Welder

Discussion in 'Metal Boat Building' started by MississippiKP, Jul 12, 2005.

  1. MississippiKP
    Joined: Mar 2005
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    Location: Alaska

    MississippiKP Just a Member

    I am a budding boat hobby designer/builder and am unsure as to what Welder would be right for my needs. I hope to start with small aluminum projects under 20 ft sail, motor and oar powered. I have elementary experience welding steel. I am looking at Hobart Ironman 250 MIG. What would you recommend?.
     
  2. kmorin
    Joined: Apr 2005
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    Location: Alaska

    kmorin Senior Member

    MIG for small boats

    Miss'KP, I've built in Kasilof in the past, primarily set net skiffs , 32-40' power boats for Cook Inlet, but a some for the Copper River Flats, Bristol Bay and a few siene skiffs thrown in. If you're SURE about the 20' limit LOA then the bottom and sides will often be .180 (3/16") and the sides 0.125" (1/8") so you can get away with 0.0.35" wire which can be handled with a smaller (<200A) machine. However, once you get going you'll run into heavier plate and want to use 1/4" or 3/8", material in engine mounts and other heavier sections so the larger (250 -300A) capactiy machine is a wise initial investment.

    Miller and Lincoln have the best distribution outlets in AK, I'm not sure where you're located, but the machine is not as important as the support. The leaders' power supplies ALL weld, and the differences are most often preferences that show up in TIME.

    I'd go to the welding distributor and ask to have them run some test coupons and help get you started; REGARDLESS of the brand they support.

    Let's look at it this way- if you live in AK-outside of Anchorage- and there's an outboard rep for Honda, Merc, and Yamaha and you buy an Italian "Rugerini" diesel - you are ON YOUR OWN. We both know it can be a long way to the store to return, repair or "repay" the fellow that sold an unsupported product.

    What happens if you get offshore with this new european outboard and it decides to get tempermental? If it were a local guy's product you can call and ask for some help- even if you have to get towed in- you can bring it to him and offer it as a "suppository" in the first person. While I know that you are a much more reasonable person than that, you get my drift; local vendors are worth more than savings, hot deals and "ebay killings". If you haven't welded much with Aluminum MIG, you need support more than you need to get advise on one or another brand of power supply and MIG torch.

    MK Products makes most of the wire feed 'guns' for Miller AND Lincoln, that should tell you that both of the main companies in the largest market on earth, consider these products to be superior to their own, now retired, products!

    I'd look at the Prince/Miller 200 or 250 package for starters. I'd suggest that you afford an AC TIG machine as soon as you can for tanks, brackets and corners. I prefer the push-pull style MIG gun but it is 2 to 3 times the cost of the 1 lb. pistol style and not worth the cost until you'r building full time, unless $ is no object.

    The combo of a Miller or Lincoln 1 lb. gun with a separate AC TIG (hand torch) is most versatile for the smaller boats and the materials implied.

    Moving upward, the first move is to equip the power supply with a push-pull wire feed (Cobra, Python or equiv by MK products) then eventually move to an OTC TIG gun which is the ultimate recreational welding tool for aluminum. When you use one of these you'll smile all day and get up early to get into the shop.

    The Osaka Transformer Co. markets under the Dahien brand, a cold wire feed TIG in a push-only pistol style wire feed - which allows long sustained AC TIG in aluminum which cannot be appraoched by any hand held torch and dip rod.

    I recommend the Metal Boat Society http://www.metalboatsociety.com (membership) as good additional source of info and comment about welded aluminum boats.

    (Full Disclosure) I am an active member and supporter of the MSB but revieve no remuneration from it. :D

    Hope my dime's worth isn't confusing; if so < iisco@acsalaska.net >

    Cheers,
    kmorin
     
  3. MississippiKP
    Joined: Mar 2005
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    Location: Alaska

    MississippiKP Just a Member

    Los Anchorage

    Thanks KMorin

    I always enjoy your posts.

    I agree completely w/ the Lincoln /Miller situation. Especially in AK.

    What lead me to the Hobart was I may be able to get an awesome deal on a new one about, 1K.

    Right now I am in Los Anchorage.

