Fastening Plywood Sheathing

I think you could add a lot of credibilty if you begin to answer with some form of civility, also providing your wares to get our attention that backs up your pointed attacks with your posting.

I have a lengthy line of thin plywood skiff, that unlike its comparible lengths in fiberglass, push the hulls at comparible speeds with 2/3 hp, with the advantages of less fuel burns and requirements of carrying lots of gas, and even in some nasty coastal waters of the Atlantic, with small children, too, no ribs, no frames nothing but blind faith I guess. These hulls also have fifty years of tradition of working hulls in winter and summer seasons for commercial waterman, too. So when you scream that some people posting are opinionated, well history is surely on my side in multiple methods with time and success on my side.











If you take a close look at the seating, at the edges there are cleats the allow for the seats to fit into a slot and is capable of being removed from the structure for a more open layout giving you a completely open midship, using a tiller feature and setting in the aft seat. You have better be confident in the structual build of sheet plywood and a single longitual. This type of construction and specific hull can also be found in number 49 edition of Wooden Boat Magazine, dating back to the middle 1980's too. Mr. Herb Jester bagan this building in the early 1950s also, changing over from thick white cedar planks. What a master of knowledge evolving into several more decades of success, and yes giving me quite an education too. Seek it out and learn something and settle down a bit and then tell us about your background.

 

my dear Oyster,did you not read my last post on this subject,I am not talking about these small runabouts ,they do not interest me in the slightest,
as regards promoting my "wares" I do not have any wares ,if you mean by that ,am I trying to sell something ,Believe me the answer is no ,I have been retired these last 10 years .Another thing you will need more than blind faith when you venture out in rough water in that thing ,taking children out in rough water in a craft such as that would be regarded here as a criminal offence.....cheers for now

 

Funny thing, in your own words you write:

[quote]Originally Posted by hartley
I think one of the problems here is a lack of understanding regarding small runabout craft[/quote]

So yes I do have an understanding of small craft. And you, up till now, have provided nothing, while I have provided two lines of hulls, in plywood, built multiple ways, used in the commercial industry offshore and in one of the largest bodies of water on the eastern seaboard with great success. Read about one of the lines in Wooden Baot Magazine, number 49, and in the past two issues of Wooden Boat just this past year. Again, history and construction methods are well documented. I addressed your earlier comments with facts and nothing more. Seems to be a problem with facts these days. Later

 

Oyster what can I say to convince you that I have no interest in the type of boats that you portray,they are probably built any way imaginable ,as I have stated before ,probably papier mache for all i know.
The lack of understanding I was referring to ,and you didn't quote the whole sentence I see,was the lack of understanding of the type of boats I was referring to ,that was ,heavily constructed boats with frame and stringer (and plenty of them ) construction ,to the order of say 30 feet and larger
All I said was, with this type of construction you do not fasten the sheet plywood to the frames ,all I have said here I have said in previous posts ,and I stand by them ,and so do others...cheers for now

 

We only have words to go on with internet forums. "Promoting wares" is a figure of speech, but comes in many forms including words on the internet. I can also provide you with 60 foot hull shots, in conjunction with the two methods provided, all built with plywood. Internet forums brings together people of all backgrounds, and no one person is absolutely 100 percent riight in it all.


But wondering into a place with a form of insults lodged at well written and experienced folks, which in turn some of us know first hand and their work, with nothing more than a few typed lines, does not give you any credibilty, unless you provided us some form of evidence that supports and explains in details what you would like to share with us. For myself, I am wide open and would like you to clarify your position in this case. For a picture is worth a thousand words.


The world is full of opinions. I shared more than just opinions, that also have a lot more credibilty behind my typed words than what you have provided in your few short postings. Or have I missed your examples somewhere else? I look foward to you clearing this matter up. For a picture is worth a thousand words.

 

oyster Your last post was quite mild ,and I thank you for it ,however you have made some quite silly statements in the past .All I have ever said was that,to put it as simply as possible,fastenings should be put in ,in the horizontal plane ,not the vertical as well,this will ensure a much fairer hull
That is my opinion ,and I may add not only mine but others as well.You have another opinion obviously and you are entitled to it ,answer me this ,do you think it is wrong for people to have different ,and differing opinions on subjects ,any subjects ,even when those opinions are quoted by "experts"
......cheers

 

Sure we all can differ in opinions. But first, as stated, we must begin by looking at each design. You have yet to provide anything to explain your position of only fastening only longitual at all. A lapstrake boat makes its own longituals, and solid planked hulls did use batten seam construction methods.
But a boat must be made rigid because a hull is subjected to twisting too. Many early forms of hulls used longituals when building sheet plywood and using thin plywoods.

That also was the reason and a requirement for fastening longituals making the hull fair. Even with thick plywood, a boat still needs to be tied together across the form. Thats done with either bulkheads or a rib frame construction or in the case of a round bilge hull, in most cases around my world, they can be called and have normally been called frames which extends from the keel area to the sheerline.

