Topic of Discussion TOD: Sheet Metal fab

[Greg]

Time for another TOD, or Topic Of Discussion-


Topic: Sheet metal fabrication.

Specifically: Where to start & how to make sheetmetal fab come together. Best materials for each job, homemade brakes and other related tools.

Discuss!!

 

[rockdog]

Sounds like a good topic Greg. I have no sheet metal skills, so post up thin metal guru's. I need to know how to weld thin stuff. I've got a hobart 250 wire feed. I can set it low and still burn through. I'm a crappy welder I'll admit. So any personal secrets would be helpful.

 

[James K]

Sounds like a good topic Greg. I have no sheet metal skills, so post up thin metal guru's. I need to know how to weld thin stuff. I've got a hobart 250 wire feed. I can set it low and still burn through. I'm a crappy welder I'll admit. So any personal secrets would be helpful.

when I welded my fuel cell up. I switched to .025 wire instead of the .030 I normally used. seem to work well.

 

[cuban b]

It's kind of a pain, but a strip of metal behind the sheet metal will help keep it from burning through.

 

[troutbum]

It's kind of a pain, but a strip of metal behind the sheet metal will help keep it from burning through.

use AL, seems to work better.

Also anyone using a bead roller? It is on my list of tools to get. pro-tools makes a kit for pretty cheap, if you could machine the gears/rollers you might be able to fab your own.

 

[Shawn]

Sounds like a good topic Greg. I have no sheet metal skills, so post up thin metal guru's. I need to know how to weld thin stuff. I've got a hobart 250 wire feed. I can set it low and still burn through. I'm a crappy welder I'll admit. So any personal secrets would be helpful.

Stich weld,

It burns for 2-3 seconds then off for a few seconds. It gives the metal a chance to cool in between weld..

 

[James K]

use AL, seems to work better.

Also anyone using a bead roller? It is on my list of tools to get. pro-tools makes a kit for pretty cheap, if you could machine the gears/rollers you might be able to fab your own.

how much are the pro tools units?

I know you can get a bead roller a HF everyonce in a while on sale for like 100.00.

 

[morty]

Here is a site I found with cool tools a some how-to videos.

 

[troutbum]

how much are the pro tools units?

I know you can get a bead roller a HF everyonce in a while on sale for like 100.00.

~200 for the kit and then you can buy rollers for 25.00 (if you buy them at the same time)

 

[Caleb]

Sounds like a good topic Greg. I have no sheet metal skills, so post up thin metal guru's. I need to know how to weld thin stuff. I've got a hobart 250 wire feed. I can set it low and still burn through. I'm a crappy welder I'll admit. So any personal secrets would be helpful.

as James said, .025 wire will help big time...also the choice of gas helps a lot too, straight CO2 will burn the hottest for using gas, so if you can, use a 75/25 mix and you wont really be able to run a solid bead unless you are tigging...so as Shawn said stiching is where its at. Also, as said something behind it helps usually a metal that is differnt than what you are welding, most common are aluminum and brass...

I wanna see some homemade brake ideas, I've seen Hickeys, now how bout some larger ones for doing sheet (just thin gauge stuff obviously )

 

[81Ramchargerman]

When using a backer, you also need to make sure it is completely flush or it won't do any good, and the only welder i've really been able to use .035 wire to successfully weld on sheet metal (and thinner) is my dads $3000ish? dollar welder from snapon. Can anyone tell me how I went to full spray transer when I was welding with 75/25? That still makes me wonder... I was told when I was in welding, that to go from globular, to spray you had to use straight argon.

 

[Rusted]

When working with sheet metal I get a lot of use out of my cut off saw, similar to this. When working with body panels I would cut a patch the size I needed with snips or the cut off saw, mark the panel with the size of the patch, then cut to the line using the cut off saw.

 

[Hickey]

I was told when I was in welding, that to go from globular, to spray you had to use straight argon.

It depends on the machine. The ratio of the Argon/C02 mixture will just change the point at which you reach Spray. Say, that your machine is set to spray with C25. Now switch to straight Argon, and you can turn down your machines wire speed and heat settings.

 

[bobdog]

It depends on the machine. The ratio of the Argon/C02 mixture will just change the point at which you reach Spray. Say, that your machine is set to spray with C25. Now switch to straight Argon, and you can turn down your machines wire speed and heat settings.

My understanding and experience is that true spray doesnot happen with 25% CO2. C25 is great with duelsheld wire at high voltage but hard wire is another story(no matter how high you turn the welder up it wont spray). Turn on the C5 though and spray away. I have read 17% is the magic number.

 

[Hickey]

You should try it with your welder. My 210 will just barely go spray with c25, much easier with the 16% I have now.

 

[bobdog]

You should try it with your welder. My 210 will just barely go spray with c25, much easier with the 16% I have now.

We have 456 Pheonix Millers at work. I have tried it at way higher voltage than my 250 will put out. To watch the true spray you get with C5 compared to what you see with the C25 is not the same. I think what you see is a kind of globular transfer. If you want to go play some weekend let me know It is pretty cool. The Subarc is pretty interesting also.

 

[Hickey]

To watch the true spray you get with C5 compared to what you see with the C25 is not the same. I think what you see is a kind of globular transfer. .

True spray may very well be different from what I have experienced with my welder, as I have only messed with that transfer mode a bit, and only on my machine. My machine is not really rated for spray either. I did notice a substantial difference between what I thought was globular, and spray transfer. As far as the two different mixtures I have used, with C16, I seemed to have more adjustability when in spray. With C25, I could only achieve spray if the settings were just right. Any adjustment to the WFS would put it back to globular.

 

[Hickey]

Anyway, back on subject. Here is a link to a page about building a small bench brake. I would guess the same design could be enlarged to build a much wider brake.
http://www.megaone.com/morpheus/brake/bench_brake.html

And another link with a different design at the end.
http://www.hobartwelders.com/mboard/showthread.php?t=1250&highlight=bench+brake

 

[OCNORB]

On a sheet metal note, I just picked up a pneumatic nibbler. Man are these things cool. One of the best ways to cut sheet metal parts that I have found.

 

[DaveB]

When you are filling a rust hole with new metal it can be a challenge to get the new piece to fit the hole you cut out. The way that I have found that works well is to lay the new metal over the hole to be fixed then with a very thin cut off wheel cut through both pieces. The new piece will fit well and have a gap for the weld.