Can you prep a boat bottom with just power washing?

[bowman316]

Assuming your bottom is in decent shape, with just a few spots where the paint is peeling, will power washing alone get it ready for bottom paint.

or do you have to sand no matter what?

there are spots on my boat, where there is good bottom paint, then a patch of no paint. do i need to sand down the transition between these 2 areas?

the last thing I do is going to be wipe it down with paint thinner, then paint.

 

[ondarvr]

Re: Can you prep a boat bottom with just power washing?

It all depends on the paint, both what's on there now, and what you plan to use over it.

 

[5150abf]

Re: Can you prep a boat bottom with just power washing?

You only need to sand if you want the paint to stick.

Power washing alone may get it almost clean but you really need to sand to give the paint something to grip, especially on the bottom.

If you are gonna take the time to do it do it right or you will be redoing it soon.

 

[tashasdaddy]

Re: Can you prep a boat bottom with just power washing?

prep is 99% of the paint job.

 

[Chris1956]

Re: Can you prep a boat bottom with just power washing?

Bowman, If the paint is solidly attached, you may paint over it w/o sanding. Sand the bare spot so the new paint has something to stick to. sand the transiton, so you get a good job. Loose paint needs to come off. A power washer will usually take it off.

Bottom paint is so soft that power washing is very much like sanding it.

 

[DYLBOSS]

Re: Can you prep a boat bottom with just power washing?

I'm in the middle of doing an overhaul of the paint on my hull. I had old spotty paint on there. Tried power washing it off. Didn't budge. I had to use a stripper, rolled it on and let it sit. Then I used the power washer to remove it. This allows the stripping product to loosen the paint. Didn't get all the paint off, so I sanded the entire thing down (tortureous).

 

[ondarvr]

Re: Can you prep a boat bottom with just power washing?

You need to find out what paint you have on there now and see if it will be compatible with what you plan to put over it.

There are also "no sand" bottom paints that claim to stick OK without the the need to abraid the gel coat surface. I don't use bottom paints, so I have no idea if they are still on the market or not, but they were at one time. I also don't know how well they worked.

This is why I said it depends on the paint.

 

[ezmobee]

Re: Can you prep a boat bottom with just power washing?

I want to see some pics of your new boat!!!!!

 

[Chris1956]

Re: Can you prep a boat bottom with just power washing?

For the record, Bottom paint applied to a new, non-sanded, non-primed hull will fall off in chunks. This is because it is very hard to get all the mold release wax off w/o sanding or priming.

If bottom paint is already on the hull, most bottom paint will be compatable with it. The exception is the very soft antifouling paint used on very slow boats in the tropics. Any paint that holds up to a planing hull is fairly hard, and can be overcoated with any single season modified epoxy or ablative bottom paint. Also, hard, racing antifouling paint or any non-antifouling paint should not be used over standard bottom paint.