45" Dumas Scarab

[Ken_NJ]

I'm typically a scale boat builder and I usually go for older boats. I wanted to build a FE boat from the offshore powerboat days of the 80's since I would watch the boats at the Benihanna Grand Prix off of Point Pleasant NJ. A friend recently gave me this Dumas 45" hull, so my goal is to build something that resembles Betty Cook's Kaama. I've been posting questions in the Q&A forum, figured I would start a build thread and see what other help I would get here. I'm a slow builder and procrastinator so bear with me on this.

I'll be keeping a continuous photo blog here unless I figure a better way for it: http://s11.photobucket.com/user/ken_...tml?sort=9&o=0

Here are some previous models I built. I'm no slouch when it comes to detail. The Miss Belmar is scratch built, 54" long and powered by 4 Dumas 12v motors with 4 props of course. The USS Marlin is a highly modified kit.
SS Miss Belmar: http://s11.photobucket.com/user/ken_...ideshow?sort=9
USS Marlin: http://s11.photobucket.com/user/ken_...0Marlin?sort=9
USS Marlin pool test: https://www.youtube.com/watch?v=IjELKbpJNfk
Complete USS Marlin build: http://www.rcgroups.com/forums/showt...ghlight=marlin

This is my goal.
wc-cook-0011sm.jpg

This is what I am working with.

[Ken_NJ]

Ordered this hardware from Hobby King, should be here Monday.

Motor: http://hobbyking.com/hobbyking/store...dProduct=42488
ESC: http://hobbyking.com/hobbyking/store...rless_ESC.html (did not order)
Batteries: ESC: http://hobbyking.com/hobbyking/store...dProduct=20676
And a charger.

Power will be 8S2P.

[Ken_NJ]

I have a lot of work to do on the hull. I have to make a new hatch-cockpit as the original one does not fit my plans. I also have some divits I need to fill in the the deck that where for railings I will not be using. I hope only to have to paint the black areas and leave the white areas alone. Between the divits and some other spots I need to fill with white Gelcoat. Anyone good with Gelcoat? A friend gave me this Evercoat paste but the paste is green and I need to add a lot of white pigment. Also, the arrow in the one picture the deck was not secured to the hull evenly. There is a noticeable bend in the deck. I think I might have to leave that alone.Any suggestions?

[lenny]

From what I hear that esc has some issues,
I think you would have been better off with the seaking HV130a esc.
As for the cells,
The normal blue turnigy 40c would have done the job.

[Ken_NJ]

Hi Lenny,
Does it? Brushless and Lipo is out of my comfort range. But building a boat is not. I feel like anything that I might order will have an issue.

I just checked my order, looks like I left off the ESC.

[srislash]

I think white pigment is your best bet if you don't want to paint it.

If I remember correctly you did not have the original cockpit right Ken? If so I would be interested if you would part with it.

[Ken_NJ]

I'd have to add a lot of pigment to overcome the green. I made a sample, it's in the previous pics I posted. From what I found, at $25 a can, I only need a teaspon's worth. Unless I Gelcoat the cockpit.

I do have it. If I don't cut it up for the replacement, it's yours. Let's wait until after I have the new cockpit done.

[lenny]

Yes the Aquastars are not very proven yet and has problems,
If you look on the discussions you will see zeeek1 and that is AKA ray schrauwen from on hear.
You just need to do little more home work and ask about stuff before you buy.

[srislash]

I'd have to add a lot of pigment to overcome the green. I made a sample, it's in the previous pics I posted. From what I found, at $25 a can, I only need a teaspon's worth. Unless I Gelcoat the cockpit.

I do have it. If I don't cut it up for the replacement, it's yours. Let's wait until after I have the new cockpit done.

Cool thanks Ken.
BTW that motor is a Proteus relabeled for HobbyKing and same for the ESC but it is called Swordfish elsewhere. Like Lenny stated, not proven but I have not heard anything bad either on them. You are not likely going to be pushing this too hard anyway, correct?

[Tbauer]

Your the master scratch builder, some really awesome work you have done, very impressive..... Do you sale them or they just for you? Just awesome

[Ken_NJ]

No problem srislash. No not pushing hard. This is for fun, no competition or anything like that. Wanted to keep costs down that's why HK. I know this will cost over $1k. I'm looking at this boat as have two processes, the mechanical and appearance.

For the mechanical I still need the running hardware, ESC, 1/4 flex and all the hardware mounted on the transom. Batteries and motor will be here any day. ESC recommendations? I know a Stinger is the way to go. I started a thread over in the Q&A forum, I'll ask here. What about a submerged drive setup, where the flex cable comes out the bottom and goes to a transom mounted strut so the propeller is always below the water surface?

For the appearance I have to start on the Gelcoat repair, hatch-cockpit and paint. I've worked with polyester and epoxy resin before but not Gelcoat, so any help is appreciated, otherwise I'll just hammer away at it. For the hatch my LHS ordered 1/16, 3/32 and 1/8 aircraft plywood for me. I'm not making a mold for this so it's going to be a one-off hatch with plywood construction keeping it as light as possible. Probably be using polyester resin (don't care about the smell) to give the hatch a finish. If white rattle can paint does not look like the white Gelcoat, then maybe I'll have to buy that $25 can and pigment. I'll start using construction paper to get the lettering on the hull side designed. The graphics I plan on getting done from Callie Graphics once I know what I need.

[Ken_NJ]

Your the master scratch builder, some really awesome work you have done, very impressive..... Do you sale them or they just for you? Just awesome

Thank you for looking at those pictures, and for the compliment. I do not sell them, they are for my fun sailing with other club members. I added a link to the Marlin build on RC Groups and a pool test.

[Tbauer]

I love scale builds and have looked at a lot, yours are right up there with the best. I don't know if your retired, but if you are or when you do and need extra cash, I know you have seen what those can sale for. Yours is easily up there bud, keep up the great work, I am jealous, I wish I had the patience to do that kinda work. Very time consuming indeed. = )

[srislash]

Well y'know, these were originally designed with submerged drive in mind. You won't need such a big prop with full submerge. I will ask how many cells you plan to run before aiming you in the ESC direction.

[Ken_NJ]

Thanks again Tbauer. Not retired yet and like I said, I'm a slow builder and procrastinator, so they can kill your building time.

Srislash, since this hull is probably from the 80's, don't think they had surface drive in mind back then. I'd like to go submerged. Batteries will be here Monday I hope. Ordered 4 5000mAh 4s batts for 8S2P.