Bottom painting ?

bigdog · 12-30-2015, 10:18 AM

Current boat was bottom painted by prior owner, when I purchased 3 years ago. Blue bottom ! FYI... Boat came from ocean.

Apparently, the paint was improperly applied by previous owner, because it has been chalking since I took ownership. What I mean by 'chalking' is that the paint surface will rub off when touched. Has anyone heard of this happening before?

In the Spring, I want to completely remove this old paint. Is there an easier way to remove, other than 'sanding' to remove?

I thought there was a chemical liquid product, which could be painted on, then hosed off?

Thanks for your feedback !

Puffin · 12-30-2015, 10:32 AM

Your boat is painted with an ablative bottom paint. This is designed to wear off as you described. typically it is used for ocean use vs. Lake use. You can strip this paint and repaint with a hard bottom paint which is more epoxy based. A lot of info can be found in the following link.

http://www.bottompaintstore.com/blog...-bottom-paint/

Descant · 12-30-2015, 10:47 AM

Some paints are intended to slough off over time or with friction. This prevents unwanted growth from attaching itself to the hull. I recall that some of these are applied in a two step process. When the finish coat wears away, the undercoat, a different color, shows and you know it is time to repaint, or at least where to touch up.

rowinghelmet · 12-30-2015, 01:58 PM

I once stripped bottom paint from a boat with chemical stripper and sanding. It's a pretty labor intensive and miserable job.

I would recommend sodablasting or walnut blasting. It's like sand blasting, but won't damage the gelcoat.

Fyi, the bottom will be dull when you're finishing. It is usually sanded with course grid sandpaper before the bottom paint is applied. You would need to re-gelcoat or sand and buff the bottom to restore the shine. This is also really labor intensive.

You might just want to re-paint with a white bottom paint like Petit Vivid White.

bigdog · 12-30-2015, 04:13 PM

Thanks to everyone who responded, much appreciated !

Bigdog

Rich · 01-04-2016, 11:31 AM

If you don't care how it looks, and you will be removing it anyway, you may want to try to remove it yourself with "On-Off" bottom cleaner.

This is the stuff we normally use to remove the lake slime from the bottom of a non-bottom-painted boat.

I noticed on an older boat that it also does a good job of removing some bottom paints.

It's messy, and not fun to work with as it is a type of acid, so you have to be careful. But you can get it in gallon quantities, and it just may remove your bottom paint. Or it may just make a mess of it and you may still have to remove it in some other method.

Good luck!

Woody38 · 05-10-2016, 07:42 PM

There is a great product for this. I've used it to remove varnish on trim in my former 100 y/o house. StarTen. Originally was Dan Swett's Striper That Works.
I had to get this straight from he manufacturer since it was not sold locally.

Comes in liquid and gel. New formula has longer wet time. The gel dried on me so I painted the liquid then wiped it off with a Bounty towel. This does not raise the grain on wood and does not have to be neutralized.

www.starten.com

12-30-2015, 10:18 AM	#1
bigdog Senior Member Join Date: Apr 2006 Location: Central MA-Gilford Posts: 1,447 Thanks: 342 Thanked 119 Times in 96 Posts	Bottom painting ? Current boat was bottom painted by prior owner, when I purchased 3 years ago. Blue bottom ! FYI... Boat came from ocean. Apparently, the paint was improperly applied by previous owner, because it has been chalking since I took ownership. What I mean by 'chalking' is that the paint surface will rub off when touched. Has anyone heard of this happening before? In the Spring, I want to completely remove this old paint. Is there an easier way to remove, other than 'sanding' to remove? I thought there was a chemical liquid product, which could be painted on, then hosed off? Thanks for your feedback !

12-30-2015, 10:47 AM	#3
Descant Senior Member Join Date: Mar 2006 Location: Merrimack and Welch Island Posts: 4,357 Thanks: 1,346 Thanked 1,623 Times in 1,055 Posts	Bottom paint Some paints are intended to slough off over time or with friction. This prevents unwanted growth from attaching itself to the hull. I recall that some of these are applied in a two step process. When the finish coat wears away, the undercoat, a different color, shows and you know it is time to repaint, or at least where to touch up.

12-30-2015, 01:58 PM	#4
rowinghelmet Senior Member Join Date: Jun 2012 Posts: 60 Thanks: 0 Thanked 25 Times in 20 Posts	Sodablasting I once stripped bottom paint from a boat with chemical stripper and sanding. It's a pretty labor intensive and miserable job. I would recommend sodablasting or walnut blasting. It's like sand blasting, but won't damage the gelcoat. Fyi, the bottom will be dull when you're finishing. It is usually sanded with course grid sandpaper before the bottom paint is applied. You would need to re-gelcoat or sand and buff the bottom to restore the shine. This is also really labor intensive. You might just want to re-paint with a white bottom paint like Petit Vivid White.

01-04-2016, 11:31 AM	#6
Rich Senior Member Join Date: Jun 2012 Location: Derry / Gilford Posts: 1,246 Thanks: 73 Thanked 345 Times in 235 Posts	If you don't care how it looks, and you will be removing it anyway, you may want to try to remove it yourself with "On-Off" bottom cleaner. This is the stuff we normally use to remove the lake slime from the bottom of a non-bottom-painted boat. I noticed on an older boat that it also does a good job of removing some bottom paints. It's messy, and not fun to work with as it is a type of acid, so you have to be careful. But you can get it in gallon quantities, and it just may remove your bottom paint. Or it may just make a mess of it and you may still have to remove it in some other method. Good luck! __________________ Don't listen to me, obviously I don't understand what I'm talking about! Let's help each other save time and money: WinniGas.com

05-10-2016, 07:42 PM	#7
Woody38 Senior Member Join Date: May 2016 Posts: 578 Thanks: 46 Thanked 110 Times in 81 Posts	Stripping bottom paint There is a great product for this. I've used it to remove varnish on trim in my former 100 y/o house. StarTen. Originally was Dan Swett's Striper That Works. I had to get this straight from he manufacturer since it was not sold locally. Comes in liquid and gel. New formula has longer wet time. The gel dried on me so I painted the liquid then wiped it off with a Bounty towel. This does not raise the grain on wood and does not have to be neutralized. www.starten.com

12-30-2015, 10:32 AM	#2
Puffin Member Join Date: Apr 2004 Posts: 43 Thanks: 10 Thanked 7 Times in 7 Posts	Your boat is painted with an ablative bottom paint. This is designed to wear off as you described. typically it is used for ocean use vs. Lake use. You can strip this paint and repaint with a hard bottom paint which is more epoxy based. A lot of info can be found in the following link. http://www.bottompaintstore.com/blog...-bottom-paint/

12-30-2015, 04:13 PM	#5
bigdog Senior Member Join Date: Apr 2006 Location: Central MA-Gilford Posts: 1,447 Thanks: 342 Thanked 119 Times in 96 Posts	Thanks to everyone who responded, much appreciated ! Bigdog