25' Skiff Build

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Yofish
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Re: 25' Skiff Build

Post by Yofish » Tue Apr 02, 2019 8:50 pm

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DrBryanJ
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Re: 25' Skiff Build

Post by DrBryanJ » Wed Apr 03, 2019 5:12 am

Yofish: It has been a pleasure following your build. She looks very nice sitting on the trailer. I look forward to seeing another of your builds.
Bryan

Building a malahini "Mona Lisa"

My wife said "If I build a boat, she's getting a divorce."

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Thu Apr 04, 2019 6:19 pm

Yofish, I know the skipper was a giant, and stand up helms are a mutual design headache when you're accommodating the owner's height, I'm current working with a 6-5" or 6-6" owner but at least he's building his own boat!

Given the 'well deck' in the house- domino effect to the bottom being hogged due to the shallower x-verse frames, and then w/normal welding requiring a 'rescue' of the bottom.... resulting in the tonnes of headaches, extra work and pain in the stern it took to accommodate the cabin's required inside ht:

Could you have just cut the sides 2-3" taller at the sheer? The 2-1/2" or 2-1/4" you mentioned that you sunk the cabin sole - what a pain it caused!! If the intent was to help the design's proportions to look a little better.... I'd have to vote for taller sides- hey! the man can reach the water with a few more inches in the sides- right? After all he's a tall man.

Was the x-verse frame hogg amidships from chine-to-chine or mainly at the keel? It appears in the strong back and jack photo you're working in the keel area- so that's why the question. But the shortening of the x-verse frames was a line taken off their entire top?- as I understand it- you lowered the entire cabin sole and that is what caused the weld contraction distortion of the bottom?

In my view- the one of her sitting on the trailer- her beam and full bow really compensates for the taller house line. I think she's nicely proportioned- it's the narrow, older skiffs with the low sides and "outhouse" helm stations that look poorly.

I've tried a couple of 'gimmicks' in skiff cabins to help the lines but frankly- they're just too tall and if the doggone skipper would just sit down to the helm..... never mind.

thanks for posting, I'll re-read the thread and see if there aren't a few more questions that I have?

Cheers,
Kevin Morin
Kenai
Kevin Morin

Yofish
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Re: 25' Skiff Build

Post by Yofish » Thu Apr 04, 2019 9:01 pm

First, a thank you to Dr Bryan. I'm glad you enjoyed the show!

To Kevin:

Could you have just cut the sides 2-3" taller at the sheer? The 2-1/2" or 2-1/4" you mentioned that you sunk the cabin sole - what a pain it caused!! If the intent was to help the design's proportions to look a little better.... I'd have to vote for taller sides- hey! the man can reach the water with a few more inches in the sides- right? After all he's a tall man.

THAT was my very first thought but it would have been a redraw for something I'm never gonna do again! And, there is a point where one can't unload on Glacier Spit with too much freeboard and this size is pushing that restriction without removing body parts to clamber off! Yeah, it was a pain to fix but I brought it upon myself; could have obviated it right off by stiffening the centerline. A straight edge showed that off the centerline, the planing surface was acceptable.

Was the x-verse frame hogg amidships from chine-to-chine or mainly at the keel? It appears in the strong back and jack photo you're working in the keel area- so that's why the question. But the shortening of the x-verse frames was a line taken off their entire top?- as I understand it- you lowered the entire cabin sole and that is what caused the weld contraction distortion of the bottom?

Chine-to-chine but paradoxically, the hog was more pronounced after welding the bottom keel strake which surprised me. Yes, I lowered the tops. Up forward the cabin sole is only 3/4" above the chines. When I flipped her back over, the frames were snakes.

In my view- the one of her sitting on the trailer- her beam and full bow really compensates for the taller house line. I think she's nicely proportioned- it's the narrow, older skiffs with the low sides and "outhouse" helm stations that look poorly.

The clients are happy, me, not so much. A well known builder around these parts just plunks the cab down on a flat deck. Makes me gag. If I could ONLY build center consoles...

I've tried a couple of 'gimmicks' in skiff cabins to help the lines but frankly- they're just too tall and if the doggone skipper would just sit down to the helm..... never mind.

Well, there's always a Hewescraft approach: "here it is, live with it". I laugh when I actually thought I'd come up with universal plans that everyone would fall over and need no edits.

BTW, if anyone would like to chat please PM me and I'll be glad to yak on the phone with any questions.

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Fri Apr 05, 2019 8:41 pm

Forum readers who're reading Yofish's build thread might be interested in some detail notes about this thread and welded skiff metal boats in general.

First and foremost is this skiff wasn't built off full gunwale-to-gunwale transverse frames OR with a set of station molds inverted on which to form the hull, as would be used in conventional wooden building methods. There are quite a few reasons for this fact of the build, and I'd like to examine a few to help readers to compare welded metal building to other materials and THEIR building methods.

