Power Washer

[York]

I recently purchased a Cape Dory 25. It has 30 years of bottom paint on it and tried using a 3000 psi power washer on a small section. It took off the paint except for the first coat. My question, can using a power washer holding the nozzle close to the bottom paint hurt the gelcoat? I can see how it can, but I want to be sure before I use it on the rest of the bottom. The part I did was easy, and I know it is not all ablative paint. It will save me hours of sanding.

[Figment]

I've seen powerwashers blast chunks of mortar out of a stone wall, and blast the sand face off bricks.

Yes it can hurt the gelcoat if the gelcoat is crazed or cracked or loose, but (one might assume that) you are NOT a blind orangutan, so you'll probably back the spray head off an inch or two if you suspect any such damage.

Really, I'd use the powerwasher for the bulk of the old layers, but leave that last layer mostly intact for a few licks with the sander.

[York]

That's my plan. I just wanted to get opinions before I started. Thank you.

[Quetzalsailor]

I use the nozzle set to a small fan on my 2500psi machine. A small fan can be aimed to peel loose paint. A tight focus won't take barnacles off but will drill neat holes through the top of your shoes. Similarly, a tight focus won't punch through paint but will destroy adjacent wood.

[York]

I have been able to use the power washer to take the paint down to the first coat and then sand. It has saved hours of sanding. The previous owner just painted every year without doing any sanding. There was 30 years of paint on the bottom. I figure I will drop 50 lbs of paint off the boat by the time I am done. Thank you for reply.

Brent