Hello, first time doing bottom paint on my Catalina 27. I got Pettit Hydrocoat and while the Pettit topside paint turned out great, I've been having a hell of a time with this hydrocoat bottom paint. Initially is was way too thick and would roll on with small clumps and chunk off when I rolled over it again. I've tried thinning it little by little which improved it a bit, but even after thinning and drill mixing it for what felt like an hour, it would still have small chunks that looked like someone mixed oatmeal in it. So after thinning it, it goes on either too thin and you can see through it or it chunks off. I'm starting to think it's just bad paint. I've spent the better part of 2 days messing with it. I'm going to take it back and tell them it has to be a bad can of paint. I'm so sick of that stuff at this point I want to try something else. What's a decent bottom paint I can use that will go on easy? And also do you use primer on the bottom? It had old paint already that I've sanded down pretty smooth for the most part. Thanks for any input.
Ablative bottom paint help
- Thread starter Catalina27
- Start date
What thickness roller are you using? Antifouling goes on best with a thin nap, like 3/16”. I’ve never used hydrocoat but the other paints I’ve used have definitely needed lots of stirring but after that are just homogenously thick, not with any kind of chunks.
Do you know what type of paint was on there before? Some paints are more tolerant of overcoating once roughed up by sanding than others. It could be that your existing paint is just incompatible. Also, is the existing paint very well adhered? Often older paint with many layers will look ok, but new fresh paint will pull it off in flakes and chunks not unlike what you’re describing.
Do you know what type of paint was on there before? Some paints are more tolerant of overcoating once roughed up by sanding than others. It could be that your existing paint is just incompatible. Also, is the existing paint very well adhered? Often older paint with many layers will look ok, but new fresh paint will pull it off in flakes and chunks not unlike what you’re describing.
I have never seen chunks in any bottom paint I’ve ever used. I’m wondering if you got a bad can? Maybe it had frozen at some point in the past!?!?
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,398
You ask about what paint. I used PETTIT TRINIDAD 75 paint. I was pleased when it was finished with 2 coats and a 3rd coat on the edge surfaces of the keel and rudder. The hull was rough sanded to address the 4 year old bottom paint. My 35ft boat used 2 gallons. Expect to get 3 plus years from the project in my waters.
I had purchased two, one gallon cans of West Marine CPP Plus which I've found is ideal for my area. The two cans sat in my basement for three years before I finally figured it was time for a re-coat. When I opened the two cans, the consistency of the copper compound on the bottom of each can was like concrete. All I could do with a screwdriver was to scar the compound on the bottom of the can. As far as mixing the paint, surely you jest.
I knew the neighbourhood paint dealer where I had purchased some house paint a few months back so I visited him and had him shake the bloody bejabbers out of the two cans with his shaker upper for about 15 minutes. Now it was a whole different story. Just as smooth and silky as you can get right to the bare metal bottom of the cans. I admit it was somewhat overly viscous for my taste, but went on like satin with a short nap roller.
Even if you pay a few bucks for the shakeup, it's worth it.
I knew the neighbourhood paint dealer where I had purchased some house paint a few months back so I visited him and had him shake the bloody bejabbers out of the two cans with his shaker upper for about 15 minutes. Now it was a whole different story. Just as smooth and silky as you can get right to the bare metal bottom of the cans. I admit it was somewhat overly viscous for my taste, but went on like satin with a short nap roller.
Even if you pay a few bucks for the shakeup, it's worth it.
As David asked ….Do you know what was on there prior to this application and what thickness and type roller did you use.
I had the worst time ever using Pettit Hydrocoat on my boat. I asked here last year for advice, I was directed to Arroworthy Silky Mohair Roller or Red Tree Mohair Rollers, both are 3/16” thickness.
This year I used the Arroworthy and found it to be “somewhat” easier to apply, but not easy.
Prior to this roller, using just a generic 3/16” roller, for me, it was like rolling a stick along the bottom of the boat and trying to get the paint to spread.
Hours of work. Protection was great but the work to apply was exhausting.
My boat has had no other bottom paint than Pettit from 2000. First was Unepoxy Plus, then to Hydrocoat.
The Unepoxy is a hard paint, not ablative, so a little more sanding, not much effort but a little more is needed prior to repainting than the ablative type.
Also, as mentioned, get a professional shake just before you apply. Stirring, pouring out and re-stirring just is not going to get the solids to incorporate into the paint.
Remember this famous quote…….shaken not stirred. It’s better.
Believe me, I feel your pain.
I had the worst time ever using Pettit Hydrocoat on my boat. I asked here last year for advice, I was directed to Arroworthy Silky Mohair Roller or Red Tree Mohair Rollers, both are 3/16” thickness.
This year I used the Arroworthy and found it to be “somewhat” easier to apply, but not easy.
Prior to this roller, using just a generic 3/16” roller, for me, it was like rolling a stick along the bottom of the boat and trying to get the paint to spread.
Hours of work. Protection was great but the work to apply was exhausting.
My boat has had no other bottom paint than Pettit from 2000. First was Unepoxy Plus, then to Hydrocoat.
The Unepoxy is a hard paint, not ablative, so a little more sanding, not much effort but a little more is needed prior to repainting than the ablative type.
Also, as mentioned, get a professional shake just before you apply. Stirring, pouring out and re-stirring just is not going to get the solids to incorporate into the paint.
Remember this famous quote…….shaken not stirred. It’s better.
Believe me, I feel your pain.
Were there actually solid clumps in the paint before you started? A bad batch or one that froze, though this seems unlikely in TX.
I assumed you thinned with water. This has to be done at high speed, not your typical cordless drill. It also depends on the mixing blade; most are not effective for this because emulsifying is not their purpose. Paddle impellers, aka axial flow turbines, work best. Difficult to buy, I made some of mine.
Are the chunks bits of old paint coming off? Sometimes the old paint can look OK, but the suction of the roller pulls it off. This is most likely.
Hydrocote is good paint.
I assumed you thinned with water. This has to be done at high speed, not your typical cordless drill. It also depends on the mixing blade; most are not effective for this because emulsifying is not their purpose. Paddle impellers, aka axial flow turbines, work best. Difficult to buy, I made some of mine.
Are the chunks bits of old paint coming off? Sometimes the old paint can look OK, but the suction of the roller pulls it off. This is most likely.
Hydrocote is good paint.