New, new and new

New guy here (lurking for years) that is going to start an Aluminum 20' center console skiff using some new (for me) ideas.

I started building boats in Alaska starting in the mid-seventies, working in a shop as a cut-out man, then in the early 80's, I started my own business building small pleasure skiffs but mostly commercial fishing boats like set-net and seine skiffs. They were all one-off jobs done for the most part with eyeballs and batons. In the late 90's I taught myself how to use a surface modeling computer program that was designed specifically for boats called ProSurf. I built some small skiffs using the program but then went on an extended tour of working in the Aleutians and left the boat building behind. Recently I quit my wild west days and got back into boat building as a slow glide into retirement. For years I've played with a design that (may) fill a niche where I live: a reasonably priced, self-bailing decked 20' skiff that doesn't take 250hp to move. The fantasy is that I can build two of these leisurely in a winter and that will keep me from drinking too much and supply the added income to live comfortably along with savings, etc.

The 20' length is to obviate the onerous 'level floatation' CG requirements. The horsepower target is 115 ideal max and hopefully adequate with less. I'm a bit of a forum junkie; I enjoy the debates, the good give and take and especially the fools, so I decided to show the progress of the first one of this design on this forum.

Here are some pics of the project: a partial lines view, a rendering and the first model. Even though it's easy to render and view surface geometry in rather dramatic fashion, nothing compares to twirling a model in the hands! The model shown told me that I needed more flair to the bow. This project will start within a couple of weeks or so. I've decided to hand cut and not send it to the router boys because I'm really not quite certain about the deck height yet. Paper plots pounced and dots connected with a baton.

 

It certainly looks like a net boat, stable, but would be a "kidney job" in a chop ?

 

Hello, thanks for the reply. One cannot have 22 degrees deadrise and beam without adding horsepower! Yes, you are correct, 13 will rattle you but that's the choice and it's quite simple. I live near a bay and there are clients that want to travel around it or across it with four aboard (beer and dogs too) and not have to plunk down 40K to do it. Throttle back, this is not an off-shore design. Hewes is the competitor with who I can't compete but there is a boutique market here AND true self-bailing is a pleasure - no plywood decks here.

 

Boats like that actually do perform better on the open sea, than in a short bay chop, where it can become a complete misery if the distances to traverse are lengthy, and you are going upwind to any extent.

 

I like the concept. There are lots of successful boats with minimal deadrise. C-Dory's, for instance, have ~5* and many loyal owners that appreciate their economy.

 

Sounded rather optimistic, till I realised you were in Alaska where I guess winter lasts longer than the "official" three months.

 

Small Adjustment to Chine?

Yofish, I'm in Kenai, and have built a few hundred skiffs for set netting and a few sport boats along the way too.

If you'd make one adjustment to the Profile Chine the KBay afternoon chop would be much more comfortable either running off the Spit or back in.

The profile I see posted, shows a flat run to the shear aft the Master Station. I'm generalizing, but essentially the chine 'hooks' more like a keel and forefoot curve in Profile.

If you'd go around the modeling a few more times, and begin the chine upward sweeping curve farther aft..... the forward edge of the waterline will be at a 'just deeper'/sharper V, I'm not arguing away from your simpler bottom concept. IN other words if the chine curve in Profile were more gradual and reached farther aft...

I'm just observing that if you raise the chine in profile just a few inches for about four or so feet aft, when compared to the lines in the post above.... the V will increase amidships, where the boat's leading edge of the waterplane will be when she runs.

This won't change costs, won't take 2x the engine to push, and will result in 'just a little softer ride' on plane in that short afternoon chop.

Next.


While not particularly popular with younger and more agile builders... I prefer to build from the deck to the keel on a rotisserie, then add the topsides afterwards. No climbing of the sides, no out of position welding, and easy down hand seams, air tests and simple fits, while positioning to do all work. Maybe your back still works like original equipment? Mine likes this method much better than my first couple hundred skiffs.



A hollow surf board method does work, and while it adds a few seams, I didn't mind the welding compared to the climbing over the gunwale and trying to weld below my knees; that was killing me.



