Gori Folding Prop. Anti-foul Success (and Failure).

[Mark Payne]

First the good:

Boat out after a season having treated the Gori prop with Hammerite Special Metals Primer as the undercoat with Trilux Prop-O-Drev spray as the active hard anti-foul layer (3 light spray coats).
Great result. Pretty much all the black anti-foul was gone and we were back to the red primer which was still well bonded to the metal. No real growth on the prop blades and body. Easy to re-prep for another touch of primer and AF again. So much easier than previous years. I really don't recommend the stuff were a coating of epoxy goes on first. Tried this twice and had to grind it all off back to bare metal after each season

Now the bad and the question!

The fold/reverse mechanism ends up locking each season. The prop ends up stuck in forward only pitch. The gears end up with too much calcium/growth/crud and the blades will not pass the fold centre to go the other way. I always have this problem. It takes me about an hour cleaning out by scraping the gear slots with a screwdriver and flushing out with WD40. Any tips on how to stop this? I re-grease the gears each year with white marine grease. Maybe I should leave them dry? Is there a grease product that will reject the build up?

Thanks in advance
Mark

 

[vyv_cox]

First the good:

Boat out after a season having treated the Gori prop with Hammerite Special Metals Primer as the undercoat with Trilux Prop-O-Drev spray as the active hard anti-foul layer (3 light spray coats).
Great result. Pretty much all the black anti-foul was gone and we were back to the red primer which was still well bonded to the metal. No real growth on the prop blades and body. Easy to re-prep for another touch of primer and AF again. So much easier than previous years. I really don't recommend the stuff were a coating of epoxy goes on first. Tried this twice and had to grind it all off back to bare metal after each season

Now the bad and the question!

The fold/reverse mechanism ends up locking each season. The prop ends up stuck in forward only pitch. The gears end up with too much calcium/growth/crud and the blades will not pass the fold centre to go the other way. I always have this problem. It takes me about an hour cleaning out by scraping the gear slots with a screwdriver and flushing out with WD40. Any tips on how to stop this? I re-grease the gears each year with white marine grease. Maybe I should leave them dry? Is there a grease product that will reject the build up?

Thanks in advance
Mark

I have been talking to another owner of this type of prop, with the same problem. He will be copper plating the teeth to try to counteract fouling and consequent sticking. He has the equipment to do this himself but it should be possible to have it done commercially.
My 16 inch three-bladed prop cost £100 a few years ago to copper plate, so your teeth should not be too expensive.

 

[alahol2]

I don't grease the cogs on my Flexofold prop. Always worried about attractng/holding sand and grit. The teeth are usually pretty clean and always operative at the end of the season. Hammerite SMP definitely the way to go for primer, it's invariable still intact.

 

[matt1]

Unfortunately I’ve had the opposite experience for 2 seasons with my new flex o fold. Abraded with 80g as per hammerite instructions and then Trilux. Trilux had come off after a few weeks of immersion leaving a nice hammerite surface for weed to grow on. I asked flex o fold if I could now polish to a high lustre but they said I will have taken too much surface off with the 80g abrasion! I’d heard about copper plating but am confused given the advice to keep copper based antifoulings off metal parts. How come we shouldn’t be concerned with galvanic action if you have your prop copper plated?

If I got the prop plated, does every part eg the disc inside, gears etc need plating? What about where the anode makes contact with the metal? Sorry, lots of questions

 

[vyv_cox]

Unfortunately I’ve had the opposite experience for 2 seasons with my new flex o fold. Abraded with 80g as per hammerite instructions and then Trilux. Trilux had come off after a few weeks of immersion leaving a nice hammerite surface for weed to grow on. I asked flex o fold if I could now polish to a high lustre but they said I will have taken too much surface off with the 80g abrasion! I’d heard about copper plating but am confused given the advice to keep copper based antifoulings off metal parts. How come we shouldn’t be concerned with galvanic action if you have your prop copper plated?

If I got the prop plated, does every part eg the disc inside, gears etc need plating? What about where the anode makes contact with the metal? Sorry, lots of questions

I find that the Hammerite develops a shiny surface that is not best for adhesion of antifouling. Abrasion with 180 grit seems to solve it.

Copper is anodic to copper alloys so if anything is going to corrode it will be the plating.

 

[Neeves]

I thought many props now had polymer inserts, but maybe my memory is at much fault - if my memory is correct - what happens with these inserts when the prop is copper plated.

I'm vaguely thinking the polymer inserts allow the prop to accept major impact, the polymer 'gives', rather than more serious damage.

Jonathan

 

[Tranona]

It is only some saildrive props that have inserts (to isolate the prop from the drive). Conventional props are solid. With folding and feathering props you can plate just the blades, but the question here is about whether it affects the gears.

 

[Neeves]

It is only some saildrive props that have inserts (to isolate the prop from the drive). Conventional props are solid. With folding and feathering props you can plate just the blades, but the question here is about whether it affects the gears.

Understand.

But someone wanting to investigate how best to keep the teeth clean, of fouling, might opt for copper plating and might also plate the hub (which has the polymer inserts). The hub also fouls and if you are going to keep the blades clean it would seem sensible to keep the hub clean - unless electro plating might damage the polymer sleeve.

It does not appear difficult to seal the gears off and simply plate the blades.

But what about the hub?

Again it does not seem impossible to seal of the interior of the hub, containing the polymer - is it necessary (to seal the centre - considering the centre also holds the splines that fit on the shaft)

Jonathan