joint filler bar

I didn't either but the unit weighs around twenty tons and is simply a giant grid of 5/8th plates with inch and a quarter skins on both sides. There is so much weld inside the grid and between the grid and skins that the welds only locate the grid rather than take any tension. The only other time I heard of doing this was from a guy who was involved in the assembly of an open pit mine drag line. They were not doing it without approval and I shudder to think what the results were years afterward. Randy

I saw large filler bars used to reduce the amount of welding in big gaps on ship repair jobs every so often. I use them myself sometimes. One time I had to fillet weld a 2" pipe lying on a piece of 3/8" plate. The fillet is of course a slowly tapering crack, not very pleasant. I did one "root pass" with 6011, then layed a round bar (maybe 5/16" OD, don't remember) over it and welded it all up solid. Stuff like that. Sure, it's better to fill it with weld, sometimes you don't need all that weld.

GWE

R. Zimmerman wrote:

Damn!

You mean I didn't invent that??

Another one of my half-baked ideas stolen by my predecessors.

The first time I heard about it was from old timers who had worked in the shipyard during WW2. Initially they were being paid piece rate on the Liberty ships. They would drop a round bar taken from the machine shop into a joint and weld over it. The Liberty ships were pumped out at rates as high as one ship a day. The poor quality resulted in some of them never seeing a torpedo. They broke up and sank in bad weather. When that started happening things changed in the yards. I will always remember one instructor I had who was starving trying to feed his family in the Dirty Thirties. When 1939 came he joined the air force. He thought at least his family would get some income from him being enlisted. He had just finished basic training when he was called by the base commander and discharged. He was to immediately return to Vancouver and start work in the very yards he had been trying to get a job at. Likely he was one of the lucky ones. He worked six days a week all through the conflict. On Remembrance Day I always think about him and more especially the ones who were not so lucky. Randy

"Vernon" wrote in message news: snipped-for-privacy@g47g2000cwa.googlegroups.com... Damn!

You mean I didn't invent that??

Another one of my half-baked ideas stolen by my predecessors.

If the joint filler bar is big enough and the topology is right, instead of thinking of the resultant structure as a 2 piece structure with something weird about the weld, you can think of it as a 3 piece structure with 2 welds.

Also, there are very likely no slag inclusions inside the filler bar! If the filler bar is the proper steel and welded in 100% everywhere, what's the issue?

GWE

R. Zimmerman wrote:

Hi Randy,

Funny you brought up Liberty ships. Last night, in the blacksmithing group, I found a link to an "e-book" on metallurgy by a professor at the University of Iowa. It's a 201 page treatise on ferrous metallurgy for bladesmiths. I can email you the link if you want it.

Anyway, in a section on "notch toughness" the author mentions how some of the Liberty ships split in two as a result of stress cracks propagating from plate to plate and finally circumnavigating the entire ship!

Vernon

Vernon,

I grew up in Iowa City and attended UI in the ME Dept. I be interested in the link to the e-book.

John,

Here's a link to the message in the blacksmithing group. The message itself contains a link to the source. The author is John Verhoeven. I hope I spelled it right.

I attempted to print the book, 201 pages, on both sides of the paper, with my laser printer. However, there were some print feed failures and I had to abort the printing. However, I did get about 50 pages of it. It is a very thorough treatise on what makes carbon steel tick.

In the foreward the author grants license for anybody to use the book provided this be for non-commercial purposes.

Let me know if you can't get it and I'll send it to you. It's a PDF file.

Vernon

The filler bar sits in the root of the weld and it is simply covered over. For this application just scabbing over is good enough I guess.

Vernon: I read an old welding text that showed several design faults in early WW2 ships dealing with hatch coamings and other openings in the decks. Cracks were developing because designers didn't understand the pathways of stress in the ship. This along with bad welding spelled disaster. I saw that post and started to download last night but it was too slow. I will try some other time. Randy

Also, there are very likely no slag inclusions inside the filler bar! If the filler bar is the proper steel and welded in 100% everywhere, what's the issue?

GWE

R. Zimmerman wrote:

I always called them 'back-up' bars - you know to keep the weld from falling out of the root.

These are not backing bars since they are between the parts rather than across the joint at the back side. Randy