Deck to lower topsides was an outside fillet with semi-automated TIG so it was downhand, fast and keyholed the entire 58' perimeter, as fast as MIG but easier to weld in this position.



some temporary frames to get the pre-cut sides to lay up right but the bottom was done already so once they were on... the rest of of the work was above the deck.



(deck) Seam was controlled in shape by the lower cut on the upper topsides panel then it was TIGged in about 40 minutes, both sides, once tacked on.



Once the bottom is built, I added the topsides- separately; she turned out OK showing that even older guys can build skiffs if they make a few fixtures to take into account their old bods and shaky hands! (well that's me, I hope you're still younger and not as shaky.)

Cheers,
Kevin Morin
Kenai, AK
k.morin@kmmail.net

 

Kevin, we live in the same 'hood' and I'm familiar with your work, how could I not be? We've never met though I thought of dropping by while driving K Beach back in the day. I started with Cliff C. in the seventies.

I absolutely agree, yes we have a monohedron here and not a warped bottom, a la Renn T. I believe that 90% of the skiffs I've repaired had the damage on the port side from that Bay chop. SW in the summer and NE in the winter - gets you comin' or goin'! The irony is that this is the first skiff I've EVER done this way. Every Vee in the past has been warped. I have a zillion iterations of this going from 10 to 22 deadrise aft, longer, wider, narrower, step chine and no step chine, even partial step chine forward only. That's the beauty (or the tyranny) of the computer you can go oingo-boingo with no expense other than time.

Believe me, I've agonized over the L/W ratio, deadrise, deck height, HP etc. and what the client wants. You remember those clients, no? The materials are ordered but I haven't plotted it yet. You push me in a direction I've already considered. I'm inclined to narrow the beam too.

And yes, at 65 years I DO understand about getting down on the knees! If my fantasy is successful, That is, getting the clients, I would have the parts cut and build a 'rotisserie', as you call it, to do positioning. I've got about 5-6 more years of actual 'workability' left in me, that is, if the trajectory of this damned arthritis stays the same.

 

Davis Jig/rotisserie fixture

Yofish, I see that you're going for the prismatic after underbody but my experience is the warp is more effective for this short a skiff?

We'll see when you run the first skiff, and compare to the other skiffs you've done with a warped bottom.

I saw Cliff not that long ago, a couple years, I did a little welded stern add-on for Gordon Giles in Seldovia on a Copper River bow picker converted from two Cummins inboards to two Honda outboards (!) Mr C. was the surveyor, and I'd not seen him in years. I don't think he recognized me? Did mention that he regretted selling the shop.



A few years ago, I was in an online discussion with a builder in Oregon, Jack Davis and he was designing and building fixture, so I did too. I've named this fixture after him so I refer to it as a Davis Jig but the idea is used widely in welding fixtures.

I've built three of them so far, the first one, here, is 20' between uprights and rolled nicely on the casters. I rolled it with the overhead monorail in that shop, but had provisions to make the roll self powered, just never that because lifting was too easy.

I was working alone, mainly, so I used the clamps on the pivot pin pipe to adjust the friction/tension, and lifted and lowered the boats to center the load on the pivot pin - pretty close. That allows me to roll the boat by hand when its mass is balanced at the pin/pipe center. The friction can be adjusted to allow the roll and stay at that angle, making hand adjusting and welding easier for me.



The hub is 3" split over a 2-1/2" pivot pin, the end of that has a 5" box, around 4" box, with some flat bars inside the 5" box (made of two 6" trimmed angles) to take up the slack and allow UHMW tape to line the flats making the lifting and lowering of the main beam (in order to center the load on the pivot centerline) very easy without binding up, but still tight enough to guide well.


here is the 30' version that was used to build my last skiff (25' LOA) but the box available when I built was too thin, I should have waited to get a 4x6 or even larger so it was less flexible, I ended fighting that till I installed some trussing below and to the sides of the main box beam on this longer model.



