I am finally getting around to getting my super sucker fabed up. I made a set of skids up from an old I beam that was welded to the wall of my shop (for some unknown reason).
My question is whats the best way to attach the skid to the tank, because of the round tank the beams only touch along their edges. I intend to stitch weld along the joint but I wonder if I should weld in a few gussets along the edge or what would be the best way to do this?
The bottom pic shows what I mean by gusset, I could cut some small triangles to weld in a few places along the length.
My fabrication skills are limited to conduit and cable tray electrical instalation type stuff and this is my first welding project so keep that in mind when advising!
Any help is greatly appreciated!
Jon

jon
-gusets aren't required there for strenght, but I would make saddles , one every two feet that extend up the side about 6" higher than the I beems. 1/4 x 4 would work well, just get a shop to run it through a roller so it fits nicely under the tank. Then just weld the 4" saddle where it meets the I beem and tank. looks like you are arc welding, turn down the heat, and watch for slag entrapment Tom

Thanks Tom!
I am a cheap bastard though and making 1/4" X 4" saddles is beyond what I was hopping to invest Do you think gussets will be sufficient? The sucker is going to be chained to the bed of a trailer via the skids.
The tank is an industrial compressor tank, anybody have any idea how thick the steel might be on it? 3/16" maybe? I dont want to burn a hole in it...
Yes I am arc welding, I was using 3/16 6011 rods at about 90 amps for welding the angles to the beams, it seamed to work ok. Does it look like I am too hot? I also tried some 1/8" 6013's on some scrap of the same steel at about 100 amps and it laid a pretty nice bead.

Thanks,
Jon

I doubt you even need gussets since you have those braces on the bottom of the skids. Just weld it to the tank, you should be fine.

Jon,

Are there feet on the bottom of the tank? Is there a compressor head plate at the top?

Thanks Hummerbk.
Eurocab, There are feet on the tank but no compressor platform.
Its a big brute, 30" diameter and about 6' tall.
Jon

quote:

Originally posted by Hummerbk:
I doubt you even need gussets since you have those braces on the bottom of the skids. Just weld it to the tank, you should be fine.

That would be the advice I would give. There's nothing wrong with the way you have it set up now.

Put a 2 inch weld every 18 inches between the top of the I beam and the tank. Flip the tank over, and lay in the same on the inside edge of the I beam to the tank.

Job complete.

Make sure you grind away the paint for a strong weld.

Stitch weld it. You are securing the skids to the tank, not the tank to the skids.

Not enough stress to need gussets.

Great!
Thanks for the advice guys!
Jon

Jon
-if you where closer I'd do them for you for free. 6011 rod has less flux than 6013, so it will be easier to control and less likely to have slag entrapment. it produces a much rougher bead than 6013, so don't be too hard on yourself if it doesn't look good. the strength of all 60 series rods is the same. both 6011 and 6012 have more bite than 6013. end of welding lesson.
-what do you expext the total weight of the tank and wvo to be. I've already stated my preffered way to tackle this job, but for sure it is not the only way, the proceedure explained by Murphy is a good one, just stager the welds on the inside of the I beem. my only other concern would be undercut at the edge of the weld, when welding in that sharpe included angle on top of the I beem. Tom the welder x40 years

Thanks Tom. None of my welds look that pretty yet anyways The 6013's do seem to make a nicer looking bead but with less penetration.
How do I check for "slag entrapment"? Also how do I avoid it? LOL
I am not sure how much it will weigh, whats 200 gallons of WVO weigh? Maybe 2000lbs?

quote:

my only other concern would be undercut at the edge of the weld, when welding in that sharpe included angle on top of the I beem.

I am not sure what you mean, what is "undercut"? Should I not have the angle of the welding rod centred between the tank and the skid?
I was thinking about using the 6013's for welding to the tank because of the lesser penetration I figure there is less chance of burning a hole in it, what do you guys think?
All this help is greatly appreciated!
Jon

