Welding a steel hull

[lazeyjack]

Originally Posted by bigbear69

just wondering if you are able to weld deck fittings/ repair work while the boat is on the water? Or will the current associated with welding cause electrolysis or something?
cheers

no problem at all, all ships are finished(usually) in the water

[Brent Swain]

I did almost all the detailing on my current boat in the water. No problem.
You can easily hook up an alternator run off your main engine if you want to do it out in some peaceful ,remote anchorage. I'd do it that way next time.
Tom , if you get the chance , go ahead and post the photos from the back cover of my book on this site.
Thanks
Brent

[lazeyjack]

you can see the cleats across the seam, the seam gap is 4mm, no vee, then a ceramic temp backing bar which is in segmants slides under the cleats and is wedged up
Advantages, , single sided welding, almost no grinding from outside
i have not tried on ally, but have used same method with steel or ss backing bar with groove in it,

[Brent Swain]

I've seen photos from Norwegian shipyards ,of welders on tracks that fill a V while a ceramic brick slides up while the weld is still molten , leaving a smooth surface behind, flush with the surounding metal, needing no grinding whatever.
Maybe ceramic backing is underutilised.
Brent

[welder/fitter]

Ceramic backing strips have a value & are utilized within the marine vessel construction & repair industry, though less in North America than in Asia or Europe. For the one-off builder, the cost would be the limiting factor. In this regard, perhaps, there would be a real value in ceramic strips when wishing to weld both sides of a joint that is relatively inaccessible from one side.

Quality joint preparation is crucial to welding proficiently with ceramics. For those members who wish to experiment with ceramics, I suggest that, when welding, keep the arc in the puddle, "wash" the puddle from side to side & use a lower current or wire speed. While ceramics can handle greater temperatures than the parent metal, they do not have the same capacity to conduct electricity and can be pushed from the parent metal by the force of the wire.
Mike

[lazeyjack]

in that case mike your backup is not right, under those cleats is a 3/8 flat bar, dogged to the ceramic full length,
the rest is ok)9/10

[welder/fitter]

LOL
Sorry Stu, I was actually commenting on ceramics in general. Still, 90%
(9/10) isn't a bad mark for something I didn't study! The ceramics we use have metal "stickum" across the back to hold them in place. They are prone to dropping off - a flat bar backing, any kind of backing, that could be dogged against the ceramic strip, holding it to the seam, seems like a good idea, though I can already hear the complaints about it taking too long to set up.

[lazeyjack]

Originally Posted by welder/fitter

LOL
Sorry Stu, I was actually commenting on ceramics in general. Still, 90%
(9/10) isn't a bad mark for something I didn't study! The ceramics we use have metal "stickum" across the back to hold them in place. They are prone to dropping off - a flat bar backing, any kind of backing, that could be dogged against the ceramic strip, holding it to the seam, seems like a good idea, though I can already hear the complaints about it taking too long to set up.

HOW MANY TIME Si HAVE TO TELL YOU BUGGERS, NO SHORT Cuts in boatbuildin' 3/10)

[Brent Swain]

Only damned fool would look for the long cut.
Brent

[tazmann]

Glad I didnt chime in on the ceramic strips, not knowing anything about them I would be in the minus LOL.
Noticed Lazzy got banned, is that permanent or just for a time?
Tom

[Landlubber]

Lazy is too good to be permanently banned, he was just sent to the corner to think for a while

[tazmann]

Originally Posted by Landlubber

Lazy is too good to be permanently banned, he was just sent to the corner to think for a while

Ok thanks, was hoping it was not permanent.
Tom

[Brent Swain]

I't would appear to a bad economic decision to hire someone to build a boat , who advocates finding the longest and most tedious way to build a boat and who opposes inovation.
Brent

[Brent Swain]

I't would appear to be a bad economic decision to hire someone to build a boat , who advocates finding the longest and most tedious way to build a boat and who opposes inovation.
Brent

[whoosh]

http://store.cyberweld.com/mirwife.html
can anybody recommend this feeder please)