Repairing a cracked trailer frame

[arch stanton]

I have had this trailer about 20 years and this is the second time that I fixed it, first time about the time I bought it, I found a few cracks that got bigger and longer more I ground I backed all the slots with T-1 and welding was done with a dual shield wire.

 

[Jed-O]

You should start by looking at why. But a solid repair should be done with a gusset

 

[monkeyswrench]

What kind of trailer is it? Big, but is it an end dump or tilt, or? Just curious, as to what and where on stress points and such. Never know, may run into one needing work or for sale cheap.

 

[arch stanton]

You should start by looking at why. But a solid repair should be done with a gusset

The why is easy the trailer was built in 1978 and it gets overloaded all the time and runs every day hauling dirt and demolition and for the gusset the outside of the frame gets plated over and the vertical gusset was removed and both will be replaced will Finnish Monday and post more pics it will make more sense when you see it finished

 

[arch stanton]

What kind of trailer is it? Big, but is it an end dump or tilt, or? Just curious, as to what and where on stress points and such. Never know, may run into one needing work or for sale cheap.

The trailer is a superior pup trailer legals 34,000 lbs on the tandem I could not find a really good pic but the one I have shows the truck that pulls one in a driveway beside a pup trailer, they were loading roofing tiles in both boxes at the same time. the trailers have a 12' box and a 15' tongue

 

[wzuber]

a fillet weld that size should have a backing plate under it and burned/penetrated in same as a structural column and base plate.

 

[River Runnin]

Better wrap that with Flex Tape for extra reinforcement!!

 

[lbhsbz]

I hope you're planning on grinding out those 2 little mending plates before you're done. That trailer needs material added and proper fish plates, not to mention better quality welds than the bullshit holding the 2 mending plates on so that they don't fall off, which is about all it's doing. It's disturbing that my wife and kid share the road with operators who overload and hackfuck fix piece of shit trailers like that.

 

[Ricks raft]

I hope you're planning on grinding out those 2 little mending plates before you're done. That trailer needs material added and proper fish plates, not to mention better quality welds than the bullshit holding the 2 mending plates on so that they don't fall off, which is about all it's doing. It's disturbing that my wife and kid share the road with operators who overload and hackfuck fix piece of shit trailers like that.

Wow. Apparently those shitty welds have held for 20 years and still didn't fail, frame failed next to it...

 

[monkeyswrench]

The trailer is a superior pup trailer legals 34,000 lbs on the tandem I could not find a really good pic but the one I have shows the truck that pulls one in a driveway beside a pup trailer, they were loading roofing tiles in both boxes at the same time. the trailers have a 12' box and a 15' tongue
View attachment 860247

Cool! I was trying to figure out the spring pack and location of air tank and such.
Never had anything quite like that for tear-offs. A 10 wheeler was about it

 

[arch stanton]

I hope you're planning on grinding out those 2 little mending plates before you're done. That trailer needs material added and proper fish plates, not to mention better quality welds than the bullshit holding the 2 mending plates on so that they don't fall off, which is about all it's doing. It's disturbing that my wife and kid share the road with operators who overload and hackfuck fix piece of shit trailers like that.

You should be so lucky as to share the road with my equipment while it's old it is kept in top shape as noted those plates were installed longer as 20 years ago but while I have repaired this trailer once before those are not my plates but there is no cracks between them or around the welds I did weld in fish plates years ago on the inside of the frame rails my plates are longer and cover the area opposite those 2 little plates the entire rusty area is covered by a plate that is welded over the outside of the I beam flange the cracks start at the end of these plates at the vertical flange you can see the front vertical still in place the rear one will be moved to the rear to move the stress back to a new area.

when rolling down the highway you should worry about aluminum framed flatbeds older than about 5 years those trailers have had a lot of catastrophic failures.

 

[mash on it]

A Toyota Brake expert says...

I hope you're planning on grinding out those 2 little mending plates before you're done. That trailer needs material added and proper fish plates, not to mention better quality welds than the bullshit holding the 2 mending plates on so that they don't fall off, which is about all it's doing. It's disturbing that my wife and kid share the road with operators who overload and hackfuck fix piece of shit trailers like that.

Overloaded.
Daily.
Get over it.
Or stay off the highways.

Dan'l

 

[flyingcolors]

many frames say not weld on them do to heat treat

 

[Ziggy]

Box it

 

[Your ad here]

I hope you're planning on grinding out those 2 little mending plates before you're done. That trailer needs material added and proper fish plates, not to mention better quality welds than the bullshit holding the 2 mending plates on so that they don't fall off, which is about all it's doing. It's disturbing that my wife and kid share the road with operators who overload and hackfuck fix piece of shit trailers like that.

