The Welding and Fabrication Thread

[RamRod4]

I've got a question tangentially related, if anyone's got an answer.

We need to fabricate roof rack mounts that will support two lengths of superstrut or square steel tubing, each length running fore-to-aft, which will be positioned directly above the two internal roof 'ribs' that also run fore-to-aft (if this doesn't make sense, I can supply pics or clarify). If the roof was flat, I'd imagine these mounts to be like an upside-down letter 'T'. But since the roof is not flat, I need to account for the curvature of the roof, and angle the vertical portion of the 'T' so the superstrut / tubing presents a flat surface upon which to mount stuff.

How would y'all suggest I measure that angle? For what it's worth, I'll probably hand this off to an experienced welder.

If I were fabricating it for myself I would build the first T bracket in place and then make the others to match the first one.

1. Level the bus left to right
2. Make flat plate for bottom of T
3. Screw down plate to roof
4. Make upright portion of T
5. Hold the upright plumb with a small level or digital angle indicator (I have a small magnetic digital angle finder from Lowe's that works well)
6. Tack upright to bottom plate while holding it plumb
7. Remove bracket as one piece and then measure the angle and re-create the same part x number of times.

Hope that makes sense.

 

[RolesvilleMarina]

Cool thread

I learned to weld when I traded a Bass Amp left behind by yet another bass player to a friend for an old lincoln 22 tombstone and a box of sticks.
(Base and drummers leave gear for some reason)

It came with a long cord so I put a dryer plug outlet and started at it.

first thing I learned

1. the missus always chose this time to want to dry clothes
2. Even though it is hot in sunny NC wear a shirt :whistling:


I had it for years, I learned to get real good at it welding thinner materials cause it was all I had

years later I sold or traded it, and got a 110 mig. I was doing other things and didn't need much for penetration so It was ok... I never did get the gas setup for it although I intended to.

fast forward today I bought the 110/220 stick from HF as a kit for the bus.

I chose stick because it was small and easier to tote in the bus.

Also I can weld different metals, especially stainless, simply by changing rods and I am a boater so this is handy.. can even do aluminium I've read...it's messy and I have never tried but it seems possible.

I am no full time welder though, so it seemed the best bang for buck as a spare tool and not take up too much space..

but the leads come with it suck and were replaced with good Lincoln set

 

[TheHubbardBus]

If I were fabricating it for myself I would build the first T bracket in place and then make the others to match the first one.

1. Level the bus left to right
2. Make flat plate for bottom of T
3. Screw down plate to roof
4. Make upright portion of T
5. Hold the upright plumb with a small level or digital angle indicator (I have a small magnetic digital angle finder from Lowe's that works well)
6. Tack upright to bottom plate while holding it plumb
7. Remove bracket as one piece and then measure the angle and re-create the same part x number of times.

Hope that makes sense.

It absolutely makes sense! Thanks so much. It's this kind of experience I definitely lack. Sincerely appreciate your advice, & this thread!

 

[Jolly Roger bus 223]

aluminum is not messy once learn them and can be quick.
sucks on small tubing because of position change if you need a continuous weld and overhead can be tricky.
the rods burn/melt like a hot stick of butter in a hot cast iron skillet.
takes practice but doable.

 

[Jolly Roger bus 223]

It absolutely makes sense! Thanks so much. It's this kind of experience I definitely lack. Sincerely appreciate your advice, & this thread!

another idea to save some grinding.
is for the curved base piece.
get a needle style contour guage, find your spot on the roof and place the guage in that area to match the exact curve then transfer that curve to a generic piece of cardboard.
cut out the curve on the cardboard then take it to the roof with a level.
tape it up where you want it and use the level from the high point of the roof to scribe or mark the level line. pencil recommended if using cardboard.
mock up a full clip/base plate out of cardboard. verify its what you want and if so you now have a template to reproduce all the other clips.
and if you are wondering yes you can bend 1/4' steel at home in the driveway for the base of the clips/feet to be able to bolt down.
let us know your intention and what tools you have and we can help.

