Beef up (fish plate) “I” beam frame

[ivbinconned]

Dealer told me some people have done this. Adding 10 or 12 feet of plate centred over axels.
This should prevent rear frame sag which I think my 34 foot Cedar Creek has some of.

Thoughts?

[JRscooby]

cummins2014 wrote:

JRscooby wrote:
When welding frames I always clamp stands well past the area I'm working to pull a strings tight, then notch a sticks for gauge. Short weld, skip weld another place, other rail whatever, then come back, repeat...

Okay, read up a little on skip welding as they call it, still stitch welding, but its actually back welding for heat purposes , but then coming back , and actually seam welding or a complete weld, only for the purpose of heat distortion.

We did a lot of pre bow. Pre bow on base plates that required a seam weld was much easier to just put in an established pre bow , let the heat pull it back straight, instead of having to mess with a bunch of stopping ,and starting welds. Of course in these frame applications ,thats not possible .

I'm sure if doing enough to know how much the welding would distort thing would be good. But I was working in a gravel parking lot, with portable tools. Need to cut the rail at angle? Clamp guide block to rail, mount a cut-off wheel on the skill saw. Use grinder to bevel the parts that hard to bevel once parts are stuck together. Use the easy to grind corner to check alignment, weld the parts that where ground, let cool, grind some more, repeat...

[cummins2014]

JRscooby wrote:
When welding frames I always clamp stands well past the area I'm working to pull a strings tight, then notch a sticks for gauge. Short weld, skip weld another place, other rail whatever, then come back, repeat...

Okay, read up a little on skip welding as they call it, still stitch welding, but its actually back welding for heat purposes , but then coming back , and actually seam welding or a complete weld, only for the purpose of heat distortion.

We did a lot of pre bow. Pre bow on base plates that required a seam weld was much easier to just put in an established pre bow , let the heat pull it back straight, instead of having to mess with a bunch of stopping ,and starting welds. Of course in these frame applications ,thats not possible .

[JRscooby]

When welding frames I always clamp stands well past the area I'm working to pull a strings tight, then notch a sticks for gauge. Short weld, skip weld another place, other rail whatever, then come back, repeat...

[cummins2014]

Me Again wrote:

Lynnmor wrote:
Lippert actually has a part number for patching their pathetic frames. While it is much shorter than your proposed fix, it shows the need for it. Patch

Our 2005 Cardinal 29WBLX with cracks is the web of the I-beans. Lippert called for welding all the way around the fish plates. My welding shop disagreed and skip welded around the edge on the fish plates and did a plug weld over the repaired crack per my suggestion. Chris

Although stitch welding is no where near as strong as seam welding, the extra heat is the problem , it may warp whats being welded, or just the fact stitch welding is sufficient . But if its possible, and will nor warp ,or braced so it won't I will weld it solid . Its never bad to weld it solid if possible .

Plus its always good to dig it out a bit before welding for better penetration.

[Bert_Ackerman]

cummins2014 wrote:

Me Again wrote:

ivbinconned wrote:
Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

Be sure to skip weld it! Chris

You do mean stitch weld it 🙂

I'd be careful doing that skip welding, might not want to broadcast you've done it.. I am pretty sure Lippert holds the rights to that skip welding.

[cummins2014]

Me Again wrote:

ivbinconned wrote:
Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

Be sure to skip weld it! Chris

You do mean stitch weld it 🙂

[Me_Again]

Lynnmor wrote:
Lippert actually has a part number for patching their pathetic frames. While it is much shorter than your proposed fix, it shows the need for it. Patch

Our 2005 Cardinal 29WBLX with cracks is the web of the I-beans. Lippert called for welding all the way around the fish plates. My welding shop disagreed and skip welded around the edge on the fish plates and did a plug weld over the repaired crack per my suggestion. Chris

[ivbinconned]

trailers are my business. I repair them and build them. I think that any “flexibility” should be addressed in the suspension. If I were to order a 12,000 lb. Trailer new I would insist in 7k - 0 degree torflex axels. This would then require a “cart” frame in order to obtain enough height.
A smoother ride I don’t think one could find.
Regarding the attachment of “fish” plate I would be spot welding and using a good many “Huck” rivets.

[Me_Again]

ivbinconned wrote:
Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

Be sure to skip weld it! Chris

[cummins2014]

Bert Ackerman wrote:

ivbinconned wrote:
Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

Are you sure what you call rear frame sag is not frame camber by design? Perhaps a call to Cedar Creek or Lippert is in order? If you start jacking out camber designed in and holding it by welding in flitch plates or stiffeners, you may create issues you currently do not have.

I agree there does become a point where its to rigid, there has to be some flex. Same with the pin box.

[Cummins12V98]

All I can say is you better have the underbelly and insulation removed. Also have a couple 5lb ABC fire extinguishers handy.

[Bert_Ackerman]

ivbinconned wrote:
Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

Are you sure what you call rear frame sag is not frame camber by design? Perhaps a call to Cedar Creek or Lippert is in order? If you start jacking out camber designed in and holding it by welding in flitch plates or stiffeners, you may create issues you currently do not have.

[ivbinconned]

Well you all have convinced me to do this.
I will use 3/16 plate 12 feet long min. I’ll jack the back end up a hair if need be to true it up.
Thanks for your comments.

[Cummins12V98]

Bert Ackerman wrote:

Cummins12V98 wrote:
Lippert produces EXACTLY what most manufacturers want plain and simple "light and cheap" !!!

Now my Mobile Suites Lippert frame is hell for stout because it was designed to meet DRV's specs.

I know of two people who own DRVs, one a camp host who I know like a brother, and both have been back to the DRV factory more than once for frame issues up at the front.

Never said they are perfect but they have very few issues. Mine is rated 21k, it's 23k with a 5,800# pin with zero issues.