The primary reason, but not the only reason, is that aluminum in our wonderful space-age time of life is available in huge, perfectly uniform thickness and alloy sheets/plates. Most all wooden or even plastic composite boats are made of materials that need support and shaping aids during the assembly process- 6' wide 20 or 25' long sheets of aluminum can be purchased and delivered anywhere in the North American continent that will make an entire hull panel. (half or whole bottom! entire topsides on either side! and other huge pieces)

So non-compound surface marine hulls can be designed to make use of large sheets that are available and the build can move ahead without a set of station molds or framing as needed in most other materials.

Second, Yofish and I, among many other builders of this type of boat/skiff/craft, have observed that we can reduce our tooling investment in jigs and fixtures and we can reduce the build time, overall, by only adding the hull shaping elements- during the build- that will become permanent parts of the final hull's structure.

There are a few props, legs, tack strips and other small items used in this "Skin-Only" building method but they're not entire frame sets with the accompanying labor and materials.

Next is: that because the material is so strong, uniform and in such large pieces from the suppplier/vendor/mill, transverse stiffening or framing can be at an absolute minimum because one welded its all one piece!

Let's explore this some more? The skiff shown doesn't have a set of 'ribs' to hold the form- instead the hull has many longitudinal elements - just outboard the chine is a set of 3" or 4" deep longs that run bow to stern on 16-18" centers and are once welded to their few x-verse elements are only supporting the bottom, sides or cabin for a 2' span!!! a 4" x 1/4" bar in 2' is enough to hang the average automobile from !

So its important to observe the longs, aft; they're straight to reinforce the planing surface- forward they're located on the Buttock lines and curve with the rise of the forefoot- but at each x-verse bulkhead or frame they're welded and so again, they only span a couple of feet!

Moving to the chine- there's a 6" wide chine flat bow to stern- in any kind of side load this is a huge beam element (yes it deflects spray, helps planing and widens the running bottom) that eliminates the potential for deflection of the chine in toward the keel!

Moving up the sides, midway from chine to sheer is a full length shelf/long/"frame" and again the sides can't come in toward the keel unless the force was enough to "bend" a 6" T (the shape formed by welding the mid side long to the topsides) !! and the boat doesn't have a total mass plus its momentum to achieve that loading!

At the sheer there is an even wider sheer clamp/guard deck/hull longitudinal which is about right angle to the topsides. As with the mid chine to sheer hull longitudinal; in order to bend the topsides in toward the keel this continuous plate would have to distort!

My point in spending time illustrating why these skiffs aren't built using frames is to help the Forum reader understand why? The reasons are in the material available and in the nature of welded metal- once assembled.

In Yofish's skiff the house fore and aft bulkheads combined with the transom and bow deck bulkhead end up providing giant transverse stiffness - reducing the span of the many longitudinal framing elements and the whole boat becomes on rigid metal form.

Cheers,
Kevin Morin
Kenai
Kevin Morin

Yofish
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Re: 25' Skiff Build

Post by Yofish » Fri Apr 05, 2019 11:28 pm

I'm about to leave on a trip to see grandpa (wife's 94 year old dad) and other family in a couple of days and I'm bunched up. But I have a comment that I would like to expand on when I land home again, and that has to do with what Kevin is saying about framing AL skiffs - it does NOT have to follow traditional methods of building with wood. As a matter of fact, IMO, it shouldn't. Building something small in AL upside down is a waste of time and other resources. Dear old Renn is clapping....

Jeez, I thought I was done and then Kevin.

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Sat Apr 06, 2019 5:31 pm

Yofish have a safe and relaxing trip to see your father-in-law and family!

Of course I can't let it go! The Forum readers could use some follow up, and look forward to your return and a few posts before the season in the K.Bay opens up and you get busy enjoying the Lord's prettiest landscape anywhere.

if Plywood Trees grew to 6 or 8' diameter and were clear from the base up to 25' feet or so.... things might be different. In the mean time... looking forward to your return and some remarks after a couple weeks' reflection.

We may need to explain who Renn Tolman was? Not everyone has heard his name or understands his design and build ideas? or know of his books and experiments. While you knew him as neighbor, friend and fellow boat builder; many here on the Forum may not have even heard his name or know his skiffs?

