Talk to me about small project welding

[Red Squirrel]

I know barely nothing about welding, I only really know the basics and that there's different types like stick welding, tig, mig, etc. Some are better for big jobs (like welding metal I beams together) or smaller jobs like welding small pieces of rebar together or something.

Specifically I'm looking for smaller project welding, like if I want to weld a small nut on a metal NEMA cabinet so I can screw in standoffs for a circuit board, what's the best equipment to use for that? I'm guessing stick welding. Where does one typically buy this kind of equipment, like the sticks? I don't think this is something I'd find at a place like Home Depot right?

I know I can probably stick weld with a lead acid battery, but want something safer/more sophisticated than that.

 

[echo4747]

I know barely nothing about welding, I only really know the basics and that there's different types like stick welding, tig, mig, etc. Some are better for big jobs (like welding metal I beams together) or smaller jobs like welding small pieces of rebar together or something.

Specifically I'm looking for smaller project welding, like if I want to weld a small nut on a metal NEMA cabinet so I can screw in standoffs for a circuit board, what's the best equipment to use for that? I'm guessing stick welding. Where does one typically buy this kind of equipment, like the sticks? I don't think this is something I'd find at a place like Home Depot right?

I know I can probably stick weld with a lead acid battery, but want something safer/more sophisticated than that.

edit to add: stick welding is used for mostly heavier gauge(thicker) steels. Stick weld uses flux coated filler rods and leaves behind slag that should be chipped/brushed away. It is somewhat forgiving on dirty/rusty steel

Tig welding would be best for the example you mention.

 

[drnickriviera]

MIG would be the easiest. i'd even look at brazing as a cheaper option. Epoxy an option?

 

[echo4747]

MIG would be the easiest. i'd even look at brazing as a cheaper option. Epoxy an option?

brazing would be a good cheaper option. Soldering may be even cheaper yet.

OP.. if you are using dissimilar metals (i.e. brass nut to be joined to steel enclosure) look at soldering or brazing as welding isnt suitable

 

[Greenman]

I know barely nothing about welding, I only really know the basics and that there's different types like stick welding, tig, mig, etc. Some are better for big jobs (like welding metal I beams together) or smaller jobs like welding small pieces of rebar together or something.

Specifically I'm looking for smaller project welding, like if I want to weld a small nut on a metal NEMA cabinet so I can screw in standoffs for a circuit board, what's the best equipment to use for that? I'm guessing stick welding. Where does one typically buy this kind of equipment, like the sticks? I don't think this is something I'd find at a place like Home Depot right?

I know I can probably stick weld with a lead acid battery, but want something safer/more sophisticated than that.

In the specific example you cited, a threadsert would be a better solution. It's a threaded sleeve that installs like a pop rivit.

As far as welding goes, Home depot sells a 120 volt tig welder that will actually join to thin pieces of metal together. They also sell an old school 220v Lincoln stick welder. I suck at welding so I won't offer any other advice.

 

[Spacehead]

If there's any sort of industry near you then there will probably be some sort of supply store for welding.

TIG is good if your welding mostly small, delicate, clean pieces.
Requires a bottle of Argon though.

 

[MongGrel]

MIG would be the easiest. i'd even look at brazing as a cheaper option. Epoxy an option?

This.

 

[Red Squirrel]

I thought about epoxy but don't think it would work well for metal which is not really porous. There will be lots of sideways force on it. Brazing sounds interesting, I'd have to read up more on it, I know it's what they use for A/C lines. It's similar to soldering right? One nice thing of learning it is I could practically DIY install central A/C at some point and just get someone to fill it, so save lot of money there.

Mig sounds interesting too but probably more expensive to get into, but could be fun to learn too.

But yeah chances are the metals would be different too, not sure what the bolts are made of but I can't assume they're the same metal as enclosure. So is any type of welding out of question then? If I can rough up the surfaces enough maybe soldering will work? It's not like it will be holding any huge weight, just circuit boards, maybe DIN rails, but it still needs to be mechanically sound and not let go at some point.

