Failing bottom job cornflake nightmare

[Capt.Go]

Howdy CF Folks-


Here's today's nightmare -- any thoughts on why we would be having a failure of our bottom paint system? It's Interlux CSC I believe, my research shows it had ample cure time, it's approx. 1yr 4mo old, the bottom was supposed to be prepped by sanding and 2 coats, 1black and 1blue applied by a "reputable" yard. I don't see any "swirl" marks from a sander where the paint has fallen off tho -- Any thoughts on what went wrong are welcome-- was original paint too thin.. not enough sanding prep?... oh the list goes on..

[GreenWave]

i am not an expert but that bubbling suggests moisture is under that top coat

[rslifkin]

CSC doesn't require sanding between coats. It looks like only the outer coat has failed, which makes me wonder if it was done in too-wet weather, or the first coat wasn't dry enough or something. Definitely seems like an application problem where the second coat didn't adhere properly.

[mikereed100]

You don't mention where you are, but some bottom paints are designed for salt water only and will flake off when exposed to fresh water. Micron 66 is notorious for this.

[Mike OReilly]

I've used CSC for years. I've never seen it look like that. It does look like there is an adherence issue between the first and second coat. Beyond my pay grade to know what that is, but maybe applied when first coat was wet with rain? Maybe there's an issue with the blue paint itself. It should adhere to itself well.

CSC is designed for both salt and fresh water.

[Baby tug]

It appears the paint’s are not compatible at this point it really doesn’t matter why everything needs to be removed and repainted , I would suggest one type and one color paint , If there’s a lot of coats of paint have it blasted and start all over , otherwise a lot of hand sanding and re-painting with quality fresh paint

[Capt.Go]

Howdy - to clarify - bottom was supposed to be "prepped" by the yard, i.e. 80 grit sanding prior to painting, paint had ample cure time (16hrs min to re-coat, 16hrs to splash according to my records) that's all on the side of the can. Never seen a bonding issue this bad.. maybe mixing paints? hard + ablative? housepaint? ug... I have pics of the fellow painting the blue -- it wasn't raining or particularly wet day. It was done in Florida tho and I have painted numerous boat there and the mid-atlantic and never seen a bonding issue this bad.. maybe mixing paints? hard + ablative? housepaint? ug...maybe Interlux needs a recall...

[Capt.Go]

one coat was a "flag" coat

[Capt.Go]

I'll post when I know the exact paint the yard used. Boat was always in saltwater, perhaps it was last winter it spent in the Chesapeake.

[ItDepends]

First, Micron CSC is fine in fresh water, so let's throw that red herring out right away. Also, the color is irrelevant to adhesion. You can put blue over black. it's done all the time for good reasons when you use ablative paints.

If I look closely at those photos, the black paint I see under the peeling paint is NOT the first coat of CSC, but rather is the old bottom paint. Based on what I see, I'll make two predictions:

• The former paint under the CSC WAS black, right?
• The hull side of the flakes coming off, that is black, right? (That's the first coat of CSC.)

You are 100% right about what you see on the exposed layer. it shows NO evidence of being sanded. You can still see the roller marks, for heavens sake.

If your "reputable" yard charged you for sanding, well let's just say they are on the way to getting a new reputation. You got ripped off. The guys who put that first coat of CSC on certainly KNEW it had not been sanded just by looking, assuming they had worked in the boat yard more than a week.

Other issues...Do you know what kind of paint the original layer was? Are you sure it was compatible? (Although Micron CSC is pretty good with most everything IF it was sanded.)

Unfortunately, the only way to fix this is to sand off ALL the CSC layers, get that base layer PROPERLY prepped, and start over. The question is, do you trust the yard who screwed it up so badly the first time to do it right THIS time, even if they did it for free???

Lesson for everybody, no matter WHAT yard is doing work on your boat, if you were not there to SEE it happen, odds are it did not, or at the very least was not done right. Only ONE person in this world actually cares about your boat...

[rslifkin]

Originally Posted by ItDepends

If I look closely at those photos, the black paint I see under the peeling paint is NOT the first coat of CSC, but rather is the old bottom paint. Based on what I see, I'll make two predictions:

• The former paint under the CSC WAS black, right?
• The hull side of the flakes coming off, that is black, right? (That's the first coat of CSC.)

You are 100% right about what you see on the exposed layer. it shows NO evidence of being sanded. You can still see the roller marks, for heavens sake.

I'm torn on this one. The staining in the exposed black paint strongly resembles staining I've seen on black Micron CSC. The flakes also look pretty thin, but I can't tell in the pictures if they're just the blue coat or both new coats. But at the same time, improper prep before the black coat would make more sense than a failure between coats.

[Capt.Go]

Howdy - the original paint was a blue Interlux Micro CSC (see pic)



this is what the boat looked like coming out of the water before the bottom paint was put on. The paint the yard used was Micron 66 which is fine in salt & brackish water. I am starting to lean on poor surface prep, i.e. inadequate sanding. I just received a copy of the invoice -- it has the worker sand, paint and tape line item as being 6.5 hrs.. with an additional helper at 1.5hrs to paint.. if your hustling I suppose 8hrs to knock out 53' boat bottom is possible..

[rslifkin]

The peeling looks an awful lot like what happens when Micron 66 sees fresh water. I'm betting this wasn't a prep issue, but a boat in brackish water that got too fresh after a burst of heavy rain issue.

[Capt.Go]

It does look like a failure between coats in places





other places it looks like both coats failed

[GreenWave]

ok, so are you now saying that the paint used on this latest job which is now flaking off is Micron 66? If so, then brackish water exposure could be a problem.