In the early days of boat building, especially in the days before epoxy and 5200 mindsets, non hardening and non adhesive bedding compounds were used. So tell me how in the world do you hold the stiffeners in place, and maintain the hull integrity in tack under seaway conditions, if you use no fasteners in the vertical supports of hull parts that also create the interfrity of the hull.

A hull should be made fair in the initial setup, whether it be the jig or the solid framing long before the any planking or sheet plywood is put in place.

In cold mould boat building, bulkheads and longituals create creates the structual integrity, along with the decking and or covering boards. So what is it, what design, or hull types, are you talking about that has nothing more but blind faith keeping the two sides from twisiting and racking and how do you achieve this if you do not build with a pretty substantial adhesive compound or glue?

Even with glues such as epoxy, glass tabs are used in conjunction with the glue replacing hardware to hold the hull sides and bottom to the framing or to bulkheads in lieu of framing, depending on the building methods. In building with an adhesive compound and no glasswork, there is also a potential of wood releasing from the framework if water gets between the two wooden parts if any racking take place.


So again, provide us the context of your statement and real evidence to support your strong opinions, and not just a slam at at least two people in the liability business end of boats that have found no other way to maintain its integrity of the hull but to use either glass tabs, or hardware in vertical frames, or a combination of rib-frame construction .

Mild or outragous as you feel my responses are or were in this case, I need more than blind faith to understand this but willing to learn here. Help me out. If not, I am done with trying to understand your opinion on this one, when you say multiple times over, that no hardware is to be used in vertical supports. What type hulls, what type construction method, what context?? Help me

 

You are absolutely right oyster.....cheers

 

Gentlemen ! Be kind to one another. I reckon Hartley is thinking of a storm in the Tasman sea and Oyster is thinking of a nasty day on the Chesapeake. Neither of those scenarios are pleasant, but I think there is a difference in scale. In any case I think both of you are right.

On the plywood fastening thing; Consider that some boats are built as monocoque structures. Frames or bulkheads are used as diaphragms to stiffen the structure in the twisting mode. In such a layout the frames/bulkheads MUSt be attached to the skin firmly, one way or the other. One can see this kind of construction on some pretty exotic vehicles. Formula one race cars for example. Aircraft airframes and wings are routinely constructed with bulkheads, ribs, longerons, etc. attached to the skin. They are stress skinned.

When I'm flying on a 727, I try not to think about structural design concepts. On more than one occassion I have seen rivets in, wing ribs, dancing around and around, a result of vibration I suppose. Unnerving, but so far I have not been killed by a structural failure in aircraft, race cars, or boats.

I like the idea of leaving a lot of space between frames and skin. The reason is that it is clean and provides generous limber. On the other hand if I build a light boat, particularly a high performance one, I'm going to use the stress skin method and not worry too much about failure. Then again I ain't gonna sail in the Tasman Sea.

Be nice, don't fight

Gene

 

Hi Hartley.

First you stand as the expert yourself - quote.
"Never, Repeat, Never glue frames to the hull"

and then a few posts later reveal that you are talking about a specific type of boat rather than the general case that you were seeming to put forward. What happened to the "Never"?

"one of the problems here is a lack of understanding regarding small runabout craft"

In general the other "experts" on this thread were putting forward opinions - but you clearly making the point that you are a bigger and better "expert" by your attitude to their posts

"re post from samsam ,here again we have sarcastic answers from so called experts"

"in my opinion this method of construction(plywood over ribs) is a very ***** way of doing things"

"par ..you have waffled on there as usual"

And then you go on about

"quite frankly I was appalled at the sarcastic and sneering comments posted to people which were seeking information"

If you think you are "just joshing" - that is not how it reads to me.
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But to your argument

If there is a problem, as you say, keeping a hull skin fair if it attached to the frames, isn't there a similar problem with the bulkheads and floors which also are at roughly the same angle to the stringers? The floors are usually of a similar spacing to the frames.

It is not uncommon for runabouts to have the skin glued (and maybe screwed) to the floors and there is no problem with fairness - there are hundreds of plans and probably thousands of boats set up this way.

What you describe is only one method - it works - no problem. There are also plenty of others that work.
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I'll finish with another of your quotes

"just an average Aussie trying to take the "mickey" out of some self important people "

No Mate, it just sounds angry to me.

Michael Storer
South Australia

 

Plywood

Hi Name is Joe

We have a small marina and have been repairing boats of all styles for years. We had a small work barge made out of an old dock section that was recently destroyed in a storm.. We are toying with the idea of constructing one out of either wood or metal framework and plywood skin. This is strictly a work barge and nothing fancy. Probably will be about 12 X 25 or 30 flat deck and flat bottom with one end raked. Should we worry about using pressure treated plywood or just use standard plywood and epoxy coat it with some fabric. I know this sounds kind of basic but this is to be a low cost alternative to the construction of a all steel barge.