Introduction and 1975 Sea Nymph 16’ Skiff Rebuild

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DaleH

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Introduction and 1975 Sea Nymph 16’ Skiff Rebuild

New poster here, but have lurked here on & off for a while. I appreciate everyone’s welcoming attitudes and willingness to share. And like the boat website I own and run, I see an extremely high ‘signal/value to noise’ ratio!

I hail from the Boston area and grew up on boats, as my Dad would buy an old wooden boat and his 4 sons would help him replank and finish her out as needed; hull, motor and/or electrical. Most of my rebuilds over the past ‘many’ year have been a mix of small aluminum skiffs or larger frp hulls.

My latest build had been buying an ‘empty’ 25’ Parker sport cabin hull that had been abandoned by Harvard University of all places. She started life as nothing but an older glass hull with the original fuel tank and glass windows (everything else, and I mean EVERYTHING, had been vandalized!) and I built her up into a complete offshore-rigged machine complete with 3 steering and control stations, including a fully equipped tuna tower, and powered by a new Suzuki DF250hp motor.

I learned so much from that ordeal that I actually started, own and run the website for Parker boats – Classic Parker. Here’s my intro post plus my boat info: https://www.classicparker.com/phpBB3/viewtopic.php?f=15&t=6 from that site.

I’m now selling her and getting back into smaller and easily trailerable skiffs for inshore estuary fishing for striped bass, bluefish, and flounder. So here I am!

Part 1 Aluminum Skiff Rebuild – Introduction

I rebuilt this skiff in the Spring of 2008 to have for fishing the estuaries when the cost of ga$oline went out of sight! My big 25’ Parker at that time had an older 2-stroke motor and she was lucky to see 1.7 to 1.8 mpg! They'll be some tips in this old post (it had been posted on my https://www.classicparker.com site) that might help one do their own boat projects.

Costs to date:

* Hull $150
* Raka Epoxy 1/2-gallon kit $50
* 3/4" marine ply, good 1-side $40
* F'Glass $8
* Zinc chromate primer, I had on hand, but new quarts 2-part mix of epoxy-based primer is ~$40
* SS bolts I had on hand too …

Total to date ~$250
 

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Part 2 Aluminum Skiff Rebuild – Tools & Tips

Galvanic Corrosion – One needs to be careful with aluminum in freshwater or salt, as aluminum is less noble than other metals. When two different metals touch or are pressed against each other, under tension or not, the less noble alloy will leech away electrolytes in deference to the electric potential of the more noble metal. Aluminum is well down there on the noble metal chart, so it will leech away. You DO NOT want this to happen on an aluminum boat and it is made much worse in a saltwater environment! See the aluminum being eaten away by the SS shaft and fasteners running through it?

In layman’s terms, if you use stainless steel (SS) fasteners on an aluminum boat and DO NOT isolate the SS fastener from the aluminum, the aluminum will erode away. See the pictures. There are a few methods one can successfully use to isolate any SS fastener used from the aluminum, so let’s take the case of a SS bolt put thru the hull sides, as that’s the typical installation example.

You can put thin 1/32” nylon washers under the heads of the bolt, as well as under the securing Nylok nut, which should also bear against a smaller SS flat washer that’s right under the nut. To cover the ‘body’ of the length of the bolt that goes through the aluminum, I now use adhesive-lined heatshrink, but in the past, I’ve used electrical tape or suitable diameters of plastic tubing. I have also used e-tape or duct under the washers, trimmed to fit. Hey, it worked! Note you can also use special greases or products like Tef-Gel, reference (https://www.tef-gel.com/contain.php?param=tefgel_infor) to isolate the fastener from the structural aluminum.

Tools – I had to re-fasten the middle seat on this old hull, so I searched and searched for THE strongest rivets that I could insert, to be installed using hand tools, without resorting to an expensive couple-hundred dollar pneumatic tool. I finally found these in the fabulous, DIY’rs dream book – McMaster-Carr catalog.

Now to properly install these puppies, I needed a large rivet tool, but I found one of these large ‘wishbone’ ones on eBay for ~$40 delivered. I put new seat cleats (think 1/8” thick angled aluminum) against the hull and refastened the middle seat, and she’s as strong as new.

Plans – You're best to think out plans of what you want to do ahead of time. See my plans below. I had intended to remove the middle seat, add a locker against the port-side, but I finally came to that the design of this hull used the middle seat as a KEY structural member, to prevent the hull from buckling in on itself, so I kept it as is.

