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Beginners Guide to Boat Building

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I'm pondering building a nesting dinghy to go on the cabin top of our yacht, to replace our inflatable that is nearing 20 yrs old, and showing it.


I've built a small dinghy in plywood, stitch and glue before, and really enjoyed it. But I get the impression there are better and more modern options available now.


My question is, what is involved with building a boat (any boat, tender, racing dinghy, small keeler) in exotics / foam / carbon etc?

What are the basics a beginner would need to understand?

1) What is peel ply?

2) Do I really need a vacuum pump to work with foam panels?

3) What basic gear do you need to make something out of carbon? (like Bad Kitty's heads, or a DIY trogear style bowsprit)

4) Could you build a dinghy / tender out of foam panels instead of ply?

5) Could you cover it with fibreglass instead of carbon, and if you did, would there be any point in doing that over doing a plywood stitch and glue?


Any thoughts and information on amateur boat building greatly appreciated.

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Jeez Fish, how long have you got?

Unless you're paranoid about weight then e glass & epoxy is fine, carbon is lighter but you can get too clever on panels & they will suffer pressure damage from a knee or foot.

On lower tech things that us mere mortals sail, unlike foiling beasts etc. then carbon more comes into it's own when you get to beams, rudders & stuff that needs lots of layers of glass, or much lighter layups of carbon.

1 layer of carbon or 1 layer of e glass on a flat panel is hardly worth the difference. 

No, you can get by without a vacuum pump, but if you can scrounge one they keep resin weight down in the laminates, and do give a good finish. 


Peel ply is God's gift to composite building, goes on top of the glass or carbon reinforcement, and once you peel it off you have a great surface that can be laminated to without grinding or further surface prep, or finished & painted.

Seriously, don't build without it.


Probably plenty of stuff on youtube about composite building, and Adhesive Technologies is great for epoxy & fillers, and Gurit for glass or carbon.


Go create!

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D5 dinghy I built. Free plans on Internet. I believe i was first to make a nester out of it, though others have since done so.



I like it. Its actually a pleasure to row and i dont think anyone ever said that about an inflatable.

It fits on the fordeck of my Young 780 so will just about fit anything i guess.

It also tows really well and goes well with 3.6 hp motor.


Plywood is lighter than fibreglass in this application as the thickness you need for practical stiffness makes it so, although fibreglass is undoubtably stronger thickness for thickness.


I did the hull in 3 mm ply and put a single layer of glass on the bottom for abrasion protection.


Good luck.





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Abel Seaman, that is gold, that is fairly much exactly what I've got in mind.


How did you get on with the 3mm ply? I see this design, and every other one I've looked at calls for 6mm ply, then almost always with a glass skin. It sounds heavy and over built, hence why I was pondering composites, to reduce the weight a bit and make hauling onto deck and handling a bit easier.


And how do you find the stability of your dinghy? esp for hoping into and out of it from the mothership? Our old deflatable has the one advantage of being very stable for climbing up the side for the missus and kids. I'm assuming the single hard chine you have, optimist style, gives the best form stability for standing on the side / loading unloading etc.


I'm primary after something about 10 ft, 3 m so it is big enough to handle a family of 4 comfortably in one go.

I have been ponder the 9'6 nutshell pram, for looks and performance, and working out how to nest it myself. But the lapstrake construction is a tad more work.



The eastport nesting pram is gold, but a bit short for what I'm after, and the Passagemaker in the same range is too big.

There are a bunch of other options, some well known, some less so, but at the end of the day I can't see why I'd put a lot of work into making a complex shape when a good simple optimist style single chine pram / punt seems to work well as a load carrier, can be made to nest, and is simple to make.


PS is that Kaiteriteri you are launching at?

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I'd be a bit concerned that it wouldn't track very well rowing or outboarding if it was flat underneath. Especially into a chop.


Everything is a compromise though and Abel seaman's one does look very cool.

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At that size you are into a law of diminishing returns with exotic construction, the gains are marginal if any.


Abel Seaman is on the money, use 3mm marine Gaboon for the hull and glass the bottom to the waterline. Keep the use of solid timber to a  minimum and use something light like Kahikatea . Finally watch the painting , as that can add a surprising amount of weight too, often for no gain in durability.


You will struggle to build lighter and it wont cost much.


There is still a simple pleasure in rowing a well designed lightweight dinghy.

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Thanks for the kind words, here are some answers;

Yes Kaiteriteri. I live not far away.

How I did the two halves was to make 2 bulkheads at the forrad side of the main seat /thwart. I used something like matchsticks  which were same thickness as my favourite handsaw to space them apart then made the boat as per normal. I did enough on the outside with cable tie stitches to hold it all together then glassed in tape over thickened epoxied fillets on all internal joints.


The moment of truth was inserting said handsaw between the double bulkheads and literally cutting  my boat in half!   Then I did all outside finishing.


Attachment of two halves is by 3 off 12 mm stainless bolts. I welded the bolts onto big square ss washers and drilled holes in the washers for small screws to keep that end in place.

On the bow end , same big washers glued and screwed on. I made nuts by welding tags onto ss 12 mm nuts then encasing them between disks of kwila cut out with a big hole saw. They can be tightened by hand and most importantly they float!

In practice it is easiest to drop both halves into the water and then get into the stern section and join them in the water though you need to hold  on to both painters. Photo shows what happens when you let go and the wind blows the bow section away!   


Realistically this design will never have the stability of a blowup. but it takes 115 kg me and my similarly proportioned friend  ashore without to many dramas. If you are  young and slender like my son and the girl in the photo then even better.


One other point to make is that it does tow brilliantly without vices and seemingly minimal drag.


I reckon it cost $400 in materials all up. 


I have been toying with doing a rebuild to make the same thing but a bit longer and maximising the space available. I reckon i could just about get to 10 ft.


I will check the actual weight and report back.














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Hi Abel, you've inspired me! Off to get ply in the next day or so.


Two questions:

1. You used 3mm for sides and bottom. Plans say 9 or 10mm for frames and transom - did you use this thickness?

2. Towing - is your tow line on an eye on the for'ard seat and then just passed thru the 'handhold' in the bow transom? Looks like that from the photos - there's no shots bow on, so I can't see an eye or other attachment. The plans don't show a towing attachment, or height it should be at.


I promise I won't keep coming back with more questions!

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Yes i did use 9 or 10 mm ply for transoms and bulkheads.

I did fit a towing eye at the lowest point on outside the forrad transom. For very short hops i have towed using the internally connected painter, but for proper towing have a floating line with a snap shackle that i hook on to the outside eye.

Floating rope to minimise chance of prop wrap! 

I normally pull the dinghy aboard for sailing along the coast in a decent sea breeze, but i have been deliberately towing in higher wind and sea conditions to see how that goes. So far so good. I take everything loose out of the dinghy and remove the motor, but have had no issues at all with towing. It just sits there following on behind...

Good luck.

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Sorry for the delay.

There are no gaskets. The two faces of the mating bulkheads pull in flat to each other and there is no leakage i am aware of.

Of course with beach landings , wet feet etc there is often a little watr in the bottom.

Handy hint: I deliberately put the gunwhales all on the outside of the sides if that makes sense. When you tip dinghy on its side to drain out water, every last drop falls out.


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Brilliant, thanks AS. And a great tip.


Hull is put together and epoxied. Buggering off to a warm island for 10 days - work on it will continue when I get back.


Must say - I'm enjoying this project - so far.

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