Newbie Questions about plywood boat builds

frost314

Cadet
Joined
Aug 17, 2016
Messages
10
So I have been looking around here and Glen L for a while and have decided to build a plywood boat of my own. While I like the Zip, flying saucer and the Ski Tow from Glen L, I also like the PM38 and the Playboy as well as certain design features from other boats. I guess that is the reason most DIY boat builders build their own boat to ensure they get a custom boat to their liking.

I am probably going to build 2 of these and ship one to Spain to keep at my family summer home.

The following are things I need/want in my boat:

Length - 13'6" to 14'
Seating - 4-5
Outboard Motor
Rear swim up ladder/swim deck
front cockpit will have middle fold down seat with walk thru to rear cockpit.

I will be painting both boats and going the budget route as they will not sit out in the elements so I will use ASH instead of mahogany.

I don't do too much fishing so the need for an open deck is not high on my list. I plan on making a removable cover for the rear cockpit that will be padded to be able to lounge on.

I am new to runabouts and have done a ton of research but still have questions. Here are some questions I have:

1 - With Runabouts how do/where do you use/store anchors for tying off when not having access to a dock? Pictures please.

2 - In order to have a rear swim up ladder/swim deck with an outboard I was looking at adding tail pieces similar to the Torpedo pictured below. Has anybody had any experience with this? If not possible I was looking at smaller tail pieces to mimic the angle of the rear of the Van Dutch 40 also pictured(My dream boat) and still have the motor inset between the tailpieces slightly. I am worried about this causing porpoising.

3 - How low do you sit in a runabout like a Zip or Playboy? I was looking at possibly raising the deck and sides about 4-6 inches in order to sit higher. In spain, we have to deal with boulders below the surface close to shore and in this case I prefer to stand and steer at low speeds. Sitting higher would allow me to stand faster in case of shallow water. What issues would there be with raising the frame sides and deck?

4 - In order to mimic the Van Dutch 40 I was also looking at keeping the rear sides straight like the center frames as opposed to curving the tops back in toward the inside of the boat to eliminate the barrelback look and look like the ski tow to have flatter deck tops on either side of the outboard. Does anybody see an issue with this as well?

5 - Also I was wondering if anybody has built or seen a wooden runabout with an open bow/bowrider? This is just a thought.. I may just put a hatch up front for anchor/misc item.

6 - What options are there to protect the keel besides the pvc keel guards?

7 - In Spain you cannot pull up onto the beach so you have to anchor about 40 meters out and then swim/row in. Does anybody have a small tender boat with their runabouts? And if so, how do you transport them? attached to front deck or tow behind?

8 - I am also thinking about adding a bimini top to the boat. Is this overkill?

9 - Can anybody post pictures of their frame glue up/joints and gussets?

10- Windshield. I am thinking about either a windshield with a pass thru to access front hatch, 2 piece lexan with custom wood brackets, or a low wood windshield like this :
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTzLKHiScr_jIYXpXtUtmnMxcDkm139h N-WUf7VLCqxLK6ODtKcFA


Budget Build:
11 - I have read a lot about Mahogany vs white oak vs ash debate. I am leaning toward using ash because of the following reasons: Price. will not be left out in the elements, and will be fully painted/sealed anyway.

12 - For this reason I was wondering about the need for Marine Plywood. I have used and really like Purebond plywood. Purebond has very few voids. and if it is properly sealed with epoxy inside and out, plus fiberglassed on the outside, why would you require marine grade plywood if it will be sealed from water?

I think that is it for now.

Appreciate any help out there. Please post pics if possible.
 

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harleyman1975

Ensign
Joined
May 12, 2003
Messages
959
The Glen-L site has a forum with very helpful people on it. You might want to check that site out too and talk to some of the guys who have actually built a boat. very few of us over here work with wood boat building...Only ones I can think of besides myself (very limited experience but some) is Ned and WOG perhaps one of them will come along and say something.
 

