Paint stainless props to reduce galvanic corrosion?
#1
Gold Member
Gold Member
Thread Starter
Join Date: Oct 2006
Location: Newark, DE
Posts: 43
Likes: 0
Received 0 Likes
on
0 Posts
Paint stainless props to reduce galvanic corrosion?
I'm curious. I've done a lot of research on galvanic corrosion and am wondering if one could paint their stainless props to reduce it. I've never seen or heard of it being done.
#5
Registered
Join Date: Mar 2008
Posts: 206
Likes: 0
Received 0 Likes
on
0 Posts
He means magnesium anodes (aka zincs) instead of aluminum. Also, you can get a prop zinc as well- this is required on Bravo 3 drives, and can be installed on Bravo 1 and 2 as well. Check out Boatzincs.com - its about $65 for a kit.
#6
Registered
If you dont have them consider adding a merchathode system or make sure the one you have works.Also if you have shore power and use consider adding a galvanic isolator.
#9
VIP Member
VIP Member
Props are painted/ coated all the time - how many black aluminum props have you seen ? Paint is not smart enough to know the difference between Aluminum & stainless - Pre-treat the Ss prop with passivation or better yet with a blast profile of 1 - 1.5 mils in profile depth. Paint the props using epoxy. A Novalac epoxy or Cycloaliphatic Amine Epoxy will give you a good dense surface that will be most resistant to cavitation bubbles, however a simple polyamide epoxy will work well. With a blast prepared surface you can expect adhesion pull test numbers to be above 2,500 psi. Reducing the total amount of wetted SS surface will reduce the corrosion rate on exposed less noble metals. Even if you run the prop into a sand bar, not all the paint will come off and you will still have a lower corrosion rate of other metals because of the reduced exposed ss - Keep your dry film thickness low for best result - probably 3-4 mils. If you get lazy - an "epoxy powder coat" not polyester, will also work.