Bottom Paint Sanding Option

[amanphoto]

Qr Bbpost Maybe the first question to ask: Why are you sanding it?

If you're trying to remove it all, I would suggest getting it soda-blasted.

If you're just prepping for a new coat, I'd suggest using acetone and a scotchbrite pad.

I am prepping for new bottom paint. I currently have ablative paint on there now and will be adding more of the same by a different manufacturer (I dot know what’s on there, but I know it has copper in it). The sides are fine with a little scuffing up with something. Bottom is not flaking, but needs some love. They do not recommend acetone because it does it does not completely evaporate and residual chemical may effect the bonding of the new paint. I may try the scotch bright pad and water (doodlebug cleaning pad) The local janator supply company has a very course black pad that I think will work nicely without clogging up. The problem is that it’s 30 degrees here and don’t love the idea of laying on the ground with water dripping on me. Maybe need to down my scuba wetsuit.

[Viper]

Ya you shouldn't use acetone. A damp rag is all you need to clean the surface. Hopefully you power washed when she came out and all you'd need to do is go over it with a damp rag to get rid of any residual growth you missed.

[km1125]

Qr Bbpost Ya you shouldn't use acetone.

Why not?

I'd understand if you were saying you shouldn't NEED it, but are you saying there's a downside to using it??

I've been using acetone with a scotchbrite pad for the last 5 years or so, and NOT painting my boat. I had several years where I prepped an applied a new coat and it was getting a little thick. Since then, I started using the scotchbrite pad wetted with acetone and you CANNOT TELL that I haven't repainted the boat every year. Do a little section on your boat and go back a couple days later, and you'll be amazed at how nice it looks. A LOT less work and it avoids the buildup. Gives a nice fresh 'face' to whatever might try and attach once in the water. Sooner or later, I'm going to have to repaint when it gets too thin.

[Viper]

Not all product is compatible with acetone. It can soften the existing coat slightly and continue to be present in it enough to affect your new coat. So to err on the side of caution, I personally don't recommend it unless the manufacturer specifically says it's okay. The OP stated that it's not recommended so I assume he got that from somewhere regarding his product. Besides, it's unnecessary from an expense and health point of view, it's very harsh stuff that you should minimize your exposure to. I use a pail of hot or warm water depending on outside temps and just wipe down with a damp rag. Works fine on an ablative application in prep for a new coat, costs nothing, and no health risk.

If acetone works for you and you have no concerns using it then do what you feel works best in your case. I'm just another point of view! The OP and others will take all of this and decide for themselves what will work best for them.

[amanphoto]

Update: Wet sanding was not possible. The water is not yet turned on at the Marina. This makes it very hard to work on the boats that are stored there. I ended up using the drywall sander and shopvac. It worked great. Have to go back and touch up by hand around around the rails on the bottom.

[amanphoto]

Done with coat one. Have to go back for coat two and to trim around stands.

[bud37]

Seem to have worked just fine, only thing is, your boat is upside down .....

[denpooch]

Unfortunately in my neck of the woods we ARE NOT allowed to paint our own bottoms if stored at a marina. It has to do with local environmental impact laws.
It opens up the boat owners wallet for the marina it dig in.
A couple of years ago I had a 34 wellcraft stored at this one place and I got a bill for 39 feet of paint.
When I questioned the yard boss he got a tape measure and said follow me. At the boat he measured from the tip of the bow pulpit to the end of the swim platform. He said...see 39 ft.
When I pointed out to him that at least 5 ft of his measurement was air...he stated that covers his overhead.
The was my last year with that skunk!
Happy Easter to all!

[km1125]

Qr Bbpost Update: Wet sanding was not possible. The water is not yet turned on at the Marina. This makes it very hard to work on the boats that are stored there.

A few years ago I started working on the boat before the marina had turned the the water on. I brought out a utility sump pump and dropped it in the nearest marina well and plugged it in. The water was cold, but you have as much water as you need. I was very clean too because there wasn't any activity in the marina to stir up the silt. I washed and rinsed the whole boat down and it worked great!!

[RGrew176]

Qr Bbpost Seem to have worked just fine, only thing is, your boat is upside down .....

Makes the painting much easier that way.