Welding to a trailer frame, cheap angle-iron frame rails.

I have one of those tractor-supply $300 no-floor 4x8 trailers, angle- iron frame rails, no railing or secondary structure except angle-iron
cross-rails.
I have decided to not drill the frame, attached the bed with bolts just next to the frame and used oversize washers.
What I would like to do is add some hooks and/or eyes for tying things down, but thought I'd sample some opinions before breaking out the welding equip.
The frame is welded (god, what horrible welds), so I'm not too worried, but what would weaken the frame the least, if at all- Brazing? O/A welding? The trusty MIG?
I know with any joint, using any of the above methods, the joint is stronger than the base material, but I'm less sure about welding a fitting onto the frame somewhere.
Thx-
Dave
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I would not attach hooks with welds. I would just bolt them to the floor. These trailers cannot handle much weight anyway. I would also suggest to revisit your use of washers, at least make sure that they are VERY oversized.
i
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wrote:

My little dilemma is that the trailer floor is a 4x8 sheet of plywood, and I want to carry 4x8 sheets of plywood and drywall.
I have 18 3/8 bolts total through the 3/4 plywood, with a nut, lockwasher, 3/8 flat washer, and a 1/2 flat washer, all bolt positions such that if the deck tries to shift one way, it will have a bolt set against the frame opposing the movement on the opposite side of the trailer.
The gross on the trailer is 1500lbs, tare is less than 300 with the - plywood and paint.
If the welding seems sketchy, I'll bolt a metal bar 10 feet long or so to the plywood under the trailer, and put eyebolts on the ends sticking out. Then any force will pull that bar up into the bottom of the trailer. Just seems to be a waste of a nice chunk of metal.
Dave
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Then you can have your tiedowns just make a circle under the bed, no?
You do not really need hooks?
i
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wrote:

Yeah, but that just seems so tacky...
Dave
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On my little fold up trailer, I drilled holes in the side of the frame, used 'U' bolts with 4 nuts for each tie down. I put 3 on each side, one at the front, one at the back, and one on the forward section. If I did it over again I'd put 4 on each side at the 1', 3.5', 4.5', and 7' locations.
As for welding on the frame it likely to be some relatively mild steel, use the MIG. . You can do a crude check of the metal by taking a file or a sharp drill to some corner of the frame. If it cuts easily it should weld fine. If the file or drill bounces off, it is high carbon steel (bed frame iron) that can be welded but has HAZ (heat affected zone) that are subject to fatigue cracking when used in a trailer.
snipped-for-privacy@yahoo.com wrote:

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That's exactly the type of tidbit I was looking for.
Most of those folding trailers have an honest-to-goodness C-section rail, I'd worry less if this had such.
Thanks-
Dave
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On Oct 16, 10:22 pm, snipped-for-privacy@yahoo.com wrote:

The MIG process is a low hydrogen process. So it is the best process of those you named if the steel is high strength steel.
Dan
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snipped-for-privacy@yahoo.com wrote:

If the trailer was purchased from some sort of retailer then it's going to be an ordinary structural steel angle iron, whatever is cheapest on the day they ordered it. No guarantees on it not having hard spots but nothing to lose sleep over.
The only issue is that you, in welding onto the frame, not weaken it to the point where it'll fail. Keep any welds away from the edges of the angle iron (say, two times the thickness of the flange) and holes should not be drilled too close to the edge, keep them a goodly distance away- maybe two hole diameters from edge of hole to edge of iron.
Keep weld beads as small as will suffice, the thinner material is what dictates the size of the weld. Try to not stiffen the frame with what you add, otherwise it'll eventually break at the point where it refuses to flex. If you have to make vertical welds and feel uncomfortable running them uphill, stitch it from the bottom- welding down on a vertical can result in remarkably weak welds, it's honestly best to leave downhill welding to the jobs where it's specified.
Don't be afraid to use the grinder before you weld, it doesn't take a lot of paint or mill scale to make a mess of your work.
John
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I have a hunch that the trailer is made from "angle iron" that was 12ga sheet stock folded up on a brake rather than hot rolled "angle iron" that comes from the mill. I've never seen one of these el cheapo units made with hot rolled product.
But good comments on the pre cleaning, weld and hole location, etc.
JohnM wrote:

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I looked closely at the frame- very sharp outside corner, just about no radius, looks like it has a fillet on the inside of the corner, and the corner is thicker.
I'm guessing it wasn't formed on a brake- does that make it more likely its high-carbon?
Dave
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Sounds like a rolled product rather than a bent/brake product. More than likely the surface will be fairly scaley or rough. It increase the odds of a high carbon product but it's not definite. Hot rolled product can be pretty variable. The one to stay away from is the bed iron that is really high carbon. Back to a file or drill test.
snipped-for-privacy@yahoo.com wrote:

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Spark testing is an old method that can tell you a lot, too- pretty easy to do, just need a grinding wheel on your angle grinder....
http://64.78.42.182/sweethaven/BldgConst/Welding/lessonmain.asp?lesNum=1 &modNum=4
Copy above link or Google spark testing steel to get lots of good info...
With practice, you can learn the spark patterns for many materials, which can save you a lot of grief down the road.
Tin Lizzie
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I was just thinking of pulling up an old thread on this- read about it before.
Thx-
Dave
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Let me see if I understand this. You're going to take a light trailer and haul plywood and drywall?
What's wrong with this picture? Nothing as long as you really watch your load weight.
Whatever you do, do it right. Others safety depends on YOU.
Steve
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Most of these trailers come with 1000 pound capacity axles, bearings, wheels, hubs, and tires. 1000 pounds of wallboard is 18 sheets of 1/2" rock. It stacks nicely, only 9" thick for low center of gravity, distributes the load evenly, and you usually hand load it so it doesn't get the forklift operator drop test. And that is a BIG project for the average DIY'er. Net is I don't really worry too much about wall board.
But I do worry about the same trailer used to haul a piece of top heavy machinery or a bigger garden tractor. Either of those will bend the trailer up nicely.
SteveB wrote:

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Then one of those light trailers ought to do it, and I'd feel safe if you were in oncoming traffic.
Steve
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My only other mig-work (other than practice) was replacing metal around my trucks windshield, all kinds of odd angles and contortions, and some upside-down to get the lip under the roof edge. Not a great job, but it didn't suck either.
A little uphill welding will be easy compared to that. I started with gas welding, so uphill is what's natural.
Thanks all,
Dave
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Dave,
You've already received a lot of good advice on here, but be cautious with those little Harbor Freight trailers if you are going to put much weight on them.
I used one to hold my first welding setup (see http://www.joeswelding.biz/redtrailer.htm ), but the thin channel iron used to mount the trailer hitch to was too flimsy. Whenever I hit a pothole or speed bump, the weight of my equipment rocking back and forth on top would cause the channel iron to twist - allowing the trailer more flexibility than I felt safe with.
Just be careful with those light duty trailers.
If you ever decide to get yourself a heavier trailer, I found that an "assembled Harbor Freight trailer" sells pretty well on eBay, so you won't be out anything.
~Joe http://www.joeswelding.biz /

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Yeah, I spent a fair bit of time at TSC loading one corner, then the other, and observing the flex, before deciding I could live with it.
The heaviest thing the trailer will see is my 350lbs XR650L, and rarely, a second bike if I ever find someone to ride with.
When I get wood or sheet rock, it will likely not be heavier than 'the pig'.
Work/personal travel has kept me from fiddling with it, but I'll post what it seems to be made of when I get a chance.
I will be adding some lighter-duty eyebolts to it, mounting them through the vertical part of the cross pieces, near the edge, where there is just about no stress on the piece.
Dave
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