Costs to date:
* Costs from Part 1, $250
* (50) high-strength rivets $25 with shipping
* ¼” adhesive-lined heatshrink from https://www.bestboatwire.com $4
* ¼” nylon washers, McMaster-Carr $4
* Heavy-duty hand-rivet tool $40

Total to date ~$323

Oh yeah, through all of the boat trading I do, I got that trailer for $0. So far, there’s a rebuilt 16' hull and trailer for < $350? Sweet!
 

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Part 3 Aluminum Skiff Rebuild – Hull

Since this skiff will be kept on a mooring 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 acetone 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 ~2008) 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!

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
 

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Part 4 Aluminum Skiff Rebuild – Motor and Console

Motor: – I guess I should add that at this time in the project (now late Summer), I went shopping around for a used motor. I found a deal I just couldn’t pass up, an electric start 40hp Yamaha with power tilt (manual trim) from a local dealer I’m friendly with and have referred many, many people to. Turns out it that in the Spring it had been tuned up and had a full waterpump and impeller service performed, but then the owner wanted to get rid of it, as the boat was junk and practically worthless. The deal to me was that I had to take the boat and dispose of it – and it had no trailer, and then de-rig & install the motor myself – with the boat FULL of mad hornets.

No problem, I knew it would be until the next Spring before I splashed the boat, so I grabbed that ol’ neglected hull on a spare boatyard trailer and waited until the 1st cool frosty morning. That put the hornets into submission and the motor came right off pronto! As a bonus, after I stripped the OB & cables off the hull, I sold the bare hull with steering controls for $100 - sweet bonus! The marina that sold me the motor said that if they had to do all of the work to de-rig and remove the OB, they would have sold it for > $1K.

Console: – Due to the OB horsepower and accessories I wanted on this skiff, I knew I’d be adding a small side console for this rig. I had briefly considered tearing out the middle seat and putting in a large flat floor, to make the hull into a mini-CC boat, but I gave up on that idea up quickly. In reality, removing the middle seat would be akin to removing one of THE main structural components of a basic v-hulled aluminum skiff.

Shopping around on my favorite boat parts website (eBay – haha!) I bought an ‘as new’, but surplus, fiberglass console complete with new Teleflex tach, volt, trim & fuel gauges installed for short money. No one bid on it (I’m assuming) since the gauges weren’t wired up and there wasn’t any instructions with them. I took the gauges out (tested them), downloaded their instruction/install manuals, wired them up together as a set, and then ended up selling them all on eBay for $60. ****, I’m good, huh! I went just with a tach for motor gauges.

So, how to mount a console? – Simple really, remember that it takes but 3-points to establish a level plane. So I used the middle seat as the main support area, with a brace down the inside of the hull to support the console’s starboard-side, and then a vertical bulkhead up from the floor that also is secured to the vertical face of the middle seat. I think the pictures tell the story. Using ‘scrap’ plywood as my templates, I cut & fit all until the console rested square or level to the sheer of the hull.

Then it was simply installing all new gauges, instruments, and steering. For steering, I went with a new Uflex (competitor to Teleflex) No-Feedback ‘NFB’ cable steering system, procured from Andy, or “SIM”, of Shipyard Island Marina. For those who’ve never used one, these NFB steering systems are great! They have a 1-way clutch or locking device that prevents the torque of the motor from turning the steering wheel as felt at the helm. They also make the boat darn safer to operate!

Supplies used for Part 4
* 40hp Yamaha OB motor
* Fiberglass console
* Uflex NFB Cable Steering
* Color Northstar GPS
* Color Navman depth/fishfinder
* Wood, aluminum channel, and associated fasteners
 

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Part 5 Aluminum Skiff Rebuild – Done!

In the water …

Epilog for this old 16’ hull: I recall I had something like $1,500 into it and used it for a few years and then had someone offer me $2,500 ca$h for it … so I sold it …

The Future: And ‘why?’ I posted here today … I just picked up a late 90s 16’ Starcraft 160 SC model with trailer and 40hp Mercury OB for $1,500. Sweet deal huh? Well, the transom needs to be replaced and looks like it was shot with a few loads of #4 buckshot, not birdshot. I believe this to have been caused by a transom with PT wood that had copper in it.

Most interestingly, I had called Starcraft’s customer support and they said no matter what they had tried, they end up completely replacing the transoms as they were never completely successful in stopping the aluminum from eroding. But maybe their perspective is from warranty repairs, i.e., for legal purposes they need to 100% know the repair is sound.

So stayed tuned for pictures of that project … as a new post ‘some day’!
 

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25yamaha said:
just curious how fast did that Yamaha push that v hull?
I had a SE Sport 200 fin/tail on that motor for stability, tracking and to allow faster planing without any bow rise and to be able to stay up on plane at lowered RPMs ... but I recall she was a rocket ship! Believed it was in the low 30s for speed.
 

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