Cheers,
Kevin Morin
Kenai
Kevin Morin

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kens
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Re: 25' Skiff Build

Post by kens » Sun Apr 07, 2019 7:42 am

I had never heard of Tolman. I went to the website and it is some very nice skiffs there.
Tolman has a good eye and a sharp pencil.
Oak is over rated, everything about it takes extra time; then it warps, splits or checks !!! :roll:

Yofish
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Re: 25' Skiff Build

Post by Yofish » Sun Apr 07, 2019 10:26 am

Renn was a good friend. We had plenty of more or less friendly arguments (discussions) about skiffs and many other things for many years. His designs have been successfully ported to aluminum. I was doing some CAD work with him on a design that was to be used in Africa before he paddled over the bar. He was quite passionate about what he did. His designs and methods put a lot of people on the water that couldn't have afforded it otherwise.

https://en.wikipedia.org/wiki/Tolman_Skiff

North
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Re: 25' Skiff Build

Post by North » Mon May 13, 2019 4:05 pm

Yofish - really enjoyed watching your build and seeing how you and Kevin approach many aspects of the builds.
Ss an amateur, first time builder I would have bee happy as a pg in sh$t if I had only had a 1/4" or hogging/ distortion.. but I see and understand that you guys build to a MUCH higher level, and how you "needed" to fix it....

I built mine starting upside down, but had it on a rotating jig as well (idea taken from Kevin and his peers) so it was easier for me to weld.
I was very happy with pow the jig worked, but...as a first timer.. if I were to go back and do it again, I would have built rightside up, and likely would have payed to have a supplier cut with CNC files..for the first one.. just so i could have seen progress right away.. it was a couple of winters before I had more than ply templates on the hull, working off and on.. to be able to unload a palet, lay out bottom pieces and start tacking and pulling together would have greatly reduce the hours (for an amateur) and that would have kept my wife and kids happier.. a lot of time spent welding the heavy duty jig (which later became the trailer) and cutting (and sweeping up...) with the worm-drive saw..

please keep the pics coming for any future builds that you Pros take on!

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Wed May 15, 2019 10:57 am

North, didn't you build the Glen-L Double Eagle, inboard ? Is that hull being offered as cut files? Not sure I'm clear on your remark about using an NC cut hull if you had it to do again?

Perhaps I don't recall which hull design you built?

Standards: Both Yofish and I try to build "clean hulls". Not the simplest thing to do in welded metal. However, everyone who is willing to spend the time to learn can build to this standard for themselves and that is why we've taken time to share the proof of our methods (not identical) with others.

We both seek clean, smooth sides, bottom and other surfaces, and that seems to be the minimum level of workmanship to us. So I'd say that expecting to do a clean job of the metal work is mainly a "sight picture" that you hold in your mind as you plan and execute the build. Once clear in mind, you want to keep working/learning/increasing knowledge until the results match your vision.

We both have some fairly extensive experience which provides methods and techniques to attain what we "see". And many of those are shown online, here, in the various posts, hoping we could pass along some of what we've learned by making countless mistakes.

Since welding is a expansion/contraction operation involving molten metal.... that skill is key to both our builds as it is a critical path for all welded boats. This key factor is most often misunderstood by the majority of newer builders who are attempting to learn to build in metal at the same time they're learning to weld. So often this is a very unrealistically steep learning curve.

So I have suggested (& think Yofish will agree) that learning to weld aluminum MIG should involve at least 100 hours of 'hood time' before even a tack is put on the boat's parts. In the case of TIG I'd up that to 150-200hr. depending on how well the beads and bend breaks are showing up along the learning/practice time?

However, as with many, many (MANY) online suggestions; most new or first time builders choose to skip the advice of those who are showing the results of the practice suggested.... and jump right in? They end up with weld distortions or poor weld quality.

Modeling is another area that both Yofish and I suggest to new builders- not super thin aluminum models (very tough to weld)- but various paper products that will work as substitution for sheet metal. Hot or CA glue as welding, maybe even fine copper wires in a stitch-n-glue process, all contribute to a builders' knowledge of the shape and stresses/forces that will arise in "pulling up" the hull.

Cheers,
Kevin Morin
Kenai, AK
Kevin Morin

North
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Re: 25' Skiff Build

Post by North » Thu May 16, 2019 11:59 am

Hi Kevin - I agree with all of your points... with lots of hood time now.. for an amateur... I would certainly agree that i would have less distortion if I were to do it again.. Now have more skill and patience that when i started.

I did build the Double Eagle and no, I do not think it is available with cut files.. my comment was that if I were to do it again, I would choose one of the plans which do have cut files available, like some of those Specmar designs which are available through this site as well. This is NOT because I am unhappy with the Double Eagle design, nbut rather because I see the potential benefits for starting with CNC cut material (for a first time builder).

This would not erase the need for lots of hood time prior to a build (for best results), and following best practices as outlined by Yofish, yourself and basic books for starting out like "Boatbuilding in Aluminum). However, i think it would increase the enjoyment for a new builder, in allowing them to see better results faster... Once the first successful build was under their belt, they would be much more prepared to do a full build (from scratch) including cutting all material.