Grandad

Lieutenant Commander
Joined
Jun 7, 2011
Messages
1,504
I agree with WOG; 5 adults in a 14' boat will be crowded and a heavy load. Every boat owner gets 2 foot-itis after awhile. Maybe you should consider going slightly larger to begin with. Every aspect of the build is only minimally more expensive or more work for a slightly larger craft. Although I've built an 8' wooden hydroplane and finished off a 15' moulded mahogany shell into a nice runabout, I don't have experience to answer all your framing questions. I can't imagine being out in sunny Spain without some form of bimini. As for anchor storage, a cheap and easy way to tangle-free store anchor line and the anchor itself is within a plastic, ventilated milk crate. Although I only store line in the crate pictured below, I'm sure an anchor sized for a small boat would fit nicely on top of the line. - Grandad
 

frost314

Cadet
Joined
Aug 17, 2016
Messages
10
Trying to get 4-5 Adults in a 14ft wooden boat is NOT gunna be practical. I'd recommend you take a look at building this...http://boatbuilders.glen-l.com/malahini/nggallery/malahini/malahini-by-doug-hodder. Ash will be fine but kinda heavy. Ext. Grade Plywood will work just fine.

4 adults will be the exception not the norm. It will most likely be 2 adults and 1 child. I have been looking at the Malahini for the boat I keep here in the US, but in Spain I am restricted to 4 meter length (13.12 FT) and 15 HP without requiring a boating license (approximately 250 class hours) and I won't waste my 2 weeks vacation in a classroom. I also have the registration from a boat that is being retired that I can transfer to this new boat and it will need to be under 4.2 meters in length. LEO's don't bother pleasure crafts so I would have to stay within these restrictions.

The Purebond plywood I mentioned isn't ext grade, but if I fully encapsulate it, why would it matter? Is it a difference of lasting 15 year vs 50?
 

frost314

Cadet
Joined
Aug 17, 2016
Messages
10
I agree with WOG; 5 adults in a 14' boat will be crowded and a heavy load. Every boat owner gets 2 foot-itis after awhile. Maybe you should consider going slightly larger to begin with. Every aspect of the build is only minimally more expensive or more work for a slightly larger craft. Although I've built an 8' wooden hydroplane and finished off a 15' moulded mahogany shell into a nice runabout, I don't have experience to answer all your framing questions. I can't imagine being out in sunny Spain without some form of bimini. As for anchor storage, a cheap and easy way to tangle-free store anchor line and the anchor itself is within a plastic, ventilated milk crate. Although I only store line in the crate pictured below, I'm sure an anchor sized for a small boat would fit nicely on top of the line. - Grandad

The water I will be on in spain is the Ria de Arousa which is similar to a fjord. It's like a bay. While it isn't open ocean, you can see 1 meter swells when the wind picks up or it can be flat calm. That is why I was looking to raise the freeboard 4-6 inches on the PLayboy model plans. And while it can be very sunny( we had 3 weeks of straight 40 degree celsius days) once it starts to rain it rains about a week to a month straight. Think of Seattles climate. I would want to make the bimini top removable.

I was thinking 2 small danforth or grapple style anchors. 1 in front and 1 in back.

What is that black think in the dashboard/console that the line is going into?
 

Woodonglass

Supreme Mariner
Joined
Dec 29, 2009
Messages
25,929
4 adults will be the exception not the norm. It will most likely be 2 adults and 1 child. I have been looking at the Malahini for the boat I keep here in the US, but in Spain I am restricted to 4 meter length (13.12 FT) and 15 HP without requiring a boating license (approximately 250 class hours) and I won't waste my 2 weeks vacation in a classroom. I also have the registration from a boat that is being retired that I can transfer to this new boat and it will need to be under 4.2 meters in length. LEO's don't bother pleasure crafts so I would have to stay within these restrictions.

The Purebond plywood I mentioned isn't ext grade, but if I fully encapsulate it, why would it matter? Is it a difference of lasting 15 year vs 50?
Using ext. grade is one more degree of insurance. Your logic is spot on.
 

