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Discussion Starter #1
I put my cab corners on the weekend. Generally it was a success.
Welds were not great looking but after grinding the seam was nearly invisible. Although I'm pleased with the results, the things that didn't go well are more on my mind that the things that did.

:rolleyes:

After welding both corners on I ground the weld the a 4 inch disk sander. I think this was the begining of the things that didn't go well. After gringing I notices numberous pin holes when viewed from inside the cab. Possibly not enough penetration? I also ground thru in a few places. When trying to touch these up with the mig, I burned thru. I think due to thinning the sheet metal from the grinding the amperage was too high. At this point I think continuing to play with it too much will start me down the road to a can of worms. I was thinking if just welding 2 or 3 1/8" holes and then leading the seam to put some metal in the pin holes. Anyone see a problem with that? I know it shouldn't be necessary, but at my skill level at this point I think it's a safer way out. The welds are otherwise strong and will stand up to hammering without breaking the weld.

Also anyone know of a good Mig video? Without watching someone else weld I have no way of knowing if what I experienced welding was "normal".

Thanks,

Keith
 

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Yeah, I went through what you are going through now a few months back. The more you weld, the better you get.

The pin holes are normal for an inexperienced welder. Make sure your pieces are very clean before welding. That means both sides of the metal if at all possible. Are you butt welding or seam welding? If you are butt welding, I found that it is best to not leave a gap between the two parts, push them right up against eachother. Always tack the pieces in before you seam them up. Always clip the weld wire with a pair of side dykes before you start welding (that means every time you strike an arc).

When it comes to finishing, I completely gave up using an angle grinder unless you are grinding thick pieces of steel. Pick up a 90 degree die grinder for use with an air compressor. Then use rotolok disks, I use 2" disks. You would be amazed with how much control you have with this tool being that it is so light and small. Sure you wear through the disks faster but you get precise control of your grinding and never cut into your base metal. I use a 24 grit disk to grind the major part of the weld and switch to an 80 to finish it up.

The pin holes just require practice, I'm still trying to prevent them as well. I am very good when welding in open areas but am having trouble in tight spots and welding overhead.

Good luck,
kev
 

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best way IMO is to put a little bevel on the edges of the panel being welded. Then after you weld and start planishing the seam, the proud weld has a place to go.

I haven't got it masted yet, but this is definitely the way to go.
 

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it just takes a little getting used to, try welding on scrap material first of different thickness.
A good way to grind the welds smooth is with a 9 inch polisher with an abrasive disc on it. A lot better than a stiff grinding wheel that could create more work
 

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Discussion Starter #5
Starquest

I'm butt welding and agree..better to keep it tight. It "seems" that exposed edges heat up more than flat surfaces. I can live with filling the pin holes..just want to close up 3-4 of the larger ones. The biggest things I learned are:

1) Learn to leave it alone when it's already plenty good enough
I seem to have a problem with that :rolleyes:

2) Use gringing techniques that focus on the weld and not
adjoining base metal. Once the base metal has thinned
touch-up welding gets hairy.

Thanks for the input...Really appreciate it.

Unstable

How's it going? I believe you've been in my shoes. I recall talking to you last year. You jumped into welding a little ahead of me. You've got a 55 or 56 also as I recall. I've checked out your journal. I think amongst other issues I used amperage setting that was too low. My bead, if you call it that was about an 1/8 wide..and at leat that tall. I made a lame atempt at planishing. The only thing it proved was the weld didn't break. Maybe someday. Good to see you here again.


Project66

I practiced somewhat..for whatever reason the practice ones were far better than my "real" ones. I'm will'n to pay my dues.
Just need to be think'n "damage control" at this early stage.
Thanks for the help.
 

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Slick,

I'm actually going to switch to gas welding...it's a much easier process to use to make quality repairs on sheetmetal.

Let's see some pictures when you get a chance. I need to take some more myself, just been busy and haven't been working on the project as much as I'd like to...it's a 57 :D
 

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Discussion Starter #7
Gas? as in Oxyacetelene(I'm sure I blew that spelling)..or Gas shielded Mig? Man I tried oxy ten years ago...still have tanks..instead of pin holes..the holes were 1/2" in diameter :pain:

Actually I did make it a point to snap a few pics..I need a few more then I'll post a few ..or start a journal.

