Our Hull is WET! Ammonia washing???

[wingNwing]

Thanx CallMeCrazy! No heating or tenting (except to keep rain off the newly painted and not yet cured epoxy), we ended up doing only the freshwater rinse.

Lancelot, I'm not sure increased frequency of rinses would make up for duration. My understanding is that the purpose of rinsing is that you're removing the salt that's exuded as the moisture in the hull migrates to the surface, and that just takes time, thus, rinse, wait 2-3 days for more saltwater to migrate, rinse again, ...

[GordMay]

Originally Posted by lancelot9898

... The other question concerned removing blush from freshly applied epoxy. I was going to just use soap and water and scrub the epoxy however someone mentioned adding vinagar to the soap?

No need to add vinegar to the water.

“Scrubbing with water and a scouring/abrasive pad, such as 3M's Scotch Brite™ pad, removes any surface contamination, specifically any potential amine blush that may form on the surface. Amine blush is water-soluble and can be removed with tap water. The scrubbing action agitates the surface to help removal. Solvents don't normally remove the amine blush because of its water solubility. So leave the lacquer thinner, acetone, vinegar, alcohol, and other solvents in the storage bin, and use water. After scrubbing, rinse again with water and dry with paper towels.”
➥ WEST SYSTEM | Modifying and Customizing Boats - Wood/epoxy composite tank guidelines

“Interlux recommends thoroughly washing the cured epoxy with clean warm water, all-purpose soap, and a stiff brush or Scotch-Brite™ pad. The amine blush is water soluble therefore the only way to completely remove this is by following the instructions above. You will want to clean the amine blush off of the epoxy before sanding as well. If you begin to sand before removing the amine blush, you may sand the blush deeper into the surface making it much harder to remove. It is a safe practice to clean all types of epoxy resin, even if the label states that it is ‘amine blush free’ or ‘no blush formula’. Please note: Aggressive solvents like Acetone will not remove the blush.”
➥ What is Amine Blush | Interlux

“Blush is noticeable as a slippery film formed over the cured surfaces. It can be removed with warm water and a sponge (rinse and wipe).”
➥ Tech Support FAQ - MAS Epoxies - Easy Epoxy Resin & Adhesives. Marine Epoxy for Boat Repair & Boat Building; Automotive Epoxy; Epoxy for Woodworking, Signs, Surfboards, Other. New: Eco-Friendly Acetone Replacement, Non-Skid Repair

[lancelot9898]

Thanks Gord and Wings. I was afraid that letting the surface dry for several days before rising again would be best. I can probably get 3 rinsing in before having to leave. The boat will dry out over the winter, but again a moisture test this coming spring will determine if further drying is necessary. Need to look into this epoxy bottom paint idea. I was just going to use the interlux products including the barrier coats and then put regular ablative bottom paint on. Has anyone used a dry wall sander on a pole to smooth out the ridges left by an electric hand gelkote peeler?

[minaret]

Originally Posted by wingNwing

Thanx everyone for the helpful suggestions, comments, and commiseration. After about 30 days drying with agressive freshwater rinse to remove any exuded salt every 2-3 days; the boat basically showed no further change in moisture meter readings. We, the marina staff, and the mfg rep (who was very responsive and helpful) agreed that it would not be profitable to wait any longer and we began painting. The process went very smoothly. I'll let you guys know how the paint performs in about a year or so. Here's a photo
and blog post:Life Afloat Archives: Oooh, Shiny!

How low did your meter readings get before they stopped changing? Did you notice I said earlier you may not be able to get to 10% relative by air drying? Did you coat at over 10%, and did the rep give you a warranty anyway? Just curious....

[minaret]

Originally Posted by lancelot9898

Has anyone used a dry wall sander on a pole to smooth out the ridges left by an electric hand gelkote peeler?

That would resemble medieval torture. Use an 8" soft pad sander with 36 grit discs. It shouldn't take more than one day.

[wingNwing]

Originally Posted by minaret

How low did your meter readings get before they stopped changing? Did you notice I said earlier you may not be able to get to 10% relative by air drying? Did you coat at over 10%, and did the rep give you a warranty anyway? Just curious....

15% at best, 19 at worst; yes, yes, and yes.

Comments here and on SailNet, and conversation with another science friend about meter calibration, helped us decide not to worry.

[onestepcsy37]

wingnwing - looks like a csy 37. i own one, hull number 38, B plan interior.

i had to haul out last fall for personal health reasons. this summer i did an agressive bottom sanding, down to the gelcoat, to remove years of pettit trinidad hard bottom paint. i hadn't intended to do anything else before reapplying pettit trinidad but now i'm wondering if i really need a barrier coat.

i've never seen or heard of a csy that had blisters so i'm thinking just go ahead and paint the bottom. what's your take on this? did you apply a barrier coat? i haven't tested the moisture content but i'm guessing after being on the hard for a year it ought to be about as dry as it's going to get...

[minaret]

Originally Posted by wingNwing

15% at best, 19 at worst; yes, yes, and yes.

Comments here and on SailNet, and conversation with another science friend about meter calibration, helped us decide not to worry.

Lucky you; our rep would never warranty a bottom at 19%. How long is the warranty? Was it for 2000E? Just trying to determine the difference between east and west coast reps...

[shamrock]

I'm hoping to restart this thread with a couple of related questions. I am going through the exact process as WingNwing, removing bottom paing, barrier coat, and maybe Coppercoat.

I bought a moisture meter, the kind with two pins. Are these worthwhile, or do I need a pinless meter? If so, which one should I get?

My readings about a week after haul out were 5-6% above the water line and 15-24 below. This was in areas where I had scraped away the antifouling to test.

I have removed the bottom paint and powerwashed the bottom a couple of times and am now reading between 5-9% below. The higgher readings are at the very bottom of the keel.

My main question is, am I using the correct moisture meter?

And, was I getting high reading because the boat was recently hauled, not because the laminate was wet?

The boat has never had a blister problem and is 30 years old, solid glass.

[minaret]

Originally Posted by shamrock

I'm hoping to restart this thread with a couple of related questions. I am going through the exact process as WingNwing, removing bottom paing, barrier coat, and maybe Coppercoat.

I bought a moisture meter, the kind with two pins. Are these worthwhile, or do I need a pinless meter? If so, which one should I get?

My readings about a week after haul out were 5-6% above the water line and 15-24 below. This was in areas where I had scraped away the antifouling to test.

I have removed the bottom paint and powerwashed the bottom a couple of times and am now reading between 5-9% below. The higgher readings are at the very bottom of the keel.

My main question is, am I using the correct moisture meter?

And, was I getting high reading because the boat was recently hauled, not because the laminate was wet?

The boat has never had a blister problem and is 30 years old, solid glass.

You are very likely using the wrong meter. The pins you describe or for reading on wood, and the meter is probably a cheap homeowners version. I recommend the JR Overseas GRP 33. I have used one for many years and it never steers me wrong. Whatever unit you get, make sure it comes with calibration plates and has an FRP scale. You are probably only reading surface moisture right now, though the readings you describe are certainly possible.