Bottom Paint Questions

[BentWheel]

I have some questions about bottom paint and would really appreciate any help

I recently bought a used boat that has a bottom job ( its black paint and when wet it kind of dusts off with your hand or water current ) from what I have read this seems normal but… what should I do to take care of the paint? I would like it to last as long as possible.. I did read somewhere that you cannot mix and match AF paint on a boat is this true? If so is there a way I can figure out what type I have?
The boat will only be in fresh water and slipped ( I live in N Texas and in the summer the algae grows quickly sometimes ) a friend has suggested I pull the boat out several times a year and power wash it… I am wondering if this will damage the paint? Is there a hardener that I can add to the paint to prolong it? if so… would that be ill advised ?

Thank you… any advice or help is much appreciated

[David M]

It sounds like you have an ablative paint. When the paint ablates it exposes fresh anti-foulant. Ablative paint, and all anti-foulant paint for that matter, has a limited life.

Pressure washing the foulant and exposing a fresh layer is not hurting the paint. You just dont want to get too aggressive with the pressure washer. All you need to do is to get the foulant off. You can also send a diver down to scrub the foulant off. A good diver will know what to do including a hull inspection for possible problems like sacrificial anodes towards the end of their effective life.

[BentWheel]

Ablative paint.. Ok thank you david

i am thinking then that it will wear down to the original (HULL) paint in some places sooner than others and when i see that happening do i need to remove the old before repainting?

is there anything i can do to prolong the life of it?

dwain

[FSMike]

If the boat is going to be in fresh water the paint ought to last quite a while, anti-fouling is primarily needed in salt water. Hop in the water occasionally in the warmer months and scrub off any growth with a sponge, or a brush if needed. Not much you can do to make it last longer that I know of, just don't clean it unnecessarily.

[SkiprJohn]

When I have just a bit of growth on the bottom I use a piece of old carpet and dust off the green algae that's growing there. You don't want a really abrasive pad if the carpet will take it off.
kind regards,

[Nicholson58]

I use a Scotch-Bright pad on a goose-neck pole from the deck. Don't work it too hard as the pad is a bit abrasive. This is better on hard bottom paints than on soft.

Sometime when you are out of the water see if you can get a smart guy from the marina or especially one of the paint reps when they visit the boat store or marina. (Inerlux or Pettit.) They all know each other's stuff and can tell you what you have and how to care and re-coat.

[Ex-Calif]

Originally Posted by BentWheel

Ablative paint.. Ok thank you david

i am thinking then that it will wear down to the original (HULL) paint in some places sooner than others and when i see that happening do i need to remove the old before repainting?

is there anything i can do to prolong the life of it?

dwain

As long as no "hard" growth is attaching the paint has some life left. Slime and such is normal and speed of build up depends on where the boat is and how often and fast you sail. More sailing means less leaning for me. Ablative paint "comes" off over time and you are right you will eventually see under coat showing through. The leading edge of the keel and the water line wear faster and when applying two extra coats are usually applied in these areas,

Aggressive cleaning with a brush or scotch brite will definitely accelerate the removal of the paint. The carpet, soft brush and even power wash is preferred by me but I do use "worn" scotch brite a lot.

Unless you are racing you might be happy to live with a coating of slime as long as there is no hard growth - i.e. plants or barnacles. If you preefer you can dive on the boat with a snorkel but you will likely only get the hull and not the keel. Scuba or a hookah system will give you more time to do a better job.

As far as mix and match. In general a soft paint can go over a soft paint or a hard paint. Hard paint can only go over hard paint. Hard paint is prefered by racers and those who dry sail as it will last a long time out of the water.

When you see the next layer or are cleaning a lot (weekly or so) t's time to prepare for a bottom job. In your case I recommend stay with soft paint. Haul out sand smooth and reapply 2-3 coats on hull and 4-5 on keel leading edge and waterline.

We are very fertile here and I get about 18 months with Micron Extra blue paint.

[BentWheel]

thanks everyone i learned a lot from the responses and will certainly follow the advice cant wait to get the winter projects completed and the boat back in the water ....

[fstbttms]

Originally Posted by Ex-Calif

As far as mix and match. In general a soft paint can go over a soft paint or a hard paint. Hard paint can only go over hard paint.

This is a wive's tale. Almost all traditional copper-based anti fouling paints are compatible with each other, regardless of whether they are hard or ablative. The only concern is preparation. West Marine has an excellent compatibility chart illustrating this:

http://www.westmarine.com/webapp/wcs...age=Boat-Hauls

Originally Posted by Ex-Calif

Hard paint is prefered by racers and those who dry sail as it will last a long time out of the water.

Also incorrect. Racers like a variety of anti fouling types but if anything, use ablatives more often than not because of reduced weight (due to the fact that there no build-up of old layers) and the self-polishing aspect of these coatings makes ablative bottoms smooth. As far as dry sailing goes- ablative paints can typically withstand prolonged periods out of the water. Hard paints cannot.

[Ex-Calif]

Originally Posted by fstbttms

This is a wive's tale. Almost all traditional copper-based anti fouling paints are compatible with each other, regardless of whether they are hard or ablative. The only concern is preparation. West Marine has an excellent compatibility chart illustrating this:

http://www.westmarine.com/webapp/wcs...age=Boat-Hauls

Also incorrect. Racers like a variety of anti fouling types but if anything, use ablatives more often than not because of reduced weight (due to the fact that there no build-up of old layers) and the self-polishing aspect of these coatings makes ablative bottoms smooth. As far as dry sailing goes- ablative paints can typically withstand prolonged periods out of the water. Hard paints cannot.

I said in general, you said almost all. What is the difference in our statements? Or are you just being argumentative again?

All reputable paint suppliers provide a compatibility chart - and of course I suggest anyone check before spending several grand on refinishing.

As far as racing goes, well we can just disagree on that one.

[fstbttms]

Am I being argumentative again? No. Simply correcting your inaccuracies.

[Ex-Calif]

Originally Posted by fstbttms

Am I being argumentative again? No. Simply correcting your inaccuracies.

So what did you mean by, "Almost all..."?

Old wives tale is a bit of an innacuarcy..

http://www.yachtpaint.com/Literature...-chart-usa.pdf

[fstbttms]

What do you think I meant? Almost all copper-based paints are compatible with each other. You stated (as if it were gospel), that hard paints can only go over hard paints. This is simply not true.

[Ex-Calif]

Originally Posted by fstbttms

What do you think I meant? Almost all copper-based paints are compatible with each other. You stated (as if it were gospel), that hard paints can only go over hard paints. This is simply not true.

I guess if "in general" means gospel then I will leave it to the preacher.

[Khagan1227]