Yellow Boat 4 twin NQD jets driven by P2632 Brushless Outrunner 3800kv Brushless

Yellow Boat 4 

Twin NQD jets modified with brass stern tubes.

I have alternate nozzels which are a little larger than standard also.

Brass impellers made from cutdown brass props

Two P2632 Brushless Outrunner 3800kv Brushless

 

Stern Tubes brass shafts wrapped in PTFE tape until they fit the tubes. Will be setting up air cooling system with small EDF fan.

Will probably run two 2200mAh Lipos and 50 Amp aero ESCs with big heatsinks


For the cooling I may have the Arduino open and close a vent with a servo if the heatsinks get hot, as well as controlling the fan speed. 

Based on yellow boat plans different deck 390 Grams as shown 
Also Ply fiberglass epoxy catamaran build log

Glass and epoxy inside balsa ply, will epoxy the outside too. Its very strong with builders fiberglass tape and epoxy 

The motors will be mounted further forward on a cooled plate 

Spray rails are bamboo barbecue skewers and wood filler  

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Boatbuilding More Progress by John Z on his Classic Moth

Hull panel offsets for the Mistral can be found here.

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In the ongoing coverage of John Zs Classic Moth build, last week I stopped over at his shop to gauge his progress and have a beer. The Classic Moth modified Mistral design is now upside down awaiting gunwhales and a layer of 4 oz. glass over the bottom.

This photo, though perhaps a tad distorted, shows how deeply Veed the Mistral design sections are around the midships.

Transom view with a pretty swirly pattern from the okoume plywood.

John, with the about-to-be-opened bottle of stout peeking up above the keel-line of his Moth.

A man and his workbench. John graciously took down a Marblehead RC sailboat he built many years ago so I could take a closer look.

A man and his workbench - take 2.

From the previous photo, you can see that John has some interesting stuff hanging from his walls. This is the box containing his F1 rubber-band indoor airplanes. These are extremely finicky to make, with a minimum weight of one gram. John has all the various tools to test balsa density and strength; tools to strip balsa into extremely narrow widths; tools to check rubber band elasticity; molds to make the tricky propellers, and the various techniques to apply the ultra-thin microfilm covering.  To make a F1 takes a methodical, painstaking craftsman.

John also has two half models of the Americas Cup, IACC keelboats, the class that precedes the current foiling catamarans. Surprisingly, it was through his wifes connections and not his Naval Architect circle of friends that these two half-models now grace his shop.

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Photos Of Metal Wastage Caused By Trapped Water

Here are some photos of what trapped water and moisture will do to a metal hulled boat. This is not to meant sway anyone from buying or owning a metal boat, I own one myself. It is to give all of us a reminder though, that we need to be diligent in maintaining and inspecting our boats. Speaking of inspecting a metal boat, I had a very good comment on the last post from a former client. He has a process that is very impressive when it comes to inspecting a metal boat for purchase. I encourage anyone who is wanting to buy a metal boat or any boat for that matter to do their own close inspection before putting an offer on a boat and hiring a surveyor. I also would advise the seller of a metal boat to hire a surveyor to inspect the boat before listing it. It is important any issues are known about before the boat goes on the market. Too often a person turns down a boat during my inspections. I would much prefer to be part of a happy exchange of a boat then not.

Saltwater was trapped in a keel of an aluminum boat that was filled with foam and lead. The boat got a new redesigned bulb keel.

This is where salt water has dried in a bilge of an aluminum hulled boat.

A view from the exterior of the same boat.

 

This is where water had sat for years on the inside of this steel boat, good news she was made as good as new.

A lot of time these problems are found while the bottom of a boat is sandblasted or a paint blister is ground down for a repair. Which is what happened in the photo below.

So what do we do to make sure we can find these problems?

Refer to the previous post for the answer:

The need of keeping water out of the bilge of a steel boat

and visit more my website for more information about my services.

dbyachtsurvey.com

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