alu sailboat buliding

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Hi list.Im building an aluminium (7 and 8 mm plates )  double ender sailboat. 40 feet long,  The boat is built upside down. First i was thinking tig welding this together, but since i built in 20 cm wide lapstrakes it will be a lot of welding, so probably i will switch to MIG to weld the laps (welding laps on both side it means at least 1000 meter of welding, so its some hours welding job to do) for tig im using a lincoln squarewave 255. for mig i have a smaller lincoln powertec 250 but probably need something bigger and better. (hopefully with wirefeeder) zeyang
Reply:O.K.  That sounds really impressive.  I for one would love to see some images of that boat or whatever stage of the building you are in.  I can offer no advice on the welding though.  My knowledge is quickly challenged even when I build things for my small tractor.  Did you buy plans or designed the boat yourself?  Just wanted to express my interest and appreciation.
Reply:Might I suggest you look at the Lincoln PowerMig 350MP!!! That is the machine just made for MIG welding aluminum. It has pulse on pulse and is programmable. Check it out.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:I have built aluminum jet boats for many years. Mig the inside corners and structural stuff, and tig weld outside corners and parts that people will see. Tig creates alot of heat and then warpage, mig will reduce the heat put into your hull.Bill
Reply:If you use the Lincoln PowerMig 350MP you can use Pulse-on-Pulse to MIG those inside corners!!! I just want more people to buy that machine so I can start a new club.   hehehehehLincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:wow, that is very impressive.  please post pics of as many stages as possible.  i just wanna see how it's done.  1,000 m of welding, thats when you say thank god for duty-cycle!
Reply:Also check out the new Lincoln Power wave C300, it is an inverter base welder.
Reply:Dear Zeyang,  At any time in the next few years you can tell me to stop bothering you... But i have a feeling i will have many questions.  I hope to build an AL sailboat in the next 3 to 10 years.  35 to 40'.  I spend all night designing in autocad, reading up on hull and sail design, figuring out the best combination of specs.  As most sailors are i am obsessed.  Are you using molten or solid balist? lead i assume? can you send me you specs (draft, beam, LOA, LatWater, Displacement, rigging type, etc)? Are you using an existing design or your own?  what do you know about these "Self-jigging" flat pack hulls kits?  ...I will flood you inbox shortly. - peteEveryone else, I know little of welding, I hope to demonstrate that by asking a lot of dumb questions when you are all done answering Zeyan.  I spend alot of time surfing welding and boat building sites.  I was SUPER exited to to see this post.I have been wrestling with the same question.  I am looking for a used TIG welder to practice with for now.  But I know it is slow moving when welding a those LONG chines.  -Does a solid AL wire feed with inert gas make as clean/strong of a weld as TIG?-My friends claim a AL with flux core (so you don't need a shielding gas) wire is out there, BUT IS THE WELD AS STRONG as TIG and MIG? -Most folks have told me wire feed AL one should use a system with the wire spool in the gun instead of the wire being fed through a long hose like on most steel wire welders.  Is this always true or just when using AL with flux core.  Please answer zeyang's questions first but since he got you attention I am going to piggy back on him.
Reply:For aluminum mig, you should have a push pull system for boat building. You can do AL without a push pull system if its shorter than about 15 feet and in a straight line. You can use Argon, but I am noticing more and more people using argon/helium mix for welding on the under side. From my boat building experience, you weld the under side during a repair. About the chines, you can use a cap chine or a extruded slide on chine. The benefit to a cap chine is that it makes hull repair a little easier should you bang your boat up. It is welded on the exterior.An extruded, slip on chine is easier during the build but very hard to repair a damaged boat. My guess is that you wont be bouncing your sailboat off the rocks in Death Valley Idaho, so I would use the extruded slip on chine.I have never used a flux core aluminum wire so I cant help in that department. If you have argon around to tig, you can have it around to mig, in my opinion.Bill
Reply:Hi Zeyang & CadmusI am in the same boat. What is the design of your boat? Go with MIG, TIG is too slow for such a big job and stick welding Aluminum is very difficult. FCAW (Flux core) welding in general is more difficult than MIG and the process create spatter and slag. I've never done aluminum flux cord welding before.A 200 to 250 amp (60% duty cycle) welder with a spool gun is probably the minimum needed for welding 3/16(7mm) aluminum plate.The push pull feeder gun system as suggested by Bill is ideal. The latest innovation in welding aluminum is the Pulse MIG welding process, that is if you can afford it.Use properly, PULSE MIG causes less heat related problem and is easier to get a good weld. The best one like Fronius TPS 2700 costs upward of $10,000, Miller and Lincoln both have welder that can PULSE MIG for a lot less. All 3 brands have machines that can be set up specifically for welding aluminum. I learn welding at a night class at the local community college and I highly recommend it for those who do not have the skill.I found the book "Boatbuilding with Aluminum" by Stephen F. Pollard very helpful. It answer most of my questions  on tools, materials and the process of building Aluminum hull.