Nice chattin Unstable
 

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mig with the gas is the best way to go
gas as in oxy and acet. you need to be REALLY carful with that it doesnt get to hot and warp everything
as far as the practice pieces goes they always look perfect .....
i think it is mind control, i guess if you just think on your good pieces that it doesnt matter if they are right or not they will probally come out perfect every time.When it comes to actually fixing stuff you get that feeling in the back of your throat, you know the one, (boy this is going to be bad if i screw this up)feeling, so it makes you nervous and you actually do end up messing it up.Atleast that is true for me
 

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yeah oxy acetylene. You can't use a huge torch, has to be a light duty deal.

take a look at these pictures, first time I ever welded using gas. Of course Wray planished it out, but considering it was flat metal I think I could have done just as good of a job planishing...

http://hotrodders.com/forums/attachment.php?s=&postid=276627

http://hotrodders.com/forums/attachment.php?s=&postid=276629

http://hotrodders.com/forums/attachment.php?s=&postid=276630



As Randy always says, it doesn't matter WHICH process you use, it is possible to get these results. BUT, as much as I have tried I haven't gotten anything close to this using MIG. using MIG with Gas I still haven't gotten these results.

Gas is the way to go...and as far as warpage, I laugh at warpage. I'm by no means a metalurgist, but here's food for thought.

When you weld, no matter which process you are using, you are either (A) doing a fusion type weld where you heat up the two pieces of metal to the point where they FLOW together or (B) heat up the two pieces of metal and add FILLER metal to join them together...

You can use MIG, TIG, Gas or whatever but you still need to get the metal to the temperature at which it is plastic and it flows.

Soooooo. What difference does it make if you are using electric to melt the metal or an open flame? UNLESS you attack the panel with a huge torch and you are creating a way bigger heat affected zone then you need to, I could understand excessive warpage...otherwise, you shouldn't get any more or less warpage using one process over the other.

that's what I think at least. but I know jack schitt about this stuff...just something that came to mind a few minutes ago.

Oh btw...I'm told that gas welding is very much like TIG, which is what the big boys use for the cleanest repairs. In fact, the pictures posted above...used a filler rod intended for TIG I believe. :D
 

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Discussion Starter #10
You mentioned TIG...You know I don't think there is 1 TV show,Orange County Choppers, Monster Garage or any
other TV show about how - to hottrodding, that doen't use TIG.

I also remember a tread here some place that mentioned using a Jewelers torch. I quess that would make it easy to control the heat. Interesting.
Keith
 

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You guys might try brazing if warpage is your greatest concern. A decent bronze brazed lap joint is almost always stronger than the base metal because the braze is in shear. You can strap a butt joint & get the same thing. T's are good as long as you're fairly generous with the rod. Not to mention you can braze copper to iron, iron to steel, steel to... well, pretty much anything with a higher melting point than the rod you're using.
 

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dumb q on brazing.....

what exactly is the difference between gas welding and brazing? I'm off to google.....
ooohhhhh brazing

brazing = enough heat is used to melt the filler rod.
welding= heating the work piece to the melting point also.
:thumbup:
 

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Gas welding, or any kind of fusion welding, MIG, TIG, stick, you're basically just melting two or more pieces together & using a filler of the same metal to fill the gaps.

Brazing & soldering, you're depending on the adhesive qualities of a different metal to hold the pieces together. Nothing fuses, it's actually more like gluing than welding. There are some exceptions, but just about any common metal can be brazed to any other so long as their melting points are higher than the brazing metal of your choice. Clean parts are far more important when brazing than fusion welding.
 

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I see I'm not the only one struggling to improve my welding skills.

I've got OA and started with that on the panels but abandoned that coz I was a bit scared of distortion.

Brazing, tried that did'nt like coz if flux not removed properly it starts to corrode good metal away quite quickly. But it is a good, easy way to do repairs that I must confess; and am using it a lot for other repairs.

Then MIGged (still am) - it's ok. Can get the job done quickly but due to lack of skill also got pinholes to worry about, lots of grinding, etc., etc. MIG with gas is best coz apart from no slag it also helps to cool the weld down. Reason I'm a bit scared of MIG is good MIG welds look good and bad MIG welds can also look good - not expert enough to visually distinguish betw. the 2.