 

[Booyah45828]

Aluminum is doable with stick. You won't get tig looking beads from it, but you'll get a functional bond that works. Although it isn't necessary, I found pre-heating with a torch helps when stick welding or even wire welding aluminum. You can strike the arc and run it at a lower heat range and not worry so much about blow through.

 

[TheHubbardBus]

another idea to save some grinding.
is for the curved base piece.
get a needle style contour guage, find your spot on the roof and place the guage in that area to match the exact curve then transfer that curve to a generic piece of cardboard.
cut out the curve on the cardboard then take it to the roof with a level.
tape it up where you want it and use the level from the high point of the roof to scribe or mark the level line. pencil recommended if using cardboard.
mock up a full clip/base plate out of cardboard. verify its what you want and if so you now have a template to reproduce all the other clips.
and if you are wondering yes you can bend 1/4' steel at home in the driveway for the base of the clips/feet to be able to bolt down.
let us know your intention and what tools you have and we can help.

I like this idea too! Thanks!
I had originally planned on making the base of each 'foot' thin enough so, when coupled with a rubber sheet gasket between it & the roof, the curvature wouldn't come into play. But I'd rather it conformed to the curve exactly if possible, which would also allow me to create a bit wider footprint.

So how would I bend 1/4" steel to match the contour of the roof? I'm assuming heat is involved?

No OA torch, although honestly I wouldn't mind getting a small rig. Do have a butane and MAP torch.

 

[RamRod4]

I like this idea too! Thanks!
I had originally planned on making the base of each 'foot' thin enough so, when coupled with a rubber sheet gasket between it & the roof, the curvature wouldn't come into play. But I'd rather it conformed to the curve exactly if possible, which would also allow me to create a bit wider footprint.

So how would I bend 1/4" steel to match the contour of the roof? I'm assuming heat is involved?

No OA torch, although honestly I wouldn't mind getting a small rig. Do have a butane and MAP torch.

I think the curve will be negligible over a small distance like 3” or so. Not sure how large you pan to make the foot or bottom piece but a flat piece with a good sealant will probably be fine.

If you want to curve it you can heat it with map gas but it will take a while. If you don’t make it too thick you could probably cold form it as slight as the curve will end up being.

 

[TheHubbardBus]

That was my initial thought (the curve being negligible). I'm going to mock it up tomorrow & see how flat it lays. I don't really need a big footprint, I don't think. I'm going to have a 'foot' every other rib, and aside from solar panels, the only thing else that will be up there is maybe some supplies we can't fit inside, or at times the Mrs & myself watching the setting sun.

 

[rossvtaylor]

Good for you, Sianas. The more you can do, the better you'll know your rig...and the more you can fix or modify. TIG is, I think, the hardest to learn...but TIG welds are generally pretty good. I see lots of new welders get a MIG welder and those are great, but it's possible to make a good-looking weld that's got poor penetration. Yes, that can happen with any kind of welder, but it seems to be easier with MIG. Stick (I may have dated myself there...I guess it's SMAW now) has a pretty steep, but brief, learning curve. Once you can strike and hold an arc, it's generally going to produce strong welds. Again, it's possible to make porous, brittle welds or get poor penetration with stick...but it's not as potentially "dangerous" as MIG.

I didn't mean to open up a can of worms here...I intended to just compliment you on learning and choosing a versatile welding type.

 

[BeNimble]

My eyesight is not so good anymore, so my welds have suffered the same fate.
However, I've seen lots of tests done that show ugly welds are just as strong as pretty ones.

I always try to overbuild to have fewer critical dependencies. bigger bolts, thicker metal, more fiberglass, etc.
I made custom brakes for my racecar, so many scared of that, which yeah thats important to not do half-ass, even with our team named Cut Corners Racing. lol

I just welded up a custom center driveshaft support for the motorhome today, much more steel than needed.

 

[RamRod4]

Good for you, Sianas. The more you can do, the better you'll know your rig...and the more you can fix or modify. TIG is, I think, the hardest to learn...but TIG welds are generally pretty good. I see lots of new welders get a MIG welder and those are great, but it's possible to make a good-looking weld that's got poor penetration. Yes, that can happen with any kind of welder, but it seems to be easier with MIG. Stick (I may have dated myself there...I guess it's SMAW now) has a pretty steep, but brief, learning curve. Once you can strike and hold an arc, it's generally going to produce strong welds. Again, it's possible to make porous, brittle welds or get poor penetration with stick...but it's not as potentially "dangerous" as MIG.

