Inexpensive Welding Solution?????

[HomeBrew2]

Fair enough. You hit the duty limit of your machine, not I You are welcome to just give my redneck cooling scheme a try if your machine peters out again though ... it's free and easy

 

[patrick_g]

Homebrew2, Unfortunately it is a bit like pouring water on top of your car to cool an overheated engine. Very little if any of the cooling effect gets to where it is needed.

Back in my free lance days I was hired to make a portable battery operated welder experimental prototype into a manufacturable product. Previous folks had done some cost cutting. They noted that the big finned extruded aluminum heat sinks were expensive so they built their own from light weight aluminum sheet using a kick shear and a box and pan break (home made U channels.) When operating, the fins were cooled very well by the very healthy internal fan (they hadn't got around to economizing on the fan yet.) Still the power transistors were burning out like crazy. It seems the transistors where they touched the home made heat sink look alike were hot enough to melt solder but were cool to the touch a couple inches away. The fan removed all the heat that got out in the fins but the base of the fins was so thin it didn't conduct the heat fast enough.

I designed a new heat sink to be extruded and SHAZAM, no heating problem.

Put another way... If you sit on a cake of ice it will not prevent blistering if you touch hot metal with a finger. The cooling needs to be where the heating is.

Pat

 

[gemini5362]

Wow, Maybe I will just go back to the sit on my hind end and drink a soda plan while I am waiting for it to cool down. That is provided I have a problem. I have not had a chance to use my welder yet to see how it is going to work.

 

[digger2]

Just came back from Lowes,you can get a 225 ac Lincoln for about $260.
ALSO,if somebody wants a light duty acetylene torch outfit,my local Lowes also has a Harris setup complete minus tanks for $178.I personally dont think the Harris brand is the best torch in the world,but i dont think they are the worst either.And a torch ,even a less expensive model ,is nice to have around in case you want to rough cut something,or heat it for bending.
Thats all i really have mine for,i dont use it for any welding purposes.
digger2

 

[thingy]

Well,,lets see,,,maybe can't help none but,,,you weld with what you can handle,,,if you are making descent welds of what ever size with one pass,,and thats as big as you need,,than you're done!,,,,its just,,that what if you can't make a descent weld with one pass,,and fill up the joint to your satisfaction,,,you gotta add more metal,,,multipass,,,multipass welding is like,,each pass is first one,,,you just keep on sticking metal to the first layer,,,if you clean it right between passes and grind the humps,,etc,,,thats what your doing,,,,,its hard to describe,,but if you was welding a three inch plate to another 3 inch plate,,,bevelded or fillit,,,you know you can't put enough weld metal on in one pass with most welding applications,,right,,,no matter how hot you are burning, even if you are using .45 wire or 5/32 rods,,,you know one pass won't be enough,,so,,in this case,,you gotta go more than one pass,,,same thing if you are using .030 or .035 or 3/32 rod,on 1/2 inch thick steel,,,,one pass ain't gonna do it,,,so you make multiple passes there too,,,,is just the way you go into it,,,welders don't look at the thickness of there joint and say well,,its 2 inches,,so I need 1 inch rod and 1,000 amp machine so's I can get her,,they prepare joint,,[bevel],,and make multiple passes,,either by stringer or weave,,,,,,once you get this in your head,,you don't worry about filling joint up with one pass,,,you make a nice weld,,clean,,grind as you need,,and add more,,when you got enough,,you stop,,,,you always make at least three passes over one another when welding pressure pipe,,,,this is by hand,,not machine,,,this is to stop pinholes,,[old timers saying],,,,but,,,what can I say,,,thingy

 

[Casey1]

,,,welders don't look at the thickness of there joint and say well,,its 2 inches,,so I need 1 inch rod and 1,000 amp machine so's I can get her,, - thingy

That is funny. I have fallen for that 1/2" in one pass stuff hook line and sinker but I think you just cured me of doing it again.

I had to wear my eyes out to read through all the commas but it was worth it. LOL

 

[HomeBrew2]

Homebrew2, Unfortunately ...

patrick_g, FORTUNATELY my car is not overheating and I am not so drunk as to want to put water on top of the car.

Interestingly, my obviously ignornatly conceived idea of additionally cooling my un-decent toy welder came from the following situation:
I have a habit of cranking my totally inadequate stereo amplifier past the point of clipping when I get out of control (weekly). The totally inadequate amplifier shuts down, as it should. I promptly point a common 16" table fan toward my totally inadequate stereo amplifier and the amp starts up again, and continues quite nicely for an unlimited time. ... as does my un-decent toy welder in 110° summer heat.
My stereo amp and toy welder both have internal fans ... they just need extra help on occasion.
Again, YOU mentioned that YOUR decent welder shut off when pushed to the limit. Mine works fine, past it's limit, with additional external air flow, as much as you prefer to poo poo the notion.

 

[Egon]

Thingy; would there not be a point at which the small welders cannot produce enough heat to get a proper weld on thick materials?

Doesn't the grinding and chipping between welds help eliminate those nasty little pin holes and slag incursions that them nasty inspectors always find with the pictures?

 

[bobodu]

Back before I got some decent welders,I bought a $40 (yep $40) 100 amp 220v stick from Homier tool because I needed something welded quick.It'd run maybe twenty seconds before shutting down.I took off the cover and directed a fan inside.It improved to thirty seconds.Some extruded aluminum heat sinks and thermal adhesive kept her going for 40 seconds.Used that $40 POS for a year....gave it away,but I had gotten my money's worth.

 

[thingy]

Egon,,yeah,,guess some of those little things they sell might not make enough heat to melt wire/rod and base metal properly,,,but any welder that will produce enough amps to properly burn what ever wire or rod your using,[size I mean],you should be able to multipass weld with,its just that if its thick,,you may end up making many passes and many starts and stops and that ain't real good either,[not to mention it might take you forever].
Just saying that you don't go about thinking you have to weld something in just one pass,[unless you are factory produceing something,maybe a small fillit weld],,for alot of stuff,yeah,one pass might get it,,but for something thick,,or beveled,,you need to make more than one pass,,take a crack for example in 1/4-3/8 inch steel,,,if you can just weld it from one side,,you bevel it out,,make a root,,clean/grind,fill maybe one pass,clean/grind,and cap.Thats how you repair a crack,,even when welding thinner stuff,,I alllways,[generally] make a root,and at least one cover over it,,just works better,,not talking sheet metal here,,,course you gotta clean,brush,you gotta grind out high spots,so you will have a even/clean surface to weld over.
You are really limiting yourself if you think you got to weld every thing in one pass,,on something thinner,you might really be able to make a better looking weld,if you run a smaller first pass and than a cap over it,,and on something thicker you won't be trying to burn so hot that you are burning holes and carry so much metal that you can't weld out of flat postion cause you think you got to fill it in one pass,,,thingy