Anti-fouling Paint

[gregs]

In my quest to build a flaoting boat lift I came up with a good source of 55 gallon plastic barells. They a white in color and I am thinking that after they sit in the water for a while they are going to start growing stuff on them. I am looking for ideas on painting them with something like antifouling paint or some other ideas to treat them with.

[messabout]

Polyethylene drums can be painted but adhesion is an issue. You can either flame treat or corona treat the surfaces prior to paint application and adhesion will improve considerably.

Corona treatment is probably not an option as it involves special electrical discharge equipment. Flame treating is easy enough. Use a torch and play it over the surface as if you were painting with it. An acetylene torch with a rosebud tip would be ideal. We are not trying to melt plastic, just exposing it to flame for a short time. The paint will need to be applied soon after the flame treatment or the surface tension of the plastic will be compromised, in which case you need to flame it again.

[gregs]

I am also looking for any ideas on inexpensive or home made antifouling paint. I checked a couple of sites and it seems very pricey.

[Bergalia]

Can be unsightly if badly applied, Gregs - but we 'Scots' always bearing 'economy' in mind used ordinary pitch. A quiet word with your local road repair company will probably get you a few 'chunks'. 'Cooking' in an old bucket over a low fire will bring it down to a 'paintable' constituency. Be careful not to have too high a flame - or "Pow"... But if it does catch fire put an old planket or such over the bucket and the flames will die.
Wear gloves, mask and clothes you no longer need. And once finished be prepared to throw away the brush.
An alternative was the 'underseal' for motorbodies. 'Anti-drum' was one name...the black rubbery stuff they put under wings and body work. I believe it now comes in a variety of colurs - even 'bronze'.
Not sure of the ecological effect...but sure is less harmful than many of the TBT based antifouls.
But no doubt others will weigh-in with their own 'home-made' recipes.
Good luck.

[gregs]

"pitch" to me refers to a product derived form pine trees. Something the native indians would use as a waterproofer. I would think anything used on a road would be a petroleum based product like the tar they use on built up roofs. I guess if it was petro based, stuff wouldnt like to grow on it. I will look into it a little more.

[erik818]

Greg,
I'm a wooden boat owner and have always used pitch/tar (the black stuff that is cooked out of wood, birch preferred). I find that tar functions well as anti-fouling on wood, but then I keep my boat in fresh water most of the time. On the positive side for tar are price and the smell when applying it in springtime. Boatyards are supposed to smell of tar. Tar has traditionally been used in my part of the world to treat wooden boats in springtime before putting them into the water.

I think the government agencies forgot to forbid tar, being a natural product, when they forbid most other effective antifouling paints. Basically, tar contains the condensed defence mechanisms of the wood. so it is no a healthy environment for organisms to grow on. I don't know if it is effective for boats that are mostly in salt or bracket water.
Erik

[Bergalia]

It's the 'Pitch' - as referred to by yourself and Eric818 that we used. A 'coal' substitute (the base for bitumen) was also handy. Like most 'anti-fouls' pitch wouldn't stop a build-up of growth over a lengthy period - but did retard it, especially the barnacles. And careening was always performed on a three year cycle. A stiff brush was all that was required to renew the smile to the bottom.

[BillyDoc]

Bergalia,

Is this the answer for an aluminum hull? Three years sounds quite a bit better than the peroxide-based anti-foul performance I've been reading about. Not to mention the price difference!

BillyDoc

[Bergalia]

Originally Posted by BillyDoc

...Is this the answer for an aluminum hull? BillyDoc

Ah, BillyDoc. Sorry - I've absolutely no experience of aluminum hulls. Wouldn't like to answer, not knowing the effects pitch might have on the metal structure. Sorry. But I'll bet some of the more experienced members will answer sooon enough.

But I can't see that the commercial automobile 'anti-drum' stuff would have an adverse effect. It's done my Land-Rover Disco no harm over the past ten years.And there's no sign of sea-weed or barnacles growing under the wings...