But when all trussed up the longer Davis Jig worked well. IN any given day I rolled this skiff /surfboard a dozen times to work opposite /inside outside on welds or tack up, and when I did the weld out, the rotation made the work a one man job: there is no discussion that having this fixture back when we were building set net skiffs would have cut time by 20% maybe more?

Best of luck with the new design, I hope folks like it and you're able to find a price point that attracts buyers. Today's metal boat costs are premium, so simplifying the form and working to keep a cost competitive skiff is looks like a good market opening. BayWeld shows little interest in the smaller hulls for less than platinum prices.

Cheers,
Kevin Morin
Kenai

 

Kevin, Cliff crossed the bar awhile ago. He used to weld with a cig (Benson 100's) sticking out sideways and never thought of any kind of breathing protection, even inside a tank. Emphysema.

I like the look of your Davis rig. The one I'm thinking off would be similar except it would be mounted on a base frame that would accommodate removable tires and axles. I have a small shop and need to get crap out of the way as boats are not the only thing I do. I will borrow some of the adjusting features you have provided.

You nailed the Bayweld situation and is indeed, part of my effort in marketing. Dennis C. designs their boats (always has) and we use the same program. My hat's off to Allen E. at bayweld, he's created a world there. I remember when he used to come in to Cliff's as a beginning welder like me. Yes, the jig would have shaved considerable time but I must say, it is the having parts CNC cut that is the amazing time saver. The last big project I did was a 40' landing craft that AK COP & B did on their 50' router table. Everything except the house was cut. This project is going to use, for the most part, the same style construction: athwart frames slotted for longitudinals. For some reason, I developed a loathing of hull stiffener. Also, the computer is persnickety about the hull plating. Some guys use the computer to do station (athwart) framing only, then cut and fit longs in between. That works for sure, but the hull plates will bend outward between them making it not as fair as it could be. The part that I've not figured yet is the best price point for having that cutting done. The router does superb cuts but plaz is cheaper. I've been talking with Glacier Craft boats in Anc, they are interested in working with me. They have a router.

You think AL is expensive these days, eh? Ah yes, a guy got good milage when 5052 was under a buck a pound, no? Didn't hurt that the UCI boys had pockets stuffed with cash American around the same time.

Off topic, but you might enjoy this series of posts wherein I tried to get some help with hooking up a Miller 30A gun to Chinese CV machine. It gets pretty hilarious at times especially when it turned somehow to using short arc on AL. I swear, some put it in the category as oxy-fuel! Apparently, these days if you ain't sprayin', you ain't weldin'! I point you to it because someone mentions you in a post. I eventually got banned for spreading bad information. My gawd, how is it possible that anyone can get kicked off a welding forum?

http://forums.everlastgenerators.com/forums/showthread.php/4979-OK-neighbors-here-I-go

Best to you...

 

terms and definitions

Yofish, I read the threads on the Everlast forum, and I don't think everyone was speaking the same language?

What jumped out at me, was that nobody defined what they were talking about regarding welding modes? Spray, Short Arc and Globular Transfer are all related but all slightly different, why didn't those terms get defined?

Honestly, I think things got off on the wrong foot right there.

I find that 80-90% of aluminum welders use these terms differently; that is one man's spray isn't- while anther's globular transfer boarders closely or short arc. I actually prefer a spray to globular transition just as you showed in your patterned beads on that site. I think you're calling it short arc and Performance/Everlast was calling it globular transfer, which can be done slow motion but doesn't have to be.... and he's not talking the same language as you.

The welds showed the power supply put down a decent bead- maybe you were pushing the smaller wattage rating, but the welds were fine. On the other hand this factory guy has to 'defend' his rice bowl, (intended) so he's going to have a bit of lawyer speak in his posts. Remember you're one guy making a wage doing real work and he's got to earn his with have dozen lawyers reminding him that he's toast if the company gets some 'californ-yay jury' to decide he promised more than he can deliver!

you're the fortunate one, he's got to live with that legal eagle monkey on his back.

There's some real problems trying to talk with people that aren't speaking the same language.