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Fri May 17, 2019 12:03 pm

North wrote:
Thu May 16, 2019 11:59 am
Hi Kevin - I agree with all of your points... with lots of hood time now.. for an amateur... I would certainly agree that i would have less distortion if I were to do it again.. Now have more skill and patience that when i started.
North, very unfortunately for the good of many first time boats.... your belated understanding of Yofish and my harping on welding (well mainly me... Yofish is not willing to be as critical of others) comes AFTER you learned the lesson we suggested - and may have put down welds you'd prefer to have done later in your learning cycle; with greater skill and experience!!

This is why I suggest that welded boats involve two complete spheres of knowledge- one is lofting, layout, fairing, cutting and joint prep; the other is welding. They are equally involved as to breadth of knowledge and developed skills. They are both a trade in themselves- in the wider labor market.


regarding cut file builds or kit boats:

I can see in your first quote above- that you're now able to see that patience and understanding increase as you build? But then you seem to value "quick gratification" in this quote?
North wrote:
Thu May 16, 2019 11:59 am
However, i think it would increase the enjoyment for a new builder, in allowing them to see better results faster...
The problem here is that anyone/someone/a potential builder whose ideas are based on quick gratification or quick satisfaction might not be the effective temperament or hold the most reliable long term concepts for welded metal boats? Isn't this the same builder who takes short cuts? "Close enough nail it" is the old construction saw or saying.

I'd hoped to illustrate in my posts, and I think Yofish shows in his... we both want to move along at the fastest pace possible in our builds. (given we're both not young men.) However, in our mutual experience, I'll presume to speak for Yofish as he's not chimed in yet; the fastest way to do a job is to "do it right"- once.

Otherwise you've got to do it wrong, take it apart and then do it right? So its three times faster to do it right - once.

That is what we're sharing in these posts.

Cut file kits may be a time savings but.... if they facilitate first time builders to take a "close enough nail it" attitude- then kit/cut boats are actually not going to save time- they'll extend the time needed to build a clean hull.

Cheers,
Kevin Morin
Kenai, AK
Kevin Morin

North
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Re: 25' Skiff Build

Post by North » Fri May 17, 2019 3:51 pm

Hi Kevin - sure - fair points you make. My point though, if not that guys should buy cnc cut plans to facilitate a "good enough" attitude. To your point, either way, they still should put in the hood time in advance.
The big reasoning though, that I guess I did not mention, but is likely apparent on his site...is that many DIY builders \(in wood or metal) never complete their builds... the option for a first time builder to start with cut pieces does NOT have to mean that he or she does not become proficient in welding techniques.. If it increases the chances of first timers completing builds and not getting divorced in the process.. i think its has merit for some...

Kevin Morin
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Re: 25' Skiff Build

Post by Kevin Morin » Sat May 18, 2019 4:18 pm

North,
i see all the additional and previously unmentioned points!! I agree that if someone is married and that relationship won't stand the extra-work hours of a boat build? then it would be a good idea to find ways to shorten the hours needed to build. Marriages are way more important (in most cases) than a homemade welded aluminum (in our discussion) boat!

With that said, I see the online comm. circumstance is again obvious for the many things one person writes and thinks/means while the other (reader initially) finds other points and answers to those- not what was intended by the original poster.

Standard online fare.

I do agree if a potential builder is married; metal boat building implies all sorts of "burdens" to the relationship starting, but not ending, with the relatively high cost of the welding system. Metal is notoriously expensive, the space (heated) to do the work might be a huge cost, not to mention the money for all the other items and finally the time investment to build a boat (of any material)!

All those items add up to many ladies'/wives viewing boatbuilding as taking away a husband from the 'honey; due' list and attention to the short people. That is very hard to balance with husbands' increased satisfaction of doing the build himself. Not a subject I've addressed, or care too!

I hadn't thought of many boats started but that are not completed. Great point, I had so much money invested in all of mine, and contracts to build 98% of them.... so I had strong incentives that aren't the same as most home builders.

Now, after seeing your points more fully explained; I agree that using a kit/cut file boat might be more likely to be completed- as they do save around 30-40% of the hours in layout and cut hours involved in a hull. Unfortunately, unless someone was already invested in the time to study a hull tack up- they'd just run aground sooner in the build.

North, thanks for taking time to explain your previous remarks, it's been many boats past that either Yofish or I have thought about these aspects of a first-time builders' welded aluminum boat build. We do tend, and my posts show that, to focus on the actual details of "doing it"- we tend to expect any one reading to want to "get-'er-done" and we only address 'how to'.

thanks for the clarification of your remarks.

Cheers,
Kevin Morin
Kevin Morin

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