Building a tender

Rory123

Hi folks.
I'm building the boat below at the minute as a bit of an easy winter project. I'm just wondering does anyone have any comments or has anyone built anything like this themselves.
I haven't built a boat before but I am a cabinetmaker and I've done a bit of boating. I've used 12mm marine ply instead of 6mm.
I might stick an outboard on her at a later date if it floats!!!... It'll prob have to be very light, maybe eletric.
What do you think?
Rory.

http://koti.kapsi.fi/hvartial/dinghy3/ekstock.htm

noby

Hi Rory. I was going to post a similar thread yesterday.
This is something I thought about last winter, so I'm going to go for it now. I have the plans for the D5 dinghy from here. The actual plans are in pdf here

I have no experience in boat building, but the stitch and glue method seems pretty fool-proof. I hope to gather the material over the weekend.

The link you posted, are you building the full size version?
All I want for a first attempt is an 8' punt. I'll skip the sailing version for now.

Pigeon Reaper

Using 12mm ply will mean the boat will be very heavy. You may be better off sticking with 6mm and just ensuring the joints are well expoxied to ensure stiffness. If you're concerned about wear and tear put some extra strips on likely wear points.

murphym7

Rory123 wrote: »

I might stick an outboard on her at a later date if it floats!!!... It'll prob have to be very light, maybe eletric.
What do you think?
Rory.
http://koti.kapsi.fi/hvartial/dinghy3/ekstock.htm

Should get 2/3 hp on the back. 2 stroke if possible. Make sure you reinforce the transom though.

Rory123

Yeah I am making the transom fairly beefy alright. The engine or motor will come eventually due to the expense.

Pigeon Reaper... Do you mean the boat will be heavy to lift and carry about or heavy in the water and may end up sitting too low? I don't really care if its heavy to lift and I'd feel safer in a 12mm boat, but it is a concern of mine that it may sit low in the water.

Noby my boat is the 8(ish) foot version... how is your construction going?

The build is going well, I'm doing a bit here and there. Just need to sort out a seat next and do a bit of sanding. Then I'm going to re-enforce the seams with fibre-glass matting. Then paint. Next stop St. Tropez!
Thanks for the replies lads!

JamesM

Rory, It will certainly sit lower in the water if it is heavier - not sure how much though.

Pigeon Reaper

It may sit too low in the water and will be more difficult to row/motor with the extra weight as the it wil change how the rocker and chines are used. The boat will be at least a few kilos heavier with the 12mm wood. I'd stiffen up the gunwales and thwarts along with the transom if you're putting on a larger engine than normal(she may not handle a large engine and could be overpowered easily) I'd also add wear strips that can be replaced easily rather than going for 12mm. if it's too heavy it will affect the stablilty and usefulness of the tender. If possible contact someone else who has built one and learn from their mistakes. On the other had 12mm might make a good icebreaker.

noby

Firstly, sorry for the size, and the quality (it was a sunny morning).







As you can see it's a snug fit in my shed. These were taken about three weeks ago, and not much has happened in the mean time. I've no power in the shed, so it's strictly a weekend operation. I have filleted the inside, save for the bottom of some of the bulkheads, and flipped it over and started fairing. It's not too bad as not much epoxy leaked through. Once I'm happy with it I'll fillet the outside, then sheath it in glass, flip it over again and finish the bulkheads etc.

JamesM

Well done Noby - that looks great. I know what you are saying about the epoxy - it's a good few years since I built, but I remember how hard it was to sand off the epoxy drips.
Jim.

JamesM

Rory, from what you say, you have started your build. How are you managing to bend the 12mm ply to your curves ? I would have thought that it would be almost impossible.
Jim.

Rory123

JamesM wrote: »

Rory, from what you say, you have started your build. How are you managing to bend the 12mm ply to your curves ? I would have thought that it would be almost impossible.
Jim.

I'm a bit of a horse. It went fine.

noby

JamesM wrote: »

Well done Noby - that looks great. I know what you are saying about the epoxy - it's a good few years since I built, but I remember how hard it was to sand off the epoxy drips.
Jim.

Thanks. I duck taped the bottom, so there wasn't too much, but there were a couple of leaks. I went at them with a chisel before sanding. Like a true novice (except for a few small fibreglass repairs) I mixed it up too thin to start with, and probably applied far too much.

Wolfsberg

Over 2 years have passed and a username has changed! :rolleyes: The boat has sat 95% done in the shed at my parents house but I am committed to finish it in the coming weeks. I bought the finishes today, it is going "Donegal Green" with a creamy or white gunwale. Then all I need to do is fit oar locks and oars a couple of bits of hardware and then pilfer a roof rack and life jacket. I tried the boat briefly after construction and the draft was minimal despite being made of 12mm.

