Welding methods

Discussion in 'Metal Boat Building' started by arthor, May 10, 2010.

  1. arthor
    Joined: Apr 2008
    Posts: 46
    Likes: 1, Points: 0, Legacy Rep: 28
    Location: UK Yorkshire

    arthor Junior Member

    Greetings all

    been looking into the possibility of fulfilling my boatbuilding dream with a steel kit. My intention would be to hire a professional welder, get him to teach me (not welded for years) during the initial jig set up and bottom plates and crack on myself whenever I feel ok with it and get him in every now and again.
    I am curious about a few things.
    1.Is there such a thing as a "boat welder" or do I just need "a welder"?
    2.Is boat welding done with a torch or is it arc (mig, tig et al)?
    3.I have looked at lots of build sequence photos of boats being built upright on a jig. After tacking, when you run the seam welds, does it run into and fill the gap underneath? If not, does this mean welding upside down to run the seam along the outside of bottom?

    Finally, does anyone know if any firm in the UK will supply a Bruce Roberts kit?

    regards

    arthor
     
    1 person likes this.
  2. apex1

    apex1 Guest

    Welcome arthor!

    I´ll let others (like Wynand) comment on welding, they know more about it than I will ever learn.

    Just to your last question:

    Is Bruce Roberts a MUST for you ???

    really..................???

    There are so many good designs on the market.


    Regards
    Richard
     
  3. arthor
    Joined: Apr 2008
    Posts: 46
    Likes: 1, Points: 0, Legacy Rep: 28
    Location: UK Yorkshire

    arthor Junior Member

    I do like the look of the Bruce Roberts Waverunners. Do hear conflicting reports about them. Have also been looking at Almarine and Vripack.
     
  4. apex1

    apex1 Guest

    Comparing a Vripack design with BR is like a comparison between a selfmade pedal scooter and a Bentley. Though both have wheels........

    Do you have a Vripack design which could attract you? A change in style is often not much of a workload, and you would have a vessel with a completely different appearence.
    The Vripack plans (if there are any) would be several times the price of BR plans though. And well worth the extra money! They provide the most thoroughly engineered and detailed plans in the world!
    BR on the other end...........well I made the comparison (and that was NOT exaggerated)

    Regards
    Richard

    Do´nt know about the Almarine
     
  5. dskira

    dskira Previous Member

    I fully agree with Richard.
    Vripack as a lot of plans, and at the end, since they are extremely accurate and well engineered, they will be not much more expensive than a BR set since we heard conflicting report on customer support and, as you says, on the finish product too.
    Going with the best designer like Vripak, is saving money at the end of the day.
    Daniel
     
  6. arthor
    Joined: Apr 2008
    Posts: 46
    Likes: 1, Points: 0, Legacy Rep: 28
    Location: UK Yorkshire

    arthor Junior Member

    I have managed to find a firm in the UK who might fit the bill and have asked them for a quote on both a bare shell and a kit for an Almarine AF1200.
    Bruce Roberts seems to be a bit like Marmite. People seem to shy away from his stuff or be quite happy with it.
     
  7. apex1

    apex1 Guest

    Could you be so nice to show us the Almarine boat? A link perhaps?

    edit: ahh, thanks, no need!!! That is just another BR designed coffin.

    BR has his rep. due to the (relatively) low cost stock plans. But you´ll get what you pay.......
    And there are others, as cheap, but better proven and performing.

    Regards
    Richard
     
  8. dskira

    dskira Previous Member

    A man who knows Marmite can't be a bad man :D
    I love Marmite, and I have a store right here in Maine where if find it.
    It is so good.
    As for Bruce Robert, I will understand and agree with people who do not like Marmite :p
    Daniel
     
  9. Wynand N
    Joined: Oct 2004
    Posts: 1,260
    Likes: 148, Points: 73, Legacy Rep: 1806
    Location: South Africa

    Wynand N Retired Steelboatbuilder

    1. No thing as a boat welder - just get yourself a good qualified welder.
    That said, the secret of boat welding is patience on the part of the welder and to religiously stick to weld sequences, weld lengths and staggering of welds. This is to say at least cumbersome for most welders to move from one point to another and back etc, and they just let it go, usually resulting in a bad unfair hull, and most commonly the cause of the "hungry horse" effect. Although this malady is also caused by bad design of boat.

