Boat Bottom Basics

Maintaining, repairing, upgrading, commissioning, decommissioning topics.

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Dan Corcoran
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Joined: Sun Jan 29, 2017 4:32 pm

Boat Bottom Basics

Post by Dan Corcoran » Wed Mar 27, 2019 5:39 pm

I have a small bit of exposed keel, and on the hull I have a few blisters next to each other. What are the recommended products to build up new coats of protection after I strip it away?

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Vento Solare
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Re: Boat Bottom Basics

Post by Vento Solare » Wed Mar 27, 2019 6:02 pm

Dan Corcoran wrote:
Wed Mar 27, 2019 5:39 pm
I have a small bit of exposed keel, and on the hull I have a few blisters next to each other. What are the recommended products to build up new coats of protection after I strip it away?
Sand to bare metal and apply Interprotect 2000e to the exposed metal on the keel. Use 4 coats, then apply bottom paint.

For blisters sand, open the blister and flush with water. Determine if the source is failed barrier coat (easy fix) or wet core from inside (a very ugly and expensive fix). Dry out the area, fill blisters with thickened epoxy and sand when cured, fair with using epoxy thickened with microlight fibers. cure, sand (longboard preferred method) then apply 4 coats interprotect 2000e (alternate grey / white makes it easier to see). Follow directions for bottom paint topcoat based on paint type.

Dan Corcoran
Posts: 85
Joined: Sun Jan 29, 2017 4:32 pm

Re: Boat Bottom Basics

Post by Dan Corcoran » Fri Mar 29, 2019 4:54 pm

Thank you!

TSweather
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Joined: Thu Aug 03, 2017 9:24 pm

Re: Boat Bottom Basics

Post by TSweather » Fri Mar 29, 2019 10:41 pm

+1 for this method
Sand to bare metal and apply Interprotect 2000e to the exposed metal on the keel. Use 4 coats, then apply bottom paint.

For blisters sand, open the blister and flush with water. Determine if the source is failed barrier coat (easy fix) or wet core from inside (a very ugly and expensive fix). Dry out the area, fill blisters with thickened epoxy and sand when cured, fair with using epoxy thickened with microlight fibers. cure, sand (longboard preferred method) then apply 4 coats interprotect 2000e (alternate grey / white makes it easier to see). Follow directions for bottom paint topcoat based on paint type.
There is one piece I would add depending on the climate and temperatures in which you are going to attempt to apply a barrier coat. In an earlier post I was having an issue around thru hulls that required a repair and barrier coat, though it was far too cold to use interprotect. As an alternative I chose to use West System 422 barrier coat additive and applied a couple extra coats beyond the required minimum. It mixes in with normal West epoxy by volume, rolls on smooth, sands relatively easy, and cures within much more flexibile temperature and humidity parameters. If you wanted to you could also alternate by adding some white West pigment to every other layer to make sure you're not burning through when sanding, but it sands in a pretty predictable way as long as you're careful. Actual material is a dark grey once mixed in. I had also touched up one small ding on the trailing edge of the keel at the same time using the same material and it bonded well to the lead. My repairs were submerged for 7 months and came out looking perfect with no blisters or crazing.

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