MonArk Mod 16' V

[Skiffing]

New member here. I really enjoy this forum!

I purchased a 2000 Monark Knight 16 w/ a 2000 Merc 40 ELPT 4s last September. My son is twelve and ready for a new challenge - and I haven't had a boat in the water since he was born.

This Monark is a fully welded hull with aluminum deck. This is the hull without the side console:

The engine has good provenance and maintenance records. Seemed to be in good shape and well maintained. Compression good, etc, etc. The hull OK good for its age no dents or dings and no evidence of corrosion. Anyway, we took it home.

We had limited time to take it out this fall [2X only] for a few hours each trip. On the first trip I noticed lots of spray coming over the transom. I kicked the poorly placed transducer up - but spray continued unless at cruise. The deck plate had a hole for the bilge pump hose - and water got into the bilge. So I wasn't suprised that the pump was cycling.

Didn't matter. I can fix that - but not until next spring.

Next trip out with 2 adults and my son hunting the last of Merrimack River Stripers the bilge float switch must have stuck. I noticed we were bow high and slow out of the hole. Switched bilge to manual and it pumped "a lot".

Uh Oh!

When we got home we flooded the hull so water was above the deck and discovered two leaks in the transom.

One on the port side:

And one on the starboard side:

So we stuck a camera under the deck plate and started taking pictures:

The port side leak was obviously a busted weld and stress related. Starboard side - who knows. Even the shop I brought it too wasn't sure - but thinks also stress.

Reading this forum I now now why! The trailer bunks end[ed] a few inches short of the transom............

Here's a list of things being done [or already done] in preparation to next year:

1. Transom repair [complete]
2. Pedestal seat removal, install bench seat with swivels [in progress]
3. Stern storage, seats, fuel tank and battery area [in progress]
4. Complete re-wire
5. Lowrance Elite 5 HDI install
6. Tach install
7. Dual bilge install
8. All lighting replaced with LED
9. Trailer bunks replaced w/ slippery stuff! and new LED

If the forum has interest I will update throughout the restoration

 

[Skiffing]

While it's cold and snowy outside we're working in the basement on some modifications.

We got a used Delta truck tool box for a full size pickup for $75 and cut it apart.

We cut the box at the red line. Flipped the lower part upside down [trimmed the ends] and will fasten it to the deck and gunnels. We'll fasten composite plastic swivels and cushioned seats on top and put a hatch in for storage.

The top section fits between the gunnels at the stern and provides additional storage - seats - and covers fuel tanks and batteries.

 

[25yamaha]

I like theboat =D>
what kind of speed do you get with that 40 and 2 men with gear?

 

[Skiffing]

^^^^
26 - 27 mph

It will be better when engine height is corrected and dinged prop replaced.

 

[Skiffing]

This is the transom brace I had welded in. There is no more flex.

Still plenty of room to get a deck plate in the new deck and access the bilge.

 

[Skiffing]

Where's the darn boat.......................




I have to get innovative and create mini-projects that can be done in the basement.

Wish the boat would fit in the garage. Wish I could find the boat!

 

[Skiffing]

I finished the fabrication of the bench seat and stern tool box mentioned in post #2 above. I have a couple of questions at the end of this post I hope you guys can help me with and offer opinions on.

I bought a used aluminum truck tool box [Delta] for a full size [F250] pickup and cut it apart. The pieces are going here:

The tool box was wider than the gunwales. So after I cut the bottom off for the bench seat I also had to remove 8" from the middle of the top tool box section and mend it together so it can be watertight storage and also provide seating, if needed.

See where the gussets are? My son & I sat on this when only supported at the ends [350 lbs] and it is rock solid.

I used "T" stock under the top - notched it to maintain the slightly curved profile and riveted it to a gusset on the outside bedded in 5200. For the bottom section I used 1" "L" on the inside and left over diamond plate from the removal and riveted everything together with more marine adhesive.

The bench seat height including swivel will be at least two inches lower than the pedestal mounts that came with the boat. They were way too high, scary & loose like a goose. The new ones will be 16" above deck - which still seem to be too high. But I can't work with the boat as it's buried in 4+ feet of snow.

I cut the boxed ends off [I have ideas what these can be used for]. The bench is 16" wide and 10 " high. It is light gauge so I bought some 1.5" x 1.5" x 1/8" anodized aluminum angle at the scrap yard for $2.00 a pound that I will use for an interior frame that will be fastened to the deck and sides. I bought six 7 foot pieces for $22.00.

I bought composite seat swivels for a couple of reasons.

The steel ball bearing type are just too "loose". You get into any kind of sea and they don't stay still - uncomfortable and dangerous. And corrosion.... I don't want carbon steel anywhere near the aluminum [I'll be in salt water mostly]. They are pretty thick though - > 1.5 inches - so I may have to cut the bench seat a little lower on final fit..............

