Bronze Propeller: to paint or not to paint?

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haydude

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Hello,

I have always used International Prop-o-Drev on saildrive and aluminium propellers with good success.

Now I have a bronze folding propeller. It came out badly fouled after two years in the water since brand new and shiny.
I have now cleaned it using starbrite bottom cleaner (it is practically sulfuric acid) and it has regained once again its lost shine (I was amazed it still had a shine under all that!)

I am very tempted to paint it this time, using 2/3 coats of international prop-o-drev primer and then prop-o-drev antifoul. However I am concerned that it might not stick well to shiny bronze. On the other hand I do not want to sand the propeller and take the shine off too.

I have been recommended to cover it with propshield, but that is only thick wax that washes off quickly, and I need something that lasts two years.

What do you recommend?
 
We have a bronze feathering prop. I paint it with prop-o-drev every year and it comes out at the end of the season without fouling. However half the paint falls off too and I have to start again by cleaning it all. It's easy to work with though.
 
I am in this dilema too
Last season I restored my bronze 3 blade flex o fold to a mirror shine with a lot of elbow grease and soft tools and brasso
On my old boat I painted the bronze prop with Hammerite special metals primer and it stuck on for years. I anti fouled the prop also but the antifoul came off pretty quick on the outer portions of the blades. Can anyone confirm that prop o dev is significantly better than the hammerite/antrifoul option?
Thanks
Martin
 
The primer to metal is possibly the most important component, the effectiveness of any antifoul depends strictly on how well the primer bonds to the propeller. If that flakes, then also the antifouling will go. I am not sure that prop-o-drev primer would stick properly to shiny bronze. Your experience with hammerite is interesting and this is the second post I read about hammerite. I am considering to put International Interprotect two part epoxy primer first, then coat with prop-o-drev primer, and then prop-o-drev antifoul.
 
On advice from this forum, this spring I tried polishing our brand-new prop to a shine and leaving it bare.

By September it was a mass of barnacles and we were seriously down on power.

Will be painting it this winter.

Pete
 
You may have seen my posts about Hammerite special metals primer. Last year I applied it to my prop, with four coats of Velox antifouling as specified. At end of season the antifouling was pretty good but quite a bit of it had chipped off. This year I sanded off the antifouling, applied two coats of antifouling, and also did the p-bracket with Hammerite and two coats of antifouling. Results excellent. Photo taken before pressure washing, as hoisted after 800 miles, four months afloat.

Velox2ndseason_zpsafce8ccd.jpg
 
Last edited:
vyv_cox said:
You may have seen my posts about Hammerite special metals primer. Last year I applied it to my prop, with four coats of Velox antifouling as specified. At end of season the antifouling was pretty good but quite a bit of it had chipped off. This year I sanded off the antifouling, applied two coats of antifouling, and also did the p-bracket with Hammerite and two coats of antifouling. Results excellent. Photo taken before pressure washing, as hoisted after 800 miles, four months afloat.

Velox2ndseason_zpsafce8ccd.jpg
Click to expand...

Out of interest, had the prop anode only done four months as well? I have same prop, and after six months, the VERY expensive anode is similarly eaten away.
 
"Thank you for your reply. That is reassuring. Do you use the primer too I assume? "


Yup, used the primer as instructed. It doesn't stick very well. Does the Hammerite primer damage the surface of the bronze at all I wonder?
 
NormanS said:
Out of interest, had the prop anode only done four months as well? I have same prop, and after six months, the VERY expensive anode is similarly eaten away.
Click to expand...

No, both anodes have done at least two seasons. I first fitted the Bruntons anode without a shaft anode, years ago. It barely lasted one season. I then added the shaft anode, increasing the life of the bruntons to two seasons. The shaft anode lasts two or three seasons.
 
vyv_cox said:
You may have seen my posts about Hammerite special metals primer. Last year I applied it to my prop, with four coats of Velox antifouling as specified. At end of season the antifouling was pretty good but quite a bit of it had chipped off. This year I sanded off the antifouling, applied two coats of antifouling, and also did the p-bracket with Hammerite and two coats of antifouling. Results excellent. Photo taken before pressure washing, as hoisted after 800 miles, four months afloat.
Click to expand...

Well if Vyv uses hammerite metal primer on bronze, so will I. Thank you Vyv!
 
I have gone across an advise to shine polish the bronze prop and threat it with silicon grease. It maybe is silly but I did that this August. Will check the prop after the winter. :D
 
Just a thought has anyone tried copper coat on their props. they say a first coat of epoxy primer then a top coat of copper coat and it should lat a long time. Te main problem with props is cavitation a the blade tips, this causes the coating to be removed by the water boiling at the tips which weakens the coating.
Like I say, just a thought
 
theguerns said:
Just a thought has anyone tried copper coat on their props. they say a first coat of epoxy primer then a top coat of copper coat and it should lat a long time. Te main problem with props is cavitation a the blade tips, this causes the coating to be removed by the water boiling at the tips which weakens the coating.
Like I say, just a thought
Click to expand...

It is difficult to get epoxy to stick to brass and bronze. I tried using West epoxy and Coppercoat on my P-bracket. Despite good efforts to roughen up the surface it didn't last at all well.
 
vyv_cox said:
It is difficult to get epoxy to stick to brass and bronze. I tried using West epoxy and Coppercoat on my P-bracket. Despite good efforts to roughen up the surface it didn't last at all well.
Click to expand...

I heard once that the recommended way of bonding epoxy to metal was to continue keying up the surface after the first coat of epoxy is on. This stops the metal oxidising which will form a much better bond.
 
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