    2. I used MIG method for obvious reasons - excellent for vertical welding when you can run a vertical down weld that is faster and "cooler" than the normal vertical up weld with an arc welder that results usually in a "hot" weld that distorts the plating. MIG process does not trap slag in weld as with arc welds. MIG welds are also stronger than arc technique when done well due to the low hydrogen content of the welding wire.
    The downside of MIG however is to be careful of wind which will blow away the inert CO2 gas and oxygen will boil the weld pool resulting in porosity. However, if shielded from wind or welding indoors, no complains then.

    3. I preferred building upside down - most welds are in downhand position and also easier to grind down. Another bonus is when shotblasting, you do not need to move a few tons of grit out of the hull..
    As for welding - after all the plating is installed with about 2-3mm gap thickness between plates, faired and tack welded from the outside, welding starts on the inside following the welding sequence mentioned above.
    After the hull is completely welded on the inside, I back grind into all the joints from the outside of hull until cutting into the inside weld with an angle grinder, (result must be solid steel with all debris etc removed) and then fill these gaps with welding using the same time consuming (patience) staggering welding sequence. Cutting back into the the inside welds also remove all the tack welds in the process.

    I agree with Richard - why BR? Have you considered Dudley Dix designs as well? Having built to many designer's plans in the past, I found his the most builder's friendly, complete detailing and free after sale advice and backup:cool:

    Unfortunately I closed my webpage: "steelboatbuilder" due to expensive hosting. That was richly illustrated with text, photos etc from deciding time, lofting to launch and everything in between, (multi chine and radius chine methods) aimed directly to assist the amateur steel boat builder. It covered over 30 years of steel boat building experience.
    Nevertheless, there are a few photos in my gallery that will answer a few of your concerns.
     
  10. waikikin
    Joined: Jan 2006
    Posts: 2,424
    Likes: 172, Points: 73, Legacy Rep: 871
    Location: Australia

    waikikin Senior Member

    Hi Arthor, I worked on a Bruce roberts kit supplied to an Australian firm but cut by Almarine, I wouldn't wish to again, many delays, discrepancies in plating thicknesss port to stb, wrong keel option, wrong cockpit option, & nonsense back up.
    Much of the kit was recut in Australia at the customers & Australian agents expense.
    The fit up of components was generally good.
     

    Attached Files:

    Last edited: May 12, 2010
  11. arthor
    Joined: Apr 2008
    Posts: 46
    Likes: 1, Points: 0, Legacy Rep: 28
    Location: UK Yorkshire

    arthor Junior Member

    Hmmm. Sounds like it won't be a BR if I go down the steel route then. Curious though. Is the coffin reference due the designs being flawed and/or the kits cut by Almarine being poor.
    If the design is sound then if I got the cutting files and got someone in the UK to cut me a kit then would that make the whole BR thing a much better proposition.
    I understood there are several (many??) built and in happy service round the world. Is this not the case?
    I have also considered a BR Waverunner 342 to build from plans in wood so if the designs are poor then I would be flogging a dead horse.

    many thanks for your replies.
     
  12. apex1

    apex1 Guest

    I did not even know that Almarine exists!

    Now you have the (personal) opinions of two Boatbuilders, one NA and one homebuilder, but none of them recommends your initial choice.

    Do´nt torture the horse............:D

    Regards
    Richard
     

  13. arthor
    Joined: Apr 2008
    Posts: 46
    Likes: 1, Points: 0, Legacy Rep: 28
    Location: UK Yorkshire

    arthor Junior Member

Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.