I don't know what "grade" this aluminum is - but it certainly is not marine grade. It's pretty soft - maybe 3300. So after I washed everything down I gave it an acid scrub and stainless steel wire brushing. After rinsing I wiped with acetone and used Scotch Brite pads in the orbital, wiped again and then primed with Rustoleum etching primer - inside and out - and all edges. I haven't decided on a final paint product.

Some questions -

This is a modified "V" w/ fairly aggressive deadrise. Deck to top of gunwale is 19"..... What do you think your comfortable seat height would be? [I'm figuring travel at cruise ~ 18 - 20 knots w/ a wind fetch chop] [I'm thinking I should be at 14" - still comfortable to stand up from]

Where should I put a lockable hatch in the bench seat? Top or rear? If I don't cut the beach seat lower I can put a 9" x 24" on the rear. Between the seats on top I can put a 12" x 14". The storage would be used for life jackets, cushions, tool box. The rear box would contain emergency equipment and be more readily accessible.

Lastly - paint. Since I've already primed w/ Rustoleum etching primer should I stay with that brand? Also - does the primer have to be sanded prior to final paint application [I hope not because it's diamond plate and a PITA to sand]?

Thanks.

 

[Skiffing]

Wow!

275 views and only one comment.

You're a hard group.

 

[ericman]

Here's my input. I am definitely not a fan of the poured in foam flotation, particularly when on a relatively flat bottomed boat. Poured foam traps moisture, moisture oxidizes just about any metal, even aluminum. I've seen boats with .100" thick bottom hulls with complete thru-wall pitting. Throw a tarp over the boat and climb in on a bright sunny day and it looks like a planetarium with all the pin-holes. If it's exposed, I'd get rid of it. It's work, but it will save your hull. You can substitute sheet foam, which moves around and sits above the hull, allowing water to drain past, and air to flow past, keeping things dry.

 

[rscottp]

+1 about the foam. The pour in stuff will cause problems unless boat is garaged IMO. You gotta get the snow off your roof, those ice damns are gonna do damage!

 

[Skiffing]

I'm aware of the potential with poured in place foam. It's a fully welded deck with closed end rivet fasteners. Weather infiltration isn't possible. The couple of places I examined were free of any corrosion. Ice dams are a problem for everyone in new England this year. In my case when I replaced the roof I also applied membrane under shingles for the 1st six feet. Not a drop getting inside. But thanks for your concern.

 

[rscottp]

Glad you're not getting the ice dams, think spring! It has been my experience that water alway gets in eventually and after removing hundreds of pounds of water logged foam from my boat I want no part of it. Just my two cents.

 

[Skiffing]

Understood - and something I'm going to keep a close eye on. I really don't want to take out a welded deck when there's no evidence of a problem. I cut a hatch into the quarterdeck. Others have suggested a little PM in the form of acid flush, rinse and forced ventilation.

 

[Skiffing]

Still over a foot of snow - but at least the boat is uncovered. Removed the console a while ago. Cleaned, etched and painted. Then new windshield and console railing.

New dashboard with switch panel, power and negative bus bars attached. That way all connections can be easily exposed by removing the four dashboard bolts.

I thought the windshield came with mounting hardware -brackets and whatnot - not so. The windshield is 1/4" plexiglass.

I had to fabricate the windshield mount. I used 1" angle with 5/16" X 1/2" "U" channel. The "U" provided a place to seat the windshield and through bolt with some rubber and teflon washers inside using #6 stainless bolts and stainless washers on the outside. - well coated with Tef-Gel.

I drilled near the top of the 1/2" "U" with 9/64" bit so there was good distance to the edge of the plexiglass - > 2X diameter of the hole.

So far so good.

When the console gets reinstalled I'll post the electrical stuff. Everything is new.

Side note - when I removed the console a couple of weeks ago I also removed the control bracket which is 0.10 5056 aluminum and appear original to the boat. The controls were bolted into the side and a FF was bolted into the top with poor quality stainless steel bolts.

You can see the corrosion which started at these fastenings and migrated out from them. Even so, for 15 years old, the corrosion is not structural - but something to keep in mind - especially if you are buying aluminum stock at Home Depot or Lowes which will probably be 3300 and not marine grade or corrosion resistant.

Also see the spot corrosion which appears to be from mill scale. Fortunately I haven't seen any mill scale on the hull - inside or out.

I'll acid wash this piece, prime and paint and it will be as good as new.

 

[Skiffing]

^^^
Regarding the control mount in previous post. Cleaned with soap and water then buffed with scotch bright and vinegar and acetone wipe.

Self etching primer, two coats finish and three coats flat clear coat - all per manufacturer recommendation short durations re-coats.... Then baked at 200*F for 90 minutes.

Finish was remarkably hard compared to air dry several days old - but similar to 2 weeks air dry. Just my take if you're interested in durability.

 

[Skiffing]

Things are starting to come together. Got all the wiring runs installed and reinstalled the side console.





I bedded the console with 5200 and fastened with #10 SS screws into stringers, rib and side. It shouldn't go anywhere.

