undercoat for antifouling?

[tim3057]

Stripping off old coats of antifoul have left bare wood in places, so much so I think I will take everything off and start afresh.

What goes on the wood? I will start with rot-proofing, but then primer & undercoat? My tin of undercoat for Toplac says 'dont use below the waterline'.

Much of the antifoul in place seems to have been slapped onto bare wood. Is this right? Or is there a specialised primer/undercoat?

Many thanks.

 

[Transcur]

Try using Primocon by International. available from most chandlers. Its expensive but very good.

 

[tillergirl]

Blakes do an underwater primer/undercoat.

 

[Casey]

Get Blakes Paint Manual & Colour Chart from your local chandlery and read the instructions!

 

[Kristal]

Sod all that sanding...

I used International, but I think they're much of a muchness. However, you might not need to strip... I was advised (and it seems to be working fine) that, in the event of not knowing which antifoul had been applied, and to prevent any unpleasant reactions, to slap on a thickish coat of primer over the patchy antifoul of last season and then apply two fresh coats of antifouling.

It also gave me the chance to change the sub-waterline colour, which I found ridiculously satisfying for something that you rarely see more than an inch of!!

Of course, as you intend to rot-proof, this doesn't help much...

/<

 

[pelorus32]

Re: Sod all that sanding...

I've just been through this with our boat. Antifoul was put onto bare wood and red lead. It peels off both of them. We had used International Micron Extra.

The advice we received was waterblast, scrape and then sand. At the end of that process any antifouling left could be accepted. We then overcoated with 4 coats of International Yacht Primer and 2 coats (three on leading and trailing edges) of Micron Extra. It's working well and is worth the effort.

Mike

BTW have spent the last 3 days at the Australian Wooden Boat Festival in Hobart with Zuline. It's been a great festival. Now for the return trip across Bass Strait.

 

[alienzdive]

Re: Sod all that sanding...

There are some chlorinated rubber undercoats that use a similar base as antifoul and are able to etch into previous coats of antifoul prior to the apliocation of subsequent coats providing the preperation is correct. Altex has a good one. It is good where the hull is patchy (but smooth)

 

[seo]

The old standard is red-lead paint, which is only available in the US for marine industrial purposes. A couple of widely used primers for steel seem to work pretty well. They are similar, both silver-colored zinc-enriched one part paints with a (tolulene, I think) vehicle, so it's nasty to breathe and impossible to clean up.
Interlux makes Primacon or Silver Primacon.
Pettit/Z-Spar makes Rust-Lok Steel primer.
These both work well on wood under the waterline. The Pettit seems stronger, but is harder to work with.
seo

 

[calloo]

'The old standard is red-lead paint, which is only available in the US for marine industrial purposes'

With due respect this satatement is not true. You can buy red lead paint from 'Traditional Boat Supplies' in Beccles Suffolk. It is expensive I agree. I have the same dilemma in that I am finding it difficult to remove the old antifoul from an Iroko hull. I have decided to use Meteclor primer. This is advertised as a primer for chlorinated rubber paints. I am not sure, however, if this stull can be applied directly to a surface which is part bare wood and part old antifoul. I am tempted to first cover with red lead, then the metacolor primer, then the final coat of antifoul. Can any body out there advise me please?