It struck me, the lawyers may have been doing some editing of Everlasts posts!!! that is; they seemed to want to be a bit vague; it would have been better for their creds to have been more hard edged in the language, and to make sure they made definitive statements where they seemed to be making " sort of " ... "Kind-a" types of statements.

I'd have preferred they simply said " Don't use any gun with wire larger than 0.035" @ so many volts to weld with our model 123XYZ."

You may be pushing their power supply but the welds you showed had good toe and top fusion, and they looked liked they held and just failed in 'tear' at the 90 bend next to the HAZ? No shame there.

I'm not sure what they're wound about, maybe they'll let me post there sometime? I would ask for some more clarity on the 'modes' just to see what they call spray, short and globular x-fer?

mean time; I'd like to hear what Glacier has to say about the costs to route a hull? I've seen AK firms think they are the only service on earth and ask for platinum bars so I've cut by hand and made serious wages doing it.

I haven't tried Ak Copper's services but I do prefer routed edges, even if plasma can be cleaned up in short order using a Vixen file and some patience.

I'm not sure what the fellow from Miami had going, I did read closely enough to see what was being exchanged, I was watching the Ev'lst posts. On Glen-L I was trying to help some total MIG newbies to get some points of reference... it was a sort of 'why to bevel' a T fillet lesson. Sort of off the points on the Ev'Lst site?

If at any time you want to go over the Davis Jig's parts or performance or reasoning let me know here or PM and I'll show what I know so far.

Cheers,
Kevin Morin
Kenai

 

You cannot argue with the ignorant

Kevin, I see that you couldn't help yourself and dove in over at Everlast. I was supposed to have my ban lifted but the Gestapo over there didn't do it nor do expect they will. You made a great effort at trying to clarify modes but alas, the man will not budge in his ignorance. I believe that it comes from welding on only heavy steel during his career. Obviously, he's never built an aluminum boat before. When he said "the only acceptable way to MIG aluminum is spray" I should have just shut up and moved on. I cringed when you mention 'globular transfer' and he blew you off. Cliff was a master at it on thin material. Of course, those Hobart Linears had the best wire control of any feeder ever made. The problem is that that is so wrong it should be challenged because it is foisting erroneous information on the public. The gobsmack is that I get banned for amongst other things, 'putting out bad information'. I never called anyone a liar. Disruptive? Hell, hell yes!

 

Who's on First?

Yofish, I got some replies that seemed like I would learn what was being talked about, but then.... the videos posted seemed to be #1 All steel; #2 didn't confirm what was being said in text; & #3 the lack of lots of experience in aluminum shows so I didn't push it too far.

one thing I did learn was that the mod. there at the green welding site is not talking the exact terms with you or me in regards MIG aluminum.

Now as to whether the way you're using their machine will hose it prematurely?

As to whether you have to be more 'circumspect' online? well its just good manners to be softer spoken with folks that don't 'know' what you do. If you went to Homer High's shop welding class (if they allow young folks to actually learn the trades any more?) and some young welder asked a 'dummb' kid question- well you'd take into account his lack of experience and limited knowledge and try to give him something useful in reply. That's the way I think about the steel only guys, they're sort of 'younger' welders in that they haven't got those thousands of hours aluminum under their belts and 'just don't know'.

(so) In general I do think its good practice to soften the terms online, if we're all sittin' around the shop of Friday evening after work and passing the ache's and pains medication around and sippin' a nice specialty brew.... well then we can say what we want and you can call me anything. But online? I think we should just not post when the others are out to lunch.

I've been flamed a bunch online, told I didn't know what I was talking about, and that I'd never done any of what I'd discussed. I was pretty sure I knew what I'd drawn, cut and built so I just found it's more productive to 'let it go'.

So, in most cases, I'd rather leave a site than waste typing out much of what I may really feel about some folks.

Back to building skiffs, I'll look forward to what you find out with Glacier regarding your cut files and handling and shipping in and out of their table (that has been a killer for me in the past- but not with Glacier as I've not done biz there).

Are you doing the egg crate intersections (half depth notching) of your transverse and longitudinal framing in ProSurf? Or are you doing those on exported outlines in another PC application?