Reply:I dont know where you would get plans for the bottom. The company I worked for pretty much winged it, found a pattern that worked and made small adjustments from there. I know there are people selling sailboat plans because I knew a guy that had them at one time.Have fun.
Reply:Thanks for help you 2.  I have the Pollard book on my ebay/amazon hit lists. Glad you mentioned it 'cause It looked  a little too heavy on the motor boats.  Do you know anything about "Elements Boat Strength" by Dave Gerr?  Does it cover the common alloys of AL?Yeah lots of folks out there with plans. Always safer to go that route, but since it is only a dream for me right now it is an excuse to get nerdy and read up on aeronautics and start from scratch.  WH, Correct on not hoping to hit boulders in ID... but that being said fetching up on coral or hitting rogue cargo containers IS why i am looking at a metal boat, otherwise composites are the way to go.  -I know AC is desirable for AL.  So as the boat switches from being the anode to cathode there is removal of built up oxidation.  Is this possible in a MIG system?  What is this called?  How new of a technology is this (as I will have to buy used for now).  -I am reading that some of the high end Lincolns and Millers let you use an uneven AC so that you get just enough of a current flow direction to remove oxidation but a longer time heating the boat. Is that what Lincoln calls "AC wave balance" or is that something different?  How necessary is this uneven AC technology and how long has it been around?-What is "Pulse" .thanks, pete
Reply:Also, i assume you all have found these Forums? lots of boat construction talk on these forums.  But far less about welding.http://www.boatdesign.net/forums/http://forums.sailinganarchy.com/
Reply:Dont worry about pulse technology if you dont have the knowledge or means. Those building aluminum boats are not using it and frankly, once you understand the principles and procedures of the welding process you would likely prefer not to have it.Your post did remind me that aluminum gets a lot of corrosion in salt water so I assume you will need a sealer of some sort. Not really my expertise there.
Reply:It's still good to know what Pulse is... if anyone wants to explain it.  I have only seen a few aluminum boats at sea that didn't have the usual marine paint job.  Even those had anti-fouling paint below water line (high in Cu and other heavy metals to keep the algae and barnacles off, real nice sealant and water barrier, hard to chip off, leaches toxic metals into the environment).  Some racer folks will use a filler to smooth out the chines or TINs and make it more of a soft/round chine and bilge.  I do not know what this filler material is, do you?  I know polyester fiberglass epoxy doesn't stick well to metal.  I have seen pics  of stainless steel boats that are left bare and brushed, pretty sexy looking, like an old airplane, sadly i don't feel safe doing it with aluminum.Last edited by cadmus; 03-29-2009 at 11:03 AM.Reason: forgot something
Reply:hi list, heck, what an interest. i always think im the only crazy guy out here welding my life away on a boatproject. here is a link: blog.sina.com.cn/gosailing. run it through translate.google.com.mind you, you will not find any welding pictures yet, since im just starting this step. It seems welding is the smallest part at this stage. making templates for laps and boatframes has taken most of my time. since its wineglass hull, double ender, i only had two option. Use a lot of bending force to make it a double curvature or make a boat in lapstrake, so i choose the latter. I will do tig welding until i can find a good second hand mig machine. actually i found a powerwave 450 but unfortunately i dont have  the wire feed part so if anyone have a wirefeeder for a powerwave 450 i would be very happy.For those interested in original double-enders rescue boat i will try to save all this templates in cadfile to make it easier to dublicate this boat at later stage. Then I think it will be possible to save up to 50% of building time.  Just put up 4-5 inverted wooden frames as template and go for cutting out  the lapstrakes from the cad and start welding pieces together. (no need to spend a lot of time for fitting out, which i have done now)lead will be made in ingots and put inside the boat. (15-20 kg each) There is one rule i follow strictly: KISS (keep it simple stupid) No fancy stuff, no gadgets and a plain simple sailrig you can build out of an old telegraph pole (junk or gaff rigged) This is purely an escape machine, fitted to go around the world.  For those dreamers out there, i just found out: building boats  is really time consuming hobby. spending 5000 hours in the boatshed is no problem.  (that is for a 12 meter long x 4.20 meter wide boat)zeyang Attached Images
Reply:lapstrake. like where skinny planks overlap each other...? you WILL have a lot of welding.  But that will be gorgeous.  How wide will the planks be?
