antifouling outdrives

[Guest]

Hi, I've just bought my first outdrive boat SS Portofino 31 with twin 290 drives and want to antifoul the drives. Different shops tell me different things. One tells me to use etching primer first, then a normal primer then the antifouling. Others tell me to give the old antifouling a rub down and apply special antifouling for outdrives. Any input welcome as I have no experience and want to get it right to avoid costly corrosion problems.

 

[Guest]

Just a quick rub down with wet and dry to knock off the shine and apply the special antifouling for outdrives (called International MpX I think)They do it in Volvo colours of which there are two dependant on the year but since it's underwater a bit academic. I usually find one coat is enough but maybe two to make sure. Remember when you antifoul the boat (with the other stuff) to leave a one inch gap around the outdrive. (some electrolysis reason that I read somewhere) hope this helps David

 

[Guest]

You probably already realise that you can't use copper-based (normal hull type) antifouling & have to leave the gap mentioned above between the hull antifouling and any part of the drive assembly.

You'll find that no outdrive antifoulings are anything like as good as hull antifoulings & the leg will need scrubbing attention during the season. International do Trilux now which should be good. They also do Veridian but that's just a slippery surface without any biocide action. I used a spray clear antifouling last year - it was absolute rubbish.

 

[Guest]

Thanks, one further question though, the drives seem cleanly painted however the transom shield show minor corrosion damage. Would a rub down and normal primer be sufficient or do I need this etching primer ?

 

[Guest]

The etching process (as far as I am aware) is to create some surface 'roughness' so that the paint will key. The corrosion will certainly have produced surface roughness so no need for any more. A rub down and prime will be sufficient. David

 

[Guest]

I just applied to my outdrive and props this new product called Veridan. Bit of a pain to apply etc, but I will let you know whether it is any good after this season. It is not an antifoul as such, just smooth surface coating that in theory will shake off marine life from the props when they turn and just a wipe with a sponge/cloth for the outdrive.

RM.

 

[Guest]

.....it's what they said about GRP boats when they first came out....best of luck though and i guess you will find out the effectiveness before the end of the season. regards Dave the sceptic

 

[Guest]

I'm think the same as you, but if you don't try it I'll never know.

RM.

 

[Guest]

Richard, Any tips re the Veridian, I,m looking at using it this weekend or next week. It looks complicated.

How did you get into all the nooks & crannies associated with outdrives?

 

[Guest]

Hi,

Well firstly you need to make sure that the temp is above 5c. Secondly make sure you get some good sand paper (medium grade I used).

I decided only to do the bottom half of the outdrive(the bit below the hull) this year to see if this product actually works. This is the area that will affect fuel and speed. Therefore I sandand upto the exhaust outlet. Make sure you rub down the whole area but not nesscary to remove the paint if in good condition.

Then wipe with thinners (I used white sprit) to remove any grime from sanding. The first coat is the easy bit, just paint it on to the point it starts to run ie. a thick layer and don't add thinners to make it go further. The instructions talk about measuring, I didn't bother, basically you must make sure you have a thick layer). I would suggest the grey veridan pack, the clear will show up all that rubbing down!

Leave that overnight to dry, then add the second (Last) layer, by mixing 3:1 ratio ie. I used an old measuring cup (mouthwash variety) and to cover one outdrive bottom takes three of those cups (20ml) and one cup of hardner. Mix that all in a jar and leave for 10mins, then paint it on in the same fashion as written above. It takes along time to dry (10hours or more in this temp).

Do the same for your props, making sure they are rub down well.

Remember the boat must not go in the water for a couple of days after the application.

I think that covers it, I do suggest you read the instructions a few times. Remember the TEMP must not be below 5c and no more than 7days between the first and second coat.

If you need more info just let me know.

RM.

 

[Guest]

have you guys ever thought of covering the outdrives with a black bag? you still need to address any paint/ corrosion problems, but the beasties that live on your legs do'nt like it with no water flowing past and no sunlight.

 

[Guest]

Won't the propellor/s cut through the bags?

 

[Guest]

I am about to paint my outdrive too. The paint has eroded at the front of the leg leaving bare pitted aluminium. I have stripped the anti fouling off and now have some bare metal and some of the original volvo coating. Can I rub down and spray etching primer over the lot or do I need to get it all back to bare?

Regards.......Rich.

 

[Guest]

Whatever you apply DO NOT COVER THE ANODES WITH ANTIFOULING. This will significantly reduce their effectiveness.

Good luck

 

[Mpb1p]

Thanks, one further question though, the drives seem cleanly painted however the transom shield show minor corrosion damage. Would a rub down and normal primer be sufficient or do I need this etching primer ?

Hi, I work in the refinishing trade mainly on aluminium cars, etch primer does exactly what it is supposed to do it chemically etches it’s self to bare aluminium but it requires I further primer to give it depth for applying further paint , another system is epoxy primer of which adheres mechanically to the aluminium, it can be applied directly to aluminium or the best of both worlds is to etch first with a two part wash etch and then apply a two part epoxy to gain some workable depth before applying your-finishing coats, would would need to abrade the cured epoxy with something like a P180 or P240 or you could scotch brite it well.
you best option for durability would to use a two part paint, you can anti foul onto the outdrives but would be best to once again scotch brite. If you dry stack your boat I wouldn’t worry about anti fouling the drives just keep them clean.

 

[russ]

I epoxied and af my 290e in white Seajet outdrive paint. . Most weekends I can see the algae come back and so clean off with an extension brush. Easy to see the fouling when in white.

 

[Sianna]

I used this stuff




and got pretty good results, it seems to be holding up ok,

Before:



and after