How are you handling/dealing with/adjusting for/ accounting for the natural convex of the bottom panels in the forward 1/3 of the hull where they tend to bulge a bit?
#1 I mean you could flatten the frames out (line from keel to chine) and pull the bottom to them\;
#2 you could bulge/convex the frame from keel to chine a 'bit' (not giving numbers just asking) and
#3 you could do something entirely different?

I've done well making outlines of entire hull panels and tacking up, BUT I've had a few designs that I laid out flat in software and my 'bulge'/convex/camber in the forward few transverse frames were WAY off - like a 1/4" off!



Here's a little 14'er for Seldovia Bay, and her panels output clean, she tacked up as shown -fair. But I had to recut the forward bulkhead (not shown) and then hand scribe a few of the eventual transverse frames as the 0.100" 5052 of the hull bulged more than I'd planned. When I put the frames in (only three) and attempted to pull the bottom 'up' to that section, the hull was not fair, so I dumped those and scribed in a few to fit. (But.. that's not what I'm asking about.)

I'm using DelftShip not Prosurf, but I'm asking about the 'allowance' or design concept you're using for the convex camber or if you're even providing for that?

I guess I may try to ask the Green Welder site some more questions but I'm feeling like he may be more steel oriented and not as used to aluminum? Also, I'm still looking for aluminum videos to see what others are calling the various modes?

k.morin@kmmail.net if you want to send email direct.

Cheers,
Kevin Morin
Kenai

 

Kevin, I'm pugnacious by nature when it comes to debate and have a hard time with <insult directed towards other person removed>. I understand what you're saying but sometimes it's just too much fun to stick your finger in someone's eyeball, metaphorically speaking!

I had the same reaction to the videos being presented as meaningful to the discourse. Why not a vid on oxy-fuel brazing of cast iron for all that it would add? Just think of some new entry thinking that you're going to weld your first skiff, out of .125 and .190, with the machine set at 24V!

The little bug-sprayer welder has already recovered the initial cost with work done. Frankly, it welds 6011, 7018 3/32 better than any other machine I have. At 20.5-21V, it does what I want it to do with .047" wire. It won't run .035" well because it does not actually produce 24VDC to run the gun up enough. The 30A gun can access 30VDC when it's 'on the reservation', so to speak. I'm very happy with it. I turn down all small harbor jobs because of the pain required to break my equipment down to mobe. I'm going to build a 2-wheeled dolly that the whole taco - power source, gun, 40' extension cord and 40CUFT bottle - fit on in one package and slides into the van. All set, ready to go and used for that only - "my gillnet reel has a crack!"

To be honest, this is only the third skiff that I will have built that uses this style of construction. The first was the 40' I mentioned that was the 'proof of concept'. I've done others but they were only station framed with the longs cut and fit between, usually hull stiffener that was relieved to make those forward curves. I know I have to say no more as to how painful that can be to do. In this 40' I had the longs fully cut from stern to stem. I won't go into why I did that but I'll say there is no need to do that where the run aft is flat. It worked better than I imagined.

I'll switch gears and talk about ProSurf as this will answer some of your questions about software and construction all at once. First, I have to praise the software. It does a fantastic job of anticipating how developable material behaves, i. e. the convextivity that you mention. The fellow that developed the software, Steve Hollister, has really helped me with this style of construction as he has clients that use it. Following his advice, I start by stitching the bottom together but not the forefoot area so the bottom panels are still flat. Then, place one transverse frame in about the center of the skiff and firmly attach it but not finish weld. Then I hippity-hop the frames fore and aft, again, securing but not welding out until you get to where the forward curvature dictates sticking the longs in the slots. Now things slow down because it is very important as you MUST fold the bottom up to the longs and frames in concert. I learned to make the slots in the frames 1/4" deeper than necessary in order to drive downward those 'wild animals', the longs, into place. So far, my experience has been that everything meets rather grandly!

