Alcanboats Forum

It seems we left off with the conclusion that there is nothing suitable for bottom paint on aluminum boats? Has anyone done any more research on the problem?

Also, boot topping tape used to be available from Marine Suppliers. I am now told that 3M no longer sells this product to the Marine Industry? I am told that the Automotive repair and detailing people have the same product as what was used in the Marine industry.., Anyone know anything about this?

Thanks. Brian "SIOUX"

Hi Brian,
That's exactly where we left off . . . .
I had a long discussion with the Interlux folks at the boat show that ended at this same place. They are not actively pursuing bringing any truly aluminum compatible bottom paint into Canada. Further, they now advise several coats on Interprotect on bare aluminum before the Trilux II to isolate even this "aluminum compatible" paint from the aluminum. (Of course, one scratch through to the metal and this isolation is eliminated)
Not a good situation for any of us . . . . .
Since paint with copper content is absolutely NOT a choice for an aluminum boat, the only alternative (at least in fresh water) is a paint with no anti-fouling properties and a good scrub from chine to waterline a few times each season.
Any other "news" out there on this topic ???

More on "bottom paint" with no antifouling properties . . . .
On Catherine Ann, after stripping off the previous copper based paint (in 1993) I applied Viny-Lux primewash and this incredibly tough industrial two-part epoxy paint made by Interlux and sold as "Intertuf". The type I used was Intertuf JJA229 which I can't find on the internet, but there are several other Intertuf paints which appear to have similar properties. The Intertuf that I put on in 1993 is still as solid as the day it went on. I did overcoat it with tin based antifouling (when it was available) and this has worn back down to the Intertuf in some places. I know that Cadoruca has only ever had Intertuf, never any anti-fouling. Depending on your water conditions, this can work with a chine to waterline scrubbing once in a while and means no cathode/anode corrosion risk to your hull.

Hi Brian, It's funny you should ask about anti-fouling paint as I'm about to re-coat my hull this week. Two years ago I took Eboness's hull down to bare metal and then applied a two part epoxy barrier coat, followed by two coats of anti-fouling red and two coats of anti-fouling black. My reasoning being that once I started to see the red I needed to add black. The anti fouling product I used was a product called Amercoat ABC4 which is available all across Canada at General Paint stores. Go to this site for more information;
http://www.amercoatcanada.com/ and click on to the link about products. I've been very happy with the results. Hope this helps.

Patrick Frampton
MV Eboness

Hi Patrick,

You have a lot riding on the epoxy barrier coat maintaining complete galvanic isolation between the hull and the antifouling paint.
Amercoat ABC4 is a copper based paint.

From the ABC4 data sheet at the site link in your message . . . .
"Improperly primed surfaces or failure to immediately repair damaged primer will result in rapid galvanic corrosion of the aluminum hull".

Hi Rob, You sure have that right. I keep a sharp eye on that barrier and so far it works great. When I had the barrier applied they put very thick two coats on it. Most of the aluminum fish boats out here use ABC#4 or #3 with a barrier coat, but I know what you mean. Some of the fisherman I've talked to tried the route you took and did not like the out come, but they are in saltwater and you are in fresh. You can realize the differences that a saltwater boat and a fresh water boat has to deal with. I have a galvanic isolator for my boat and when I re-powered in '97 I replaced all the bonding ground wiring and had everything go together back to a large zinc on the back stern area. Your boat looks alot better than mine, shape wise, and if money was no object I'd maybe go a different route. Brian should deal with your suggestion before mine, just because he is in fresh water.

Take care all.

Patrick

The April issue of MotorBoating has an advertisement for Aluminum boat anti-fouling paint. This really looks like what we need. The website
www.aquagard-boatkpaint.com

I hope everyone will have a look and see if it is as good as I think it may be?

The Company has, apparently, been around for a long time and, the paint meets US EPA standards.

The trade name is Alumi-Koat.

Brian - Sioux

Hi Brian, Thanks for the information, it looks interesting. I found the web page @ http://www.aquagard-boatpaint.com/products.htm and your link has a "K" in it. Just thought everyone should know. Thanks again.

Patrick

Eboness wrote:Hi Brian, Thanks for the information, it looks interesting. I found the web page @ http://www.aquagard-boatpaint.com/products.htm and your link has a "K" in it. Just thought everyone should know. Thanks again.

