Dumas 7.5 HS

[dsl_raven]

I just ordered this in kit form. It'll be my first boat in quite some time. The last wood boat I built ended up being fiberglassed on the bottom (as part of the normal build process).

Should I consider glassing this hull or does it just not need it? I was considering using a few patches of aramid fiber in the servo / radio tray, all the way back to the motor mount. I figure stiffening the area up couldn't hurt - but I'll definately wait till the kit gets here to decide.

I typically use epoxy mixed with microballoons for a joining material. I much prefer it over CA where I can get away with it. Has anyone here built this kit? If so... will I really need the CA + kicker or is it 'straight' enough for me to use epoxy and clamps?

I guess the KB is obvious, but does anyone have any suggestions on motors? I like the idea of an air-cooled engine vs something that can overheat if debris blocks the coolant path. Are there options / bolt-on add-ons to this motor, such as tuned pipes etc? If so, where can I get a look at these?

Thanks -

 

[wswatzell]

Welcome!!

I have only built 1 Dumas boat, but from what i have been told, it might be a good idea to use there wood as a pattern , & buy different wood. I didn't do that, & I am happy with how my Dragon Fly 60 turned out. It probably isn't necessary to glass the hull at all, but that is just an opinion. But it won't hurt anything expect to add a little weight.

Sorry I don't know much about the 7.5Pro air cooled OB.

There is an Outboard Forum here where you could get the answers you are looking for about that engine.

 

[gil sonsino]

I've already built some Dumas kits like the Chris Craft 36",old Hot Shot 45, Sprint 3.5,Hawk 3,5/7.5 for friends and considering their price all "foot the bill".

I agree that you can substitute some parts for another wood but take care with the final weight in your boat.Using only epoxy slow cure you certainly will have a strong light tunnelboat that does not need any apply of fiber glass.Also use epoxy finishing resin to seal the wood before have it painted.Personally I never use C.A's on my boats but you can use it as a good help to hold parts during the building.

I had only one fast experience with a 3.5cc KB outboard that broke the rod during break in but do know that they run great like a .67 I had in an old crapshooter.

Nowadays you also have the choice for powerheads like the CMB45 that is a target but more expensive.

Take a look to the outboard forum for more specific input and happy boating.

Gill

 

[dsl_raven]

Thanks - I'm looking now at some finishing products. I figure wood, light filler for any depressions that pop up, block-sanding, aligning, trim... ugh.

Then... probably I'll cover the model with Coverite. I've had good experience with them in the past and their stuff is fuelproof. They say up to 15% but I've seen it shrug off even more. It also won't eat the ABS cowl. I may well try a cast - n - glass on the cowl just so I have a spare. If my casting works out I guess I could make a few to have around. I actually thought about doing that with the entire hull, but probably I'll decide it'd be a PITB and won't do it.

Still working out the paint in my head. Ugh. Tough place to work.

 

[wswatzell]

15% is a bit low for boats. The K&B's love nitro. I run 45% in my boats. I would just coat the hull in epoxy, prim & paint it using auto paint.