Set the bench seat and rear storage in place to determine best location. Still a little more work before they are finally installed.

Still have to etch, prime and paint the rear deck repair. You can also see a stand-off welded on the port stern for a water separation filter.

After reviewing some photos of the cavitation plate [actually it was under water] while underway I decided the best option is a jack plate. You can also see a stand-off welded on for an anode.

There's a stand-off for the transducer too. No more holes in the transom.

Also replaced the bunks - extending them past the transom and covered with vinyl. Hope it's a slippery as everyone says.

PS - Shad should be running in the Merrimack in a couple of weeks.

ETA - replaced duplicate photo

 

[Skiffing]

Wiring Schematic

 

[Skiffing]

There are many threads here about factory foam leading to corrosion and factory foam getting waterlogged and adding 100's of pounds to the boat.

My skiff has factory foam and a welded deck - so no access. Members here have cautioned me - or, in fact, told me to get rid of the boat due to these potential problems.

I've done a fair amount of research on this so I can assess my risk - my 13 year old boy will be using this boat in bay conditions this summer........

I sought some expert advice and will outline what I did to mitigate my potential corrosion below. But before I do that I want to bullet point the causes of aluminum corrosion [happy to provide technical citations if requested by PM]:

- A pH condition outside of 4.5 - 8.5 will dissolve the naturally occurring protective aluminum oxide layer and expose the sheet to the environment - and corrosion.

While this is a pretty broad pH range there are lots of common household substances that will upset the balance:

-Lemon juice - 2.8
-Vinegar - 2.3
-Ammonia - 11.8
-Bayer Aspirin in 5 cc water - 3.3

So - anytime that protective layer is breached the aluminum is subject to corrosion - and if it cannot heal - the corrosion will continue. It will not heal and will continue to corrode if the assaulting material is not removed - like pressure treated plywood that contains copper - brass / bronze / steel fittings /steel fish hooks, copper wire ends clipped and left in the bilge, etc.......... So if you see suggestions and images of brass fittings and such on this site run away.

How does aluminum heal? It heals by being cleaned & exposed to dry air or pure water - with some exceptions............

-Crevice corrosion - this is a cancerous condition that travels laterally through the sheet and is impossible to stop chemically once it takes hold. I understand that this occurs due to builders not removing manufacturer mill scale. There may be other causes. But mill scale can be removed with acid etching and prevent [but not stop] crevice corrosion.

So that's my take on corrosion............ Here's what I did about it with my 15 year old boat with a welded deck:

Leveled the boat then used:

One gallon aluminum trailer wash concentrate [$20 WAB Brand Name]. Sulfuric acid / Hydrogen Fluoride diluted 20:1 and flooded below deck.

Let site 1/2 hour admitted 20+ gallons fresh water. Let sit 1/2 hour. Flushed while draining 2 hours and tilting high.

Leveled boat again then used:

4 gallons ammonia while flooding below deck. Let sit for one hour. Flushed while draining and tilting high 2 hours drained.

Checked pH of residual in bilge - 9

This is a digital pH meter from Ebay less than $10 delivered:

I have left the flush working slowly overnight and will check pH in the morning.

Once I have an acceptable pH I will high tilt [hang] the boat in the sun and force ventilate below deck with fan and vacuum. That will dry out all latent foam absorption.

Check the pictures on page 1 of this thread to see the original condition of this bilge.

Here's what it looks like today:

Comments welcome

 

[Skiffing]

Stopped flushing and drained the boat this morning and put it on high tilt ~ 30 degrees. By mid-afternoon there was no more water accumulation in the bilge. Before I wet vacuumed the remaining water I tested pH - 7.3. Perfect.

I made a cardboard shroud to cover the deck hatch and place a 24" window fan into. This will exhaust and pull air from the stern plug hole and deck plate. I will leave this running w/ the boat on high tilt when I'm not working on it and may also force air in through the deck plate at the stern with a shop vac to enhance ventilation.

Theoretically, once things are sealed up the only water that gets in the bilge should be condensation. In order for that to trigger corrosion there will need to be something to move the pH outside of the safe range of protective aluminum oxide layer. Occasional pH testing will show if there is a problem.

Since moisture laden acidity will end up in the bilge tossing a box of baking powder [pH 9] into that mix will neutralize any acid.

As far as moisture trapped by foam and turning acidic - there's no easy answer. Except the work I just performed will have killed it for quite a while.

For a long term "solution" I'm investigating methods to dissolve the foam and release it from the aluminum - but not hopeful.

Another tact is to plate the aluminum. Alodine is not expensive - but nasty to work with and dispose of properly.

 

[Skiffing]

A couple of posts up is the wiring schematic.

I used a small compartment in the tool box for power distribution and will fabricate an interior cover for it.

I ran all exposed wires in Liquid Tight non-metallic electrical conduit.

Here's the console switch panel and distribution buses on the panel. The panel is held to the console with 4 SS bolts and is easily removed. All connections are made here so they are accessible and easy to work on.