Sound enough?

[bclaypole]

Hi,
As I'm very new to salt water boats... Would you consider this as sanded down to a "sound layer" in the preparation for new antifoul?

[Orion Jim]

It doesn’t look uniformly sanded. It appears large areas were skipped over and the areas which seemed needy were given priority.
This photo illustrates a bottom which has been uniformly sanded with 120 Grit using a random orbital sander.

[Chotu]

I’m with Jim. Your purpose here is to scuff up the old anti fouling to get the new to stick, not to create a fair surface by sanding bottom paint.

Just touch every hill and valley with your sandpaper and get it looking like Jim’s pic.

[gamayun]

If the old peels off easily you need to get to good but otherwise you're just trying to scuff up the old to get good adhesion with the new Where you've gone all the way to the gel coat, then make sure there's a smooth transition to good bottom paint so you don't have any sharp edges. I had a problem on my boat in which the underlying layers were "rotten" and kept flaking off as I tried to find solid paint, so I sanded everything off and started from scratch. But do think hard about going down that path. It's time consuming and expensive....

[JPA Cate]

Originally Posted by gamayun

If the old peels off easily you need to get to good but otherwise you're just trying to scuff up the old to get good adhesion with the new Where you've gone all the way to the gel coat, then make sure there's a smooth transition to good bottom paint so you don't have any sharp edges. I had a problem on my boat in which the underlying layers were "rotten" and kept flaking off as I tried to find solid paint, so I sanded everything off and started from scratch. But do think hard about going down that path. It's time consuming and expensive....

....and if you do it yourself with a 2-1/4" scraper to get rid of the paint sickness, it will take one man in good shape 4-5 days, days that you pay for the use of the hardstand. Plus for the Tylenol. It will make you sore, find your weak spots.

As Jim and gamayun both said, you need to really scratch deep to give tooth for the new paint.


Ann

[bclaypole]

Thank you for all your responses. I feel better about the job done (was done by a reputable yard on the other side of the world from me). They have removed the rotten old antifoul and roughed up the stuff that was 'sound'.
Brad