Reply:If you guys would like, you can go up to the left side of the page, to User CP, and fill in your location. It will show up in all of your posts, where mine says Colorado. It's interesting to know what parts of the World everyone lives. 9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:Originally Posted by cadmuslapstrake. like where skinny planks overlap each other...? you WILL have a lot of welding.  But that will be gorgeous.  How wide will the planks be?
Reply:Originally Posted by rhapsodyHi Zeyang & CadmusI am in the same boat. What is the design of your boat? Go with MIG, TIG is too slow for such a big job and stick welding Aluminum is very difficult. FCAW (Flux core) welding in general is more difficult than MIG and the process create spatter and slag. I've never done aluminum flux cord welding before.A 200 to 250 amp (60% duty cycle) welder with a spool gun is probably the minimum needed for welding 3/16(7mm) aluminum plate.The push pull feeder gun system as suggested by Bill is ideal. The latest innovation in welding aluminum is the Pulse MIG welding process, that is if you can afford it.Use properly, PULSE MIG causes less heat related problem and is easier to get a good weld. The best one like Fronius TPS 2700 costs upward of $10,000, Miller and Lincoln both have welder that can PULSE MIG for a lot less. All 3 brands have machines that can be set up specifically for welding aluminum. I learn welding at a night class at the local community college and I highly recommend it for those who do not have the skill.I found the book "Boatbuilding with Aluminum" by Stephen F. Pollard very helpful. It answer most of my questions  on tools, materials and the process of building Aluminum hull.
Reply:Sorry for the late reply"Elements Boat Strength" by Dave Gerr is a very good book on boat scantlings. It has a section on Aluminum and Steel. The book have lots of formula, charts and engineering info on scantlings. You need AC to TIG and Stick weld Al. I would still clean the surface prior to welding. Any inclusion may cause the weld to corrode and water may leak thru over time.Lincoln Electric has a very good explanation on Pulse MIG, search for "Next Weld" in Lincoln's sitePulse Mig is a different way of transferring metal to the weld. In short, The pulse MIG machine uses a build in computer to control the electric current  and sent it to the MIG gun in pulses instead of a constant stream. The computer regulates the frequency and the  wave form of each pulse and thus control the strength, length and shape etc of the arc. By setting the type of metal, its thickness and the welding speed, you can achieve the optimal arc pre-program either by the manufacturer or the user. Since the current is sent in pulses, there are less heat generated during the weld and therefore any heat related problems are reduced The learning curve is much shorter for a OK welder to lay down his first decent Al weld. If you are good with the newer pulse welding machine mentioned in earlier in this thread or miller equivalents, you can weld thin gauge Al previously consider too thin for MIG welding.
Reply:is the URL to your blog:http://blog.sina.com.cn/gosailingbaor http://blog.sina.com.cn/gosailingThe URL you sent in your recent email seems to be more sailing related than the one you listed above.
Reply:The self jigging flat packs I spoke of above are advertised hereon the Corus websites.  You may have to play with the background colors on your PDF reader, the font is white on white background?  http://www.staaltagmester.dk/file_so..._DATASHEET.pdfor also found herehttp://www.corusservicecentres.com/f...aflet2page.pdfI have ideas as to how i would do this... but if someone knows how the pros are doing it i would love to hear about it.
Reply:Originally Posted by cadmusThe self jigging flat packs I spoke of above are advertised hereon the Corus websites.  You may have to play with the background colors on your PDF reader, the font is white on white background?  http://www.staaltagmester.dk/file_so..._DATASHEET.pdfor also found herehttp://www.corusservicecentres.com/f...aflet2page.pdfI have ideas as to how i would do this... but if someone knows how the pros are doing it i would love to hear about it.
Reply:Originally Posted by Craig in DenverIf you guys would like, you can go up to the left side of the page, to User CP, and fill in your location. It will show up in all of your posts, where mine says Colorado. It's interesting to know what parts of the World everyone lives.Originally Posted by oxy moron(the OP) He's located in Beijing, China.  unfortunately, the location is listed in chinese, so, that leaves the other 75% of the world unable to read it
Reply:actually, thanks to the public education in Taiwan, all 6 years and 2 months of it.
Reply:Oxy Moron:Yep, I laughed when I saw that. But now I know, thanks. Zeyang:Thanks for adding your location, I think. 9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:I understand this site is of intrest for metal fabricators mostly, but wouldn't fiberglass be a more suitable material for a boat sent into salt water?Years ago I looked into building  a small boat using a woven matt that had fishing pole sized rods loosly woven into it lengthwise. The matt would stretch over widely spaced bulkheads forming nearly perfect contourss with few forms.
