Welded Aluminum Crestliner Runabout

[Art]

I'm hoping to soon go see a 1991 17' fully welded hull aluminum Crestliner Runabout with 10 hrs. on 1997 70 hp rebuilt Johnson o/b. Have spoken with owner and seen plenty photos. Boat/engine both look great. Style/layout is what we seek seek. This 17' Crestliner would replace our current (really nice) 14'8" FRP Crestliner with its 50 hp Johnson... giving us more room and better stability for boarding off our Tollycraft's swim step or off a floating dock. We use this type of little boats as tow-behind runabout for our Tolly.

I've never owned an aluminum boat.

Questions:

What is the durability factor for aluminum compared to fiberglass? This aluminum boat has been and will continue for the foreseeable future to be in fresh water.

Will salt water fairly quickly ruin a relatively thin skinned small aluminum runabout?

What is the weight difference between aluminum and fiberglass?

Does aluminum dent easily?

Are there paints that adhere well to aluminum?

Thanks for any input you may be able to provide!

Happy Runabout-Choice Daze! - Art

 

[DavidM]

Here you go.

Questions:

What is the durability factor for aluminum compared to fiberglass? This aluminum boat has been and will continue for the foreseeable future to be in fresh water. Aluminum boats hold up well in fresh water

Will salt water fairly quickly ruin a relatively thin skinned small aluminum runabout? Not quickly and it may take a long time to see any effect. Dashew built his Windhorse power cruiser out of aluminum.

What is the weight difference between aluminum and fiberglass? Aluminum is generally lighter.

Does aluminum dent easily? Easier than fiberglass.

Are there paints that adhere well to aluminum? Yes, you need to prime with Alodine first, but why paint?

Thanks for any input you may be able to provide!

Happy Runabout-Choice Daze! - Art

 

[Old deckhand]

We own a 22 Hewescraft that we use for fishing. It is lighter then fiberglass and durable. Most new small boats sold here are now of this type, almost no new fiberglass boats sold here for the past 20 years. About 95% of the several dozen fishing charter boats are aluminum. I have owned aluminum skiffs for 30 years and believe they work the best for where we boat. I am not familiar with Crestliner and wish you the best with the boat.

 

[Art]

Thanks Guys!

 

[Nomad Willy]

See this classic old crestliner on craigslist.
CL id# 5661369756 Seattle listing.
It's an 18' cabin cruiser .. Low and narrow like they were in the day.

 

[psneeld]

Not all aluminum alloys are created equal. So salt water can be an issue for older boats without the newer, better alloys.

Can't really comment on that particular boat.

IIRC, a couple TFers have reported their aluminum dink deterioration quickly when near the exhaust. I think they were diesel exhausts, but can't say one way or another whether gas exhaust could do it too.

Other than that, aluminum boats are great...with a couple exceptions like they can be hot in direct, strong sun...but so can dark anything. They can be noisy for fishing, but interiors can fix that.

 

[Conall63]

A fully welded aluminum boat in that length requires some skills to build. The scantling on a welded boat are going to be heavier than a riveted boat, so without looking at it I'm already thinking it's going to be robust.

Aluminum for sure will dent, but again, this boat should be much more stout than a riveted boat. Aluminum is fairly easy to repair to the point that good repairs are hard to see.

Painting aluminum is similar to painting steel in regards to prep work such as sand blasting gives best results. After blasting though, aluminum requires a special wash before priming. Once primed, all paint steps are the same as steel or plastic.

Look for cracks in frame members, plates, and chines. Aluminum can crack.

The right topside paint and color for sure will help with the hot metal.

If properly built, I don't think you'll find a tougher boat.

Conall

 

[Wood]

ETAI've owned a number of aluminum skiffs and larger. It's not a big deal to properly maintain - just need to know how.

Embedded below:

Questions:

What is the durability factor for aluminum compared to fiberglass? This aluminum boat has been and will continue for the foreseeable future to be in fresh water.
A 17' is probably 0.10 or 0.12 hull thickness. It is durable in both fresh and salt. Try to determine if Mill Scale was removed from aluminum when manufactured. If so - Good. If not - something to keep in mind as it can promote crevice corrosion. Most corrosion starts inside - especially where there is flotation foam that traps moisture.

A standing wet bilge is the worst enemy with a skiff [next to bone-head manufacturer short-cuts]. A wet [or even damp] bilge will turn acidic. the acid will remove the aluminum oxidation protection and attack the base material. If corrosion starts, the area above can reoxidize and seal the corrosion in. In this case a strong acid wash is needed. Then treatment with a base until the bilge has a neutral or slightly basic pH.

Where foam interfaces aluminum moisture will persist. Periodic flushing with a base such as household ammonia is recommended.

If this is a used boat I would flood the bilge with Zep aluminum cleaner or equiv. These are industrial strength phosphoric & hydrochloric acid mixes. Care is required.



Will salt water fairly quickly ruin a relatively thin skinned small aluminum runabout?
Salt is not necessarily a big factor in corrosion - see above. Adoline is dangerous [poisonous] stuff and a serious hazardous waste. It cannot be applied well to a hull with foam insulation and deck without first removing deck and all foam. This is not a homeowner application and not cost effective.

What is the weight difference between aluminum and fiberglass?
Significant.

Does aluminum dent easily?
It dents. How easily? Relative. I'd rather dent an aluminum boat than crack or fracture a GRP and have to do gellcoat or other repair to prevent core damage.

Are there paints that adhere well to aluminum?
Many. Acid wash. Aluminum primer and paint away. Prep is [always] the key.

Thanks for any input you may be able to provide!

Happy Runabout-Choice Daze! - Art

Dirty bilge [2000 16' MonArk Knight welded hull]. Never cleaned - even. Minor pit corrosion - but progressive.

Clean bilge. After acid flood. Rinse, rinse. Ammonia flood.

See the pit corrosion now? It's arrested and treatable.

ETA: Don't forget a good anode on the hull. This one had maybe 100 hours in salt water last season. See the pitting? A welded standoff for attachment eliminates through hull bolts.

 

[Wood]

Not all aluminum alloys are created equal. So salt water can be an issue for older boats without the newer, better alloys.

Can't really comment on that particular boat.

IIRC, a couple TFers have reported their aluminum dink deterioration quickly when near the exhaust. I think they were diesel exhausts, but can't say one way or another whether gas exhaust could do it too.

Other than that, aluminum boats are great...with a couple exceptions like they can be hot in direct, strong sun...but so can dark anything. They can be noisy for fishing, but interiors can fix that.

Exactly - exhaust is acidic and will corrode aluminum.

 

[Art]

Thanks to you all. I've decided to stick with FRP for our runabout... matter of fact pretty much for all our boats.