DaleH
FOUNDER of Classic Parker Forum
PART 3 in a series ...
Since this will be moored in saltwater from May to October, I really wanted to protect this hull from the ravages of saltwater and/or galvanic corrosion. Where I’ll moor her, we actually have quite a bit of “stray” electrical activity in the water, presumably from dock lights or some other house/dock that may be wired incorrectly. Whatever, this river eats zincs on submersed metals, so I really want to protect her bottom
. And for the like-minded boat-nut ‘techies’ who read my posts , note that zinc chromate primer itself does not provide any ‘sacrificial’ protection. However its corrosion inhibiting properties will retard, if not prevent, any corrosion likely to impact the parent aluminum hull itself – at least on a properly prepared hull that is.
Hull Bottom: I settled on a 3-part paint system, where Coat #1 is a 2-part epoxy-based zinc chromate acid etch (see paragraph above), with Coat #2 being a rubber-based tie coat primer that serves to further insulate and protect the aluminum, and then where Coat #3 is the special anti-fouling paint made for aluminum.
As they say whenever painting – to get good results – most of the work is in the prep! The running hull was sanded back to bright aluminum, then solvent washed (never going back over a previously cleaned area with a dirty rag) and then immediately etched with the zinc chromate base. This was followed with 2-coats of the rubber-based primer and then the special (read expen$ive) anti-fouling paint made for aluminum boats, TriLux 33 in this case.
Some boaters I know don’t make any effort to paint the bottoms of their aluminum skiffs; they just wax them. Seems to work, at least in the early part of the season, but they do have to beach the boat every 3-4 weeks to scrape the growth off. I believe a prepped hull will last longer though, in the ravages of saltwater. I have seen a few aluminum hulls that were taken out of the water in late OCT and the running bottoms were literally covered with barnacles and limpets (they look like 1-sided smooth ‘scallops’ attached to the hull, sized about 1” across), plus lots of slime and weed growth. I get no heavy growth using the paint system and while I had a few barnacles on the side of a few strakes, my running surface was otherwise very clean. NOTE: if you trailer the boat, there is no need to paint the bottom with anti-fouling paint.
Hull Sides & Interior: The hull topsides and interior was sanded to remove any loose paint. Bare spots were hit with Rust-Oleum primer, followed by 2-coats of their topcoat color. The Rust-Oleum enamels are arguably the least costly and best value paint you could ever apply to an aluminum boat IMHO (costing only $8/quart) and it dries to a hard, durable, and glossy finish! And if ever needed, it is simple to touch-up a small spot/area without re-doing the entire hull or surface.
Hull Upgrades: What I added here & now to the painted hull included a thru-hull water pickup or ‘scoop strainer’ for the baitwell pump so I can have a continuous raw water supply for when fishing live pogies, mackerel, or pollack. The pickup connects to a seacock – as with any boat – any thru-hull-penetration under the waterline should be equipped with a shut-off valve, or ‘seacock’ in a mariner’s term.
Zinc Info: A picture is worth a thousands words here, so I’ll be brief. Quite simply I remove the paint where I’ll affix a common ‘rudder’ zinc to the hull. For a zinc anode to work correctly, it must be in full contact with bare, clean metal. I drilled out, then wet out the wood transom core with thin epoxy, and then imbedded a SS threaded insert into the wood using thickened epoxy, once the thin stuff had ‘kicked’ (tacky, i.e., starting to cure). This makes sure the 2 epoxy layers chemically bond with each other, which makes a stronger junction. Then I just affix the rudder zinc with a short SS bolt. Simple and it works!
See below for the pictures.
