Bottom Paint Prep

[Jwatson]

I have a 1979 53’ Convertible and am painting the bottom this week. Has anyone ever had the yard lightly pepper the bottom with the sandblaster for paint prep instead of sanding the bottom with 80 grit sandpaper? The yard I use offers that service. The intention is to abrade the surface for paint prep and not complete paint removal. Thanks!

 

[racclarkson@gmail.com]

I have a 1979 53’ Convertible and am painting the bottom this week. Has anyone ever had the yard lightly pepper the bottom with the sandblaster for paint prep instead of sanding the bottom with 80 grit sandpaper? The yard I use offers that service. The intention is to abrade the surface for paint prep and not complete paint removal. Thanks!

Guess it comes down to how good the existing paint is sticking.

 

[Jwatson]

Existing paint is adhering well to the hull with no peeling or flaking. There are a few “barnacle discs” on existing paint. I used Pettit Hydrocoat in Mar 2018 and it did not do well in the waters of Port Canaveral, FL. I am going to apply Trinidad Sr hard paint this time. Sanding the entire hull last time was murder on my shoulder and I don’t care to have the paint dust get on me anymore. Next haul out in the future will be a complete removal of all bottom paint with new application of a barrier coat. I am hoping the light peppering of sand will do the trick for surface prep.

 

[Photolomy]

I had mine sand blasted at cape marina, and then painted it with SR 60. The sand blasting did a good job. I will definitely do it that way again. The previous paint was ablative, and past due for painting, but it spent its life up in St Louis on the Mississippi, so I don't know if that makes a big difference. Why are you switching to hard paint?



By the way, how is it going over there?

 

[Jwatson]

Good to hear from you and hope all is well down in Melbourne. Life is the same at Cape Marina. Plan on taking the boat to Marsh Harbor and staying there July and August. I do want to try the hard paint to see if it does better in these waters. Over the years, since I don’t run my boat every week because of travel, I don’t get the performance out of the ablative type paints. I have read and been told that hard paint gives better protection when the boat is not used every week and Trinidad SR is a great way to go. I do realize that the hard paint can build up over time, but I do plan on starting over with a new barrier coat next haul out.So Cape Marina just did a light dusting of your hull? Did it take long? I do have them blast the running gear. Was it effective in removing those pesky “barnacle discs”?

 

[Photolomy]

I didn't really have any barnacles on it. It was up north on the river, and it had just made an 1800 mile journey down here, and was only in the slip a few weeks at cape marina before I painted it, and it was winter. I thought the sand blasting did great at least with respect to removing the old paint and prepping the surface. It was only 1.5 hours, I remember because they charge by the hour. Did you ask the dock master? I thought they were pretty honest about what it would and wouldn't do. Now you have me worried that I had it way too easy on my first bottom paint.

 

[Jwatson]

I did talk to Mike about doing it...just lightly enough to abrade the surface but not to deeply to cut to the barrier coat. I would not worry. Applying paint is the easy part. All the work is in the prep and I am done sanding the hull of a boat. If this works well on prepping the bottom then I am sold on it.