Here are some pics of the last (my second) skiff using this method, it's a 19' power skiff for Grant Fritz's grandkid. Unfortunately, I'm rather bad at photo documentation and did not take pictures of the 'banana peel' look the whole affair has as you're folding it up.

It is absolutely essential to have enough transverse framing to maintain the shape that the computer describes, otherwise all is for naught and you will be doing a lot of cut and fit. As you can see, all the framing meets the hull plating

The very first computer skiff I built years ago was merely the outward shapes, bottom sides etc. and all the guts were cut and fit. It worked but I was not really happy with the results. Bayweld has done, until recently, the same. It's just plain stupid, IMO, to do that when the computer does it soooo much better. The rest of the story is that I do export the surface geometry and the 'Hull Cuts' (as the ProSurf describes all the slice and dice which constitute the framing, longs, decks etc.) to other programs to do rendering (Bryce) and manipulate the framing and plate nesting to send to the cutters (DesignCad). This may sound strange but it took me along time to 'trust' the computer. Building numerous models help bellay them; art board and hot glue, 1"=12" scale.

 

modeling applications versus surface applications

Yofish, I understand that some folks post without much knowledge or based on ideas that your experience shows to be faulty, but... instead of labeling them a fool its best, to try, to give an explanation otherwise anyone's post ends up in a flame exchange!

I always try to get new Aluminum MIG welders to avoid 4043 (like the plague) because its not 'really' welding with all that silicone in it. But time after time the major sites will have someone who says "I always use 4043 and it's OK for me ... soooo... its OK for such a such a newbie".

I don't agree and have seen one entire skiff 'unzip' from that alloy wire on 5052 and 5086 sheet. But.. that's just my experience, and if someone old enough to vote wants to use that alloy? who am I to say otherwise?

If you're having a control voltage problem - the 30A needing more to run full out on the drive motors, you might look for a proportional voltage converter?
Solid State Power Controllers (SSPC) They're solid state and not cheap but could help? There's likely someone's stock 30 to 32V model that would drive the 30A's motor?

If the green welder provides wire feed speed in a related rate to the MIG torch drive motor??? I'd prefer they didn't, I'd like to adjust the wire independent of the voltage circuit personally. But in the case of a variable voltage supply, you'd just power the supply and use the gun's speed pot to control that -not the Green Welder's control circuit, just use that for contactor and voltage. Let the motor for the 30A run purely off a secondary power supply.

I do realize that portability is an equipment issue if you're not already geared up. I've done several different 'things' in the past and they all 'worked' but it was not as clean as being able to pull the boat into the shop and have all the tools at hand. I don't care for portable work much, truth be told.

From the pictures it appears you're running the longs on buttock lines or hull intersections? I generally don't run the longs in the forward third of the hull on the butts. I usually run them on waterlines because then I can use flat bar or sheared strips as the waterlines are flat in the Profile, so flat bars can always be pulled around, cold, to the waterlines with minimal effort. I've also run a bunch of bow framing on the radian of the conic section, so again, the longs are bars or sheet cut off's that are straight on one side and that avoids work and fitting.

I've seen some longs that were on diagonals cut from the hull intersections of the lines plan and that seemed like a very clean way to do the framing of the forward conic sections.

OK, regarding surface modeling, I did have Profsurf for years and moved to DelftShip because I like the interface more.... but in the last few versions they've become less different and more alike. I use Rhino or AutoCAD to produce the 'mechanical' fits and tool paths, but have to export to a G code post processor- depends on whose cutting service I'm trying to use- they all seem to have their 'own' software needs but most will accept a *.dxf or *.dwg file?

If I understand your current method is to design the bottom hull panels (and topside?) with a straight line from keel to chine? and a second line from chine to sheer? Then working fore and aft from about amidships, you put the panels AND the framing together working from the middle "outward"? This method allows the sheets to lay to the framing drawn?

I've not tried that, since I've had the experience of missing the convexity in my framing, I've been doing the field fit of framing, even if I'd like to let the NC table cut the frame.

I've been able to produce a fair hull, but it could have been done faster that's for sure.

cheers,
Kevin Morin
Kenai