I didn't mean to open up a can of worms here...I intended to just compliment you on learning and choosing a versatile welding type.

You’re on the right track there haha. Generally speaking, MIG welding does not penetrate as well as stick welding or TIG welding with the exception of flux-core MIG. That said, it’s not really an issue with our buses and most projects you’d find at home. Where it becomes a problem is in structural welding thicker materials. This is why you don’t see MIG welding used to erect building or bridges that rely heavily on weld quality and penetration. TIG takes too long, so stick is the go to for these situations.

While I prefer TIG welding, each process has its place and learning when to use one or the other is an endeavor in and of itself.

 

[Booyah45828]

Tig and mig aren't used in structure welding for several reasons. It's not that those processes are incapable of it, it's just that it isn't efficient to do so, especially when an experienced welder is involved.

All 3 processes can make similar strength welds on a multitude of materials. For instance, a company nearby builds several hundred ton stamping presses, and they weld the castings together with wire welders, so the process is definitely capable. Granted, they get wire in by the 55 gallon drum, and I believe it's flux core, but it's still a wire welding process.

One reason they're not used in structural welding is because tig and mig both require a shielding gas, whereas stick doesn't. Although shielding gas isn't rare or hard to get, it's one more thing to keep track of and have present on a job site, and not having it means the job screeches to a halt.

Another reason, is that structural welding typically requires the welder to be outdoors in the elements. Shielding gas in both tig and mig can be blown away by the wind, which creates porosity and poor welds. Whereas wind won't blow the flux off a stick electrode.

Another reason mig and tig isn't used is because the welder has to be in close proximity (10 feet or less) to the machine. Where as stick welding can be done 100+ feet away from the machine. You can't get mig wire to push that far without creating a mess, and the wait time on your shielding gas to flow is also pretty great from that distance.

You could likely do fluxcore wire welding with a spool gun successfully in structure stuff, but why? SMAW welding is just as easy, and you can change stick electrodes quickly, where as rewiring a spool gun is a longer process.

 

[RamRod4]

Tig and mig aren't used in structure welding for several reasons. It's not that those processes are incapable of it, it's just that it isn't efficient to do so, especially when an experienced welder is involved.

All 3 processes can make similar strength welds on a multitude of materials. For instance, a company nearby builds several hundred ton stamping presses, and they weld the castings together with wire welders, so the process is definitely capable. Granted, they get wire in by the 55 gallon drum, and I believe it's flux core, but it's still a wire welding process.

One reason they're not used in structural welding is because tig and mig both require a shielding gas, whereas stick doesn't. Although shielding gas isn't rare or hard to get, it's one more thing to keep track of and have present on a job site, and not having it means the job screeches to a halt.

Another reason, is that structural welding typically requires the welder to be outdoors in the elements. Shielding gas in both tig and mig can be blown away by the wind, which creates porosity and poor welds. Whereas wind won't blow the flux off a stick electrode.

Another reason mig and tig isn't used is because the welder has to be in close proximity (10 feet or less) to the machine. Where as stick welding can be done 100+ feet away from the machine. You can't get mig wire to push that far without creating a mess, and the wait time on your shielding gas to flow is also pretty great from that distance.

You could likely do fluxcore wire welding with a spool gun successfully in structure stuff, but why? SMAW welding is just as easy, and you can change stick electrodes quickly, where as rewiring a spool gun is a longer process.

All good points. I'll add that usually any wire-fed MIG welding done for structural purposes in a shop is done with dual-shield wire. It has flux built in but also requires a shielding gas. It penetrates well and looks similar to a stick bead. That's likely what the company near you is using.

 

[Native-SKO]

Okay, I'll ask ... what is SMAW?


(I am an ox-acetylene welder myself. Yeah, that dates me.)

 

[RamRod4]

Okay, I'll ask ... what is SMAW?


(I am an ox-acetylene welder myself. Yeah, that dates me.)

