How would you repair this?

[Paladin]

About half of the support beams that cross above the bays are like the one below. I'm not really a metal man so I'm not the best with gauges and types etc but can anyone suggest what I might try to use to weld in to replace these? I'm guessing that there might be several choices but trying to match the gauge of steel and if possible especially the shape would be a good thing. I guess the shape really wouldn't matter if I cut it off at the intersection and just put in my own type.

I'm thinking of angle steel welded back to back and then cut to fit in place?

Suggestions?

-Dave

[bobofthenorth]

If it was me I'd use rectangular or square tubing as close as possible to the original dimensions (but no smaller) and of similar gauge to what was in there before.

[Charles in SC]

Hi there, that style of metal is known as hat section shape. You probably will not find it readily available. You said it was above the bays which I am guessing you mean that it supports the floor. If this is correct then it will not be supporting a lot of weight. You might look at useing square tube or angle iron back to back so that it forms a T shape. that will quite strong. Remember that you must have something strong to weld it to as well.
Good luck!

[gus]

I've seen mattress supporting bed cross rails that look a lot like that stuff.

[NJT5047]

Bet you can find the OEM material at MCI and IBP.  You may not like the price, but replacement parts are available.  Light square tubing with a matching depth and width (that'd be rectangular I reckon) would be ideal if you can weld it in place? That may be why the hat sections are used.    Rectangle would be stronger than the hat section.  Cutting and welding angle iron will be a lot of work...and you still got to get under the "T" to weld it? 
Might want to make up one section and see how it goes...the angle iron would be the least expensive way to fly. 
What do your wall frames look like? 
JR

[JohnEd]

The frame running down the center of the coach is mild steele, right?  That should weld OK.  But, isn't the attachment point on the outside made of SS?  Shouldn't that be riveted?  I also think there should be a min wall thickness for that square tubing.

John

[ake1994]

Jr is right. Those hat sections are available from MCI and IBP. When I did my roof raise I had three sections of this same hat channel in the side wall, near the floor, on the passenger side that was completely rusted away. I bought the hat channel from IBP (best price), cut it to length and welded it in. There were several places where the carbon steel is welded to the stainless steel. That requires special weld wire and gas to do the weld. Was like new when completed.

It was interesting because all of the structural steel in the walls on the driver side of my 87 Ex NJT MC9 was in perfect condition, like new. The passenger side required a lot of rust repair. I figured the windows must have leaked on that side only?

I would cut those out and replace with the same hat channel.

Breck

[pete81eaglefanasty]

 Boy all this talk about MCI rusting away, I thought only EAGLES had rust. Well maybe MCI don' rust after all. they just ROT AWAY.

              Pete & Jean
                FANTASY

[Dallas]

Hat Section Steel is available from Trailmobile and Lufkin Trailer too.
FWIW

Dallas

[kyle4501]

Breck is right, easiest fix is to use the same hat profile. If you have access to a sheet metal fab shop, cut out a rusted section & take it to them & have the profile copied in the length you need.

Go to a GOOD welding supply store & tell them what you're welding & they can tell you what you need.
(Usually 309 filler rod is used to weld carbon steel to 304 stainless.)

[gumpy]

If I recall correctly, those pieces are tapered (i.e. they are thinner at the outer end than at the rail end). I think if I were replacing them, I'd probably cut a rectangular piece of 1/4" flat steel about 3 inches across, and weld across the gap. Then I'd cut some triangular pieces and gusset it to the inner rail on either side of the rectangular piece.

Or, maybe easier would be to take some 3" channel iron and taper the sides and weld that in there.

craig

[Charles in SC]

Another way to do this would be to weld a piece of angle iron on the outside bottom angle of the hat section in what is known as a sister beam when repairing floor joists and such in a house. It is not real hard to weld ss to carbon steel. I guess it depends on how original you want it and how much effort you are willing to put forth.

[NJT5047]

Be careful when adding anything to the outside edge that increases the overall height of the hat section (or replacement thereof).  The lateral beams have to be kept flat relative to the upper surface of the longitudinal main frame sections.  However that's achieved. 
Also might want to have a look at the sides of the bus and verify that it's still straight.  May have a need to "align" the sides as you weld the new steel in place.   Either push it out with a port-o-power, or weld on some attachments and pull it in as you go. 
Are there larger cross beams at some point?  Maybe interspersed with the hat sections? 
JR 

[Green-Hornet]

That hat channel stock looks a lot like the posts that are holding the stop sign at the end of my street. 
take a look around in yer hood. If it is close ask the road depatment for some for a patch. Or a hacksaw late at night.......

[NJT5047]

That hat channel stock looks a lot like the posts that are holding the stop sign at the end of my street. 
take a look around in yer hood. If it is close ask the road depatment for some for a patch. Or a hacksaw late at night.......

It does at that!   Also looks like stamped steel electric fence posts....got any farms nearby? 
JR