Transom question

[pennsycrabber]

Hi,

Started building a boat a few weeks ago and just now found this site, it's great!!
Let me say the boat is roughly 22' long and 7' wide. I made it pretty much a flat bottom, small v.

Any way, I have 2 question. I noticed most boat transoms are tilted, sloping towards the front of the boat as it nears the water. I constructed mine so it is at a 90 degree angle with the bottom, will this work? I didn't know if the motor will be able to tilt down enoungh.

My other question, assuming what I did above would be ok, is what width to cut the transom out. I know I need to come up from the bottom of the boat 20", but sure how much clearnce I will need on either side of the motor.

Thank you all for your help and look forward to many hours on your site

Paul

 

[5150abf]

Re: Transom question

You built a 22' boat from scratch??

That is pretty ambitious of you, get up some pics for us.

Your transom should work but I believe you wanted between 16-20 degrees of negative angle on that.

As far as the boat going through the water I don't think it will cause a problem, only at slower speeds and while accelerating where you want to keep the bow down.

Just measured my transom and it is 20 3/4'' but my boat has a small amount of dead rise.

Is this boat an I/O or an outboard?

Wood, glass, aluminum?

What horsepower?

This is a fabulous site for all things boating, if you have a question, someone on here has an answer.

Answer my questions so people will have a better idea of what we are looking at here and I am sure you will get more than a few replies.

 

[83ProLine]

Re: Transom question

I constructed mine so it is at a 90 degree angle with the bottom, will this work?

How did you install the transom at 90degrees and not end up grinding down the leftover hull sides?

Post some pics and someone smarter than me will definately help you out!

Regards,

James

 

[pennsycrabber]

Re: Transom question

Here are a few pictures, hopefully it makes a little better sense


Paul

 

[Bondo]

Re: Transom question

Ayuh,....

How Big of a motor are you planning,..??

How fast do you expect to go,..??

I can see Serious Problems with the 90? transom.....
At any more than displacement speeds,.. The motor is going to send the bow into the Sky....

 

[pennsycrabber]

Re: Transom question

I'm really not trying for any speed. I don't want to creep out there, but not looking to do 40mph.
I don't have a motor yet, but was thinking of something small 30 or 40 hp 4 stroke, what do think?

Paul

 

[Bondo]

Re: Transom question

Ayuh,....

I'm thinking much more than a small electric trolling motor is going to be Too Big....

 

[pennsycrabber]

Re: Transom question

could the top of where the motor mounts be shimmed out to create that angle when the motor is installed?

 

[Bondo]

Re: Transom question

Ayuh,... No Disrespect intended,.... But,...

From the pictures you posted,...
It appears to be a simple plywood box, pointed on 1 end....
It appears you intend to mount a 20/ 40hp motor on a piece of 3/4" plywood....
And,..
That piece of plywood appears to have No support what so ever....

What does the bottom of the boat look like,..?? Flat, or structured,..??
Is there any Framing in the hull,..??

Yes,... An angled motor mount could be built...

 

[pennsycrabber]

Re: Transom question

The bottom of the boat in ply wood as well, it has what I would call a slight vee. It slopes from the sides to the middle of the boat, probaly 1" per 1ft. I have four wood supports that a attached the plwood on to create the shape, I guess that would be the framing The transom is 2 pieces of 3/4" ply. I plan on now fiberglassing all the seams and joints and then going over the whole thing with another layer of fiberglass

 

[Bondo]

Re: Transom question

Ayuh,....

I'm probably not the 1 to be explaining Naval Architecture,..
But,....

Maybe you should post a few more pictures showing Us what you've got going on....

You're well into a very noble endeavor, with Alot of labor,+ Love involved...

What you've got Done, looks pretty good,.. But Now is the time to take corrective actions, before you get Too far along...
Like the Transom...
It Really should be at an Angle,+ not Shimmed....
The V of the hull sounds pretty Flat for the horsepower you're talking,... Strakes will absolutely be Necessay...
And,...
With Only 4 framing members,... It just sounds weak,+ possibly Dangerous....

Or,... Maybe I've just got it all wrong.... Donno.... Got somemore Pics,..??

 

[pennsycrabber]

Re: Transom question

a few more

 

[pennsycrabber]

Re: Transom question

I plan on adding stringers from framing to framing every 12" or so to allow me to put a floor in. I would fiberglass this the side as well

 

[superpop]

Re: Transom question

No disrespect here as it looks like you are a good carpenter, but are you working off of any kind of a design or set of plans. If you are going to go any faster than say 15MPH then you need to make sure you have some sort of stringer set up as well as a much thicker and more integrated transom. Even if you covered the whole thing in fiberglass it is still going to flex wildly and probably come apart at any speed over about 15-20 MPH unless it is properly reinforced and constructed. If on the other hand you are simply building a float that you can use to fish from then what you have should work fine for slow trolling ect.

 

[83ProLine]

Re: Transom question

Paul,

When you said you mounted the transom at 90degrees, I thought you were replacing an existing transom and simply chose not to angle it when reinstalling it - I didnt know you had built the whole boat from scratch! Pretty damn impressive!

What kind of boat is that behind your project - did you rebuild any part of it? I would guess this isnt your first time at the rodeo. . .

Stay well,

James

 

[fishrdan]

Re: Transom question

Looks like he's shooting for something like this

http://www.oldwharf.com/ow_workskiffs.html

Fish/crab/lobster boat instead of a speed boat?

I've seen that style of construction before (internet,,, not in person ) and often wondered how they held up since it seems like a very simple way to build a boat.

 

[tmcalavy]

Re: Transom question

Way cool. Nice work. I think you need to double up on your lateral frames..twice what you've got now, then do the fore-aft stringers and the floor. You could redo the transom, or add an angled jack-plate to it. Another option is a cut-out well for the motor, inward of the transom...forget what they call that design. Kind of like a box console over the motor, with the motor inside. Might also want some reinforcing around the edges of the existing transom. I wouldn't plan on power until you know approximately what it weighs...I'd think at least a 25 hp though, once you get the transom sweep figured out.

 

[pennsycrabber]

Re: Transom question

I plan on using the boat for crabbing in md.
This is my first boat project. I'm not working off plans except a crazy idea I have in my head. The only thing I did with the boat in the background was replace a small piece of floor, so my fiberglass expiernce is limited to that.
I figure my construction is similiar to that of a boat a found called the ladybug , ladybugboats.com. looks very similiar in construction, if you watch the video, they have 60 hp on one off them. What to you think of there construction?

thanks for the help

Paul

 

[jonesg]

Re: Transom question

Its almost an east coast lobstah skiff.
An engine wedge might be enough, 25hp 2 stroke would be enough, theres no hole shot on those anyway and they are very light.
More power requires designing the hull to take it, whatchagot isn't designed for lots of power and don't need it.

They usually have 3 stringers, laying flat on the hull, 4-5 cross braces (formers) and a ply deck.

Heres some designs
http://www.smallboatforum.com/PDFfiles/SkiffDesigns.pdf

 

[pennsycrabber]

Re: Transom question

Those designs look great, thanks. I now see what your talking about with more support

Paul