 

[Spacehead]

But yeah chances are the metals would be different too, not sure what the bolts are made of but I can't assume they're the same metal as enclosure. So is any type of welding out of question then?

You can weld dissimilar metals as long as it's not welding metal to aluminum, copper, brass etc.

 

[drnickriviera]

I wouldn't rule out the strength of epoxies. They will work on smooth metal too. Not sure how much load you are talking about, but i'd get a tube of jb weld and do a test run. That will be by far the easiest/cheapest way. Are the enclosures painted? Any heat will burn the paint so keep that in mind. I'd also look at the threadsert greenman mentioned. It will be exposed on the opposite side of where you want the nut to be, so it isn't going to be pretty if you can see it

 

[Greenman]

I wouldn't rule out the strength of epoxies. They will work on smooth metal too. Not sure how much load you are talking about, but i'd get a tube of jb weld and do a test run. That will be by far the easiest/cheapest way. Are the enclosures painted? Any heat will burn the paint so keep that in mind. I'd also look at the threadsert greenman mentioned. It will be exposed on the opposite side of where you want the nut to be, so it isn't going to be pretty if you can see it

It will be a lot prettier than a mass of chard paint.
The other issue with welding is holding a single nut in place while it's welded. A few hundredths of an inch off and he'll have to grind it off. I have to wonder if simple sheet metal screws wouldn't do the job just as well. How heavy are the actual components being attached?

You're right about epoxy, it's extremely strong and bonds to almost anything. The stuff we use in construction works as well under water as dry.

 

[DrPizza]

If the surfaces are painted, he'll need a grinder or other mechanical device to prep the surface anyway, to remove the paint where the nut will go, prior to burning the rest of the paint.

 

[Red Squirrel]

Yeah plan is to sand off the paint where needed. The standoffs are similar to what is used for a motherboard so all small stuff, so basically the plan is to fasten a nut so that I can put the standoff in it then put the circuit board in it and then screw. The load is not that much, one of the boards will be a raspberry PI and then an assortment of relay controllers and stuff. I was thinking if I can tack weld the nut on two sides that would be more than enough to hold it. Was thinking stick welder on lowest setting as it seems like the simplest type of welder to use and still versatile enough for other projects I may want it for in future but would that even be too much?

 

[echo4747]

Yeah plan is to sand off the paint where needed. The standoffs are similar to what is used for a motherboard so all small stuff, so basically the plan is to fasten a nut so that I can put the standoff in it then put the circuit board in it and then screw. The load is not that much, one of the boards will be a raspberry PI and then an assortment of relay controllers and stuff. I was thinking if I can tack weld the nut on two sides that would be more than enough to hold it. Was thinking stick welder on lowest setting as it seems like the simplest type of welder to use and still versatile enough for other projects I may want it for in future but would that even be too much?

I think a stick welder even with the thinnest filler rods will burn right thru the sheet metal of your enclosure (especially if you don't have any welding experience) I am assuming both the nuts and enclosure you are using are both some type of steel. If they are... solder would surely be strong enough to hold the load. I think even something "cheap" like this will meet your needs:
http://www.ebay.com/itm/Heavy-Duty-...s-FREE-SHIP-/371406414984?hash=item56798c2488

 

[Red Squirrel]

I think a stick welder even with the thinnest filler rods will burn right thru the sheet metal of your enclosure (especially if you don't have any welding experience) I am assuming both the nuts and enclosure you are using are both some type of steel. If they are... solder would surely be strong enough to hold the load. I think even something "cheap" like this will meet your needs:
http://www.ebay.com/itm/Heavy-Duty-...s-FREE-SHIP-/371406414984?hash=item56798c2488

I do have a solder torch for plumbing, could that work or overkill? I have a regular electronics soldering station too. 60w I think, temp controlled. I just checked and the nuts are still in the bag says they are stainless steel. The enclosure is Nema type 1, guessing that would be made of steel.

 

[echo4747]

I do have a solder torch for plumbing, could that work or overkill? I have a regular electronics soldering station too. 60w I think, temp controlled. I just checked and the nuts are still in the bag says they are stainless steel. The enclosure is Nema type 1, guessing that would be made of steel.