Recently bought TIG, am still learning but IMHO that is the way to go. Have'nt used it for any practical repair job but practice show that on thin sheet if your fit is very very accurate, no filler rod is needed, weld is 100% waterproof, full penetration, HAZ very small + welds does'nt need as much work as MIG. Downside; it's slower than MIG - but I've got lots of time. Also at this stage I'm not skilled enough to TIG out of position welds, which is what I'm doing most of the time with the MIG.

TIG to me is like an electrical OA torch, but it's a little faster + you've got finer control over the amount of heat deposited on a panel. BUT if you're prepared to practice and fine tune your OA skills you're don't need TIG.

If you get small enough tips and small enough torch for OA then you're set. You'll do the same quality of work as a guy with a TIG.

Good luck guys and happy welding. :thumbup:
 

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One thing that Randy said...pretty sure it was Randy...but I didn't try it until just recently is using a cut-off tool to grind down the mig welds. It works a HELLUVA lot better than using an angle grinder.
 

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I think a good thing for anyone who hasn't welded or not very much, is to look into a night class at a community collage. Just the basic class should go over Oxy/Acetylene (and Brazing), Arc, Mig, and maybe Tig
and you can ask the instructor questions and you learn some basic metallurgical properties, all in all if you want to spend the money its worth it.

just my $0.02
 

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Discussion Starter #17 (Edited)
Sehlah

I actually did braze a few things many years ago..Came out OK.
If you look around this forum there are post about brazing that are somewhat unflattering. Some say the repared areas become
raised and or bumpy. Something like that. Welcome to Hotrodders Sehlah.

Cassidy

Thanks for the reply. I enjoy responses from hackers(like me) as well as pros. Sometimes a beginner can tell you how he got around a particular situation with out the proper tools etc..in other words how he improvised to get the job done. Ya I have a sneaky feeling that if I continue to do body work..A TIG will likely be in my arsenal someday. Your comments about removing brazing flux may explain some of the bad rap that brazing has. Possibbly it's the corrosive action of the flux that later raises the filler. Welcome Cassidy.

Unstable..

I also tried the die grinder to grind weld. Does work well plus it gives you fine control. My compressor runs out of air too quickly for the die grinder so I took the 3" abrasive wheel off and put it on my disk sander sandwiched between two washers. Worked like a charm. I did get a little too agressive and now I have some holes to close up on sheet metal that has been ground thin. I'm hoping the Harris "20 guage" helps with that.

Stokednova

You know I looked for a course here in CT and couldn't find one. YA know what I'd like even better? A chance to be a goffer for a talented bodyman. Nothin beats watch'n a pro. That would be a great education.

Thanks and ave fun all. Afterall, it is hump day!

Keith
 

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Slick,

I know it's been said time and time again...if you haven't already, definitely check out www.metalmeet.com

There are pro metal shapers all across the country who are usually more than willing to let someone work in their shop on the weekend.

I usually drive about an hour and a half each way to go up to Wrays shop on the weekends. Being around someone who knows so much definitely helps. I wouldn't have believed the entire thing about Oxygen/Acetylene if he had not showed me. Nearly everyone on this board and everyone I've come into contact with said "O/A will just warp your panels...use a mig"
 

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You'll find me hiding on metalmeet as well. :D

Another good BB where you can learn a lot about welding is at Hobart's;
www.hobartwelders.com and the guys are very very helpful and clued up there. Plus it's a very small community so you'll get good advice very quickly.

It really is best if you can attend a class or get a pro to show you the ropes even if it's only for an hour or so.

I'm learning the hard way; buy a few books, troll the net, ask a few questions and then jump in, do it, evaluate and try to do better the next time around.

Interesting tidbit re brazing; here in South Africa lots of panelshops still braze raher than weld panels. It's only the few "upmarket" ones that MIG and even less that TIG. I asked the pro's and every single last one insisted that the only way is to braze.

But do'nt shun brazing - the hand coordination skills you use with brazing will help a lot with OA and TIG welding. Also sometimes brazing is the only way to "weld" diff types of metal together.

Remember each process has it's pros and cons - pretty soon you'll be able to pick the most suitable one for the job. Eg. TIG's only really suitable if the metal is so clean that you can eat off it.
 
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