Great video on proper way to weld reinforcement on a rv frame

[Nuffsaid]

This is a great video of how I would recommend welding braces in a I beam 5th wheel frame for maximum strength.

https://www.youtube.com/watch?v=eeKcDUI_8qY

 

[Hoopy Frood]

Looks impressive, but you can't always go by looks. I'm no engineer so I have no idea.

 

[Nuffsaid]

Looks impressive, but you can't always go by looks. I'm no engineer so I have no idea.

When I looked at this video my first inclination was that the person who made the video was a structural Ironworker, which is what I started my career as and where I became a ceritfied welder. I asked him and sure enough he is a retired ironworker! In structural steel buildings you will almost always see full length vertical braces welded in to the I beam from lower flange to upper flange to distribute the loade when there is a column attached at that location. The braces are welded in on both sides of the beam as stiffeners and it keeps the flange from being able to deflect at that point. I have personally welded in hundreds of them and I understand the engineering behind them. I worked on many high rise buildings and many times we had to go into occupied buildings and add support to existing floors to support heavy equipment that the floor wasn't originally designed for. This usually required welding in heavy steel plate beneath the bottom flange of the beam to support the added weight. We would also reinforce beams where penetrations to the web of the beam needed to be made so that a large hole could be placed in the center of the beam for possibly the addition of plumbing or HVAC duct work and this would require welding in stiffeners and then cutting out the center portion of the beam. All of these changes were designed by Structural Engineers and after a while I got a knack for seeing how they would make design changes. Late model trailer frames are designed using the lightest gauge steel they can use to keep weight down and the minimum amount of gussets in the frame to keep labor costs down. If you were to look at the way Northwood builds their frames in house, you will see a single verticle gusset installed over every spring hanger. This guy installed two which is the way all of the buildings and bridges I ever worked on were designed. Back in the mid 90's when I built several trailers all of the spring hangers that you would purchase off the shelf were made out of .250 or 1/4 inch steel. You never heard of spring hanger failures back then. Spring hangers used now are in the .180 range and break a lot. Same with the I beams on the frames. They have been lightened up to reduce weight, but when these trailers get a lot of road miles put on them, the frames fatigue because they weren't built with enough reserve strength factored in.

 

[Nuffsaid]

Here is a lippert approved frame reinforcement on a Solitude for cracked frame above the spring hangers:

https://www.youtube.com/watch?v=5HI3Y0_jizk