Grandad

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Jun 7, 2011
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Ned L

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Sep 17, 2008
Messages
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A couple of quick comments,... As for your plywood choice, I would NOT use plywood that is not at least "exterior" rated. From what I can tell with a quick look Purebond is interior plywood.
Interior vs exterior is not a 15yr vs 50 year difference, think more like 15 month vs 50 yr difference. I know what you are saying about "totally encapsulating it",........ Talk to everyone here who has replaced stringers and transoms that were " totally encapsulated". The fact is polyester resin is hygroscopic. Expoxy resin is better. If cost is such a concern you would be better off using exterior plywood and polyester resin than interior plywood and epoxy resin (that's like putting gold plating on a cardboard box).

As for raising the shear and increasing the freeboard of an existing design,.... I wouldn't even go there (especially on a first time build). Choose a design that suits your needs.
About the only kind of tender that could work for a 15 - 16 foot boat is a small inexpensive inflatable raft. Any sort of wood or glass boat that will hold 2-3 people (tightly) will be at least 8 feet long (half the size of your boat.
 

Woodonglass

Supreme Mariner
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Dec 29, 2009
Messages
25,929
Uhmmm, I agree that Poly resin IS hygroscopic but...It will NOT allow water to penetrate to the interior wood core UNLESS a Poor job of lamination is done or an external device penetrate the encapsulation. It takes many many years of total submersion in water for water to penetrate and even then it's miniscule. The damage done to the stringers is due to poor workmanship or improper maintenance or installations. There are also examples of 50 year old boats with NO stringer damage too. If the below deck structure is not exposed to water, and barring any external issues, it shouldn't be, then in effect there shouldn't be an issue with the core material used. I AGREE that for added insurance ext. grade should be used but... It will only extend the life of the boat a little bit. The wood of ext. plywood will also eventually rot away. Even Marine Grade plywood will rot. Just takes longer. Just an Old Dumb Okies opinion. Prolly not worth much!!!
 

frost314

Cadet
Joined
Aug 17, 2016
Messages
10
Uhmmm, I agree that Poly resin IS hygroscopic but...It will NOT allow water to penetrate to the interior wood core UNLESS a Poor job of lamination is done or an external device penetrate the encapsulation. It takes many many years of total submersion in water for water to penetrate and even then it's miniscule. The damage done to the stringers is due to poor workmanship or improper maintenance or installations. There are also examples of 50 year old boats with NO stringer damage too. If the below deck structure is not exposed to water, and barring any external issues, it shouldn't be, then in effect there shouldn't be an issue with the core material used. I AGREE that for added insurance ext. grade should be used but... It will only extend the life of the boat a little bit. The wood of ext. plywood will also eventually rot away. Even Marine Grade plywood will rot. Just takes longer. Just an Old Dumb Okies opinion. Prolly not worth much!!!

hey I just took a look at your write up on painting fiberglass and aluminum boats with tractor paint. Can this be done on wood boats. I ask because I have done a lot of rattle can spray jobs and am pretty good at it, just not sure about painting ove plywood encapsulated with epoxy or resin.
 

Ned L

Commander
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Sep 17, 2008
Messages
2,268
Except we are discussing the moisture required to delaminate interior plywood, which can be a lot less than is needed for the plywood to rot.
I do realize that polyester resin is not typically hygroscopic enough on its own to allow enough moisture transfer to support the growth of the fungus that causes 'rot'. I was more intending to point out that "totally encapsulating" is not as easy, nor is it the cure all that people tend to think.

Really two different issues and topics here. Water soluble glue dissolving vs wood rotting.
 
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mickyryan

Rear Admiral
Joined
Apr 18, 2016
Messages
4,216
yeah also think about this cheaper wood swells more and then the glass cracks then its more water then freeze thaw and bam you got a real mess exterior is minimum I would use , try ply underlayment is great except for fact that the veneer is so thin you cant sand it you have to coat it and sand that, but its great for curves and is waterproof glue, I tested for a month in water to see if it would fall apart.
 
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