Patrick

Sorry about my mistake the website is www.aquagard-boatpaint.com

Brian
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I contacted Aquagard about Alumi-Koat properites and availability in Canada. Following is the reply. Note that antifouling is at least partially by copper content, so a barrier coat would still be advisable.
Just FYI . . . . .

Hi Rob,
Thanks for your email. The paint contains a small amount of Cuprous Oxide (3.88%). It also has Irgarol as it's slime/algae prohibiter. The waterbased paint is currently at the Canadian DEP awaiting approval. Our bottom paint for fiberglass is approved, but the Alumi-Koat is not yet. We do sell a "solvent" based version of the Alumi-Koat into Canada. Payne's is one of our distributors that carry it.
Let me know if you have any other questions.
Regards,
Greg

Greg Devine
Executive Director
Flexdel/Aquagard
1969 Rutgers Univ. Blvd.
Lakewood, NJ 08701
gdevine@flexabar.com

An article in Canadian Yachting suggests a hydrogen peroxide based bottom paint with no copper is available.

www.epaint.com is the website.

http://www.epaint.com/shared/PDF/TDS-EP ... 07-01_.pdf

I had the Marina apply a biocide free bottom paint to Sioux. It cost $193.00 per 4 litre gallon.
They used 2 gallons?

The URL above takes you to a Specification Sheet for this paint. I would appreciate comments. I will soon have to decide on what to use this Spring.

Brian - SIOUX

Hi Brian,

You did not mention whether or not you are happy with the performance and durability of this paint ?
$400 per season for bottom paint (in fresh water) is rather on the high side.

Unfortunately, once you go to a soft bottom paint, designed to keep itself clean by wearing away,
it is almost impossible to change to another type of paint without first removing all of the soft paint.
If you are reasonably happy with the ePaint, I would suggest going with this again.

Usually the bottom paint below the chine stays in better shape than between the chine and the waterline,
because it sees less sunlight. Perhaps you just need to touch up the sides every season and do underneath
every 2nd or 3rd season ?

Rob

Rob - sorry for the delay in replying. I was not happy with the result. The Marina used 2 gallons of paint remover in an effort to remove the remanents of the Black XXX. They sanded the existing expoxy paint on the hull and then applied several coats of the Bioside free paint.
Those materiels cost $597.00, to do the work they charged $1731.00 -all totalled about $3000.00. They stated that they just followed the Manufacturer's instructions on how to apply the paint!.

When SIOUX was lifted there was little growth on the hull. A quick pressure rinse removed any sign of the Bioside Free Paint.

I will not use that Anti Fouling paint again - nor woould I use the Marina to apply it.

I am looking for another solution? Any idea would be most welcome.

Brian SIOUX

A sure sign that Spring is coming. . . . . .the anti-fouling paint discussion

Brian, we are all in a difficult situation (particularly in Canada) where we still don't have access to proper anti-fouling paint for aluminum boats. Since Tin based paints were removed from the market and until biocide paints become available in Canada, there really is no "best alternative". The choices are to use a copper based anti-fouling and completely isolate it from the aluminum hull with a barrier paint (usually epoxy) or use a bottom paint which does not have anti-fouling properties (ie no copper) and scrub it regularly. The latter alternative is probably only realistic for fresh water boats.

For Sioux, the best alternative depends on a) is your barrier epoxy coat still in good shape ? and b) is the Interlux XXX realy completely removed ? and c) do you see any signs of galvanic corrosion (usually white crystals) on the hull or outdrives ?

There are anti-fouling paints which are less reactive with aluminum (a barrier coat is still required) such as Interlux Trilux II, and although these are soft (sloughing) paints they cannot be applierd over the Interlux XXX.

So, if the XXX and the biocide-free paints are truly removed and the barrier epoxy coat is in good shape, I would suggest switching to Trilux II.

If the barrier epoxy coat is truly in good shape, you see no signs of galvanic corrosion and there are still traces of the old XXX, you could return to using the XXX. Others are getting away with this, but the integrity of the barrier coat must be carefully monitored. (This assumes that all of the biocide free paint has been completely washed away)

If there is any sign of galvanic corrosion, or if the barrier epoxy coat has been broken by sanding or other abrasion, the right (and unfortunately expensive) thing to do, is to go right back to bare aluminum, and start again.

Rob

And here I've been looking for Robins.

There is no anti-fouling paint on our boat. I just give it a good scrubbing every spring and touch-ups to the waterline a few times during the season while lazing around on a sand bar. Unless there are some long term problems I don't know about yet, everything seems to be working fine.

Looking forward to the season.