My Micro Hydro

[Sneasle]

can do.

I'm going to cut the template at the joint with the forward bulkhead. That ok with you?

Just as a note, if you look at my images, you'll notice the stringers are taller then the bulkhead. That is because the stringer fit into a raised groove in the deck, while the bulkhead goes all the way across the hull and I didn't feel like doing the fancy cutting required to make it match up perfectly.

[JimClark]

How bout just the side to side template

[Sneasle]

Sounds good. You still want my templates?


Question for Randy/Doc.

I notice that neither the hull edge or the deck edge is cut straight. What should I do to the hull to ensure that I get a good, even, twist free hull when I go to glue them together?

If I had a really big belt sander I would smooth the hull on that, but I don't.

[JimClark]

Ok I think I have brainstormed enough on this one and have a plan. I am going to make several frames for it and want a wide stringer to support the top (see picture below). I also would like to add balsa on the outside edges of the bottom to give a good glue surface for the top then I can hopefully sand off the top flange flush for a cleaner looking hull. I may put a light fiberglass over the edge also.

Jim

[Sneasle]

The cab-o-sil and epoxy method is what Doc used in his MTH thread (the original SSSH thread I think) to get rid of the lip on his version 2 boat. The cab-o-sil is a filler of some sort.

Basically, you mix the stuff up and smear it into the lip after the halves are glued together. I think it should be thin enough to work it's way in, and then you go in and sand it down to bring that lip in line with the hull and make it nice and smooth. It will take several applications and lots of elbow grease, but that is how Doc got his hull as nice looking as it is.

[JimClark]

I guess I missed something "cab-o-sil/epoxy method for getting rid of the lip" ?

@ Jim

I haven't, but I would be worried it would eat/melt more of the abs then you really wanted. I plan on sticking with the Gorilla glue for joining my halves, and then using the cab-o-sil/epoxy method for getting rid of the lip.

@ Doc

Thanks for the info, we do appreciate it. Have a look at my images if you have time. Where would you suggest additional framework?

[Sneasle]

Ya, gorilla glue can make a mess. I've used it quite a bit and have learned how to handle it.

Biggest thing to keep in mind is a little goes a long way. If you think you put just enough, wipe it off and put half that in it's place.

Plus, I like the foaming action :)

[RandyatBBY]

I think Gorila glue makes a mess, Ok on lexan. I use nothing but Thick, thin and med CA with kicker. I have not ran one of these boats with any FG or wood frame work. I just run a transom and turn fin doubbler (wood). With the power we have the stiffness will not hurt anything and the extra weight does helps. I just use lead for more weight.

[Sneasle]

@ Jim

I haven't, but I would be worried it would eat/melt more of the abs then you really wanted. I plan on sticking with the Gorilla glue for joining my halves, and then using the cab-o-sil/epoxy method for getting rid of the lip.

@ Doc

Thanks for the info, we do appreciate it. Have a look at my images if you have time. Where would you suggest additional framework?

[Dr. Jet]

Doc, what kind of ply are the MH frames cut from?

1/32 aircraft ply.

Are the frames really necessary?

Yes and no. I have found that they add a lot of torsional rigidity. Coupled with foam-filled (and bonded) sponsons, my MTH is stiff as a board. With such a small hull, you may get away with some strategically-placed carbon and fiberglass, but that lacks the "Coolness Factor" of the wood, and I don't know if it would be as stiff.

Does it need to be that stiff? I don't know for certain, but I would rather have a rigid hull than one that flexes, and "soaks up" power in so doing.

Years ago, I used to race track bikes (fixed-gear, velodrome bicycles), where sprinting is the name of the game. Stiffer is better in that arena. My custom-built track bike used a downtube from a tandem bike (WAY heavy-duty), ovaled front fork blades for chainstays (WAY heavy duty), steel handlebars and stem, cross-4 spokes that were tied and soldered. It was the stiffest thing I ever rode. You felt every bump on the track. You could throw it through a brick wall. BUT...all that stiffness translated into every ounce of power going into speed, not flexing some wimpy frame. That bike was an absolute rocket!

I would suspect the same would apply to a boat hull. My Campbell hydro is equally stiff and I am amazed at how well it handles; it's like nothing I have had before (H&M Viper, various vacuum-formed hydros).

If you can keep it light, stiffer is better.

[JimClark]

Anyone ever tried this to glue together these hulls?

http://www.micromark.com/SAME-STUFF-PROFESSIONAL-PLASTIC-WELDER-WITH-TOUCH-N-FLOW-APPLICATOR,9014.html

[Sneasle]

Ok.

I'm gonna have to remake up one of the stinger templates.. I scavenged them to make the transom and bulkhead templates.

I'm about to head to bed, got a 9am class. I'll try and get them scanned and on their way to you at some time tmrw.

Glad you like it. I figured it would give you a decent starting point. Maybe we can talk Doc into refining them :).

[JimClark]

Just scan the card templates you have and email me the scans. no need to send wood
Looks like a good start
Thanks much

Jim

[Sneasle]

More images

[Sneasle]

Whoa.. this was a long evening.

After some severe mutilation of a nice stack of note cards, I have some frame templates made and transferred over to balsa.

The frames are pretty rough and were very hard to cut to fit this hull. The deck of this hull is not flat like the MTH, which made this very hard for me to do. Also, the angled indent in the bottom of the back of the hull near the transom causes my stringer to angle in. The angles of the top deck and the inside angle of the sponsons causes my stringer to tilt at an angle, even more so when you squeeze the deck on tight.

I'm sure there is a better way to do this, but I'm not sure how.

Jim, what I can offer to you is to make another copy of the front bulkhead, one stringer, and the transom piece and either make a copy/trace and mail it to you, or I can cut one of those out of balsa and mail you that. That will save some time on your end. If you want the templates, you can cut some balsa forms from that and refine the fit on your hull and then transfer that over to ply. If you want the balsa, you can directly fit them to your hull and then make some ply templates.

It would probably be a good idea to add a crossbrace in the front like in the Doc's frame, but I haven't done that yet.

I also checked my ply inventory and I don't have anything suitable to cut a set of frames from, nor does my LHS when I called them.

So.. whatcha think Jim,Randy,Joe,Doc?