    Until I am more comfortable I am going to keep to small (less to lose, faster to finish) inland boat projects.

    Is it worth getting a MIG at all? While I’m at the “Only one machine” phase, which would be best to have Mig or Tig?

    My boat ideas are light skinned for lower weight. I’m not looking to make a bruiser, more so a ballerina or gymnast.

    MississippiKP
     
  4. kmorin
    Joined: Apr 2005
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    Location: Alaska

    kmorin Senior Member

    light skinned aluminum boats

    MississippiKp, boats thinner than 0.080" aluminum are often riveted for a reason! That stuff is hard to weld with conventional eqiupment.

    While it can be welded fairly simply with TIG -the speed is so slow that distortion is still a tall hurdle and leads back to rivets.

    With a pulsed MIG and small wire you can weld thin material (below 0.080") but you may need heat sink bars and other fixtures not commonly used by those building in .125" or thicker. I believe most welded boat builders would say it was more difficult to build the very light wt. skiff compared to a 20'er with a 3/16" or 1/4" bottom.

    There is a related rate of welding which includes the amperage and voltage combined to create the arc which melts the wire. The arc cone is aimed along the weld seam by hand at some speed, angle to the metal, and with some gas coverage to keep out the air. So YOU are moving the torch while the power supply takes care of the electrons and the wire feeder delivers wire and gas.

    The hitch comes from the minimum power needed to create the heat of vaporization and melt the parent metal. Since alum melts so low in relation to the arc heat, very thin plate gets so hot the entire weld seam will fall away if you aren't moving extremely fast -the thinner the metal the relatively faster you've got to move. This has to happen right when you are learning! so the downward spiral into frustration can seem like crashing and burning.

    This is the main reason for riveting alumium products in the under 0.08" range- PROPORTIONAL heat compared to the thickness. MIG won't dial down too well below certain minimums, and the wire you'd need would be pretty small (<0.030") All in all most people would consider a thickness limit to standard aluminum MIG at 1/8" and while I've worked below that regularly, it took plenty of experimentation and practice; (plenty = yearS).

    If you target 0.100" and 0.125" hull thicknesses; then MIG will work the best, although a small AC TIG hand torch for the corners will make the boats vastly more finished.

    If you get a "deal" on a welder will you find help operating, obtaining parts and 'setting up'? At one time Hobart made some wire feeders and my experience with one push-pull model was extremely poor. I can't speak for current products but they've always made a decent power supply.

    sometimes a DEAL turns out to be a cheap mill stone for a life vest.

    Cheers,
    kmorin
     
  5. MississippiKP
    Joined: Mar 2005
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    Location: Alaska

    MississippiKP Just a Member

    Rivets are guys bestfriend

    The Info is great!

    Sounds like MIG will work fine for the skeleton. And while I'm on the light skin Rivet it.

    Do you know of a cleco supplier around here?

    Know I just need to know what I think about Hobart?

    Thanks
    MKP
     
  6. kmorin
    Joined: Apr 2005
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    Location: Alaska

    kmorin Senior Member

    riveting

    MississippiKP, Aerotwin in Anchorage would know,OR, stop at any hangar on Merrill Fld. and they'd know who, what and where and likely how much.

    Cheers,
    kmorin
     

  7. lazeyjack

    lazeyjack Guest

    welders

    in my time as a full time builder i used all transfomer welders, big Hobart, Miller grunters
    the guy who posted in reply covered lots BUT the most important thing you need is the ability to run 210 amps all day, this usually means a machine that can output 350,
    you wont weld 6mm plate or above with a 200 amp machine

    hobart had the only true pulling gun, the LINEAR but they stopped making em years ago, most guns these days are assist guns, by that I mean if you turn of f the push motor, then the assist would not pull the wire through, the linear would do that,
    I would go for a miller spoolamatic If you have 3ph power buy a second hand miller or Hobart, the 450 hobart mig, tig(dc tig ss) and stick machine was very versatile, you can fit one of these up with remotes and or a spool amatic

    If you need any actual welding advice give me a email, I have all the tickets all positions Writing a book on alloy boatbuilding at mo, see my gallery
    cheers Stu
     
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