Adding to Barrier Coat

[zboss]

Hi Folks,

So I have an offer out on a boat that has had a barrier coat applied at some point. There are currently no blisters on the bottom but my understanding is that once the boat is cruised extensively in warmer tropical waters, this may cause blisters to appear.

There are lots of layers of paint on the bottom that is flaking off but the bottom probably has not been painted in 5 years. I would like to soda blast the bottom to remove all the built up layers of the paint and its my understanding that the soda-blasting will not effect the barrier coat.

I was thinking that I would then apply an additional four layers of barrier coat before repainting.

My question is this: can I apply new barrier over old barrier?

Thanks!

- z

[model 10]

Our boat had the bottonm soda blasted. It does not look like they that much control of the process to not remove a layer of paint. Gel coat is thick enough to perhaps live through a soda blast job but not a barrier coat unless it was pretty thick. That said, it leaves a nice surface for adding more barrier coating.

[brankin]

Barrier coat are generally made of epoxy with a very few being vinylester. Once the bottom paint is removed, pressure wash the bottom with hot water and let dry. Then start coating with epoxy if the soda blasting left an adequate profile....if not sand with 80 grit. Systems that have mica filler like interlux 2000e, create an effectively thicker barrier coat with less actual build by creating a longer path for the water molecule to travel to get to the substrate. Hope my musings helped.

[zboss]

Originally Posted by brankin

Barrier coat are generally made of epoxy with a very few being vinylester. Once the bottom paint is removed, pressure wash the bottom with hot water and let dry. Then start coating with epoxy if the soda blasting left an adequate profile....if not sand with 80 grit. Systems that have mica filler like interlux 2000e, create an effectively thicker barrier coat with less actual build by creating a longer path for the water molecule to travel to get to the substrate. Hope my musings helped.

How much time do you need between the last 2000e coat and a coat of paint?

[brankin]

Here is a video that might help

Interlux Interprotect 2000E Howto - YouTube