Supplies used for Part 3
* Quart-kit 2-part Aluma-Protect acid etching primer
* Quart Pettit Tie Guard primer (rubber-based) to further insulate aluminum hull
* Quart TriLux 33 anti-fouling paint
* Quart each, Rust-Oleum enamel paints – primer, white, & gray
* Brushes and 3” rollers
* Marlon thru-hull
* Marlon seacock
* Zinc anode and SS threaded-insert
Links:
Aluminum Skiff Rebuild Part 1 – Intro
Aluminum Skiff Rebuild Part 2 – Tools & Tips
Since this will be moored in saltwater from May to October, I really wanted to protect this hull from the ravages of saltwater and/or galvanic corrosion. Where I’ll moor her, we actually have quite a bit of “stray” electrical activity in the water, presumably from dock lights or some other house/dock that may be wired incorrectly. Whatever, this river eats zincs on submersed metals, so I really want to protect her bottom
. And for the like-minded boat-nut ‘techies’ who read my posts , note that zinc chromate primer itself does not provide any ‘sacrificial’ protection. However its corrosion inhibiting properties will retard, if not prevent, any corrosion likely to impact the parent aluminum hull itself – at least on a properly prepared hull that is.Hull Bottom: I settled on a 3-part paint system, where Coat #1 is a 2-part epoxy-based zinc chromate acid etch (see paragraph above), with Coat #2 being a rubber-based tie coat primer that serves to further insulate and protect the aluminum, and then where Coat #3 is the special anti-fouling paint made for aluminum.
As they say whenever painting – to get good results – most of the work is in the prep! The running hull was sanded back to bright aluminum, then solvent washed (never going back over a previously cleaned area with a dirty rag) and then immediately etched with the zinc chromate base. This was followed with 2-coats of the rubber-based primer and then the special (read expen$ive) anti-fouling paint made for aluminum boats, TriLux 33 in this case.
Some boaters I know don’t make any effort to paint the bottoms of their aluminum skiffs; they just wax them. Seems to work, at least in the early part of the season, but they do have to beach the boat every 3-4 weeks to scrape the growth off. I believe a prepped hull will last longer though, in the ravages of saltwater. I have seen a few aluminum hulls that were taken out of the water in late OCT and the running bottoms were literally covered with barnacles and limpets (they look like 1-sided smooth ‘scallops’ attached to the hull, sized about 1” across), plus lots of slime and weed growth. I get no heavy growth using the paint system and while I had a few barnacles on the side of a few strakes, my running surface was otherwise very clean. NOTE: if you trailer the boat, there is no need to paint the bottom with anti-fouling paint.
Hull Sides & Interior: The hull topsides and interior was sanded to remove any loose paint. Bare spots were hit with Rust-Oleum primer, followed by 2-coats of their topcoat color. The Rust-Oleum enamels are arguably the least costly and best value paint you could ever apply to an aluminum boat IMHO (costing only $8/quart) and it dries to a hard, durable, and glossy finish! And if ever needed, it is simple to touch-up a small spot/area without re-doing the entire hull or surface.
Hull Upgrades: What I added here & now to the painted hull included a thru-hull water pickup or ‘scoop strainer’ for the baitwell pump so I can have a continuous raw water supply for when fishing live pogies, mackerel, or pollack. The pickup connects to a seacock – as with any boat – any thru-hull-penetration under the waterline should be equipped with a shut-off valve, or ‘seacock’ in a mariner’s term.
Zinc Info: A picture is worth a thousands words here, so I’ll be brief. Quite simply I remove the paint where I’ll affix a common ‘rudder’ zinc to the hull. For a zinc anode to work correctly, it must be in full contact with bare, clean metal. I drilled out, then wet out the wood transom core with thin epoxy, and then imbedded a SS threaded insert into the wood using thickened epoxy, once the thin stuff had ‘kicked’ (tacky, i.e., starting to cure). This makes sure the 2 epoxy layers chemically bond with each other, which makes a stronger junction. Then I just affix the rudder zinc with a short SS bolt. Simple and it works!
See below for the pictures.
Supplies used for Part 3
* Quart-kit 2-part Aluma-Protect acid etching primer
* Quart Pettit Tie Guard primer (rubber-based) to further insulate aluminum hull
* Quart TriLux 33 anti-fouling paint
* Quart each, Rust-Oleum enamel paints – primer, white, & gray
* Brushes and 3” rollers
* Marlon thru-hull
* Marlon seacock
* Zinc anode and SS threaded-insert
Links:
Aluminum Skiff Rebuild Part 1 – Intro
Aluminum Skiff Rebuild Part 2 – Tools & Tips
