it’s in a direct line from where you remove the cap, to the ocean. You loose the smooth flow of an elbow but it’s not critical unless you have too small a seacock to begin with. Now you can clean / brush / stick...from inside the boat. A rag will reduce the amount of water. Make sure the seacock works first. LOL.
There are lots of wire brushes and this set up is great for removing barnacles without diving. You could use a cross, then you could have another source of seawater.
Happy trails to you.
Mark