I will post back soon,
Wolfsberg (formerly Rory123)

fergal.b

And I thought I was a slow builder
Good to see you getting back into it, poor girl must be dying for a drink.:)

Wolfsberg

fergal.b wrote: »

And I thought I was a slow builder
Good to see you getting back into it, poor girl must be dying for a drink.:)

I'm a couple of years older and a couple of pounds heavier! :D:D
Yes I cannot wait to get out in her... hopefully she's not damaged as I didn't do an inspection on her before I dropped €70 on the finish this afternoon... fingers crossed!... I'll know if it's worth finishing at the weekend!

While I'm at it where's the most cost effective place to get oar locks (the screw-on ones) and oars etc?... Marine Parts Direct is my most local place.
Are there any "boat scrap yards"?

fergal.b

Marine parts is where I do all my shopping
I think the only boat scrap yard is my back garden. :eek:

Wolfsberg

Hi folks. Have had a couple of great summers floating around the grand canal. I'm thinking this summer of an outboard to go with my oars. I'm not sure what kind.
The portability of an electric motor appeals to me but the "range anxiety" doesn't.
The go-all-day ability of a small 2 stroker would be a bonus but the possibility of petrol leaking in the car and the noise pollution don't appeal. Short shaft?! Long shaft?!
Anyway, enough of my thinking-out-loud. I feel the only way that I'll find what works for me is if I try it out....

Does anyone know of anywhere I could HIRE an motor (electric or petrol) before I commit to buying a certain one???

Cheers!

fergal.b

Hi Wolfsberg and welcome. I not sure about anywhere that will rent out a motor as I don't think there would enough of a demand for it, your best bet would be to ask one of the other boat owners around you for a loan or you could just buy an electric one for about €150 and if you don't like it just sell it on with very little to lose, remember you will also have to carry a battery on the boat about another €100 and think about the room it will take up. Another option is a Torqeedo electric outboard some come with built in batteries but will cost you :eek:
You can get a small 4 stroke with a built in tank for about €600 they are quite and once stored right will not leak any fuel in you car if your still worried you can get a waterproof carrier bag. If your transom is 15" high you will need a short shaft and 20" long also make sure your transom is built to take an outboard these little engines can put out a lot of force where they are clamped to the transom.
Good luck.


.

Wolfsberg

Hi Fergal. Thanks very much for your input and advice again! ...Some of it I already have considered and some of it very helpful to me.
I have grown up with my dad sailing and he has a bigger boat but the outboard he has would sink my boat!
I am lucky enough to have friends who own a fishing shop who have offered to get me an electric motor for cost and vat.
I think I will probably go down that route despite the "range anxiety" of electric. As I do my boating on the canal I would still consider a 4 stroke to be quite loud.
As you'll see in the start of the thread I made the boat from 12mm instead of the 6mm on the plans and the seams are reinforced with glass so I reckon the transom should cope fine with a small motor. The battery will probably even help with weight distribution if I put it in front of the seat.

Cheers!

fergal.b

The recommended thickness of a transom for under 5hp engine is 1-1/4" to 1-3/4 so I would be thinking about building it up a bit. A small electric outboard will put out about 30 Lbs of thrust at the prop when you think of the shaft going up the transom about 20" working like a lever on 2"x 4" where it will clamp to your 1/2" 12mm transom it's a lot of force for a small space.:eek:

Wolfsberg

fergal.b wrote: »

The recommended thickness of a transom for under 5hp engine is 1-1/4" to 1-3/4 so I would be thinking about building it up a bit. A small electric outboard will put out about 30 Lbs of thrust at the prop when you think of the shaft going up the transom about 20" working like a lever on 2"x 4" where it will clamp to your 1/2" 12mm transom it's a lot of force for a small space.:eek:

Hmm. You're right. Do you think it only needs that thickness around the motor's point of contact with the transom or does almost the whole transom need to be that thick? Would an A4 sized piece of hardwood or similar suffice to act as a motor mount/ reinforcement?

Although any depth of water is deadly dangerous I'm glad my backyard science can be tested on a quiet, narrow, shallow canal and not on the open sea or a lake!... Either way I don't really want to go into the drink!

fergal.b

I would go with plywood as the hardwood could crack along the grain, the bigger the load spread the better so if you cover the transom on the inside you wouldn't even notice it you could also put a bit of aluminium plate where the clamps go. Ideally you should have a knee or two coming up from the floor and fixed to the transom like this.



And at the top of the transom put in some corner supports to make a bigger bond to the sides.

Wolfsberg

Hi everybody.
Still having great fun with my little boat. I've had the use of a 1.5hp Seagull for the last couple of years which suits very well.

My plan for this winter is to add some kind of extra floatation for safety, stability and comfort. I'm thinking either outriggers or air filled pontoons along the sides and bow. There isn't enough room for added flotation inside the hull. Anybody have any input?
Cheers,
Rory.

fergal.b

You can get outriggers for kayaks that might work they would be easy to make using some boat fenders or closed cell foam.

Wolfsberg

Thanks Fergal. At the minute I'm thinking of some outriggers made from 12' PVC pipe, filled expanding foam and capped at both ends. I'll post back if I make any developments.
Rory.