If the nuts are stainless steel you would need whats called "silver braze" Silver braze due to its higher melting point requires a torch ( i use oxy acetylene but mapp gas might work too) This works well for brazing stainless steel: http://www.zoro.com/harris-brazing-...oE7avPzJs41NvwBvzF-LsaArJC8P8HAQ&gclsrc=aw.ds I assume you would want a small torch like a jewelers torch. It would probably be much more cost effective for you to just buy regular steel or brass/copper nuts and give your 60w soldering iron a try with regular tin/lead solder.. if that doesn't give enough heat your plumbers torch will

 

[Red Squirrel]

These nuts were kind of special order though, designed to fit on the standoffs which I also ordered. I can try to find more on ebay but I don't really know what they're made of till I get them. Stainless steel seems kinda oddball though especially considering these were from China.

Random thought, I'm also not opposed to drilling holes in the enclosure, if I drill a hole, put epoxy in it and put the standoff in the hole will that hold pretty well? I can just forget the nut altogether and put the standoff directly.

Oh and figured I'd post a pic of what I'm actually working with:

 

[joutlaw]

I recently ran into a similar problem with my BrewPi - RPi based fermentation controller.

You could secure a thin board inside that panel, and mount your RPi and relays that way. Or hot glue the relays and RPi to the enclosure itself like I did.

 

[SMOGZINN]

These nuts were kind of special order though, designed to fit on the standoffs which I also ordered. I can try to find more on ebay but I don't really know what they're made of till I get them. Stainless steel seems kinda oddball though especially considering these were from China.

Random thought, I'm also not opposed to drilling holes in the enclosure, if I drill a hole, put epoxy in it and put the standoff in the hole will that hold pretty well? I can just forget the nut altogether and put the standoff directly.

Oh and figured I'd post a pic of what I'm actually working with:

I've recently done something similar and I used velcro and a thin piece of acrylic that was at one time part of a window in a computer case. I drilled tiny pilot holes in the acrylic and screwed the mounting offset directly into it since the material is soft enough to grip the threads. Then I got some velcro strips and and attach them directly to the acrylic and case. It is strong enough that I need to use more than a little muscle to put it off. But it you didn't care about it being easily removed you could just expoxy the acrylic to the case, with a little scuffing from some sandpaper it would just about be the ideal surface for epoxy.

 

[Red Squirrel]

Actually never thought of velcro... that may be another option. No idea where I'd get acrylic though, but they do make plastic standoffs that the board just clips in and they are meant to be glued or velcroed, so I could look into that.

Though I want to minimize the amount of combustible materials in there so I might try out the drill hole + epoxy route and putting the standoff directly in the hole and secure with epoxy. If ever I want to take it off (rare chance) I could always just grind it off with dremel.

 

[drnickriviera]

is it possible to just drill the enclosure and tap it? Not much different than mounting a motherboard right?

 

[Howard]

If you are working with panels (enclosures) on a regular basis, just get a stud welder. It's a godsend, especially with SS panels.

 

[Howard]

is it possible to just drill the enclosure and tap it? Not much different than mounting a motherboard right?

Nope. The sheet metal isn't going to be meaty enough to hold any stress on a tapped thread. You typically want at least 3 threads' worth of thickness (in steel, and more in softer materials) before it can be considered OK to tap.

 

[Howard]

Random thought, I'm also not opposed to drilling holes in the enclosure, if I drill a hole, put epoxy in it and put the standoff in the hole will that hold pretty well? I can just forget the nut altogether and put the standoff directly.

How will the epoxy stay in the hole while the assembly cures?

If it's a low-load application, just get some right-angle weld studs from McMaster-Carr (e.g. 96466A040) and epoxy it right to the paint. If there'll be a decent amount of load then grind off the paint and epoxy the stud right to the base metal, covering up the exposed metal to prevent corrosion.

If highly loaded, I would go with the stud welder.

 

[echo4747]

If you have an extra stainless steel nut why not try tinning one with solder. If its a "cheap" grade of stainless the solder may adhere to it.