Reply:Knotbored, Nowadays Fiberglass is the most common hull material, and not just fiberglass, carbon fibers and other composites are common too.  Composites (including fiberglass) are great if you are making 1 mold then going into production with many boats.  They are also Lighter. They have maintenance issues even if they don’t rust, they require painting just like all boats, they develop blisters, all materials have there cons.  Fiberglass allows you to have perfectly round curves (no chines) to reduce resistance.  Fiberglass is MUCH lighter than steel and a little lighter than AL.  But if you hit a cargo container, ice berg, rock or coral at full speed you are going to poke a hole in that fiberglass.  It is very hard to make a single fiberglass boat, it has been done, but it will not be the quality of one that came out of a perfectly symmetrical mold, so if you want fiberglass you might as well buy a mass produced boat.  It is done frequently with little boats.  My family used to build cedar strip canoes which is really just fiberglass over wood and most open design skiffs do not come out of molds... but those are small boats.  Metal Is burly.  It is a little smoother in rough water.   If you hit something you have a chance at survival.  And you can build a single boat without having to build a mold.  AL has issues in salt water but it is comparable to the issues one has with fiberglass and FAR BATTER than steel.  Stainless is nice if you are rich.  Plenty of websites out there to explain the pros and cons.  I will try to find some for you later.Last edited by cadmus; 03-30-2009 at 09:34 PM.Reason: oops
Reply:Originally Posted by KnotboredI understand this site is of intrest for metal fabricators mostly, but wouldn't fiberglass be a more suitable material for a boat sent into salt water?Years ago I looked into building  a small boat using a woven matt that had fishing pole sized rods loosly woven into it lengthwise. The matt would stretch over widely spaced bulkheads forming nearly perfect contourss with few forms.
Reply:Originally Posted by zeyangThere must be a reason why they didnt make this in fiberglass :-)
Reply:Originally Posted by cadmusKnotbored, Nowadays Fiberglass is the most common hull material, and not just fiberglass, carbon fibers and other composites are common too.  Composites (including fiberglass) are great if you are making 1 mold then going into production with many boats.  They are also Lighter. They have maintenance issues even if they don’t rust, they require painting just like all boats, they develop blisters, all materials have there cons.  Fiberglass allows you to have perfectly round curves (no chines) to reduce resistance.  Fiberglass is MUCH lighter than steel and a little lighter than AL.  But if you hit a cargo container, ice berg, rock or coral at full speed you are going to poke a hole in that fiberglass.  It is very hard to make a single fiberglass boat, it has been done, but it will not be the quality of one that came out of a perfectly symmetrical mold, so if you want fiberglass you might as well buy a mass produced boat.  It is done frequently with little boats.  My family used to build cedar strip canoes which is really just fiberglass over wood and most open design skiffs do not come out of molds... but those are small boats.  Metal Is burly.  It is a little smoother in rough water.   If you hit something you have a chance at survival.  And you can build a single boat without having to build a mold.  AL has issues in salt water but it is comparable to the issues one has with fiberglass and FAR BATTER than steel.  Stainless is nice if you are rich.  Plenty of websites out there to explain the pros and cons.  I will try to find some for you later.
Reply:The lapstrake has always been the classiest looking boats... It will look sexy in AL.  And (as i said) BURLY!!!!!!!!
Reply:Hi Zeyang,Wow, Nice Fair Hull. I want one.I could not believe a steel hull can be that nice. Did you built it or this is the design you are building?I would like to know more about your built.Is bending the 8mm aluminium around the wood frame easy?Do you need stringers and frames?Can you get by with welding one pass on each side?I've sent you a PM.
Reply:Originally Posted by rhapsodyHi Zeyang,Wow, Nice Fair Hull. I want one.I could not believe a steel hull can be that nice. Did you built it or this is the design you are building?I would like to know more about your built.Is bending the 8mm aluminium around the wood frame easy?Do you need stringers and frames?Can you get by with welding one pass on each side?I've sent you a PM.
Reply:Her lines are beautiful.  Are you building ca166 Losbåt 1905 or ca168 Losbåt 1906-08.
Reply:Originally Posted by rhapsodyHer lines are beautiful.  Are you building ca166 Losbåt 1905 or ca168 Losbåt 1906-08.