Calm down. He obviously inspects his equipment and makes repairs rather than waiting for a complete failure. You would be surprised just how many trailers have cracks just due to regular use. Toyhaulers come to mind. My bumper pull cracked and many 5th wheel owners I've met have had to have their frames repaired. You should be more worried about these type of guys. Friday on 101 in Phoenix.

 

[johnnyC]

the way i would repair it is by grinding out the cracks re-weld them grind down the welds then then fish plate both sides with 3/8 plate at least 12 in on both sides of the repair weld them in, angle the ends to spread any stress, then box it the i-beam the same amount on both sides and angle the boxing plates as well

 

[arch stanton]

many frames say not weld on them do to heat treat

This brand of trailer is built with structural I beam 10" tall with 4" flange it is not the same as a heat treated truck frame and is easily welded these trailers have been built basically the same since the 1970's there has been design changes in that time but they are not much different, don't screw with something that works.

I am familiar with the recommend procedure with welding and fish plating a heat treated truck frame and have done repairs that were successful long term like decades fuck I have been doing this tooooo long.

I learned a lot about how these trailers are built and repaired by Chuck Schultz who copied the design and built a few and repaired many for a company that owned about 30 of them and for many other companies that owned them around southern California.
Back in 1998 chuck built 2 dump boxes for me and I helped with every step and in trade I helped him repair and or build a number of different projects the man knew steel and how to fab, Chuck passed about 10 years ago he was by far the best teacher I ever had.

The job is now complete the other side had a crack on the lower flange and up the web a few inches both the flange and web had fish plate opposite the crack and the crack did not go all the way though they were just hidden by the box section that I cut off.
the top flange had a small crack at the vertical at the end of the box and it did not go through or across the flange .

The inside were painted with silver POR 15 rust preventing paint base coat and the outside paint black POR 15 top coat the wire used for welding is fabco excel arc 71 dual shield with co2 this is a structural and pipe wire all fish plate is Weldox 100 [ T-1 ] If you don't know what all that means then you really don't know enough to criticize my process and if you do know then please enlighten me on how it should be done but keep in mind I own 4 of these trailers and have decades of successful maintenance learned from a man with decades of maintenance before me. first pick boxed section full of dirt and rust
2nd pick start of grinding crack, 3rd pick first crack welded and top flange ground out. 4th 5th pic I outside box section welded in

 

[arch stanton]

Cool! I was trying to figure out the spring pack and location of air tank and such.
Never had anything quite like that for tear-offs. A 10 wheeler was about it

We don't do roof tear offs very often anymore we did these when work was slow and usually it was only a 4 hour min the guy I got the jobs from got the all day work and they only hired us for the tile jobs because we can legal 24 tons, makes you wonder when you have an earth quake that you have that many tons overhead.

 

[Carlson-jet]

Good luck.

 

[rrrr]

Looks good. Next few times someone posts photos of their vertical welds, notice how many have been run downhill, especially MIG welds. Downhill is fast and easier to make pretty, but I use uphill on critical work like trailer frames or other similarly stressed applications.

While the argument about vertical up vs vertical down started three weeks after welding was invented, vertical up welds provide a stronger joint.

American Welding Society certifications for structural MIG welds are uphill. AWS D1.1 GMAW 3G ⅜" and 1" beveled steel plate cert tests are done vertical up.

 

[Icky]

Typically, we drill a hole at the end of crack to stop it from cracking further, then grind out and weld.

 

[arch stanton]

Looks good. Next few times someone posts photos of their vertical welds, notice how many have been run downhill, especially MIG welds. Downhill is fast and easier to make pretty, but I use uphill on critical work like trailer frames or other similarly stressed applications.

While the argument about vertical up vs vertical down started three weeks after welding was invented, vertical up welds provide a stronger joint.

American Welding Society certifications for structural MIG welds are uphill. AWS D1.1 GMAW 3G ⅜" and 1" beveled steel plate cert tests are done vertical up.

Yes that is a vertical up and that is the 3rd pass as the first pic of grinding does not show the depth of finished deep v, its hard with 2 of us working on these projects to get pics of every step. On the other side we did a vertical down because the tire was in the way.
I should post some pics of our better welds but to tell the truth the Dual shield wire we use makes everything look better I don't use anything else now

 

[arch stanton]

Typically, we drill a hole at the end of crack to stop it from cracking further, then grind out and weld.

Yes we could drill a hole but we move the vertical bulkhead that the outside plate welds to, to the rear if we get another crack it will be in the new location and should take more than 10 years to show up.