SMAW is the technical name for stick welding

SMAW = Stick
GMAW = MIG
FCAW = Flux Core
GTAW = TIG

 

[john61ct-SKO]

I want to learn structural fabbing with aluminium,

ideally working off grid using DC power inputs, supplied from alternators / "DC generators" and/or straight off big battery banks.

Also often working outdoors, so sounds like stick welding's best?

I see modified "weldernators" from Leece Neville have been discontinued

the ones sold these days based off Delco CS-144, 250A with dual rectifiers

but Zena's 200A "Engine Driven Welder" Alternator looks better engineered?

Any suggestions for getting started, how to find a good teacher / mentor for this specific niche

would be most welcome

 

[RamRod4]

I want to learn structural fabbing with aluminium,

ideally working off grid using DC power inputs, supplied from alternators / "DC generators" and/or straight off big battery banks.

Also often working outdoors, so sounds like stick welding's best?

I see modified "weldernators" from Leece Neville have been discontinued

the ones sold these days based off Delco CS-144, 250A with dual rectifiers

but Zena's 200A "Engine Driven Welder" Alternator looks better engineered?

Any suggestions for getting started, how to find a good teacher / mentor for this specific niche

would be most welcome

Your biggest issue is that most alternators are built with rectifiers to convert the AC power to DC. I do not know enough about them to know if you can draw straight AC power off of an alternator. Aluminum will require AC power, not DC.

It all depends on what exactly you plan to weld and how much time you have to tinker. Keep in mind that for any heavy aluminum welding you will want a water-cooled torch. This requires a water cooler and associated power for that as well.

Personally, I'd be looking into buying a multiprocess machine like the Miller Multimatic 220 AC/DC welder ($3000) and plugging it in to a standard generator. That machine isn't cheap with the TIG package but it runs really well and will allow you to MIG and stick weld off the same machine. Its portable as well. My field service trucks use these quite a bit and love them. 110v or 220v input as well.

The cheaper option is a Harbor Freight Vulcan OmniPro 220 ($1000). This machine is DC only. It will not weld aluminum in TIG fashion. It can be run with a spoolgun though. I do not prefer aluminum spoolgun welding for a couple reasons that I can elaborate on if necessary.

As for learning, Watching videos will help to a point. You really just need to get a machine and start welding. You can watch over someone's should or on Youtube all day long, but the real learning comes from time behind the hood. No way around it. Pick it up and start welding.

 

[Booyah45828]

I want to learn structural fabbing with aluminium,

ideally working off grid using DC power inputs, supplied from alternators / "DC generators" and/or straight off big battery banks.

Also often working outdoors, so sounds like stick welding's best?

I see modified "weldernators" from Leece Neville have been discontinued

the ones sold these days based off Delco CS-144, 250A with dual rectifiers

but Zena's 200A "Engine Driven Welder" Alternator looks better engineered?

Any suggestions for getting started, how to find a good teacher / mentor for this specific niche

would be most welcome

If you're serious about structure welding aluminum remotely(building a prefab shop somewhere?) Then get a used bobcat welder, do your work, and then resell it.

I wouldn't mess with those alternator/welder combos. They're neat in a highschool science project way, especially if you can repurpose a 20 dollar alternator out of an ambulance in the junkyard. But by the time you buy that zena unit and get it installed, you could have bought a used bobcat welder and would actually have a welder.

You can stick weld aluminum, I've done it. It won't be tig pretty, but it will work. Anytime you weld aluminum, just know that cleanliness is next to godliness. So make sure your base metal is perfectly clean. Preheating the base material also helps a bunch.

Once again, if you're doing structural stuff, you'll likely be in the elements where any gas shield welder won't be optimal.

 

[john61ct-SKO]

get a used bobcat welder, do your work, and then resell it.
…
You can stick weld aluminum, I've done it. It won't be tig pretty, but it will work.
…
Once again, if you're doing structural stuff, you'll likely be in the elements where any gas shield welder won't be optimal.

Yes good stuff, thanks I'll look into that.

Suggestions on where to look for deals, ideally setting alerts?

And yes I'd probably need to build a shed, to keep the bobcat secure