Jon
-welding is 99% practice. Prepare the tank as recommended by Murphy. Remove all the paint in the weld area. An angle grinder will work well for this.
- After thinking about this for a bit, it will be easier for you to tack weld the base in place, say 4-1” welds where the tank meets the I beams (at the ends) roll the tank upside down, and do all welding from the underside. Start at one end of the I beam, and place a 2” bead. Now move to the far end of the other I beam do the same, cross over two the first I beam and weld. I’m not sure if I explained this well, but your weld pattern should be in the form of an X, after doing 4 welds,(each end of the I beams will be welded to the tank). Now measure off 10”, 2” spaces along each I beam, then weld the 2’ segments, going from side to side in an X pattern as you did for the first 4 welds. This will reduce the stress on the weld line, as apposed the stress that will be created by welding all 2” segments in the row one after the other.
- 6013 would be a good choice here, it has a thicker flux coating, and with a steady hand will curl up from the weld on it’s own. Flux or slag entrapment occurs when the molten metal surround flux that has leaked in front of the molten puddle. In the sharp included angel where the tank meets the I beam (looks like the angle is about 30 degrees,) It would be difficult for the inexperienced to control the flux. improper weld speed and or heat will cause the molten metal from the tank to flow onto the weld bead, causing a small crater along the edge of the weld (undercut) this really reduces the intended strength of the base metal, in the case the tank. Tom

Ok got it...
I am going to give her a go now and I will let y'all know how it went later...

Well it went pretty damn good! I hit it with the 1/8" 6013's at around 90 amps. I laid down way more weld then needed because I NEED practise!
I was starting to get great looking beads near the end when I had to shut her down for the night...
Its all in the wrist. LOL
I found once I got focused and relaxed with my head in nice and close to observe the puddle I would lay the nicest weld, I found it also has a distinct sound when its welding well...
Where I had the most trouble was where there were some dings in the tank and there was around an 1/8" to a 1/16" gap between the beam and tank, is there a technique to filling the gap without making a mess? Also what is the best technique to continue a bead when you have to stop to start a new rod?
I didn't attempt welding the topside in the steep angle yet, the 1/8" rod is too thick to even make into the joint. I am thinking with the amount of weld I have laid on the inside that I will only have to hit a couple of times in the angle?

Thanks,
Jon

Jon
-for the gaps, lay a small bead in then first, then just weld over the spots . as for stop and start, you must chip the flux away first, then just start with the next weld. I like to finish the step welds in one pass, so if the electrode isn't long enough I change it out. If I where you, i wouldn't weld in the angle. it's a whole different ball game. If you insist , try the technique on some scrap pieces first, then use 6011, it has much less flux that solidifies faster than the flux on 6013 rod, reducing the chance of slag inclusions (they do nothing for weld strength and look like chit Tom

Thanks man!
Jon

I hope you welded a couple temporary strongback braces across the flat bottoms of your I-beam skids before doing the rest of the welding.

Initiating an arc, getting a puddle started & running a good weld bead is one thing, but having a finished workpiece that's dimensionally correct after welding is another...

90 amps on 1/8 rod is ballpark correct. I weld pressure pipe root in all positions with 1/8 6010 at about 75-80 amps, but that's with a 3/32 landing & a 3/32 gap, so running your 1/8 rod a little hotter on a tightly fitted fillet weld is reasonable.

I hope it works out well for you.

quote:

I hope you welded a couple temporary strongback braces across the flat bottoms of your I-beam skids before doing the rest of the welding.

I am not sure what a "strongback" is?
I did not brace anything but I did follow Tom's advice of using a criss cross pattern to minimize the heat and I had no warping.
I ended up welding the entire length of both skids just for practise and they are still square so no worries. I am already seeing a huge improvement in my skill, I can now start a new rod instantly , (I am sure this is the easiest part for most but I struggled with it...) I am also now able to connect the beads together without any inclusions and maintaining the flattened stack of dimes appearance...
I am going to need all the practise I can get before I attempt to weld up my bio boiler this winter...
Cheers,
Jon

Tonight I welded a few angles on the tank to strap the pipes to. I thought I was getting decent but I was just getting cocky I guess because they were a bit troublesome.
Couple things;
The angles were 90 to the tank and I had the rod at a 45 into the joint. Correct?
I found a few times the tip of the rod would start to do a 60Hz dance or vibration back and forth at the tip (magnetic field) screwing up my bead, how do I avoid that?
Thanks,
Jon

Welp I will giver a go again tonight and see how I make out, maybe I will try turning down the heat a bit. I cut some angle iron up last night to make brackets to bolt lifting eyes on either side of the tank, I just need to weld them up and then weld them to the tank. Once thats done I just have to finish the plumbing, painting, wand and then load her up and go collect some oil...
I am leaving in the morning for my annual "deep woods" fishing trip and wont be back till Sunday so dont feel slighted if I dont get back to any of you until then.
Cheers,
Jon