Reply:Thanks,Your new engine location is a brilliant idea, I understand the benefit of keeping weights off the bow and stern of the boat; and the the level prop will increase efficiency. Being a full keel double ender, have you consider using a fair size prop? The feathering type that can set different pitch for forward and reverse will give you better stopping and reversing power when you most needed it such as turning into a short finger dock from a narrow fair way. What engine are you going to use? Are you keeping the same sail plan?
Reply:My ex-young-lady wants to know whether Zeyang means West Ocean in Chinese?
Reply:Very Cool!!!!-is that the waterline when wood or when AL? How did you alter it for the mass of AL or don't you need to? -are you going to do junk or gaff? 1 or 2 mast?  -is the mast set on the deck or down to the keel/hull?-Full rudder. very sea worthy and easy to fix at sea.Thats great.  I am excited for you.Pete(props: yeah, I hate the idea of spending tons of money on something like a prop... but if it reduces drag you are using it every second under sail, it is worth it.  Motors... evil necessities now a days, although i have toyed with just having 2 huge oars.  They are nice for setting anchor and scaring wildlife away) Last edited by cadmus; 04-02-2009 at 11:36 PM.Reason: typo
Reply:rhapsody...Western Ocean should be Xi-yang.  Although, Zeyang could be, too.  Due to lack of standard in translating chinese into english phonetically.sorry, didnt mean to high jack the thread, just inserting little blip.  now, back to the ship/boat/vessel/welding.
Reply:Originally Posted by oxy moronrhapsody...Western Ocean should be Xi-yang.  Although, Zeyang could be, too.  Due to lack of standard in translating chinese into english phonetically.sorry, didnt mean to high jack the thread, just inserting little blip.  now, back to the ship/boat/vessel/welding.
Reply:Originally Posted by rhapsodyThanks,Your new engine location is a brilliant idea, I understand the benefit of keeping weights off the bow and stern of the boat; and the the level prop will increase efficiency. Being a full keel double ender, have you consider using a fair size prop? The feathering type that can set different pitch for forward and reverse will give you better stopping and reversing power when you most needed it such as turning into a short finger dock from a narrow fair way. What engine are you going to use? Are you keeping the same sail plan?
Reply:ni hao listLast pic before i go for 10 day easter holiday. Finished the keel yesterday. Took me approx one week to finish this step. I cant understand. I used up a 25 kg of argonbootle (200 bar bootle)! I thought it would last much longer than one week.  will cost me a fortune if i spend 25 kg argon a week for next one year.I try to fake it so it looks like a wood keel ((sort of). between 15 cm wide at stem 30 cm in middle and 20 cm in stern (the make space for throughhull propshaft) tig welded on both side. 30 cm in middle of this boxkeel is pretty wide but i can stuff it full of lead so it will be usable space. (some part can also be used as watercooler for engine (instead of welding tubing on the outside)happy easter. regards,林择洋 Attached Images
Reply:ops. i meant 20 litre bottle at 200 bar. How many hours can i expect this to last when i tig weld 8 mm plates? zeyang
Reply:Thanks for the pics.Looking Good.You seems to have all bases covered.More pictures when you come back, please.
Reply:How in the hell do you move something that big once you get it built?Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:Not trying to highjack this thread... just had the thought that some readers might be interested in perusing this sailboat build by two gals in Canada.  It is an amazing piece of work.http://www.thebigsailboatproject.com/sail1fr.htm
Reply:How long the bottle lasts depends on the flowrate.Impressive project.But have you thought about the applicability of the aluminum as a boat material?  The specific alloy and the weld filler and the effect of welding and the HAZ on the strength of the aluminum?  And aluminum's annoying (from an engineering/design standpoint) property of having a finite fatigue life, as opposed to steel which can have an infinite fatigue life?An ocean-going sailboat is going to be exposed to some varying structural loading (wind, waves, engine vibration, etc, etc), and that means fatigue could be a concern of the structure or parts of the structure.And no offense meant, but didn't anyone else find it funny or ironic that someone from China is lamenting "cheap asian imports in the eighties" and "You cant compare a 70 HP asian importengine with this beast"?  Yup, the Canadian gals' sailboat project (welded steel hull and welded lots of other things as well) was neat, eh.    I read it a while ago.    Their project was interesting, to the tune of it made me spend a lot of time reading all about it.Joker, how do you move something big after you build it?  The Canadian gals hired a crane to flip their welded steel boat hull over.Zeyang,  double check your welding and make SURE you have complete penetration welds and no craters or dimples or such.  Your 'close-up' pic (pic #2 in post #45) of some welds looks a bit questionable as to the weld quality.  Aluminum is not very forgiving of questionable welds or any sort of crack initiation site.  The best laid schemes ... Gang oft agley ...